fix: history calls an execute or multicall a Swap only when sent to a router (closes #580)

The history labelled any call named execute or multicall a Swap, whatever
contract it went to, so a multisig or smart account call showed as a Swap
in the list and on TransactionDetail's Type line. Such a call is now a Swap
only when sent to a Universal Router address listed for the network the
transaction is on, the list the approval screen uses (routerRelease(), now
exported from uniswap.js). Any other is labelled by its method name and its
Type line reads Contract Call. The named router swap methods keep their
label.

Model: opus-5-5

README.md

@@ -418,6 +418,10 @@ Each group of these assertions records a coverage key and a final case demands
 the exact set, so a section that silently stopped running reddens the suite
 instead of quietly shrinking it.
 
+It also covers the red banner on the Settings screen: switching the network
+there to Sepolia must put up the `[TESTNET]` banner, and switching back to
+mainnet must take it down, both while Settings is still on screen.
+
 It also covers the confirmation screen, for both a native ETH send and an ERC-20
 send: Send disabled while the fee estimate is in flight, enabled once it lands,
 the fee block quoting the expected cost and the reserve separately, the distinct
@@ -430,6 +434,15 @@ reserve while sitting on the same side of the estimate, so swapping the two in
 what [#154](https://git.eeqj.de/sneak/AutistMask/issues/154) was, and it was
 previously correct by reading only.
 
+It also covers a send that Sign & Send refuses for its network fee: the stub
+node quotes an ordinary fee while the confirmation screen is drawn and one over
+the bound when Sign & Send asks again, and the refusal must broadcast nothing
+and leave the password field and Sign & Send where they were. It checks the same
+for a send refused because the selected wallet does not hold its From address:
+with the confirmation screen showing a send from the HD wallet, the key wallet
+is selected by writing it straight into extension storage, as another popup
+selecting it would save it, and the popup is reopened onto that screen.
+
 It also covers both ways the wait for a sent transaction's receipt ends on the
 error screen: lookups that still find no receipt 60 seconds after the broadcast,
 and six lookups in a row that fail. Each must show its own message, and Done
@@ -487,9 +500,12 @@ papered over:
   forced by clicking Reveal and the settings gear in one page task, which a
   person cannot do; the case a person can hit, the first decrypt after the popup
   opens while libsodium is still loading, is not driven.
-- Approval windows open at 1280x720 whatever size the extension asks for, so
-  whether an approval screen fits its window is checked in the Firefox suite
-  only.
+- Approval windows open at 1280x720 whatever size the extension asks for. The
+  site-connection prompt and the transaction approval are checked for sideways
+  scrolling at 396x600 by sizing the page itself for that measurement only, and
+  the rest of each test runs at 1280x720. That leaves out the window's frame and
+  the page widening its window, so whether an approval screen fits its window is
+  checked in the Firefox suite only.
 
 Any test that drives a failure path on purpose declares the `console.error` it
 is about to provoke, via `errors.expect()`. That is not a mute: the declaration
@@ -571,9 +587,12 @@ the worker stopping. It starts Chromium itself, speaks the DevTools protocol
 over `--remote-debugging-pipe`, and attaches to pages only. Before raising the
 approvals it requires the worker to stop on its own with nothing pending, so a
 run in which something else keeps the worker running fails. The site is
-connected and the RPC endpoint set through the extension's own screens, against
-the loopback dApp page and stub node the Firefox suite also uses
-(`tests/e2e/dapp.js`). Unlike the suite above, it does not fail on page errors.
+connected, without "Remember my choice for this site", and the RPC endpoint set
+through the extension's own screens, against the loopback dApp page and stub
+node the Firefox suite also uses (`tests/e2e/dapp.js`). Once the worker has
+stopped, the run requires the site still to be told the address
+([#526](https://git.eeqj.de/sneak/AutistMask/issues/526)). Unlike the suite
+above, it does not fail on page errors.
 
 ### Firefox (`make test-e2e-firefox`)
 
@@ -857,7 +876,11 @@ on the next event. Two consequences shape every recurring job in the background:
 - Module-level variables do not survive either. Anything that must be remembered
   across a restart goes in extension storage. `localStorage` does not exist in a
   service worker at all — the one remaining user of it, `src/shared/ens.js`,
-  runs only in the popup and is marked as such.
+  runs only in the popup and is marked as such. The sites allowed without
+  "Remember my choice for this site" are kept in the browser's session storage
+  (`storage.session`), which outlives the worker but not the browser, so such a
+  connection lasts until it is ended or the browser closes. Firefox has session
+  storage from version 115, the minimum `manifest/firefox.json` declares.
 
 Pending approvals are the exception: an approval waiting for the user, and the
 site's request waiting on it, live only in the worker's memory, and only the
@@ -1006,14 +1029,16 @@ rendered differently on two screens.
 
 The native token's label is a network's `nativeCurrency` in
 `src/shared/networks.js`: `ETH` on mainnet, `SepoliaETH` on Sepolia. The
-wallet's balances and the Send and confirmation screens, which send on the
-active network, use the active network's. A transaction's figures use the one of
-the network its chain id names, whichever network is active: the value and fee
-on the approval screen, the amount on the wait, success and error screens, the
+wallet's balances and the Send screen, which sends on the active network, use
+the active network's. The confirmation screen uses the one of the network its
+transaction was reviewed on, the network active when Send showed it, even after
+the network is switched in Settings. A transaction's figures use the one of the
+network its chain id names, whichever network is active: the value and fee on
+the approval screen, the amount on the wait, success and error screens, the
 transaction history and the transaction detail screen, and the refusal of a fee
 above 1 ETH. A chain id that names no network reads `ETH`. Wherever this
 document shows ETH as the label of a native balance, value or fee, in a "Native
-ETH transfer" type line, in the contract-recipient warning or in that refusal,
+ETH transfer" type line, in the two recipient warnings or in that refusal,
 Sepolia shows `SepoliaETH`. The swap lines keep `ETH`, the router's own name for
 the native currency, and the ETH/USD price line, shown on mainnet only, keeps
 its fixed wording.
@@ -1068,42 +1093,49 @@ The rule and its exception live in `src/shared/amountDisplay.js` as
 confirmation screens display goes through the floored one — the ERC-20 amount,
 the ETH value and max fee (`src/popup/views/approval.js`), the swap's `Amount`
 and `Min. received` lines (`src/shared/uniswap.js`), the Send screen's
-`Current balance` (`src/popup/views/send.js`), and the balance and network fee
-on the confirmation screen for the wallet's own send
-(`src/popup/views/confirmTx.js`). Both screens render a network fee through
-`formatFee()` in `src/popup/views/helpers.js`, which prices the exact fee in USD
-rather than its truncated figure, so the same fee reads the same on both, USD
-value included. Balances are stored exactly (`src/shared/balances.js`), whatever
-decimals a token declares, so a balance below the floor reaches these screens as
-it is. The history list (`src/shared/transactions.js`) uses the unfloored one:
-the transaction detail view is the authoritative record and already shows exact
-precision. The balance lists use neither: they round to four places with
-`toFixed(4)` (`balanceLine()` in `src/popup/views/helpers.js`). The 4-decimal
-rule is unchanged everywhere else, including for amounts at or above the floor
-on the approval screens.
+`Current balance` (`src/popup/views/send.js`), and the amount, balance and
+network fee on the confirmation screen for the wallet's own send
+(`src/popup/views/confirmTx.js`), which hands the wait, success and error
+screens the amount as it showed it. The transaction is still signed for the
+exact amount, and its USD value is priced from it. Both screens render a network
+fee through `formatFee()` in `src/popup/views/helpers.js`, which prices the
+exact fee in USD rather than its truncated figure, so the same fee reads the
+same on both, USD value included. Balances are stored exactly
+(`src/shared/balances.js`), whatever decimals a token declares, so a balance
+below the floor reaches these screens as it is. The history list
+(`src/shared/transactions.js`) uses the unfloored one: the transaction detail
+view is the authoritative record and already shows exact precision. The balance
+lists use neither: they round to four places with `toFixed(4)` (`balanceLine()`
+in `src/popup/views/helpers.js`). The 4-decimal rule is unchanged everywhere
+else, including for amounts at or above the floor on the approval screens.
 
-The floor applies only where the token's scale is known. Where it is not, the
-approval screen states base units instead of a quantity — see Unknown token
-scale below — and no truncation happens at all.
+On the approval screen and the wait, success and error screens that carry its
+amount forward, the floor applies only where the token's scale is known. Where
+it is not, they state base units instead of a quantity — see Unknown token scale
+below — and no truncation happens at all. On ConfirmTx and the wait, success and
+error screens that follow it, the amount of a token whose scale is unknown,
+which cannot be sent, is the text from Send's amount field cut to four decimals
+with the same floor (`.5` reads `.5000`).
 
 **Specific Exception — unknown token scale:** Calldata carries base units and no
 scale, so every amount on the dApp approval screen needs the token's `decimals`.
-It is resolved from the bundled token list, then from the tokens the user
-tracks, then from what the block explorer reported for the contract
-(`resolveTokenDecimals()` in `src/shared/approvalAmount.js`). Where none of them
-answers, the amount is not formatted: the line reads
-`5000000000 base units (decimals unknown)`. A guessed scale is not an
-approximation but a different number — 1,000 units of a 6-decimal token
-formatted at 18 decimals reads `0.000000001` — on the screen whose only job is
-to state what is being authorized. Both amount paths of that screen take this
-rule: the ERC-20 `transfer`/`approve` line (`src/popup/views/approval.js`) and
-the swap's `Amount` and `Min. received` lines (`src/shared/uniswap.js`). The
-token permission warning on the signature screen takes the same rule for its
-amounts. An unbounded allowance or permit needs no scale to describe and is
-still shown as `Unlimited`. A source's answer counts only if it is a whole
-number from 0 to 80: `decimals()` returns a `uint8`, but `formatUnits()` cannot
-format more than 80 decimal places, so a token that reports 81 to 255 is shown
-as one whose scale nothing knows.
+It is resolved from the bundled token list, then from the tokens the user tracks
+on the network the transaction is for, then, when that is the active network,
+from what the block explorer reported for the contract in the wallet's balances,
+which are the active network's only (`resolveTokenDecimals()` in
+`src/shared/approvalAmount.js`). Where none of them answers, the amount is not
+formatted: the line reads `5000000000 base units (decimals unknown)`. A guessed
+scale is not an approximation but a different number — 1,000 units of a
+6-decimal token formatted at 18 decimals reads `0.000000001` — on the screen
+whose only job is to state what is being authorized. Both amount paths of that
+screen take this rule: the ERC-20 `transfer`/`approve` line
+(`src/popup/views/approval.js`) and the swap's `Amount` and `Min. received`
+lines (`src/shared/uniswap.js`). The token permission warning on the signature
+screen takes the same rule for its amounts. An unbounded allowance or permit
+needs no scale to describe and is still shown as `Unlimited`. A source's answer
+counts only if it is a whole number from 0 to 80: `decimals()` returns a
+`uint8`, but `formatUnits()` cannot format more than 80 decimal places, so a
+token that reports 81 to 255 is shown as one whose scale nothing knows.
 
 The rule holds only if nothing invents a scale UPSTREAM of it. Those three
 sources are read as authoritative, so a value written into one of them cannot be
@@ -1135,8 +1167,9 @@ fetched, without that cross-address check, and shows the row's figure.
 
 **Decoded amount lines on the transaction approval screen:** the `Amount` line
 of a decoded ERC-20 call, and the `Amount` and `Min. received` lines of a
-decoded swap (see TxApproval below), do not always read as a number. They can
-read:
+decoded swap (see TxApproval below; `Min. received` reads `Min. paid out` unless
+only the user is paid, see Transaction Decoding), do not always read as a
+number. They can read:
 
 - A formatted quantity, e.g. `17.1900 USDT`, when the token's scale is known:
   truncated to four decimals, with the floor and the zero cases described above.
@@ -1146,26 +1179,22 @@ read:
 - `Unlimited`: on the ERC-20 `Amount` line, an `approve` of the `uint256`
   maximum, an unbounded allowance. On the swap's `Amount` line, any amount at or
   above the `uint160` maximum, whichever step set the line: a `PERMIT2_PERMIT`
-  amount at that maximum, which is an unbounded permit, or a V2 or V3 exact-in,
-  V2 exact-out or `WRAP_ETH` amount that large, which is not an allowance. The
+  amount at that maximum, which is an unbounded permit, or a V2 or V3 exact-in
+  or exact-out or `WRAP_ETH` amount that large, which is not an allowance. The
   router's whole-balance value, `CONTRACT_BALANCE` (`2^255`), is one such
   amount.
-- `Up to <amount>`: the swap's `Amount` line, when the transaction has a V2
-  exact-out step, whichever step set the line, including the `WRAP_ETH` of a
+- `Up to <amount>`: the swap's `Amount` line, when the transaction has a V2 or
+  V3 exact-out step, whichever step set the line, including the `WRAP_ETH` of a
   swap paid in ETH and a `PERMIT2_PERMIT`. The swap spends at most that figure,
   not necessarily all of it; the wait, success and error screens show it with
   the same words. `Unlimited`, `All available (V4 open delta)` and
   `Whatever an earlier step sent to the pair (V2 already paid)` keep their
-  wording. When a V2 exact-out step sets `Min. received`, that line shows its
-  `amountOut`, the exact amount it buys.
+  wording. When a V2 or V3 exact-out step sets `Min. received`, that line shows
+  its `amountOut`, the exact amount it buys.
 - `All available (V4 open delta)`: the swap's `Amount` line, when the amount it
   shows is a V4 exact-in `amountIn` of zero. V4 reads that zero as "use the
-  whole open delta", so the calldata states no quantity. The line shows the
-  amount of one step that names an input token or amount: the last
-  `PERMIT2_PERMIT` step if there is one, otherwise the first V2 or V3 exact-in,
-  V2 exact-out, `WRAP_ETH` or V4 swap step. A V2 exact-out step gives its
-  `amountInMax`, and a V4 swap step the `amountIn` of the swap action that
-  spends its input currency, as described below.
+  whole open delta", so the calldata states no quantity. Transaction Decoding
+  below gives the steps whose amounts the line shows.
 - `Whatever an earlier step sent to the pair (V2 already paid)`: the swap's
   `Amount` line, when the amount it shows is a V2 exact-in `amountIn` of zero.
   The router reads that zero as "the pair already holds the input tokens": the
@@ -1181,40 +1210,67 @@ read:
   guarantees nothing: it sets `Token Out` and `Min. received` only when the
   output side holds no minimum, not even a zero one, at the point the check is
   reached, and otherwise leaves the current token and figure in place. A nonzero
-  `minBalance` sets both lines, as a swap step does.
+  `minBalance` sets both lines, as a swap step does. Only a check of the
+  transaction's sender's own balance sets either line; a check of any other
+  address sets neither (see Transaction Decoding). A `BALANCE_CHECK_ERC20` step
+  that the router lets fail without reverting the transaction (see Transaction
+  Decoding) guarantees nothing either, whatever its `minBalance`, and is read as
+  one whose `minBalance` is zero. A minimum stated by a V4 swap step the router
+  lets fail is likewise read as zero.
 
 The swap's `Token In` and `Token Out` lines name a currency, not an amount; each
 reads `Unknown (not named in the calldata)` when the decoder found no token for
 that side, or `Unknown (could not be decoded)` instead when a V4 swap action in
-the transaction could not be read (see Transaction Decoding below). A V4 step's
-sides follow three rules:
+the transaction could not be read or the transaction has an `EXECUTE_SUB_PLAN`
+step, which leaves both sides unknown (see Transaction Decoding below). A V4
+step with a swap action always sets the output side, and sets the input side
+only when no earlier step set it. It finds each side by three rules:
 
 1. Its input side is the currency its `SETTLE` or `SETTLE_ALL` names, or else
    the one currency that some swap action in the step spends and none buys. Its
    output side is the currency its `TAKE` or `TAKE_ALL` names, or else the one
    currency that some swap action buys and none spends. If there is not exactly
-   one such currency, that side is unknown. A step that buys WETH with USDT and
-   USDC with that WETH, with nothing naming its sides, reads `Swap USDT → USDC`.
-2. `Amount` is the `amountIn` of the swap action that spends the input currency.
-   If several exact-in actions spend it, each with a stated amount, it is their
-   sum; in any other case there is no `Amount` line. The decoder reads no amount
-   from an exact-out action, and an open delta is not a stated amount.
-   `Min. received` is found the same way, from the `amountOutMin` of the actions
-   that buy the output currency.
+   one such currency, that side is unknown, and the step sets it as unknown with
+   no figure. A step that buys WETH with USDT and USDC with that WETH, with
+   nothing naming its sides, reads `Swap USDT → USDC`.
+2. Its `Amount` is the `amountIn` of the swap action that spends the input
+   currency. If several exact-in actions spend it, each with a stated amount, it
+   is their sum; in any other case the step gives no `Amount`. The decoder reads
+   no amount from an exact-out action, and an open delta is not a stated amount.
+   Its `Min. received` is found the same way, from the `amountOutMin` of the
+   actions that buy the output currency.
 3. If any swap action in the step could not be read, only `SETTLE`,
-   `SETTLE_ALL`, `TAKE` and `TAKE_ALL` name its sides, and there is no `Amount`
-   or `Min. received` line. Such a step still sets each side as a swap step
-   does, and no other step's token or figure is shown for a side they did not
-   name.
+   `SETTLE_ALL`, `TAKE` and `TAKE_ALL` name its sides, and the step gives no
+   `Amount` or `Min. received`. A side they did not name is unknown, and the
+   step sets it as unknown with no figure.
 
-An `UNWRAP_WETH` step makes `Token Out` ETH only when the output side is WETH,
-on mainnet or Sepolia, or when no step set the output side; a WETH
-`Min. received` figure then reads in ETH. Otherwise `Token Out` and
-`Min. received` keep the output side's own token and figure, whether the swap
-was paid in ETH or in a token: a V2 exact-out swap that buys USDC and then
-unwraps the WETH it did not spend shows USDC. The token permission warning on
-the signature screen has its own amount wording, including `Unknown`; the
-SignApproval section below describes it.
+Under each of these rules, when the user pays the step any of the input
+currency, its `Amount` is instead what the user pays it of that currency when
+the decoder knows that amount, and otherwise there is none (see Transaction
+Decoding). So a step whose USDT-for-USDC swap action could not be read, with a
+`SETTLE` of 400 USDT paid by the user, reads `Amount 400.0000 USDT`.
+
+A V4 step with no swap action sets only the sides its `SETTLE`, `SETTLE_ALL`,
+`TAKE` or `TAKE_ALL` names.
+
+An `UNWRAP_WETH` step makes `Token Out` ETH only when no step set the output
+side, or when the output side is WETH, on mainnet or Sepolia, that the step that
+set it paid to the router and that the router still holds when the `UNWRAP_WETH`
+runs (Transaction Decoding below gives what the router holds). The router
+unwraps only the WETH it holds, so WETH that step paid to the user, or to anyone
+else, stays WETH: a swap that pays the router WETH, then a swap that pays the
+user WETH, then an unwrap, shows WETH with the second swap's minimum. The
+minimum reads in ETH when that step paid all its WETH to the router. When it
+paid only part of it to the router, as a V4 step does that `TAKE`s some of its
+WETH to the user and the rest to the router, or paid the router WETH beside a
+payout the decoder cannot read, the swap shows ETH with no minimum: the decoder
+does not count how much of that step's minimum reaches the router, nor read the
+`UNWRAP_WETH`'s own minimum. A later step that sets the output side sets it
+anew. Otherwise `Token Out` and `Min. received` keep the output side's own token
+and figure, whether the swap was paid in ETH or in a token: a V2 exact-out swap
+that buys USDC and then unwraps the WETH it did not spend shows USDC. The token
+permission warning on the signature screen has its own amount wording, including
+`Unknown`; the SignApproval section below describes it.
 
 The swap's `Deadline` line is the router's deadline as a UTC date and time, e.g.
 `2026-02-27 08:25:51`. A JavaScript date reaches only to 275760-09-13 00:00:00
@@ -1481,6 +1537,21 @@ such as an edit typed into Settings and not yet saved. Home is the one screen
 "Back" always re-renders, so the wallet list reflects anything that changed
 while the user was away from it.
 
+A network switch in Settings leaves every screen beneath Settings showing the
+previous network, so after it "Back" behaves as in a reopened popup: every
+screen on the stack counts as not yet rendered, and the stack is cut at the
+first screen that cannot be rendered from saved state, such as Send or AddToken,
+or at AddressToken for any token but the native one, because that token was
+picked on the previous network. The cut stack is saved with the switch, so a
+popup closed straight after it and reopened onto Settings lands in the same
+place. "Back" then renders the screen it lands on for the new network, and
+anything typed there and not saved, which belonged to the previous network, is
+dropped. ConfirmTx, WaitTx, SuccessTx, ErrorTx and TransactionDetail are
+rendered instead for the network of the transaction they show: the network it
+was reviewed on for ConfirmTx, and the network it was sent on for the others.
+Without a wallet the stack is not cut, because it starts at Welcome, which shows
+nothing from a network.
+
 Every screen that holds secret material in the page registers a cleanup with
 `onViewLeave()` (`src/popup/views/helpers.js`), which `showView()` runs on every
 exit from that screen rather than only on its "Back" button, so nothing secret
@@ -1722,40 +1793,59 @@ view would leave a wallet one click from deletion.
     - Token contract: full address + etherscan link (ERC-20 only)
     - From: blockie + color dot + full address + etherscan link + wallet title
     - To: blockie + color dot + full address + etherscan link + ENS name
-    - Amount: value + symbol (USD in parentheses). An ETH amount Send's "Max"
-      filled in is worked out again from this screen's own fee estimate when it
-      arrives, as the balance minus the reserve, and the transaction is signed
-      with that estimate's fee fields, so a fee fetched again at signing cannot
-      exceed what the amount leaves behind. The address keeps whatever part of
-      the reserve the transaction does not use. If the balance no longer covers
-      the fee, the amount is left as it was and the amount-plus-fee error below
-      blocks the send
-    - Your balance: value + symbol (USD in parentheses), or `unknown (SYMBOL)`
-      for a token whose scale is unknown
+    - Amount: value + symbol (USD in parentheses), the value to four decimal
+      places with the nonzero floor, as on TxApproval (see Display Consistency),
+      however Send's amount field wrote it (`.5` and `0.5` both read `0.5000`).
+      For a token whose scale is unknown, which cannot be sent, the value is the
+      text from Send's amount field cut the same way (`.5` reads `.5000`). An
+      ETH amount Send's "Max" filled in is worked out again from this screen's
+      own fee estimate when it arrives, as the balance minus the reserve, and
+      the transaction is signed with that estimate's fee fields, so a fee
+      fetched again at signing cannot exceed what the amount leaves behind. The
+      address keeps whatever part of the reserve the transaction does not use.
+      If the balance could not be read or no longer covers the fee, the amount
+      is left as it was and one of the errors below blocks the send
+    - Your balance: the From address's balance on the network its transaction
+      was reviewed on, read from that network's RPC endpoint each time the
+      screen is shown, so a screen the popup reopens onto states and checks that
+      network's balance as it is then, whichever network is active. "Loading..."
+      until the read returns, then value + symbol (USD in parentheses), or
+      `unknown (SYMBOL)` for a token whose scale is unknown or when the read
+      failed. The amount check uses the same balances: the ETH balance, and for
+      a token transfer the token balance as well
     - Network fee: "Estimating..." then two lines, or "Unable to estimate",
-      fetched async. The first line is what the transfer is expected to cost,
-      `gasLimit * gasPrice` (USD in parentheses); the second is the
-      `gasLimit * maxFeePerGas` reserve the node requires, which is what the
-      balance check gates on. The second line is omitted on a network with no
-      type-2 pricing, where the two are the same number, but its space is
-      reserved either way
+      fetched async once the balance is read. The first line is what the
+      transfer is expected to cost, `gasLimit * gasPrice` (USD in parentheses);
+      the second is the `gasLimit * maxFeePerGas` reserve the node requires,
+      which is what the balance check gates on. The second line is omitted on a
+      network with no type-2 pricing, where the two are the same number, but its
+      space is reserved either way
     - Warnings: inline warnings from the local checks (scam address, self-send)
       plus four reserved warning boxes made visible by the async checks —
-      recipient with no transaction history, recipient is a contract, burn
-      address, and an Etherscan phishing/scam label
-    - Errors (insufficient balance), plus three reserved error boxes — the
-      amount plus the fee exceeds the balance (ETH transfers), not enough ETH to
-      pay the fee for the transfer (ERC-20 transfers), and the fee could not be
-      estimated. The first two are mutually exclusive per transfer type, so only
-      the applicable one holds space. The last names its cause: for a token
-      whose scale is unknown the fee can never be estimated, and it says the
-      wallet does not know how many decimal places the token uses and that the
-      transaction cannot be sent; for any other failure it asks the user to go
-      back and try again
+      recipient that has never sent a transaction and holds no ETH, recipient is
+      a contract, burn address, and an Etherscan phishing/scam label. An address
+      that has received ETH but never sent a transaction still holds that ETH,
+      so it gets no warning
+    - Errors (an invalid amount), plus five reserved error boxes, so the balance
+      and the fee arriving later move nothing — the amount exceeds the balance
+      (for a token whose scale is unknown it says the token's balance is
+      unknown), the balance could not be read (it asks the user to go back and
+      try again), the amount plus the fee exceeds the balance (ETH transfers),
+      not enough ETH to pay the fee for the transfer (ERC-20 transfers), and the
+      fee could not be estimated. The third and fourth are mutually exclusive
+      per transfer type, so only the applicable one holds space. The last names
+      its cause: for a token whose scale is unknown the fee can never be
+      estimated, and it says the wallet does not know how many decimal places
+      the token uses and that the transaction cannot be sent; for any other
+      failure it asks the user to go back and try again
+    - Three more reserved error boxes, made visible when "Sign & Send" refuses a
+      send because the active network changed, because the selected wallet does
+      not hold the From address, or because of its gas limit or fee (see
+      Transitions), so the refusal moves nothing
     - Password: an inline field on this screen, not a modal, with its own error
       line
-    - "Sign & Send" button (disabled if errors, and while the network fee
-      estimate is pending or unavailable)
+    - "Sign & Send" button (disabled if errors, while the balance is being read,
+      and while the network fee estimate is pending or unavailable)
 - **Transitions**:
     - "Sign & Send" (correct password) → broadcast tx → **WaitTx**
     - "Sign & Send" (correct password) → broadcast fails → **ErrorTx**
@@ -1766,19 +1856,38 @@ view would leave a wallet one click from deletion.
       the contract's own answer is read at signing time only to be compared with
       it, and a disagreement is a refusal rather than a preference for either
       value (`src/shared/transferAmount.js`)
-    - "Sign & Send" after the active network was switched in Settings while this
-      screen was open → nothing is signed; "The active network changed after
-      this transaction was reviewed, so it was not sent. Please go back and
-      review it again." in the errors box, no screen change. The transaction
-      carries the chain id of the network the screen was shown for, so it cannot
-      be signed for another
+    - "Sign & Send" after the active network was switched in Settings since this
+      transaction was reviewed → nothing is signed; "The active network changed
+      after this transaction was reviewed, so it was not sent. Please go back
+      and review it again." in its own box, no screen change. After a switch,
+      "Back" from Settings draws this screen again from the saved transaction,
+      as a popup reopened onto it does; when Send is beneath it on the stack, as
+      when Send showed it in the same popup, "Back" lands below Send instead
+      (see the top of Screen Map). The transaction carries the chain id of the
+      network active when Send showed this screen, and keeps it when the screen
+      is drawn again from the saved transaction, so it cannot be signed for
+      another. The screen describes it on that network, whichever network is
+      active: its amounts are in that network's native currency, its USD values
+      are that network's, so a testnet transaction shows none, its From, To and
+      token contract links open that network's explorer, the balance read, the
+      fee estimate and the contract and never-sent recipient checks ask that
+      network's RPC endpoint, and the Etherscan label check asks that network's
+      explorer
+    - "Sign & Send" (correct password) when the gas limit, a fee per gas or the
+      total fee the RPC endpoint fills in at signing is over its bound in
+      `assertWithinCeilings()` (`src/shared/approvalVerify.js`) → nothing is
+      signed; "The gas limit or fee the RPC endpoint quoted for this transaction
+      is more than this wallet will sign for, so it was not sent. Please go back
+      and try again." in its own box, the same sentence for all three, no screen
+      change
     - "Sign & Send" (wrong password) → "Wrong password." on the password error
       line, no screen change
     - "Sign & Send" signs as the From address above, not as whichever address is
       selected: the two are saved separately, so the popup can reopen onto this
       screen with another address selected. When the selected wallet does not
-      hold the From address → full-sentence error on the password error line,
-      nothing sent (no screen change)
+      hold the From address → nothing is signed; "The selected wallet does not
+      hold the From address above, so nothing was sent. Please go back and send
+      again." in its own box, no screen change
     - "Sign & Send" (correct password, but the From address's key is refused,
       see Data Model) → nothing is signed → **ErrorTx** saying why
     - "Back" → **Send**
@@ -1798,14 +1907,17 @@ view would leave a wallet one click from deletion.
       no recipient." instead
     - Transaction hash: full hash (tap to copy) + etherscan link
     - Count-up timer: "Waiting for confirmation... Ns"
-- **Behavior**: Polls `getTransactionReceipt` every 10 seconds. The wait is
-  persisted: closing and reopening the popup resumes the poll, with the elapsed
-  counter and the timeout deadline still measured from the original broadcast. A
-  lookup that fails is retried on the next tick rather than counted as a missing
-  receipt, because a failed lookup says nothing about the transaction; but six
-  failures in a row (60 seconds at the poll cadence) end the wait, so an RPC
-  that never answers cannot leave it running indefinitely. Any lookup that
-  answers resets that count.
+- **Behavior**: Polls `getTransactionReceipt` every 10 seconds. The screen
+  describes the transaction on the network it was sent on, whichever network is
+  active: the receipt is asked of that network's RPC endpoint, the one Settings
+  has for it, and the To and hash links open that network's explorer. The wait
+  is persisted: closing and reopening the popup resumes the poll, with the
+  elapsed counter and the timeout deadline still measured from the original
+  broadcast. A lookup that fails is retried on the next tick rather than counted
+  as a missing receipt, because a failed lookup says nothing about the
+  transaction; but six failures in a row (60 seconds at the poll cadence) end
+  the wait, so an RPC that never answers cannot leave it running indefinitely.
+  Any lookup that answers resets that count.
 - **Transitions**:
     - Receipt found → **SuccessTx**
     - A lookup that answers "no receipt" 60 seconds or more after broadcast →
@@ -1826,9 +1938,12 @@ view would leave a wallet one click from deletion.
     - Amount + symbol
     - To: color dot + full address + etherscan link, or for a contract creation
       the same sentence as on WaitTx
-    - Block number
+    - Block number + etherscan link
     - Transaction hash: full hash (tap to copy) + etherscan link
     - "Done" button
+- **Behavior**: As on WaitTx, every etherscan link on the screen opens the
+  explorer of the network the transaction was sent on, whichever network is
+  active.
 - **Transitions**:
     - "Done" in the approval popup → closes the popup window
     - "Done" otherwise → resets the navigation stack, then → **AddressToken**
@@ -1848,6 +1963,9 @@ view would leave a wallet one click from deletion.
     - Transaction hash section (hidden if broadcast failed before getting hash):
       full hash (tap to copy) + etherscan link
     - "Done" button
+- **Behavior**: As on WaitTx, every etherscan link on the screen opens the
+  explorer of the network the transaction was sent on, whichever network is
+  active.
 - **Transitions**:
     - "Done" in the approval popup → closes the popup window
     - "Done" otherwise → resets the navigation stack, then → **AddressToken**
@@ -1870,7 +1988,10 @@ view would leave a wallet one click from deletion.
 #### TransactionDetail (`transaction`)
 
 - **When**: User tapped a transaction row on Home, AddressDetail, or
-  AddressToken.
+  AddressToken. The screen describes the transaction on the network it was sent
+  on, whichever network is active: its block, network details, decoded details
+  and raw data are read from that network's Blockscout, the one Settings has for
+  it, and its etherscan links open that network's explorer.
 - **Elements** (grouped into logical blocks using light well containers; field
   labels are self-explanatory so groups have no headings):
     - "Transaction" heading, "Back" button
@@ -1878,7 +1999,11 @@ view would leave a wallet one click from deletion.
     - Type: transaction classification — one of: Native ETH Transfer, ERC-20
       Token Transfer, Swap, Token Approval, Contract Call, Contract Creation. A
       transfer with a token contract is an ERC-20 Token Transfer whatever symbol
-      the token reports.
+      the token reports. A call named `execute` or `multicall` is a Swap, here
+      and on its history row, only when it was sent to one of the Universal
+      Router addresses Uniswap publishes for the network it was sent on (see
+      Transaction Decoding); sent to any other contract, its history row shows
+      the method name and this line reads Contract Call.
     - Status: "Success" or "Failed"
     - From: blockie + color dot + full address (tap to copy) + etherscan link;
       ENS name if available
@@ -1909,13 +2034,18 @@ view would leave a wallet one click from deletion.
     - Contract address input
     - Status line ("Looking up token...", cleared or replaced on failure)
     - Common token quick-pick buttons (top 25 by market cap), which fill the
-      contract address input
+      contract address input. Shown on Ethereum Mainnet only, because the
+      bundled token list holds mainnet contracts
     - "Add" button
 - **Transitions**:
     - "Add" (valid contract) → tracks the token, pops the stack, and re-renders
       **AddressDetail**
     - "Add" with a token already tracked, a scam-listed address, or a failed
       contract lookup → flash message, no screen change
+    - "Add", then a network switch in Settings before the contract lookup
+      answers → nothing is tracked; "The active network changed before the
+      lookup finished, so the token was not added." flash message, no screen
+      change
     - "Back" → previous screen (AddressDetail)
 
 #### Settings (`settings`)
@@ -1926,16 +2056,19 @@ view would leave a wallet one click from deletion.
     - Wallets: one row per wallet with its name (tap to rename inline), a
       `[recovery phrase]` button on HD wallets only, and an `[x]` delete button,
       plus a "+ Add wallet" button
-    - Tracked Tokens: one row per tracked token with an `[x]` remove button,
-      plus a "+ Add token" button
+    - Tracked Tokens: one row per token tracked on the active network with an
+      `[x]` remove button, plus a "+ Add token" button
     - Display: "Show tracked tokens with zero balance" checkbox, "UTC
       Timestamps" checkbox, and a Theme selector (System / Light / Dark)
     - Network: network selector (Ethereum Mainnet / Sepolia Testnet). The
       network changes only here, or when the user approves a site's request on
       **NetworkApproval**; either way, switching restores the RPC and Blockscout
       endpoints last used on that network, or that network's defaults if it has
-      none, and sends `chainChanged` with the new chain id to every open tab.
-      Choosing the network already active changes nothing and sends nothing
+      none, and the tokens tracked on that network, and sends `chainChanged`
+      with the new chain id to every open tab. A token is tracked only on the
+      network it was added on, because a contract address names a token on one
+      network only. Choosing the network already active changes nothing and
+      sends nothing
     - Ethereum RPC: endpoint URL input + "Save" button (validated against
       `eth_chainId` before being saved)
     - Blockscout API: endpoint URL input + "Save" button (validated against
@@ -1954,7 +2087,7 @@ view would leave a wallet one click from deletion.
       under any address, with remove buttons
     - Connected Sites: the origins of the sites allowed without "Remember my
       choice" that are still connected, with remove buttons. Only the background
-      holds these, in memory, and Settings asks it for them with
+      holds these, in session storage, and Settings asks it for them with
       `AUTISTMASK_GET_CONNECTED_SITES`
     - Denied Sites: the origins remembered as denied, under any address, with
       remove buttons
@@ -1973,13 +2106,15 @@ view would leave a wallet one click from deletion.
       its origin is dropped from Allowed Sites under every address, and
       `AUTISTMASK_REMOVE_SITE` has the background end every connection approved
       without "Remember" from that origin, under any address, and send
-      `accountsChanged` with an empty list to the open tabs of that origin. The
-      same host under another scheme or port is another site and is left alone.
-      Only the extension's own pages may send either message
+      `accountsChanged` with an empty list to the open tabs of that origin.
+      Settings waits for the background's answer before it draws the lists
+      again. The same host under another scheme or port is another site and is
+      left alone. Only the extension's own pages may send either message
     - `[x]` on a denied site → forgets the refusal, in place; it connects
       nothing and tells the background nothing
     - Ten clicks on the version → reveals the Debug well (no screen change)
-    - "Back" (or Settings gear again) → previous screen (Home)
+    - "Back" (or Settings gear again) → previous screen (Home); after a network
+      switch, the stack is cut first (see the top of Screen Map)
 
 #### ShowRecoveryPhrase (`show-phrase`)
 
@@ -2020,7 +2155,9 @@ view would leave a wallet one click from deletion.
 - **Elements**:
     - "Back" button, "Delete Wallet" heading
     - Warning naming the wallet and stating that deletion is permanent and any
-      funds are unrecoverable without the recovery phrase
+      funds are unrecoverable without the recovery phrase, the private key or
+      the extended private key, according to the wallet's kind
+      (`keyMaterialName()` in `src/popup/views/helpers.js`)
     - Password input
     - Error line
     - "Confirm Delete" button
@@ -2036,8 +2173,8 @@ view would leave a wallet one click from deletion.
       (`src/shared/walletDelete.js`)
     - Either way, every address the wallet held loses its site permissions of
       both kinds: the remembered ones in storage, and the connections approved
-      without "Remember", which only the background holds, in memory, and drops
-      on `AUTISTMASK_ADDRESSES_REMOVED`
+      without "Remember", which only the background holds, in session storage,
+      and drops on `AUTISTMASK_ADDRESSES_REMOVED`
     - "Confirm Delete" (wrong password) → "That password is incorrect. Please
       try again." on the error line, nothing deleted
     - "I have lost my password" → **DeleteWalletLostPassword**
@@ -2061,9 +2198,10 @@ view would leave a wallet one click from deletion.
       cannot be unlocked again, and that no password is needed to delete it
     - What deletion does and does not do: it erases the copy of the key stored
       on this device; nothing on chain changes and no money is moved
-    - The route back — adding the wallet again with the recovery phrase and a
-      new password — and, in bold, that without that phrase written down the
-      deletion loses everything the wallet holds, forever
+    - The route back — adding the wallet again, with a new password, from a kept
+      copy of its recovery phrase, private key or extended private key (named as
+      on DeleteWallet) — and, in bold, that without that copy the deletion loses
+      everything the wallet holds, forever
     - That the other wallets are not touched
     - The wallet's name, and a text input asking for it to be typed back. A name
       that shows nothing at all (only spaces, or only characters that paint
@@ -2121,8 +2259,9 @@ view would leave a wallet one click from deletion.
       the address **only if it has on-chain activity**. An address that was
       never used is not found by that scan. The text is written by
       `recoveryPathText()` rather than sitting in `index.html`, so it can name
-      the wallet's own kind of key material: an xprv wallet has no recovery
-      phrase to re-import.
+      the wallet's own kind of key material through `keyMaterialName()`, as
+      DeleteWallet and DeleteWalletLostPassword do: an xprv wallet has no
+      recovery phrase to re-import.
     - A warning when the address holds anything, ETH or any tracked ERC-20,
       followed by the holdings themselves via `balanceLinesForAddress()` and the
       USD total via `formatAddressTotal()` (see
@@ -2150,15 +2289,16 @@ view would leave a wallet one click from deletion.
   one in this wallet follows the splice.
 - The address loses its site permissions of both kinds, whether or not it was
   the active one: the remembered ones in storage, and any connection approved
-  without "Remember", which only the background holds, in memory, and drops on
-  `AUTISTMASK_ADDRESSES_REMOVED`.
+  without "Remember", which only the background holds, in session storage, and
+  drops on `AUTISTMASK_ADDRESSES_REMOVED`.
 - The wallet's derivation counter (`nextIndex`) is not rewound, so "+" derives a
   fresh address rather than handing back the one just removed.
 
 #### SettingsAddToken (`settings-addtoken`)
 
 - **When**: User tapped "+ Add token" in Settings. Tokens added here are tracked
-  across every address, unlike AddToken which is reached from one address.
+  across every address on the active network, unlike AddToken which is reached
+  from one address.
 - **Elements**:
     - "Back" button, "Add Token" heading
     - Instruction text
@@ -2167,11 +2307,19 @@ view would leave a wallet one click from deletion.
     - "Or pick from top 100:" dropdown (already-tracked tokens are disabled) +
       "Add selected" button
     - "Or enter contract address:" input, a status line, and an "Add" button
+    - The two lists from the bundled token list, "Top tokens:" and "Or pick from
+      top 100:", are shown on Ethereum Mainnet only, because that list holds
+      mainnet contracts. On any other network the contract address is the only
+      add path
 - **Transitions**:
-    - Any of the three add paths, on success → adds the token and shows an
+    - Any of the add paths shown, on success → adds the token and shows an
       "Added SYMBOL" flash message (no screen change)
     - A duplicate, a scam-listed address, or a failed contract lookup → flash
       message, no screen change
+    - "Add" by contract address, then a network switch in Settings before the
+      lookup answers → nothing is tracked; "The active network changed before
+      the lookup finished, so the token was not added." flash message, no screen
+      change
     - "Back" → previous screen (Settings)
 
 #### SiteApproval (`approve-site`)
@@ -2185,14 +2333,17 @@ view would leave a wallet one click from deletion.
   code `4100` and opens no prompt. Two such origins are `null`, which the
   browser reports for a page with an opaque origin, such as one its server
   sandboxes with a Content-Security-Policy, and `file://`, which Chrome reports
-  for a local file. The background script prefers the toolbar popup
-  (`action.openPopup()`) and falls back to a separate popup window
-  (`src/background/index.js`, `requestApproval()`). Only one exists per site at
-  a time: a further connection request from a site whose prompt is still
-  unanswered is refused with EIP-1193 code `-32002` and opens no new prompt. If
-  that prompt was in a toolbar popup that closed before it connected, and the
-  toolbar popup has since been set to open something else, the refused request
-  shows that prompt again.
+  for a local file. Nor is such a page told the active address by
+  `accountsChanged`, even at a connected site's URL: the background names the
+  origin of the tab's URL on the event, and the content script passes the
+  address on only to a page whose own origin is that one. The background script
+  prefers the toolbar popup (`action.openPopup()`) and falls back to a separate
+  popup window (`src/background/index.js`, `requestApproval()`). Only one exists
+  per site at a time: a further connection request from a site whose prompt is
+  still unanswered is refused with EIP-1193 code `-32002` and opens no new
+  prompt. If that prompt was in a toolbar popup that closed before it connected,
+  and the toolbar popup has since been set to open something else, the refused
+  request shows that prompt again.
 - **Elements**:
     - "Connection Request" heading
     - Phishing warning banner (shown when the hostname is on the phishing
@@ -2245,17 +2396,28 @@ view would leave a wallet one click from deletion.
     - Site origin (bold, scheme and port included) + "wants to send a
       transaction"
     - Decoded action (if calldata is recognized): action name, token details,
-      amounts, steps, deadline (see Transaction Decoding)
+      amounts, what each swap step spends that the `Amount` line does not give,
+      what each `PERMIT2_TRANSFER_FROM` moves and where to, steps, deadline, and
+      unless a swap pays only the From address, a `Paid to` line for each other
+      address it pays, or saying that a token stays in the router or who it pays
+      is unknown (see Transaction Decoding)
     - From: color dot + full address + etherscan link
     - Contract: color dot + full address + etherscan link, token symbol label if
       known; for a contract creation, the same sentence as on WaitTx
-    - Value: amount in ETH (4 decimal places, USD in parentheses)
-    - Network fee (max): gas limit × fee per gas in ETH (4 decimal places, USD
-      in parentheses), with the gas limit and the fee per gas in gwei below it
+    - Value: amount in ETH (4 decimal places with the nonzero floor, USD in
+      parentheses)
+    - Network fee (max): gas limit × fee per gas in ETH (4 decimal places with
+      the nonzero floor, USD in parentheses), with the gas limit and the fee per
+      gas in gwei below it
     - Network and nonce
     - Raw data: full calldata displayed inline (shown if present)
     - Password input and an error line
     - "Confirm" / "Reject" buttons
+- **Behavior**: Every etherscan link on the screen opens the explorer of the
+  network the transaction was populated on, whichever network is active. The
+  Value and Network fee lines each give the USD value of the exact amount at the
+  price on that network, as on ConfirmTx: none for a testnet transaction or one
+  on a chain id that names no network.
 - **Transitions**:
     - "Confirm" (correct password) → decrypts and signs the transaction it was
       shown, exactly as shown, hands the signed transaction to the background to
@@ -2383,8 +2545,9 @@ view would leave a wallet one click from deletion.
 - **Transitions**:
     - "Switch" → closes popup; the background switches the network as
       **Settings** does, restoring the RPC and Blockscout endpoints last used on
-      that network (or that network's defaults if it has none), sends
-      `chainChanged` to every open tab, and answers the site with success
+      that network (or that network's defaults if it has none) and the tokens
+      tracked on that network, sends `chainChanged` to every open tab, and
+      answers the site with success
     - "Reject" → closes popup; the site is answered with EIP-1193 code 4001 and
       nothing changes
     - Popup window closed without answering → the same as "Reject"
@@ -2861,11 +3024,236 @@ Currently supported:
   or recipient, and amount.
 - **Uniswap Universal Router**: `execute()` calls — shows swap direction (e.g.
   "Swap USDT → ETH"), token addresses, amounts, execution steps, and deadline.
-  Decodes Permit2, V2/V3/V4 swaps, wrap/unwrap, and balance checks. A V4 swap
-  action is read only in the parameter shape deployed on mainnet and Sepolia,
-  not in the newer one on `v4-periphery` `main`, which adds a `minHopPriceX36`
-  field. An action in any other shape is not read, and its step is listed as
-  `V4 Swap (could not be decoded)`.
+  The swap summary is shown only for a transaction sent to one of the Universal
+  Router addresses Uniswap publishes for the network: on TxApproval the network
+  the transaction is for, on TransactionDetail the network it was sent on. The
+  same calldata sent to any other address is shown as raw data. Decodes Permit2,
+  V2/V3/V4 swaps, wrap/unwrap, and balance checks. A V3 swap step's path is read
+  as the router reads it: a `V3_SWAP_EXACT_IN` path runs from the token it
+  spends to the token it buys, and a `V3_SWAP_EXACT_OUT` path from the token it
+  buys to the token it spends, so that step's input token is its path's last
+  token and its output token the first. The router reads a path as one token
+  address followed by whole hops of a 3-byte fee and a token address, and
+  ignores any bytes after the last hop, so the decoder does not read a path with
+  such bytes. A V4 swap action is read only in the parameter shape deployed on
+  mainnet and Sepolia, not in the newer one on `v4-periphery` `main`, which adds
+  a `minHopPriceX36` field. An action in any other shape is not read, and its
+  step is listed as `V4 Swap (could not be decoded)`. Each step is named and
+  read as the command that the release of the router at that address runs for
+  its command type, as that release's `contracts/libraries/Commands.sol` names
+  it. The decoder reads the type from the command byte with the mask that router
+  uses: `0x1f` for `UniversalRouterV1`, `0x3f` for
+  `UniversalRouterV1_2_V2Support` and `UniversalRouterV2`, and `0x7f` for
+  `UniversalRouterV2_1_1` and `UniversalRouterV2_1_2`. The allow-revert flag
+  (`0x80`) therefore does not change the command a step is read as. Releases run
+  different commands for some types: on `UniversalRouterV1` and
+  `UniversalRouterV1_2_V2Support`, `0x10` to `0x13` are NFT commands, where the
+  later routers run `V4_SWAP`, `V3_POSITION_MANAGER_PERMIT`,
+  `V3_POSITION_MANAGER_CALL` and `V4_INITIALIZE_POOL`. The decoder does not read
+  those routers' NFT commands, and lists each by its name there, for example
+  `Seaport` for `SEAPORT` (`0x10` on `UniversalRouterV1`). A type a release
+  names no command for is listed by its number, for example `Command 0x0e` on
+  `UniversalRouterV1`, which has no `BALANCE_CHECK_ERC20` and reverts on it. The
+  router reverts the whole transaction when a step fails, unless the step's
+  command byte has that flag set and its command is one the router lets fail, as
+  each release's `contracts/base/Dispatcher.sol` shows: on `UniversalRouterV2`,
+  `UniversalRouterV2_1_1` and `UniversalRouterV2_1_2`, `PERMIT2_PERMIT`,
+  `PERMIT2_PERMIT_BATCH`, `BALANCE_CHECK_ERC20`, `V3_POSITION_MANAGER_PERMIT`,
+  `V3_POSITION_MANAGER_CALL`, `V4_INITIALIZE_POOL`, `V4_POSITION_MANAGER_CALL`
+  and `EXECUTE_SUB_PLAN`; on `UniversalRouterV1_2_V2Support`,
+  `BALANCE_CHECK_ERC20`, `EXECUTE_SUB_PLAN` and its NFT market calls and NFT
+  owner checks; on `UniversalRouterV1`, its NFT market calls and NFT owner
+  checks. Such a step may then fail while the transaction goes on to the next
+  step, and it is listed with ` (allowed to fail)` after its name, for example
+  `Balance Check (allowed to fail)`. On every other command, among them each V2,
+  V3 and V4 swap and each payment of ETH or an ERC-20 token, the flag has no
+  effect: the step succeeds or the whole transaction reverts, so the step reads
+  as it does without the flag. A `BALANCE_CHECK_ERC20` the router lets fail
+  guarantees nothing, so it is read as one whose `minBalance` is zero. Only the
+  routers with the `0x7f` mask have `PAY_PORTION_FULL_PRECISION` (`0x07`),
+  listed as `Pay Portion (Full Precision)`, and `ACROSS_V4_DEPOSIT_V3` (`0x40`),
+  listed as `Across Bridge Deposit`; the other routers revert on `0x07`, and it
+  is listed there as `Command 0x07`. The decoder does not read the commands
+  inside an `EXECUTE_SUB_PLAN` (`0x21`) step, and wherever that step stands they
+  may spend the user's tokens or pay the user. That step is listed as
+  `Execute Sub-Plan (its steps are not shown)`, and whatever the other steps
+  state, the summary names no swap direction, `Token In` and `Token Out` read
+  `Unknown (could not be decoded)`, and there is no `Amount` or `Min. received`
+  line. Each swap step, `SWEEP`, `WRAP_ETH`, `UNWRAP_WETH`, `TRANSFER`,
+  `PAY_PORTION`, `PAY_PORTION_FULL_PRECISION`, `PERMIT2_TRANSFER_FROM` (which
+  moves the user's own tokens) and V4 `TAKE` and `TAKE_PORTION` names the
+  address it pays, and `TAKE_ALL` pays the transaction's sender. The router
+  reads `address(1)` as the transaction's sender, and `address(2)` as the router
+  itself, which holds what it is paid until a later step pays it out; a payment
+  to the router, as `address(2)` or by its own address, is not counted as paid
+  out. `UniversalRouterV1` alone pays a `PERMIT2_TRANSFER_FROM` to `address(1)`
+  or `address(2)` as those addresses, and the decoder names them. A
+  `PERMIT2_TRANSFER_FROM` into the router is named with the amount it moves,
+  because the decoder does not check that later steps spend all of it.
+  `ACROSS_V4_DEPOSIT_V3` pays the bridge, which pays the deposit's recipient on
+  another network and refunds a deposit nobody fills to its depositor; the
+  router passes both on as written, so `address(1)` and `address(2)` there are
+  addresses, and each that is not the transaction's sender is named. A
+  `BALANCE_CHECK_ERC20` pays nobody: the router checks that its owner holds at
+  least `minBalance` of its token, and reads the owner as written, so
+  `address(1)` and `address(2)` there are addresses too. A check of any address
+  but the transaction's sender's says nothing about what the user receives: it
+  sets neither `Token Out` nor the minimum, and it is listed as
+  `Balance Check (of another address)`. A check whose input does not decode,
+  such as one whose owner word has a nonzero top byte (the router reads the
+  owner from the word's last 20 bytes), likewise sets neither, and it is listed
+  as `Balance Check (could not be decoded)`. When a swap step, `TAKE` or
+  `TAKE_PORTION` pays the router any token, the swap's output or another, a
+  `WRAP_ETH` pays it WETH, or an `UNWRAP_WETH` into the router turns WETH a step
+  paid it into ETH, that token stays in the router unless a later step pays out
+  or spends all the router holds of it: a `SWEEP` of that token to anyone but
+  the router, an `UNWRAP_WETH` when it is WETH, a `WRAP_ETH` of
+  `CONTRACT_BALANCE` when it is ETH, a `TRANSFER` of `CONTRACT_BALANCE`, a
+  `PAY_PORTION` of 10,000 bips or a `PAY_PORTION_FULL_PRECISION` of 1e18 of that
+  token to anyone but the router, an `ACROSS_V4_DEPOSIT_V3` of
+  `CONTRACT_BALANCE` of that token, or of ETH when it sets `useNative`, or a V2
+  or V3 exact-in swap step or V4 `SETTLE` that pays `CONTRACT_BALANCE` of that
+  token from the router (`payerIsUser` false). V2 and V3 exact-in swap steps and
+  V4 `SETTLE`s that pay WETH from the router also spend all the WETH a
+  `WRAP_ETH` paid it once together they spend the amount the `WRAP_ETH` states,
+  as a swap paid in ETH does, but only when that amount is not
+  `CONTRACT_BALANCE` and the router held no WETH from an earlier step when the
+  `WRAP_ETH` ran: after two `WRAP_ETH`s of 0.5 ETH into the router, a swap of 1
+  WETH from it reads as leaving the WETH there. A V2 or V3 exact-out step paid
+  from the router spends an amount the calldata does not state, at most its
+  `amountInMax`, so the decoder counts it as spending nothing the router holds.
+  A `SETTLE` of `OPEN_DELTA` (zero), and a `SETTLE_ALL`, pay only what the step
+  still owes of their token when they run. The decoder takes that to be the
+  amounts the step's swap actions state they spend of that token only when every
+  action in the step could be read, every swap action names the token it spends
+  and the token it buys (a swap action with an empty path swaps nothing), the
+  `SETTLE` or `SETTLE_ALL` is the step's only `SETTLE` or `SETTLE_ALL` of that
+  token and comes after every swap action, no swap action buys that token, no
+  `TAKE`, `TAKE_ALL` or `TAKE_PORTION` in the step takes it (a `TAKE` of a
+  stated amount adds to what the step owes), and the swap actions that spend it
+  state a quantity together; otherwise it does not know the amount, and such a
+  `SETTLE` from the router counts as spending nothing. So the rest of a V4
+  `SETTLE` of more than its swap spends, taken to the router, the WETH of a
+  `WRAP_ETH`, and a token a swap pays the router on the way to the output, each
+  stays in the router when later steps do not spend all of it, where anyone can
+  take it in a later transaction. The router sends ETH as written, so a
+  `TRANSFER` of `CONTRACT_BALANCE` of ETH always reverts and pays out nothing. A
+  step paying a token to the V2 pair that the very next step spends, as a V2
+  exact-in of that token whose `amountIn` is `ALREADY_PAID` (zero) or
+  `CONTRACT_BALANCE`, is a hop, not a payout: Uniswap's mixed routes pay the
+  next V2 pair directly, and the router enforces that swap's own minimum. The
+  decoder checks that the address paid is that pair, deriving it from the V2
+  factory and pair init code hash the network's routers were deployed with and
+  the first two tokens of that step's path; a payment to any other address is
+  named. (Sepolia's `UniversalRouterV1_2_V2Support` was deployed with
+  placeholders for both values, so no V2 swap step can succeed on that router.)
+  Every other payment counts, in whichever step and of whatever token, a share
+  of the output included: an interface fee paid to another address by
+  `PAY_PORTION`, `TRANSFER` or `TAKE_PORTION` is named, and the minimum reads
+  `Min. paid out`, because the swap's minimum includes the fee. The minimum
+  reads `Min. received` only when some step pays the transaction's sender (the
+  From address on TxApproval, the sender the explorer reports on
+  TransactionDetail) and no `Paid to` line is shown. `Paid to` lines after
+  `Token Out` name each other address paid; one reads
+  `The bridge, which pays the deposit's recipient on another network` for a
+  bridge deposit; one reads, for example,
+  `The router, 2000.0000 USDT from the sender (later steps may not spend all of it)`
+  for each move into the router, followed by a `Token moved into the router`
+  line that gives the moved token's address as the `Token In` line does; one
+  reads `The router, where it stays (no later step pays it out)` for each token
+  that stays in the router, followed, for any token but the output, by a
+  `Token moved into the router` line giving that token in the same way (ETH by
+  name); and one more reads `Unknown (could not be decoded)` when a step that
+  may pay an address went unread. When no step pays anyone, a single line reads
+  `Unknown (not named in the calldata)`. Wherever there is a `Paid to` line, the
+  minimum reads `Min. paid out`. The `Amount` line gives the total the steps
+  take of `Token In`, from the step that sets the input side on: the first V2 or
+  V3 exact-in or exact-out, `WRAP_ETH` or V4 swap step that names an input token
+  or amount. A V4 step with a swap action sets the input side when no earlier
+  step set it, even when it names neither (see Display Consistency). That step
+  counts its own amount, whoever pays it: a V2 or V3 exact-out step its
+  `amountInMax`, and a V4 step what it takes of its input token from the user's
+  wallet, as below, or, when the user pays it none of that token, the `amountIn`
+  of the swap action that spends it. Each later V2 or V3 exact-in or exact-out
+  step whose `payerIsUser` is true takes its amount, found in the same way, from
+  the user's wallet. Every V4 step, with a swap action or without, takes from
+  the user's wallet what its `SETTLE`s paid by the user (`payerIsUser` true) and
+  its `SETTLE_ALL`s pay, for each token on its own; what the step that sets the
+  input side takes of any other token counts as a later step's take. A `SETTLE`
+  of any amount but `OPEN_DELTA` pays that amount, and a `SETTLE` of
+  `OPEN_DELTA` or a `SETTLE_ALL` pays what the step owes, as above. So a V4 step
+  that swaps 400 USDT, with a `SETTLE` of 5,000 USDT paid by the user and the
+  rest taken to another address, reads `5000.0000 USDT`. A later step paid from
+  the router spends what the router holds and takes nothing, and so does a V2
+  exact-in whose `amountIn` is `ALREADY_PAID`. A later take of `Token In` is
+  added to the total while both are quantities: a V3 exact-in of 600 USDT and a
+  V2 exact-in of 400 USDT, both paid by the user, read `1000.0000 USDT`. When
+  the decoder does not know a take's amount, the total is not known and there is
+  no `Amount` line. `Token In` is the token of the last `PERMIT2_PERMIT` the
+  decoder reads, when there is one. Its amount, `Unlimited` included, stands as
+  the `Amount` figure in place of the total only in the plain shape of Uniswap's
+  own routes: it is the only `PERMIT2_PERMIT`, its spender is the router, the
+  router may not let it fail, no step before it takes its token or a token the
+  decoder does not know, and the decoder reads every step after it in full.
+  Permit2 then lets the router take no more of the token than that amount, so
+  the permit covers every take of it. A step the decoder does not read in full
+  may raise what Permit2 lets the router take, as a `PERMIT2_PERMIT_BATCH` can:
+  a command the decoder does not read (listed at the end of this section), a
+  step whose input it cannot read, in whole or in part, and a step it fails on.
+  In any other case the line gives the total, as with no permit. When the step
+  that sets the input side spends a token other than the permit's, or one the
+  decoder does not know, its amount gets lines of its own, unless it states no
+  amount and the user pays it none of its input token, and the total has no
+  figure to start from: unless the permit's amount stands there is no `Amount`
+  line, and each take of the permit's token gets lines of its own. Each take the
+  total does not count gives three lines after the `Amount` line (after
+  `Token In` when there is none): one of a token other than `Token In`; one of
+  `Token In` after an amount that is not a quantity (a V4 open delta,
+  `ALREADY_PAID`, which keep their wording on the `Amount` line, or no stated
+  amount, as of a V4 exact-out step); and one whose amount the decoder does not
+  know. When the step that sets the input side states no amount, the user pays
+  it some of its input token, and there is no `Amount` line, that step gets them
+  too whenever another take's lines give a figure, or a `PERMIT2_TRANSFER_FROM`
+  of its token gives one, on the lines below or, into the router, on its
+  `Paid to` line, so that figure cannot read as all that leaves. When it states
+  no amount and the user pays it none of its input token, as when the router
+  pays it, that step takes none of that token from the user's wallet and never
+  gets them, with a permit or without. They come in step order, the step that
+  sets the input side first when it has them: `Moved from the sender`, its
+  amount, worded as the `Amount` line words one, or
+  `Unknown (could not be decoded)` when the decoder does not know it;
+  `Token moved`, giving the token's address as the `Token In` line does; and
+  `Moved to`, which reads `The swap step that spends it`. A token the decoder
+  does not know gives the `Moved from the sender` line alone. A step may also
+  take from the user's wallet what the decoder did not read: a V4 step whose
+  input or one of whose `SETTLE`s or `SETTLE_ALL`s it cannot read, which the
+  router still runs; a V2 or V3 exact-in or exact-out step or a
+  `PERMIT2_TRANSFER_FROM` whose input it cannot read, such as a V3 step whose
+  path is shorter than one token address or has bytes after its last hop; every
+  `PERMIT2_TRANSFER_FROM_BATCH`; every `EXECUTE_SUB_PLAN`, wherever it stands;
+  and every step it fails on. Each such step gives one `Moved from the sender`
+  line among those, reading `Unknown (could not be decoded)`. That line, or any
+  line for a token the decoder does not know, leaves no `Amount` line, whose
+  figure might be too low, and such a step before a `PERMIT2_PERMIT` keeps the
+  permit's amount from standing. Then each `PERMIT2_TRANSFER_FROM` but one into
+  the router, in step order, gives three lines: `Moved from the sender`, the
+  amount it moves, for example `1000000.0000 USDT`; `Token moved`, giving the
+  token's address as the `Token In` line does; and `Moved to`, which reads
+  `The V2 pair the next swap spends` for a hop and `The sender` for `address(1)`
+  on every router but `UniversalRouterV1`, and otherwise gives the address. A
+  move into the router needs none of them, because its `Paid to` line and
+  `Token moved into the router` line already give the amount, the token and
+  where it goes, and so its amount is shown once. These lines change neither the
+  `Paid to` lines nor the minimum's label. A step goes unread when its recipient
+  does not decode as an address, when it is a V3 swap step whose path is shorter
+  than one token address or has bytes after its last hop, or when it is a
+  command the decoder does not read: every command other than `PERMIT2_PERMIT`,
+  `PERMIT2_TRANSFER_FROM`, `V2_SWAP_EXACT_IN`, `V2_SWAP_EXACT_OUT`,
+  `V3_SWAP_EXACT_IN`, `V3_SWAP_EXACT_OUT`, `V4_SWAP`, `SWEEP`, `TRANSFER`,
+  `PAY_PORTION`, `PAY_PORTION_FULL_PRECISION`, `ACROSS_V4_DEPOSIT_V3`,
+  `WRAP_ETH`, `UNWRAP_WETH` and `BALANCE_CHECK_ERC20`
+  (`PERMIT2_TRANSFER_FROM_BATCH`, `EXECUTE_SUB_PLAN` and the NFT commands among
+  them), or a type its release names no command for.
 
 ### Non-Goals Forever
 

docs/README.md

@@ -306,7 +306,14 @@ enter your password and click "Confirm" to authorize it. Message and typed-data
 signature requests work the same way, with a "Sign" button, and also require
 your password.
 
-If the requesting site's domain is on the phishing blocklist, all three approval
+A connected site can also ask to switch the wallet's network. A popup shows the
+site's origin, the current network and the requested network. Nothing changes
+unless you click "Switch"; clicking "Reject" or closing the popup leaves
+everything as it was. Switching works exactly as it does in Settings, and
+changes the network for the whole wallet and for every site, not only for the
+one that asked.
+
+If the requesting site's domain is on the phishing blocklist, all four approval
 screens show a red phishing warning before you decide.
 
 You can manage site permissions in Settings. Allowed and denied sites can be
@@ -378,7 +385,8 @@ Click the gear icon on the home screen to access settings:
 - **Display**: Toggle whether tracked tokens with zero balance are shown, switch
   timestamps to UTC, and choose the theme (System, Light, or Dark).
 - **Network**: Switch between Ethereum Mainnet and Sepolia Testnet. Switching
-  resets the RPC and Blockscout endpoints to that network's defaults.
+  restores the RPC and Blockscout endpoints you last used on that network, or
+  that network's defaults if you have not used it before.
 - **Ethereum RPC**: Change the Ethereum node endpoint. Default is a public RPC.
   You can use your own node for maximum privacy.
 - **Blockscout API**: Change the Blockscout instance used for token balances and

manifest/firefox.json

@@ -27,7 +27,8 @@
     "web_accessible_resources": ["src/content/inpage.js"],
     "browser_specific_settings": {
         "gecko": {
-            "id": "autistmask@sneak.berlin"
+            "id": "autistmask@sneak.berlin",
+            "strict_min_version": "115.0"
         }
     }
 }

src/background/index.js

@@ -49,6 +49,9 @@ const {
     actionApi,
     getPlatformInfo,
     runtimeApi,
+    sessionStorageGet,
+    sessionStorageRemove,
+    sessionStorageSet,
     tabsQuery,
     tabsSendMessage,
     windowsApi,
@@ -61,12 +64,31 @@ const runtime = runtimeApi();
 const windowsNs = windowsApi();
 const actionNs = actionApi();
 
-// Connected sites (in-memory, non-persisted): { "origin:address": true }
+// Connections the user allowed without "Remember my choice for this site".
+// Each is one item in the browser's session storage, key
+// origin + ":" + address and value true, and session storage holds nothing
+// else. Session storage outlives this worker being stopped when idle and
+// started again, so such a connection lasts until it is ended below or the
+// browser closes. One item per connection means that making one is a single
+// write, and two never overwrite each other.
 //
 // A site is its full origin (scheme://host[:port]), here and in the
 // remembered allowedSites/deniedSites lists alike: a grant to
 // https://dapp.example says nothing about http://dapp.example or another port.
-const connectedSites = {};
+// An origin can carry a port, so the address is what follows the key's last
+// colon and the origin is what precedes it.
+async function isConnected(origin, address) {
+    const key = origin + ":" + address;
+    const items = await sessionStorageGet(key);
+    return items[key] === true;
+}
+
+// End every connection allowed without "Remember" whose key `ends` returns
+// true for.
+async function endConnections(ends) {
+    const keys = Object.keys(await sessionStorageGet(null)).filter(ends);
+    if (keys.length > 0) await sessionStorageRemove(keys);
+}
 
 // Pending approval requests: { id: { origin, resolve } }
 const pendingApprovals = {};
@@ -764,10 +786,10 @@ async function handleConnectionRequest(origin) {
         };
     }
 
-    // Check allowed list or in-memory connected
+    // Check allowed list or a connection allowed without "Remember"
     if (
         allowed.includes(origin) ||
-        connectedSites[origin + ":" + activeAddress]
+        (await isConnected(origin, activeAddress))
     ) {
         return { result: [activeAddress] };
     }
@@ -804,7 +826,7 @@ async function handleConnectionRequest(origin) {
         if (decision.remember) {
             await rememberSiteChoice("allowedSites", activeAddress, origin);
         } else {
-            connectedSites[origin + ":" + activeAddress] = true;
+            await sessionStorageSet({ [origin + ":" + activeAddress]: true });
         }
         return { result: [activeAddress] };
     } else {
@@ -858,7 +880,7 @@ async function handleRpc(method, params, origin) {
         const allowed = s.allowedSites[activeAddress] || [];
         if (
             allowed.includes(origin) ||
-            connectedSites[origin + ":" + activeAddress]
+            (await isConnected(origin, activeAddress))
         ) {
             return { result: [activeAddress] };
         }
@@ -894,7 +916,7 @@ async function handleRpc(method, params, origin) {
         const allowed = s.allowedSites[activeAddress] || [];
         if (
             !allowed.includes(origin) &&
-            !connectedSites[origin + ":" + activeAddress]
+            !(await isConnected(origin, activeAddress))
         ) {
             return { error: { code: 4100, message: "Unauthorized" } };
         }
@@ -987,10 +1009,10 @@ async function handleRpc(method, params, origin) {
         const s = await getState();
         const activeAddress = activeAddressOf(s);
         const allowed = s.allowedSites[activeAddress] || [];
-        const isConnected =
+        const hasPermission =
             allowed.includes(origin) ||
-            connectedSites[origin + ":" + activeAddress];
-        if (!isConnected || !activeAddress) {
+            (await isConnected(origin, activeAddress));
+        if (!hasPermission || !activeAddress) {
             return { result: [] };
         }
         return {
@@ -1017,7 +1039,7 @@ async function handleRpc(method, params, origin) {
         const allowed = s.allowedSites[activeAddress] || [];
         if (
             !allowed.includes(origin) &&
-            !connectedSites[origin + ":" + activeAddress]
+            !(await isConnected(origin, activeAddress))
         ) {
             return { error: { code: 4100, message: "Unauthorized" } };
         }
@@ -1071,7 +1093,7 @@ async function handleRpc(method, params, origin) {
         const allowed = s.allowedSites[activeAddress] || [];
         if (
             !allowed.includes(origin) &&
-            !connectedSites[origin + ":" + activeAddress]
+            !(await isConnected(origin, activeAddress))
         ) {
             return { error: { code: 4100, message: "Unauthorized" } };
         }
@@ -1142,7 +1164,7 @@ async function handleSendTransaction(params, origin) {
     const allowed = s.allowedSites[activeAddress] || [];
     if (
         !allowed.includes(origin) &&
-        !connectedSites[origin + ":" + activeAddress]
+        !(await isConnected(origin, activeAddress))
     ) {
         return { error: { code: 4100, message: "Unauthorized" } };
     }
@@ -1254,10 +1276,6 @@ async function broadcastChainChanged(chainId) {
 
 // Broadcast accountsChanged to all tabs, respecting per-address permissions
 async function broadcastAccountsChanged() {
-    // Clear non-remembered approvals on address switch
-    for (const key of Object.keys(connectedSites)) {
-        delete connectedSites[key];
-    }
     // Reject and close any pending approval popups so they don't hang. An
     // approval an attempt has already claimed is left alone entirely: it is
     // being signed and broadcast right now, and neither rejecting it to the
@@ -1276,6 +1294,10 @@ async function broadcastAccountsChanged() {
         }
     }
     resetPopupUrl();
+    // An address switch ends every connection allowed without "Remember". This
+    // waits on storage, so it comes after the pending approvals above, which
+    // are still rejected the moment the switch arrives.
+    await endConnections(() => true);
     const s = await getState();
     const activeAddress = activeAddressOf(s);
     const allowed = activeAddress ? s.allowedSites[activeAddress] || [] : [];
@@ -1286,17 +1308,24 @@ async function broadcastAccountsChanged() {
         return;
     }
     for (const tab of tabs) {
+        // The tab's URL is all the background knows of the page in it, and a
+        // page at a site's URL may have another origin: a page its server
+        // sandboxes with a Content-Security-Policy has the origin "null". So
+        // the event names the origin it was judged by, and the content script
+        // passes the address on only to a page whose own origin is that one
+        // (src/content/index.js).
         const origin = tab.url ? new URL(tab.url).origin : "";
         const hasPermission =
             activeAddress &&
             (allowed.includes(origin) ||
-                connectedSites[origin + ":" + activeAddress]);
+                (await isConnected(origin, activeAddress)));
         // Same as chainChanged above: a tab without our content script
         // rejects, and that is expected rather than a fault.
         tabsSendMessage(tab.id, {
             type: "AUTISTMASK_EVENT",
             eventName: "accountsChanged",
             data: hasPermission ? [activeAddress] : [],
+            origin,
         }).catch(() => {});
     }
 }
@@ -1917,41 +1946,57 @@ runtime.onMessage.addListener((msg, sender, sendResponse) => {
     }
 
     // The popup removed these addresses, so no site stays connected to them.
-    // A connectedSites key is origin + ":" + address, and an origin can carry
-    // a port, so the address is what follows the last colon.
     if (msg.type === "AUTISTMASK_ADDRESSES_REMOVED") {
         const removed = Array.isArray(msg.addresses) ? msg.addresses : [];
-        for (const key of Object.keys(connectedSites)) {
+        endConnections((key) => {
             const address = key.slice(key.lastIndexOf(":") + 1);
-            if (removed.some((a) => sameAddress(a, address))) {
-                delete connectedSites[key];
-            }
-        }
+            return removed.some((a) => sameAddress(a, address));
+        }).catch((err) => {
+            log.errorf(
+                "ending the removed addresses' connections failed:",
+                err,
+            );
+        });
         return false;
     }
 
-    // Settings lists the sites connected without "Remember", which only this
-    // worker knows. The origin is what precedes the key's last colon.
+    // Settings lists the sites connected without "Remember", which only
+    // session storage holds.
     if (msg.type === "AUTISTMASK_GET_CONNECTED_SITES") {
-        sendResponse(
-            Object.keys(connectedSites).map((key) =>
-                key.slice(0, key.lastIndexOf(":")),
-            ),
-        );
-        return false;
+        sessionStorageGet(null)
+            .then((items) =>
+                Object.keys(items).map((key) =>
+                    key.slice(0, key.lastIndexOf(":")),
+                ),
+            )
+            .catch((err) => {
+                log.errorf("listing the connected sites failed:", err);
+                return [];
+            })
+            .then(sendResponse);
+        return true;
     }
 
     // Settings removed this site (msg.origin) and has already dropped its
     // remembered entries. Its connections approved without "Remember" end
     // here, under every address, and its open tabs are told it has no account.
+    // The answer goes back once they have ended, and Settings waits for it
+    // before it lists the connected sites again.
     if (msg.type === "AUTISTMASK_REMOVE_SITE") {
-        for (const key of Object.keys(connectedSites)) {
-            if (key.slice(0, key.lastIndexOf(":")) === msg.origin) {
-                delete connectedSites[key];
-            }
-        }
-        broadcastSiteRemoved(msg.origin);
-        return false;
+        endConnections(
+            (key) => key.slice(0, key.lastIndexOf(":")) === msg.origin,
+        )
+            .catch((err) => {
+                log.errorf(
+                    "ending the removed site's connections failed:",
+                    err,
+                );
+            })
+            .then(() => {
+                broadcastSiteRemoved(msg.origin);
+                sendResponse(null);
+            });
+        return true;
     }
 
     // Settings switched the network and has saved it. Open tabs are told the

src/content/index.js

@@ -49,14 +49,23 @@ window.addEventListener("message", (event) => {
 
 // Listen for events pushed from the background (e.g. accountsChanged)
 runtimeApi().onMessage.addListener((msg) => {
-    if (msg.type === "AUTISTMASK_EVENT") {
-        window.postMessage(
-            {
-                type: "AUTISTMASK_EVENT",
-                eventName: msg.eventName,
-                data: msg.data,
-            },
-            "*",
-        );
+    if (msg.type !== "AUTISTMASK_EVENT") return;
+    // The background chooses the addresses in accountsChanged for the site
+    // at the origin the event names, which is the origin of the tab's URL.
+    // This page hears them only when its own origin is that one. A page whose
+    // origin has no host is not a site: one its server sandboxes with a
+    // Content-Security-Policy has the origin "null" whatever its URL, and is
+    // told no address, as its requests are refused.
+    let data = msg.data;
+    if (msg.eventName === "accountsChanged" && msg.origin !== window.origin) {
+        data = [];
     }
+    window.postMessage(
+        {
+            type: "AUTISTMASK_EVENT",
+            eventName: msg.eventName,
+            data,
+        },
+        "*",
+    );
 });

src/popup/index.html

@@ -90,7 +90,7 @@
                 <div id="add-wallet-section-mnemonic">
                     <!-- The die button shares the instruction's row: on a row
                          of its own it pushes Import below the fold at
-                         360x600. -->
+                         396x600. -->
                     <div class="mb-2 flex justify-between items-start gap-2">
                         <p>
                             Enter your 12 or 24 word recovery phrase below, or
@@ -212,7 +212,7 @@
                     />
                 </div>
                 <!-- The error line sits beside Import, not above it: at
-                     360x600 the button already starts near the bottom of
+                     396x600 the button already starts near the bottom of
                      the popup, and a line of its own would push it below
                      the fold. The longest error fits on one line here. -->
                 <div class="flex items-center gap-2">
@@ -634,17 +634,12 @@
                     </div>
                 </div>
                 <div id="confirm-warnings" class="mb-2 invisible"></div>
-                <div id="confirm-recipient-warning" class="mb-2 invisible">
-                    <div
-                        class="border border-red-500 border-dashed p-2 text-xs font-bold text-red-500"
-                    >
-                        WARNING: The recipient address has ZERO transaction
-                        history. This may indicate a fresh or unused address.
-                        Double-check the address before sending.
-                    </div>
-                </div>
-                <!-- Its sentence names the network's native token, so show()
-                in confirmTx.js sets it. -->
+                <!-- These two sentences name the network's native token, so
+                show() in confirmTx.js sets them. -->
+                <div
+                    id="confirm-recipient-warning"
+                    class="mb-2 border border-red-500 border-dashed p-2 text-xs font-bold text-red-500 invisible"
+                ></div>
                 <div
                     id="confirm-contract-warning"
                     class="mb-2 border border-red-500 border-dashed p-2 text-xs font-bold text-red-500 invisible"
@@ -669,6 +664,20 @@
                     id="confirm-errors"
                     class="mb-2 border border-border border-dashed p-2 invisible min-h-[1.25rem]"
                 ></div>
+                <!-- Its sentence names the token, or why the token's balance
+                is unknown, so show() in confirmTx.js sets it. -->
+                <div
+                    id="confirm-balance-error"
+                    class="mb-2 border border-border border-dashed p-2 text-xs invisible"
+                ></div>
+                <div
+                    id="confirm-balance-read-error"
+                    class="mb-2 border border-border border-dashed p-2 text-xs invisible"
+                >
+                    Your balance could not be read from the network, so this
+                    transaction cannot be checked against it. Please go back and
+                    try again.
+                </div>
                 <div
                     id="confirm-amount-fee-error"
                     class="mb-2 border border-border border-dashed p-2 text-xs invisible"
@@ -688,6 +697,33 @@
                     id="confirm-fee-unknown-error"
                     class="mb-2 border border-border border-dashed p-2 text-xs invisible"
                 ></div>
+                <!-- Shown when Sign & Send refuses a send for its network, for
+                a From address the selected wallet does not hold, or for its
+                gas limit or fee. Each holds its space from the first paint, so
+                the refusal moves nothing. -->
+                <div
+                    id="confirm-network-changed-error"
+                    class="mb-2 border border-border border-dashed p-2 text-xs invisible"
+                >
+                    The active network changed after this transaction was
+                    reviewed, so it was not sent. Please go back and review it
+                    again.
+                </div>
+                <div
+                    id="confirm-from-address-error"
+                    class="mb-2 border border-border border-dashed p-2 text-xs invisible"
+                >
+                    The selected wallet does not hold the From address above, so
+                    nothing was sent. Please go back and send again.
+                </div>
+                <div
+                    id="confirm-fee-bound-error"
+                    class="mb-2 border border-border border-dashed p-2 text-xs invisible"
+                >
+                    The gas limit or fee the RPC endpoint quoted for this
+                    transaction is more than this wallet will sign for, so it
+                    was not sent. Please go back and try again.
+                </div>
                 <div class="mb-2">
                     <label class="block mb-1 text-xs">Password</label>
                     <input
@@ -843,7 +879,7 @@
                     id="add-token-info"
                     class="text-xs text-muted mb-2 min-h-[1.25rem] invisible"
                 ></div>
-                <div class="mb-2">
+                <div id="add-token-common" class="mb-2">
                     <label class="block mb-1 text-xs text-muted"
                         >Or pick a common token:</label
                     >
@@ -929,9 +965,9 @@
                 <div class="bg-well p-3 mx-1 mb-3">
                     <h3 class="font-bold mb-1">Network</h3>
                     <p class="text-xs text-muted mb-1">
-                        Select the Ethereum network. Switching networks will
-                        update the RPC and Blockscout endpoints to their
-                        defaults.
+                        Select the Ethereum network. Switching restores the RPC
+                        and Blockscout endpoints last used on that network, or
+                        that network's defaults if it has none.
                     </p>
                     <div class="text-xs flex items-center gap-1">
                         <select
@@ -1128,7 +1164,8 @@
                 <p class="text-xs mb-3">
                     Deleting
                     <strong id="delete-wallet-name"></strong> is permanent. Any
-                    funds will be unrecoverable without your recovery phrase.
+                    funds will be unrecoverable without your
+                    <span id="delete-wallet-key-material"></span>.
                 </p>
                 <div class="mb-2">
                     <label class="block mb-1">Password</label>
@@ -1179,13 +1216,13 @@
                     money at its addresses is not moved or destroyed.
                 </p>
                 <p class="text-xs mb-2">
-                    If you have the recovery phrase for this wallet written
-                    down, add the wallet again afterwards with a new password
-                    and you will have it back.
+                    If you have kept a copy of this wallet's
+                    <span id="delete-wallet-lost-key-material"></span>, add the
+                    wallet again afterwards with a new password and you will
+                    have it back.
                     <strong
-                        >If you do not have it written down, deleting this
-                        wallet means losing everything it holds,
-                        forever.</strong
+                        >If you have not, deleting this wallet means losing
+                        everything it holds, forever.</strong
                     >
                 </p>
                 <p class="text-xs mb-3">Your other wallets are not touched.</p>
@@ -1326,36 +1363,39 @@
                 <h2 class="font-bold mb-2">Add Token</h2>
                 <p class="text-xs text-muted mb-3">
                     Pick a common token or enter a contract address manually.
+                    Common tokens are offered on Ethereum Mainnet only.
                 </p>
 
-                <!-- top 10 quick-pick buttons -->
-                <div class="mb-3">
-                    <label class="block mb-1 text-xs text-muted"
-                        >Top tokens:</label
-                    >
-                    <div
-                        id="settings-addtoken-top10"
-                        class="flex flex-wrap gap-1"
-                    ></div>
-                </div>
+                <div id="settings-addtoken-common">
+                    <!-- top 10 quick-pick buttons -->
+                    <div class="mb-3">
+                        <label class="block mb-1 text-xs text-muted"
+                            >Top tokens:</label
+                        >
+                        <div
+                            id="settings-addtoken-top10"
+                            class="flex flex-wrap gap-1"
+                        ></div>
+                    </div>
 
-                <!-- top 100 dropdown -->
-                <div class="mb-3">
-                    <label class="block mb-1 text-xs text-muted"
-                        >Or pick from top 100:</label
-                    >
-                    <select
-                        id="settings-addtoken-select"
-                        class="border border-border p-1 w-full font-mono text-sm bg-bg text-fg"
-                    >
-                        <option value="">-- select --</option>
-                    </select>
-                    <button
-                        id="btn-settings-addtoken-select"
-                        class="border border-border px-2 py-1 mt-1 hover:bg-fg hover:text-bg cursor-pointer"
-                    >
-                        Add selected
-                    </button>
+                    <!-- top 100 dropdown -->
+                    <div class="mb-3">
+                        <label class="block mb-1 text-xs text-muted"
+                            >Or pick from top 100:</label
+                        >
+                        <select
+                            id="settings-addtoken-select"
+                            class="border border-border p-1 w-full font-mono text-sm bg-bg text-fg"
+                        >
+                            <option value="">-- select --</option>
+                        </select>
+                        <button
+                            id="btn-settings-addtoken-select"
+                            class="border border-border px-2 py-1 mt-1 hover:bg-fg hover:text-bg cursor-pointer"
+                        >
+                            Add selected
+                        </button>
+                    </div>
                 </div>
 
                 <!-- manual contract address -->

src/popup/index.js

@@ -64,8 +64,8 @@ window.addEventListener("pagehide", () => pageClosed.abort());
 
 let refreshInFlight = false;
 
-// The ten-second refresh init() starts, stopped when the popup moves to the
-// recovery screen: there is no profile left to refresh.
+// The ten-second refresh startRefresh() starts, stopped when the popup moves to
+// the recovery screen: there is no profile left to refresh.
 let refreshTimer = null;
 
 async function doRefreshAndRender() {
@@ -99,9 +99,23 @@ async function doRefreshAndRender() {
     }
 }
 
+// Refreshes now and every ten seconds from then on. Called once a wallet
+// exists: by init() when the popup opens with one, and by AddWallet when it
+// adds one, which in a popup that opened on Welcome is the first
+// (https://git.eeqj.de/sneak/AutistMask/issues/530). With the refresh already
+// running it starts no second one, and on the recovery screen it does nothing.
+function startRefresh() {
+    if (!$("view-state-recovery").classList.contains("hidden")) return;
+    doRefreshAndRender();
+    if (refreshTimer === null) {
+        refreshTimer = setInterval(doRefreshAndRender, 10000);
+    }
+}
+
 const ctx = {
     renderWalletList,
     doRefreshAndRender,
+    startRefresh,
     pageClosed: pageClosed.signal,
     showAddWalletView: () => {
         pushCurrentView();
@@ -318,8 +332,7 @@ async function init() {
     } else {
         renderWalletList();
         restoreView();
-        doRefreshAndRender();
-        refreshTimer = setInterval(doRefreshAndRender, 10000);
+        startRefresh();
     }
 }
 

src/popup/viewRouter.js

@@ -13,6 +13,7 @@
 // cannot be required outside a browser.
 
 const { RESTORABLE_VIEWS } = require("../shared/restorableViews");
+const { SUPPORTED_CHAIN_IDS } = require("../shared/networks");
 
 // The views this page load has rendered.
 //
@@ -37,9 +38,11 @@ function markViewRendered(view) {
     if (view) renderedViews.add(view);
 }
 
-// Begin a fresh page-load scope. The popup gets one by being loaded; the
+// Begin a fresh page-load scope. The popup gets one by being loaded, and
+// asks for one when the user switches the network, because every screen
+// then on the page shows the previous network (views/settings.js); the
 // unit tests, which simulate several page loads against one module
-// instance, ask for one.
+// instance, ask for one too.
 function resetRenderedViews() {
     renderedViews.clear();
 }
@@ -124,25 +127,33 @@ function isRenderableDecoded(value) {
 }
 
 // The pending transaction confirmTx.show() renders: `token` reaches
-// renderAddressHtml() when it is not "ETH", and `from`/`to` reach
-// addressTitle(), makeBlockie() and getLocalWarnings().
+// renderAddressHtml() when it is not "ETH", `from`/`to` reach
+// addressTitle(), makeBlockie() and getLocalWarnings(), and `amount` reaches
+// truncateAmountNeverZero(), which splits it. `chainId`, which show() fills in
+// when it is absent, picks the network whose explorer the address links open,
+// so it has to name one.
 function isRenderablePendingTx(value) {
     return (
         isRecord(value) &&
         isText(value.token) &&
         isAddressText(value.from) &&
-        isAddressText(value.to)
+        isAddressText(value.to) &&
+        isText(value.amount) &&
+        (!value.chainId || SUPPORTED_CHAIN_IDS.has(value.chainId))
     );
 }
 
 // The stored transaction transactionDetail.render() shows. contractAddress is
 // optional on an ETH transfer, and reaches addressDotHtml() when it is there.
+// `chainId` picks the network whose explorer the links open and whose
+// Blockscout the transaction is read from, so it has to name one.
 function isRenderableTx(value) {
     return (
         isRecord(value) &&
         isAddressText(value.from) &&
         isAddressText(value.to) &&
-        (!value.contractAddress || isAddressText(value.contractAddress))
+        (!value.contractAddress || isAddressText(value.contractAddress)) &&
+        SUPPORTED_CHAIN_IDS.has(value.chainId)
     );
 }
 
@@ -194,11 +205,19 @@ function renderView(view, state, views) {
             if (!data.hash) return false;
             if (!isAddressText(data.to)) return false;
             if (!isRenderableDecoded(data.decoded)) return false;
+            // `chainId` picks the network whose explorer the links open, so
+            // when it is there it has to name one. Likewise on error-tx.
+            if (data.chainId && !SUPPORTED_CHAIN_IDS.has(data.chainId)) {
+                return false;
+            }
             views.txStatus.renderSuccess();
             return true;
         case "error-tx":
             if (!data.message) return false;
             if (!isAddressText(data.to)) return false;
+            if (data.chainId && !SUPPORTED_CHAIN_IDS.has(data.chainId)) {
+                return false;
+            }
             views.txStatus.renderError();
             return true;
         default:
@@ -213,9 +232,10 @@ function renderView(view, state, views) {
 // in the two cases where the view is known to be on the page already:
 //
 //   - It is not one the popup renders from persisted state. The restored
-//     stack is filtered against RESTORABLE_VIEWS, so such a view can only
-//     be on the stack from this page load, where forward navigation
-//     rendered it on the way in.
+//     stack is filtered against RESTORABLE_VIEWS, and a network switch cuts
+//     it the same way (views/settings.js), so such a view can only be on the
+//     stack from this page load, where forward navigation rendered it on the
+//     way in.
 //   - This page load has rendered it. Re-rendering would re-fetch and
 //     clobber what it holds; Home is rendered anyway, see above.
 //

src/popup/views/addToken.js

@@ -1,6 +1,6 @@
 const { $, showView, showFlash, escapeHtml, goBack } = require("./helpers");
 const { getTopTokens } = require("../../shared/tokenList");
-const { state, saveState } = require("../../shared/state");
+const { state, saveState, currentNetwork } = require("../../shared/state");
 const { lookupTokenInfo } = require("../../shared/balances");
 const { isScamAddress } = require("../../shared/scamlist");
 const { log } = require("../../shared/log");
@@ -9,6 +9,12 @@ function show() {
     $("add-token-address").value = "";
     $("add-token-info").textContent = "";
     $("add-token-info").style.visibility = "hidden";
+    // The bundled list holds Ethereum Mainnet contracts, which name no token
+    // on any other network.
+    $("add-token-common").classList.toggle(
+        "hidden",
+        state.networkId !== "mainnet",
+    );
     const list = $("common-token-list");
     list.innerHTML = getTopTokens(25)
         .map(
@@ -46,6 +52,9 @@ function init(ctx) {
         infoEl.textContent = "Looking up token...";
         infoEl.style.visibility = "visible";
         log.debugf("Looking up token contract", contractAddr);
+        // The network the lookup asks, which Settings may switch away from
+        // before it answers, as for a transaction in confirmTx.js.
+        const chainId = currentNetwork().chainId;
         try {
             const info = await lookupTokenInfo(
                 contractAddr,
@@ -53,6 +62,15 @@ function init(ctx) {
                 state.networkId,
                 ctx.pageClosed,
             );
+            // A contract address names a token on one network only, so an
+            // answer after a switch is not added to the new network's list.
+            if (currentNetwork().chainId !== chainId) {
+                showFlash(
+                    "The active network changed before the lookup finished," +
+                        " so the token was not added.",
+                );
+                return;
+            }
             log.infof("Adding token", info.symbol, contractAddr);
             state.trackedTokens.push({
                 address: contractAddr,

src/popup/views/addWallet.js

@@ -234,7 +234,7 @@ async function importMnemonic(ctx) {
         showFlash("Ready.", 1000);
     }
 
-    ctx.doRefreshAndRender();
+    ctx.startRefresh();
 }
 
 async function importPrivateKey(ctx) {
@@ -274,7 +274,7 @@ async function importPrivateKey(ctx) {
     ctx.renderWalletList();
     showView("main");
 
-    ctx.doRefreshAndRender();
+    ctx.startRefresh();
 }
 
 async function importXprvKey(ctx) {
@@ -368,7 +368,7 @@ async function importXprvKey(ctx) {
         showFlash("Ready.", 1000);
     }
 
-    ctx.doRefreshAndRender();
+    ctx.startRefresh();
 }
 
 function init(ctx) {

src/popup/views/approval.js

@@ -11,6 +11,7 @@ const {
     onViewLeave,
     formatFee,
     tokenLabel,
+    tokenSourcesByChainId,
 } = require("./helpers");
 const { state, saveState, currentNetwork } = require("../../shared/state");
 const {
@@ -57,9 +58,15 @@ const { notify, runtimeApi, sendMessage } = require("../../shared/browserApi");
 
 const erc20Iface = new Interface(ERC20_ABI);
 
-function approvalAddressHtml(address) {
+// The link opens the explorer of the network with `chainId`, or of the active
+// network when none is given. A chain id that names no network has no
+// explorer, so the address is drawn without a link.
+function approvalAddressHtml(address, chainId) {
     const title = addressTitle(address, state.wallets);
-    return renderAddressHtml(address, { title });
+    if (chainId && !networkByChainId(chainId)) {
+        return renderAddressHtml(address, { title, noLink: true });
+    }
+    return renderAddressHtml(address, { title, chainId });
 }
 
 // The amount line for a decoded ERC-20 call. With a known scale it is the
@@ -79,18 +86,18 @@ function tokenAmountText(rawAmount, decimals, symbol) {
     };
 }
 
-// Try to decode calldata using known ABIs.
+// Try to decode calldata sent from `fromAddress` to `toAddress` on the network
+// with chain id `chainId`, using known ABIs.
 // Returns { name, description, details } or null.
-function decodeCalldata(data, toAddress) {
+function decodeCalldata(data, toAddress, chainId, fromAddress) {
     if (!data || data === "0x" || data.length < 10) return null;
 
-    // Where a token's scale is looked for, for every decoder below: the ERC-20
-    // amount line and the swap's Amount and Min. received lines resolve it the
-    // same way, and refuse to format the same way when it is nowhere.
-    const decimalsSources = {
-        trackedTokens: state.trackedTokens,
-        wallets: state.wallets,
-    };
+    // Where a token's name and scale are looked for, for every decoder below:
+    // what the wallet knows of the tokens on the network with `chainId`, which
+    // need not be the active one. The ERC-20 amount line and the swap's Amount
+    // and Min. received lines resolve the scale the same way, and refuse to
+    // format the same way when it is nowhere.
+    const decimalsSources = tokenSourcesByChainId(chainId);
 
     // Try ERC-20 (approve / transfer)
     try {
@@ -185,7 +192,13 @@ function decodeCalldata(data, toAddress) {
     }
 
     // Try Uniswap Universal Router
-    const routerResult = uniswap.decode(data, toAddress, decimalsSources);
+    const routerResult = uniswap.decode(
+        data,
+        toAddress,
+        chainId,
+        decimalsSources,
+        fromAddress,
+    );
     if (routerResult) return routerResult;
 
     return null;
@@ -218,10 +231,11 @@ function showTxFee(approvedTx) {
     const feePerGas = BigInt(approvedTx.maxFeePerGas || approvedTx.gasPrice);
     // Through formatFee(), as the confirmation screen's fee is, so the same
     // fee reads the same on both. In the native currency of the network shown
-    // above, as the value is.
+    // above, and at the price on it, as the value is.
     $("approve-tx-fee").textContent = formatFee(
         gasLimit * feePerGas,
         nativeCurrencyByChainId(approvedTx.chainId),
+        approvedTx.chainId,
     );
 
     let detail =
@@ -254,10 +268,7 @@ function showTxApproval(details) {
 
     const toAddr = approvedTx.to;
     const ethValue = formatEther(approvedTx.value || "0");
-    const sources = {
-        trackedTokens: state.trackedTokens,
-        wallets: state.wallets,
-    };
+    const sources = tokenSourcesByChainId(approvedTx.chainId);
 
     // Build txInfo for status screens
     pendingTxDetails = {
@@ -269,8 +280,15 @@ function showTxApproval(details) {
         chainId: approvedTx.chainId,
     };
 
-    // If this is an ERC-20 call, try to extract the real recipient and amount
-    const decoded = decodeCalldata(approvedTx.data, toAddr || "");
+    // If this is an ERC-20 call, try to extract the real recipient and amount.
+    // Decoded for the network the transaction is for, which the Network line
+    // names, and the address the From line names.
+    const decoded = decodeCalldata(
+        approvedTx.data,
+        toAddr || "",
+        approvedTx.chainId,
+        details.approvedFrom,
+    );
     if (decoded && decoded.details) {
         // The asset the status summary is counted in: an ERC-20 call's Token
         // contract, or a swap's input token. Its symbol is resolved from the
@@ -327,27 +345,35 @@ function showTxApproval(details) {
         };
     }
 
+    // Every address link on this screen opens the explorer of the network the
+    // transaction is for, which the Network line names, whichever network is
+    // active.
     $("approve-tx-origin").textContent = details.origin;
-    $("approve-tx-from").innerHTML = approvalAddressHtml(details.approvedFrom);
+    $("approve-tx-from").innerHTML = approvalAddressHtml(
+        details.approvedFrom,
+        approvedTx.chainId,
+    );
 
-    // Show token symbol next to contract address if known
-    const symbol = toAddr ? tokenLabel(toAddr) : null;
+    // Show token symbol next to contract address if known on the network the
+    // transaction is for
+    const symbol = toAddr ? tokenLabel(toAddr, approvedTx.chainId) : null;
     if (toAddr) {
         let toHtml = "";
         if (symbol) {
             toHtml += `<div class="font-bold mb-1">${escapeHtml(symbol)}</div>`;
         }
-        toHtml += approvalAddressHtml(toAddr);
+        toHtml += approvalAddressHtml(toAddr, approvedTx.chainId);
         $("approve-tx-to").innerHTML = toHtml;
     } else {
         $("approve-tx-to").innerHTML = escapeHtml(CONTRACT_CREATION_TEXT);
     }
 
-    const ethValueFormatted = formatTxValue(
-        formatEther(approvedTx.value || "0"),
-    );
-    const ethPrice = getPrice("ETH");
-    const ethUsd = ethPrice ? parseFloat(ethValueFormatted) * ethPrice : null;
+    const ethValueFormatted = formatTxValue(ethValue);
+    // Priced from the exact value, not the four-decimal figure, at the price
+    // on the network the transaction is for, as the confirmation screen prices
+    // its amount, so the same value reads the same on both.
+    const ethPrice = getPrice("ETH", approvedTx.chainId);
+    const ethUsd = ethPrice ? parseFloat(ethValue) * ethPrice : null;
     const usdStr = formatUsd(ethUsd);
     // In the native currency of the network the transaction is for, which the
     // Network line names, not the active network's: the active network can
@@ -374,9 +400,12 @@ function showTxApproval(details) {
             detailsHtml += `<div class="text-muted">${escapeHtml(d.label)}</div>`;
             if (d.address) {
                 if (d.isToken) {
-                    detailsHtml += `<div class="font-bold">${escapeHtml(tokenLabel(d.address) || "Unknown token")}</div>`;
+                    detailsHtml += `<div class="font-bold">${escapeHtml(tokenLabel(d.address, approvedTx.chainId) || "Unknown token")}</div>`;
                 }
-                detailsHtml += approvalAddressHtml(d.address);
+                detailsHtml += approvalAddressHtml(
+                    d.address,
+                    approvedTx.chainId,
+                );
             } else {
                 detailsHtml += `<div class="font-bold">${escapeHtml(d.value)}</div>`;
             }

src/popup/views/confirmTx.js

@@ -2,7 +2,13 @@
 // Shows transaction details, warnings, errors. On Sign & Send,
 // reads inline password, decrypts secret, signs and broadcasts.
 
-const { parseEther, parseUnits, formatEther, Contract } = require("ethers");
+const {
+    parseEther,
+    parseUnits,
+    formatEther,
+    formatUnits,
+    Contract,
+} = require("ethers");
 const {
     $,
     showError,
@@ -11,15 +17,16 @@ const {
     addressTitle,
     escapeHtml,
     displaySymbol,
-    nativeCurrency,
     renderAddressHtml,
     blockieHtml,
     attachCopyHandlers,
     goBack,
     onViewLeave,
     formatFee,
+    reviewedNetworkProvider,
 } = require("./helpers");
 const { state, currentNetwork } = require("../../shared/state");
+const { nativeCurrencyByChainId } = require("../../shared/networks");
 const { getSignerForAddress } = require("../../shared/wallet");
 const { walletDefect } = require("../../shared/walletDefects");
 const { decryptWithPassword } = require("../../shared/vault");
@@ -32,11 +39,12 @@ const {
 const { ERC20_ABI, isBurnAddress } = require("../../shared/constants");
 const {
     displayedDecimals,
+    toDecimals,
     transferAmountUnits,
 } = require("../../shared/transferAmount");
 const { assertWithinCeilings } = require("../../shared/approvalVerify");
-// The balance lines, the fee reserve and the insufficient-balance messages go
-// through it, as the approval screen's amounts do.
+// The amount, the balance line and the fee reserve go through it, as the
+// approval screen's amounts do.
 const { truncateAmountNeverZero } = require("../../shared/amountDisplay");
 const {
     CODES,
@@ -60,6 +68,13 @@ let feeWei = null;
 // amount was derived from. Null for any other send, which ethers prices from
 // the node at signing time.
 let maxSendFees = null;
+// The From address's balances on the network this screen is drawn for, read
+// from that network's node by readBalances() each time the screen is shown,
+// so a screen the popup reopens onto states them as they are then, not as
+// Send knew them. Null until the read returns; then `eth` and `token` are
+// decimal strings, `token` null for an ETH send or a token whose scale is
+// unknown, and both null if the read failed.
+let balances = null;
 
 function restore() {
     const d = state.viewData;
@@ -68,11 +83,11 @@ function restore() {
     }
 }
 
-function confirmAddressHtml(address, ensName, title) {
+function confirmAddressHtml(address, ensName, title, chainId) {
     const blockie = blockieHtml(address);
     return (
         `<div class="mb-1">${blockie}</div>` +
-        renderAddressHtml(address, { title, ensName })
+        renderAddressHtml(address, { title, ensName, chainId })
     );
 }
 
@@ -83,34 +98,96 @@ function valueWithUsd(text, usdAmount) {
     return text;
 }
 
-// The Amount line, with its USD value. A max ETH send's line is drawn again
-// once its amount is re-derived from the fee estimate.
+// The amount as this screen and the wait, success and error screens show it,
+// written as the approval screen writes a site's amount: the amount being
+// signed, parsed at the scale it is encoded with and written back as plain
+// decimal text, then cut to four decimals with the nonzero floor. So `.5` and
+// `00.5` read `0.5000`, as `0.5` does, except for a token whose scale is
+// unknown, which cannot be sent: its amount is cut as typed, so `.5` reads
+// `.5000`. txInfo.amount, which is what gets signed, is left as it is.
+function shownAmount(txInfo) {
+    let exact = txInfo.amount;
+    try {
+        if (txInfo.token === "ETH") {
+            exact = formatEther(parseEther(txInfo.amount));
+        } else {
+            const decimals = displayedDecimals(txInfo.tokenDecimals);
+            exact = formatUnits(parseUnits(txInfo.amount, decimals), decimals);
+        }
+    } catch {
+        // A token whose scale is unknown, which is never signed, or an amount
+        // the amount check refuses: cut as Send's amount field held it.
+    }
+    return truncateAmountNeverZero(exact);
+}
+
+// The Amount line, with its USD value, which is priced from the exact amount.
+// A max ETH send's line is drawn again once its amount is re-derived from the
+// fee estimate.
 function renderAmount(txInfo) {
     const isErc20 = txInfo.token !== "ETH";
-    const rawSymbol = isErc20 ? txInfo.tokenSymbol || "?" : nativeCurrency();
-    const price = isErc20 ? getPrice(rawSymbol) : getPrice("ETH");
+    const rawSymbol = isErc20
+        ? txInfo.tokenSymbol || "?"
+        : nativeCurrencyByChainId(txInfo.chainId);
+    const price = getPrice(isErc20 ? rawSymbol : "ETH", txInfo.chainId);
     const amountUsd = price ? parseFloat(txInfo.amount) * price : null;
     $("confirm-amount").textContent = valueWithUsd(
-        txInfo.amount + " " + displaySymbol(rawSymbol),
+        shownAmount(txInfo) + " " + displaySymbol(rawSymbol),
         amountUsd,
     );
 }
 
+// The balance line, with its USD value: "Loading..." until readBalances()
+// returns, then the balance it read.
+function renderBalance(txInfo) {
+    const isErc20 = txInfo.token !== "ETH";
+    const rawSymbol = isErc20
+        ? txInfo.tokenSymbol || "?"
+        : nativeCurrencyByChainId(txInfo.chainId);
+    const symbol = displaySymbol(rawSymbol);
+    if (balances === null) {
+        $("confirm-balance").textContent = "Loading...";
+        return;
+    }
+    // A null balance is one nobody established, for a token whose scale is
+    // unknown or after a read that failed, and is stated as unknown, never as
+    // zero (https://git.eeqj.de/sneak/AutistMask/issues/349).
+    const bal = isErc20 ? balances.token : balances.eth;
+    if (bal === null) {
+        $("confirm-balance").textContent = "unknown (" + symbol + ")";
+        return;
+    }
+    const price = getPrice(isErc20 ? rawSymbol : "ETH", txInfo.chainId);
+    const balUsd = price ? parseFloat(bal) * price : null;
+    $("confirm-balance").textContent = valueWithUsd(
+        truncateAmountNeverZero(bal) + " " + symbol,
+        balUsd,
+    );
+}
+
 function show(txInfo) {
     pendingTx = txInfo;
     feeStatus = FEE_PENDING;
     feeWei = null;
     maxSendFees = null;
-    // The network this screen is drawn for, and the only one it sends on:
-    // Settings can switch the active network while the screen is open. The
-    // wait, success and error screens label the amount by it too.
-    txInfo.chainId = currentNetwork().chainId;
+    balances = null;
+    // The network this screen is drawn for, and the only one it sends on: the
+    // one active when Send handed the transaction over. Drawn again from the
+    // saved transaction, as when the popup reopens onto this screen, it keeps
+    // that network, so Sign & Send refuses once Settings has switched to
+    // another. Everything this screen shows is that network's: native
+    // currency, USD values, explorer links, the balance, and the node and
+    // explorer its checks ask. The wait, success and error screens label
+    // amounts by it.
+    if (!txInfo.chainId) txInfo.chainId = currentNetwork().chainId;
 
     const isErc20 = txInfo.token !== "ETH";
     // The raw symbol is the price-table key; the capped one is what the
     // screen says. Truncating before the lookup would silently drop the
     // price of any token whose symbol is long enough to be capped.
-    const rawSymbol = isErc20 ? txInfo.tokenSymbol || "?" : nativeCurrency();
+    const rawSymbol = isErc20
+        ? txInfo.tokenSymbol || "?"
+        : nativeCurrencyByChainId(txInfo.chainId);
     const symbol = displaySymbol(rawSymbol);
 
     // Transaction type
@@ -126,7 +203,7 @@ function show(txInfo) {
     if (isErc20) {
         $("confirm-token-contract").innerHTML = renderAddressHtml(
             txInfo.token,
-            {},
+            { chainId: txInfo.chainId },
         );
         tokenSection.classList.remove("hidden");
         attachCopyHandlers(tokenSection);
@@ -140,6 +217,7 @@ function show(txInfo) {
         txInfo.from,
         null,
         fromTitle,
+        txInfo.chainId,
     );
 
     // To (with blockie)
@@ -148,37 +226,12 @@ function show(txInfo) {
         txInfo.to,
         txInfo.ensName,
         toTitle,
+        txInfo.chainId,
     );
     $("confirm-to-ens").classList.add("hidden");
 
     renderAmount(txInfo);
-
-    // Balance (with inline USD)
-    const ethPrice = getPrice("ETH");
-    const tokenPrice = getPrice(rawSymbol);
-    if (isErc20) {
-        // null is a balance whose scale nothing knows, not a balance of zero
-        // (https://git.eeqj.de/sneak/AutistMask/issues/349). The send is
-        // refused at encode time for the same missing scale; what this line
-        // must not do is state a quantity nobody established.
-        const bal = txInfo.tokenBalance;
-        const balUsd =
-            tokenPrice && bal != null ? parseFloat(bal) * tokenPrice : null;
-        $("confirm-balance").textContent =
-            bal == null
-                ? "unknown (" + symbol + ")"
-                : valueWithUsd(
-                      truncateAmountNeverZero(bal) + " " + symbol,
-                      balUsd,
-                  );
-    } else {
-        const bal = txInfo.balance || "0";
-        const balUsd = ethPrice ? parseFloat(bal) * ethPrice : null;
-        $("confirm-balance").textContent = valueWithUsd(
-            truncateAmountNeverZero(bal) + " " + symbol,
-            balUsd,
-        );
-    }
+    renderBalance(txInfo);
 
     // Check for warnings (synchronous local checks)
     const localWarnings = getLocalWarnings(txInfo.to, {
@@ -212,15 +265,22 @@ function show(txInfo) {
     $("confirm-gas-error").classList.toggle("hidden", !isErc20);
     $("confirm-gas-error").textContent =
         "You do not have enough " +
-        nativeCurrency() +
+        nativeCurrencyByChainId(txInfo.chainId) +
         " to pay the network fee for this transfer. Please add " +
-        nativeCurrency() +
+        nativeCurrencyByChainId(txInfo.chainId) +
         " to this address and try again.";
 
-    // Shown later, once checkRecipientHistory() finds a contract.
+    // Both shown later, by checkRecipientHistory(). The first sentence says
+    // exactly what getFullWarnings() checks.
+    $("confirm-recipient-warning").textContent =
+        "WARNING: The recipient address has never sent a transaction and" +
+        " holds no " +
+        nativeCurrencyByChainId(txInfo.chainId) +
+        ". This may indicate a fresh or unused address. Double-check the" +
+        " address before sending.";
     $("confirm-contract-warning").textContent =
         "WARNING: The recipient is a smart contract. Sending " +
-        nativeCurrency() +
+        nativeCurrencyByChainId(txInfo.chainId) +
         " or tokens directly to a contract may result in permanent loss of" +
         " funds.";
 
@@ -237,11 +297,29 @@ function show(txInfo) {
               " cannot be checked against your balance. Please go back and" +
               " try again.";
 
+    // So does the message for an amount the balance does not cover. It is
+    // set here, before the first paint, so the balance read returning only
+    // makes it visible and moves nothing, which is why it quotes no balance.
+    // Without the token's scale readBalances() reads no token balance.
+    $("confirm-balance-error").textContent =
+        isErc20 && toDecimals(txInfo.tokenDecimals) === null
+            ? "This token's balance is unknown, because nothing this wallet" +
+              " can consult reports how many decimal places it uses, so the" +
+              " amount you are trying to send cannot be checked against it."
+            : "Your " +
+              symbol +
+              " balance does not cover this amount. Please go back and send" +
+              " a smaller amount.";
+
     renderValidation(txInfo);
 
-    // Reset password field and error
+    // Reset password field and error, and any refusal of an earlier Sign &
+    // Send.
     $("confirm-tx-password").value = "";
     hideError("confirm-tx-password-error");
+    setVisible("confirm-network-changed-error", false);
+    setVisible("confirm-from-address-error", false);
+    setVisible("confirm-fee-bound-error", false);
 
     // Gas estimate — show placeholder then fetch async
     $("confirm-fee").style.visibility = "visible";
@@ -262,69 +340,78 @@ function show(txInfo) {
         $("confirm-burn-warning").style.visibility = "visible";
     }
 
-    estimateGas(txInfo);
+    // The fee is estimated once the balances are read, because a max ETH
+    // send's amount is the ETH balance minus the estimate's reserve.
+    readBalances(txInfo).then(() => estimateGas(txInfo));
     checkRecipientHistory(txInfo);
 }
 
+// Read the From address's balances from the node of the network this
+// transaction was reviewed for: ETH, and for a token send the token, at the
+// scale the screen renders the amount with. A token whose scale is unknown has
+// no balance to read. Never rejects.
+async function readBalances(txInfo) {
+    let read;
+    try {
+        const provider = reviewedNetworkProvider(txInfo);
+        const decimals = toDecimals(txInfo.tokenDecimals);
+        const readToken = txInfo.token !== "ETH" && decimals !== null;
+        const [ethWei, tokenUnits] = await Promise.all([
+            provider.getBalance(txInfo.from),
+            readToken
+                ? new Contract(txInfo.token, ERC20_ABI, provider).balanceOf(
+                      txInfo.from,
+                  )
+                : null,
+        ]);
+        read = {
+            eth: formatEther(ethWei),
+            token: readToken ? formatUnits(tokenUnits, decimals) : null,
+        };
+    } catch (e) {
+        log.errorf("balance read failed:", e.shortMessage || e.message);
+        read = { eth: null, token: null };
+    }
+    // The user may have left this transaction while the read was in flight.
+    if (pendingTx !== txInfo) return;
+    balances = read;
+    renderBalance(txInfo);
+    renderValidation(txInfo);
+}
+
 // Render the balance check for the transaction on screen. Called once during
-// show() and again when the fee estimate resolves or fails. Every element it
-// touches already occupies its space, so re-running it never moves anything.
+// show(), again when the balances are read, and again when the fee estimate
+// resolves or fails. Every element it touches already occupies its space, so
+// re-running it never moves anything.
 function renderValidation(txInfo) {
     const isErc20 = txInfo.token !== "ETH";
-    const symbol = isErc20
-        ? displaySymbol(txInfo.tokenSymbol || "?")
-        : nativeCurrency();
+
+    // Null while the balances are being read and after a read that failed.
+    // validateTransfer() takes a missing balance as nothing to spend from, so
+    // sending stays blocked either way, and the only message shown for it is
+    // the one saying the read failed.
+    const ethBalance = balances ? balances.eth : null;
+    const tokenBalance = balances ? balances.token : null;
+    const balanceRead = ethBalance !== null;
 
     const { canSend, codes } = validateTransfer({
         isErc20,
         amount: txInfo.amount,
         tokenDecimals: txInfo.tokenDecimals,
-        ethBalance: txInfo.balance,
-        tokenBalance: txInfo.tokenBalance,
+        ethBalance,
+        tokenBalance,
         feeStatus,
         feeWei,
     });
 
-    // Messages carrying the user's own numbers are built here; the fixed
-    // sentences live in the reserved elements in index.html, except the
-    // gas and fee-unknown ones, which show() sets.
+    // An invalid amount is known before the first paint, so its message is
+    // written here. Every message a later result brings has a reserved
+    // element, its sentence fixed in index.html or set by show(), and is only
+    // made visible below, so nothing moves when the result arrives.
     const messages = [];
     if (codes.includes(CODES.AMOUNT_INVALID)) {
         messages.push("Please enter a valid amount to send.");
     }
-    if (codes.includes(CODES.INSUFFICIENT_TOKEN)) {
-        messages.push(
-            txInfo.tokenBalance == null
-                ? "This token's balance is unknown, because nothing this" +
-                      " wallet can consult reports how many decimal places it" +
-                      " uses, so the amount you are trying to send cannot be" +
-                      " checked against it."
-                : "Insufficient " +
-                      symbol +
-                      " balance. You have " +
-                      truncateAmountNeverZero(txInfo.tokenBalance) +
-                      " " +
-                      symbol +
-                      " but are trying to send " +
-                      txInfo.amount +
-                      " " +
-                      symbol +
-                      ".",
-        );
-    }
-    if (codes.includes(CODES.INSUFFICIENT_ETH)) {
-        messages.push(
-            "Insufficient balance. You have " +
-                truncateAmountNeverZero(txInfo.balance || "0") +
-                " " +
-                symbol +
-                " but are trying to send " +
-                txInfo.amount +
-                " " +
-                symbol +
-                ".",
-        );
-    }
 
     const errorsEl = $("confirm-errors");
     if (messages.length > 0) {
@@ -337,13 +424,20 @@ function renderValidation(txInfo) {
         errorsEl.style.visibility = "hidden";
     }
 
+    setVisible("confirm-balance-read-error", balances !== null && !balanceRead);
+    setVisible(
+        "confirm-balance-error",
+        balanceRead &&
+            (codes.includes(CODES.INSUFFICIENT_TOKEN) ||
+                codes.includes(CODES.INSUFFICIENT_ETH)),
+    );
     setVisible(
         "confirm-amount-fee-error",
-        codes.includes(CODES.INSUFFICIENT_ETH_WITH_FEE),
+        balanceRead && codes.includes(CODES.INSUFFICIENT_ETH_WITH_FEE),
     );
     setVisible(
         "confirm-gas-error",
-        codes.includes(CODES.INSUFFICIENT_ETH_FOR_FEE),
+        balanceRead && codes.includes(CODES.INSUFFICIENT_ETH_FOR_FEE),
     );
     setVisible(
         "confirm-fee-unknown-error",
@@ -364,7 +458,7 @@ function setVisible(id, visible) {
 
 async function estimateGas(txInfo) {
     try {
-        const provider = getProvider(state.rpcUrl, state.networkId);
+        const provider = reviewedNetworkProvider(txInfo);
         const feeData = await provider.getFeeData();
         let gasLimit;
 
@@ -412,12 +506,17 @@ async function estimateGas(txInfo) {
         // does, so the same fee reads the same on both.
         if (estimateWei !== null && estimateWei < gasCostWei) {
             $("confirm-fee-amount").textContent =
-                "~" + formatFee(estimateWei, nativeCurrency());
+                "~" +
+                formatFee(
+                    estimateWei,
+                    nativeCurrencyByChainId(txInfo.chainId),
+                    txInfo.chainId,
+                );
             $("confirm-fee-reserve").textContent =
                 "up to " +
                 truncateAmountNeverZero(formatEther(gasCostWei)) +
                 " " +
-                nativeCurrency() +
+                nativeCurrencyByChainId(txInfo.chainId) +
                 " reserved";
             setVisible("confirm-fee-reserve", true);
         } else {
@@ -426,20 +525,21 @@ async function estimateGas(txInfo) {
             // cost is not below the reserve. Show the reserve alone.
             $("confirm-fee-amount").textContent = formatFee(
                 gasCostWei,
-                nativeCurrency(),
+                nativeCurrencyByChainId(txInfo.chainId),
+                txInfo.chainId,
             );
             setVisible("confirm-fee-reserve", false);
         }
         feeStatus = FEE_KNOWN;
         feeWei = gasCostWei;
-        // A max ETH send is the balance minus this estimate's reserve, not the
-        // Send screen's, and is signed with this estimate's fee fields: fees
-        // fetched again at signing could exceed the reserve it leaves, and the
-        // node would refuse it for want of funds. Where the balance no longer
-        // covers the fee, the amount is left as it is and the balance check
-        // below says so.
+        // A max ETH send is the balance readBalances() read minus this
+        // estimate's reserve, not the Send screen's, and is signed with this
+        // estimate's fee fields: fees fetched again at signing could exceed
+        // the reserve it leaves, and the node would refuse it for want of
+        // funds. Where the balance is unknown or no longer covers the fee, the
+        // amount is left as it is and the balance check below says so.
         if (txInfo.max && txInfo.token === "ETH") {
-            const amount = maxEthAmount(txInfo.balance, gasCostWei);
+            const amount = maxEthAmount(balances?.eth, gasCostWei);
             if (amount !== null) {
                 txInfo.amount = amount;
                 renderAmount(txInfo);
@@ -468,16 +568,17 @@ async function estimateGas(txInfo) {
     }
 }
 
-// Populate the transaction this send describes, enforce the fee bound against
-// the fees that were actually filled in, then sign and broadcast it. Apart
-// from a max ETH send, which passes its estimate's fee fields as `fees`, the
-// send pins no fee fields, so ethers fills maxFeePerGas and the gas limit from
-// what the configured RPC node answers, with nothing otherwise bounding what a
-// hostile node can set — the dApp path's ceilings never reached this one.
-// Populating before the check is what makes assertWithinCeilings() see the
-// same numbers that would be signed; it throws an ApprovalMismatchError when
-// the product gasLimit × maxFeePerGas is over the bound, which the caller
-// shows in the reserved error area rather than sending.
+// Populate the transaction this send describes, enforce the bounds against the
+// gas limit and fees that were actually filled in, then sign and broadcast it.
+// Apart from a max ETH send, which passes its estimate's fee fields as `fees`,
+// the send pins no fee fields, so ethers fills maxFeePerGas and the gas limit
+// from what the configured RPC node answers, with nothing otherwise bounding
+// what a hostile node can set — the dApp path's ceilings never reached this
+// one. Populating before the check is what makes assertWithinCeilings() see
+// the same numbers that would be signed; it throws an ApprovalMismatchError
+// when the gas limit, a fee per gas, or the product gasLimit × maxFeePerGas is
+// over its bound, and the caller then shows the one refusal reserved for all
+// three rather than sending.
 async function populateVerifyAndSend(connectedSigner, tx, fees = null) {
     let request;
     if (tx.token === "ETH") {
@@ -505,21 +606,16 @@ async function populateVerifyAndSend(connectedSigner, tx, fees = null) {
     return connectedSigner.sendTransaction(populated);
 }
 
-// Show a full-sentence send failure in the reserved errors box, the same
-// element and markup renderValidation() uses for messages carrying the user's
-// own numbers, so it never moves anything on the screen.
-function showSendError(message) {
-    const el = $("confirm-errors");
-    el.innerHTML = `<div class="text-xs">${escapeHtml(message)}</div>`;
-    el.style.visibility = "visible";
-}
-
 async function checkRecipientHistory(txInfo) {
     try {
-        const provider = getProvider(state.rpcUrl, state.networkId);
+        const provider = reviewedNetworkProvider(txInfo);
         const asyncWarnings = await getFullWarnings(txInfo.to, provider, {
             fromAddress: txInfo.from,
+            chainId: txInfo.chainId,
         });
+        // The user may have left this transaction while the checks were in
+        // flight; its warnings must not reach another recipient's screen.
+        if (pendingTx !== txInfo) return;
         for (const w of asyncWarnings) {
             if (w.type === "contract") {
                 $("confirm-contract-warning").style.visibility = "visible";
@@ -548,6 +644,11 @@ function init(_ctx) {
     onViewLeave("confirm-tx", clearPassword);
 
     $("btn-confirm-send").addEventListener("click", async () => {
+        // A press shows only its own refusal, if any.
+        setVisible("confirm-network-changed-error", false);
+        setVisible("confirm-from-address-error", false);
+        setVisible("confirm-fee-bound-error", false);
+
         const wallet = state.wallets[state.selectedWallet];
         // Every Send button refuses a defective wallet before this screen,
         // but the popup also reopens onto it from a saved view.
@@ -557,14 +658,12 @@ function init(_ctx) {
             return;
         }
 
-        // Back from Settings only unhides this screen, still drawn for the
-        // network that was active when it was shown.
+        // The screen describes the network the transaction was reviewed for,
+        // which Settings may have switched away from since: "Back" from
+        // Settings after a switch draws this screen again from the saved
+        // transaction, as a popup reopened onto it does.
         if (currentNetwork().chainId !== pendingTx.chainId) {
-            showSendError(
-                "The active network changed after this transaction was" +
-                    " reviewed, so it was not sent. Please go back and review" +
-                    " it again.",
-            );
+            setVisible("confirm-network-changed-error", true);
             return;
         }
 
@@ -573,11 +672,7 @@ function init(_ctx) {
         // address selected.
         const addr = wallet.addresses.find((a) => a.address === pendingTx.from);
         if (!addr) {
-            showError(
-                "confirm-tx-password-error",
-                "The selected wallet does not hold the From address above, " +
-                    "so nothing was sent. Please go back and send again.",
-            );
+            setVisible("confirm-from-address-error", true);
             return;
         }
 
@@ -609,6 +704,10 @@ function init(_ctx) {
         $("btn-confirm-send").disabled = true;
         $("btn-confirm-send").classList.add("text-muted");
 
+        // The wait, success and error screens show the amount as this screen
+        // does, so they are handed a copy carrying that text. pendingTx keeps
+        // the exact amount, which is the one signed.
+        const shownTx = { ...pendingTx, amount: shownAmount(pendingTx) };
         let tx;
         try {
             const signer = getSignerForAddress(wallet, addr, decryptedSecret);
@@ -625,19 +724,23 @@ function init(_ctx) {
             // Note: JS strings are immutable; this nulls the reference but
             // the original string may persist in memory until GC.
             decryptedSecret = null;
-            txStatus.showWait(pendingTx, tx.hash);
+            txStatus.showWait(shownTx, tx.hash);
         } catch (e) {
             decryptedSecret = null;
-            // A fee over the bound is refused before anything is broadcast, so
-            // there is no transaction that may have reached the network to warn
-            // about: the message stays on the confirmation screen where the
-            // user can go back, rather than routing to the sent/failed screen.
+            // A gas limit or fee over its bound is refused before anything is
+            // broadcast, so there is no transaction that may have reached the
+            // network to warn about: the refusal stays on the confirmation
+            // screen where the user can go back, rather than routing to the
+            // sent/failed screen. Its sentence is fixed in index.html, so that
+            // its box can hold its space from the first paint; the reason in
+            // full, naming the bound, is logged.
             if (e && e.approvalMismatch) {
-                showSendError(e.message);
+                log.errorf("send refused:", e.message);
+                setVisible("confirm-fee-bound-error", true);
                 return;
             }
             const hash = tx ? tx.hash : null;
-            txStatus.showError(pendingTx, hash, e.shortMessage || e.message);
+            txStatus.showError(shownTx, hash, e.shortMessage || e.message);
         } finally {
             $("btn-confirm-send").disabled = false;
             $("btn-confirm-send").classList.remove("text-muted");

src/popup/views/deleteAddress.js

@@ -17,9 +17,9 @@ const {
     attachCopyHandlers,
     addressHoldsFunds,
     balanceLinesForAddress,
+    keyMaterialName,
 } = require("./helpers");
 const { formatAddressTotal, getAddressValue } = require("../../shared/prices");
-const { walletHasRecoveryPhrase } = require("../../shared/wallet");
 const { state, saveState } = require("../../shared/state");
 const {
     canRemoveAddress,
@@ -54,9 +54,7 @@ function setFlash(msg) {
 // The noun follows the wallet: an xprv wallet holds no recovery phrase, and
 // this screen is offered on xprv wallets too.
 function recoveryPathText(wallet) {
-    const secret = walletHasRecoveryPhrase(wallet)
-        ? "recovery phrase"
-        : "extended private key";
+    const secret = keyMaterialName(wallet);
     return (
         "Getting the address back into this list is not easy, so be sure. " +
         "Adding an address derives the next unused one, not this one, and " +

src/popup/views/deleteWallet.js

@@ -7,6 +7,7 @@ const {
     goBack,
     clearViewStack,
     onViewLeave,
+    keyMaterialName,
 } = require("./helpers");
 const { state, saveState } = require("../../shared/state");
 const { decryptWithPassword } = require("../../shared/vault");
@@ -75,6 +76,9 @@ function show(walletIdx) {
     clear();
     deleteWalletIndex = walletIdx;
     $("delete-wallet-name").textContent = displayName(walletIdx);
+    $("delete-wallet-key-material").textContent = keyMaterialName(
+        state.wallets[walletIdx],
+    );
     showView("delete-wallet-confirm");
 }
 
@@ -94,6 +98,9 @@ function showLostPassword() {
     clearLostPassword();
     $("delete-wallet-lost-name").textContent = name;
     $("delete-wallet-lost-name-echo").textContent = name;
+    $("delete-wallet-lost-key-material").textContent = keyMaterialName(
+        state.wallets[walletIdx],
+    );
     // showView() runs the leave hook of delete-wallet-confirm, which nulls
     // deleteWalletIndex, so this screen's own selection is recorded after
     // it and not before.

src/popup/views/helpers.js

@@ -1,4 +1,7 @@
-// Shared DOM helpers used by all views.
+// Helpers the views in this directory share: showing a view and going back,
+// error and flash lines and the warning banners, formatting of amounts, fees,
+// balances, addresses and dates, the RPC and Blockscout URLs, node and tokens
+// of the network a chain id names, explorer links, and click-to-copy.
 //
 // Escaping rule for every view in this directory, since they all build
 // markup by concatenation: any VALUE interpolated into an innerHTML string
@@ -19,12 +22,15 @@ const {
     isBelowOneMillionth,
 } = require("../../shared/amountDisplay");
 const { resolveTokenSymbol } = require("../../shared/approvalAmount");
+const { getProvider } = require("../../shared/balances");
 const { DEBUG } = require("../../shared/constants");
 const { escapeHtml } = require("../../shared/html");
 const { isDebug } = require("../../shared/log");
+const { networkByChainId } = require("../../shared/networks");
 const { formatUsd, getPrice } = require("../../shared/prices");
 const { state, saveState, currentNetwork } = require("../../shared/state");
 const { displaySymbol } = require("../../shared/symbolDisplay");
+const { walletHasRecoveryPhrase } = require("../../shared/wallet");
 const { markViewRendered } = require("../viewRouter");
 
 // When views are added, removed, or transitions between them change,
@@ -126,7 +132,8 @@ function showView(name) {
 }
 
 // Create or update the debug/insecure warning banner.
-// Called on every view switch and after the settings debug toggle changes.
+// Called on every view switch, after the settings debug toggle changes, and
+// after a network switch in Settings.
 // The banner is shown when the compile-time DEBUG constant is true OR when
 // the user has enabled runtime debug mode via the settings easter egg, OR
 // when the active network is a testnet.
@@ -283,34 +290,51 @@ function unknownableAmount(balance) {
 
 // The active network's native token symbol, `ETH` on mainnet and `SepoliaETH`
 // on Sepolia, as src/shared/networks.js names it. The wallet's balances and
-// the Send and confirmation screens, which send on the active network, label a
-// native amount with this; a transaction already made or requested is labelled
-// by its own chain id, through nativeCurrencyByChainId() in networks.js. The
-// "ETH" that state.selectedToken and txInfo.token hold is the native token's
-// id, not its label, and stays "ETH" on every network.
+// the Send screen, which sends on the active network, label a native amount
+// with this; the confirmation screen, and a transaction already made or
+// requested, label it by the transaction's own chain id, through
+// nativeCurrencyByChainId() in networks.js. The "ETH" that state.selectedToken
+// and txInfo.token hold is the native token's id, not its label, and stays
+// "ETH" on every network.
 function nativeCurrency() {
     return currentNetwork().nativeCurrency;
 }
 
-// The symbol shown for a token line, resolved from the bundled list, the
-// tokens the user tracks, and the explorer's report — the same chain the
-// amount line's scale comes from. Null when no source names one, so the token
-// lines keep saying `Unknown token` for a token nothing knows.
-function tokenLabel(address) {
-    return resolveTokenSymbol(address, {
-        trackedTokens: state.trackedTokens,
-        wallets: state.wallets,
-    });
+// What the wallet knows of the tokens on the network with this chain id, or
+// on the active network when no chain id is given, as the `sources` that
+// resolveTokenSymbol() and resolveTokenDecimals() take. A contract address
+// names a token on one network only, and every token balance held is the
+// active network's, so another network gets the tokens tracked on it
+// (state.networkTrackedTokens, see applyChainSwitchFields()) and no balances.
+function tokenSourcesByChainId(chainId) {
+    const net = chainId ? networkByChainId(chainId) : currentNetwork();
+    if (net && net.id === state.networkId) {
+        return { trackedTokens: state.trackedTokens, wallets: state.wallets };
+    }
+    return {
+        trackedTokens: (net && state.networkTrackedTokens[net.id]) || [],
+        wallets: [],
+    };
+}
+
+// The symbol shown for a token line on the network with `chainId`, or on the
+// active network when none is given: from the bundled list, the tokens the
+// user tracks, and the explorer's report, the sources the amount line's scale
+// comes from. Null when no source names one, so the token lines keep saying
+// `Unknown token` for a token nothing knows.
+function tokenLabel(address, chainId) {
+    return resolveTokenSymbol(address, tokenSourcesByChainId(chainId));
 }
 
 // A network fee in wei as the confirmation and approval screens both show it:
 // the ETH figure through truncateAmountNeverZero() and labelled `symbol`, the
 // native currency of the network the fee is paid on, then its USD value when
-// the ETH price is known. The USD value is of the exact fee, not of the
-// truncated figure.
-function formatFee(wei, symbol) {
+// the ETH price is known on the network with `chainId`, or on the active
+// network when no chain id is given. The USD value is of the exact fee, not of
+// the truncated figure.
+function formatFee(wei, symbol, chainId) {
     const eth = formatEther(wei);
-    const ethPrice = getPrice("ETH");
+    const ethPrice = getPrice("ETH", chainId);
     const usd = ethPrice ? formatUsd(parseFloat(eth) * ethPrice) : "";
     return (
         truncateAmountNeverZero(eth) +
@@ -418,6 +442,16 @@ function addressHoldsFunds(addr) {
     return false;
 }
 
+// The name of a wallet's key material, which is also its only backup: the
+// recovery phrase of an HD wallet, the private key of a key wallet, the
+// extended private key of an xprv wallet. DeleteWallet,
+// DeleteWalletLostPassword and DeleteAddress name the backup with it.
+function keyMaterialName(wallet) {
+    if (walletHasRecoveryPhrase(wallet)) return "recovery phrase";
+    if (wallet.type === "key") return "private key";
+    return "extended private key";
+}
+
 // The fewest characters of an address any caller may ask to display. The
 // 10-character cap inside truncateMiddle() is the other half of the same
 // guarantee; this is the half that used to be spelled out at each call
@@ -592,18 +626,44 @@ const EXT_ICON =
     `<path d="M7 1.5h3.5V5M7 5.5L10.5 1.5"/>` +
     `</svg></span>`;
 
-// Block-explorer URLs. The origin is a per-network constant from
-// src/shared/networks.js; only the path segment is data, and it comes out
-// of explorer JSON (a transaction's from/to, a token's address_hash), which
-// nothing upstream validates as hex. percent-encoding it keeps a segment
-// that contains a slash, a query or a fragment from re-pointing the link
-// somewhere else in the explorer.
-function explorerUrl(kind, value) {
-    return `${currentNetwork().explorerUrl}/${kind}/${encodeURIComponent(value)}`;
+// The RPC and Blockscout URLs Settings has for the network with this chain id,
+// which need not be the active one: ConfirmTx, WaitTx and TransactionDetail
+// use the network their transaction's chain id names, and the popup can reopen
+// onto them after Settings switched the network. The active network's are
+// state.rpcUrl and state.blockscoutUrl, any other's the ones remembered for it,
+// or its defaults (see applyChainSwitchFields()).
+function endpointsByChainId(chainId) {
+    const net = networkByChainId(chainId);
+    if (net.id === state.networkId) {
+        return { rpcUrl: state.rpcUrl, blockscoutUrl: state.blockscoutUrl };
+    }
+    const remembered = state.networkEndpoints[net.id] || {};
+    return {
+        rpcUrl: remembered.rpcUrl || net.defaultRpcUrl,
+        blockscoutUrl: remembered.blockscoutUrl || net.defaultBlockscoutUrl,
+    };
 }
 
-function etherscanAddressUrl(address) {
-    return explorerUrl("address", address);
+// The node of the network a transaction was reviewed for.
+function reviewedNetworkProvider(txInfo) {
+    const net = networkByChainId(txInfo.chainId);
+    return getProvider(endpointsByChainId(txInfo.chainId).rpcUrl, net.id);
+}
+
+// Block-explorer URLs. The origin is a per-network constant from
+// src/shared/networks.js, the explorer of the network with `chainId`, or of
+// the active network when no chain id is given; only the path segment is
+// data, and it comes out of explorer JSON (a transaction's from/to, a token's
+// address_hash), which nothing upstream validates as hex. percent-encoding it
+// keeps a segment that contains a slash, a query or a fragment from
+// re-pointing the link somewhere else in the explorer.
+function explorerUrl(kind, value, chainId) {
+    const network = chainId ? networkByChainId(chainId) : currentNetwork();
+    return `${network.explorerUrl}/${kind}/${encodeURIComponent(value)}`;
+}
+
+function etherscanAddressUrl(address, chainId) {
+    return explorerUrl("address", address, chainId);
 }
 
 // The URL still has to be escaped on the way into href="...": encoding
@@ -669,16 +729,18 @@ function attachCopyHandlers(container) {
 //              with them, and the "at least 32 characters" guarantee has
 //              to survive having no current callers to be a guarantee.
 //   noLink   — if true, omit etherscan link
+//   chainId  — the network whose explorer the link opens; the active
+//              network's when absent
 //
 // After inserting the returned HTML into the DOM, call
 // attachCopyHandlers() on the parent to wire up click-to-copy.
 function renderAddressHtml(address, opts) {
-    const { title, ensName, maxLen, noLink } = opts || {};
+    const { title, ensName, maxLen, noLink, chainId } = opts || {};
     const dot = addressDotHtml(address);
     const displayAddr = maxLen
         ? truncateMiddle(address, Math.max(ADDRESS_MIN_DISPLAY_LEN, maxLen))
         : address;
-    const link = etherscanAddressUrl(address);
+    const link = etherscanAddressUrl(address, chainId);
     const extLink = noLink ? "" : etherscanLinkHtml(link);
 
     let html = "";
@@ -725,8 +787,10 @@ module.exports = {
     balanceLine,
     balanceLinesForAddress,
     addressHoldsFunds,
+    keyMaterialName,
     unknownableAmount,
     nativeCurrency,
+    tokenSourcesByChainId,
     tokenLabel,
     formatFee,
     addressDotHtml,
@@ -742,6 +806,8 @@ module.exports = {
     attachCopyHandlers,
     etherscanLinkHtml,
     explorerUrl,
+    endpointsByChainId,
+    reviewedNetworkProvider,
     EXT_ICON,
     truncateMiddle,
     isoDate,

src/popup/views/send.js

@@ -164,8 +164,9 @@ function renderSendTokenSelect(addr) {
     }
 }
 
-// The token balance and scale the Send screen states and hands the
-// confirmation screen, so the two screens describe the holding the same way.
+// The token balance the Send screen states, and the scale it hands the
+// confirmation screen, which reads the balance itself from the network it is
+// drawn for.
 //
 // The scale is resolved the same way balances.js resolved the scale it
 // DISPLAYED this token's balance at: bundled list, then the user's tracked
@@ -188,13 +189,11 @@ function renderSendTokenSelect(addr) {
 //
 // The two resolutions can therefore differ, and where they do, the stored
 // `balance` is a quantity computed at a scale this screen has just declined to
-// stand behind. Stating it would leave validateTransfer() checking the amount
-// against a number the wallet does not vouch for, so it is withdrawn: unknown
-// scale means unknown balance. It is null rather than "0": both screens state
-// an unknown balance as unknown, and validateTransfer() treats it as no balance
-// to spend from, which is the fail-closed side of an amount nobody can check.
-// Only a stored quantity is withdrawn: the "0" for a token that has no row at
-// all is an absence of holdings, which is true at every scale.
+// stand behind, so it is withdrawn: unknown scale means unknown balance. It is
+// null rather than "0": this screen states it as unknown, as the confirmation
+// screen does, and Max fills nothing in for it. Only a stored quantity is
+// withdrawn: the "0" for a token that has no row at all is an absence of
+// holdings, which is true at every scale.
 function tokenBalanceAndDecimals(addr, token) {
     const tb = (addr.tokenBalances || []).find(
         (t) => t.address.toLowerCase() === token.toLowerCase(),
@@ -378,7 +377,6 @@ function init(_ctx) {
         const addr = currentAddress();
 
         let tokenSymbol = null;
-        let tokenBalance = null;
         let tokenDecimals = null;
         if (token !== "ETH") {
             tokenSymbol = resolveSymbol(
@@ -386,10 +384,7 @@ function init(_ctx) {
                 addr.tokenBalances,
                 state.trackedTokens,
             );
-            ({ tokenBalance, tokenDecimals } = tokenBalanceAndDecimals(
-                addr,
-                token,
-            ));
+            ({ tokenDecimals } = tokenBalanceAndDecimals(addr, token));
         }
 
         // The confirmation screen's own amount check, so it is never shown
@@ -424,9 +419,7 @@ function init(_ctx) {
             ensName: ensName,
             amount: amount,
             token: token,
-            balance: addr.balance,
             tokenSymbol: tokenSymbol,
-            tokenBalance: tokenBalance,
             tokenDecimals: tokenDecimals,
             max: amountIsMax,
         });

src/popup/views/settings.js

@@ -16,6 +16,8 @@ const {
 } = require("../dustThreshold");
 const { state, saveState, currentNetwork } = require("../../shared/state");
 const { onChainSwitch } = require("../../shared/chainSwitch");
+const { restorableStack } = require("../../shared/persistedState");
+const { resetRenderedViews, markViewRendered } = require("../viewRouter");
 const {
     log,
     debugFetch,
@@ -76,11 +78,13 @@ function forgetOrigin(siteMap, origin) {
 
 // Removing a site from Allowed Sites or Connected Sites disconnects it: it is
 // no longer allowed under any address, and the background ends its
-// connections approved without "Remember" and tells its open tabs.
+// connections approved without "Remember" and tells its open tabs. The
+// background answers once those have ended, so the lists drawn after it no
+// longer show the site.
 async function removeAllowedSite(origin) {
     forgetOrigin(state.allowedSites, origin);
     await saveState();
-    notify({ type: "AUTISTMASK_REMOVE_SITE", origin });
+    await sendMessage({ type: "AUTISTMASK_REMOVE_SITE", origin });
     await renderSiteLists();
 }
 
@@ -230,8 +234,8 @@ async function renderSiteLists() {
         Object.values(state.deniedSites).flat(),
         removeDeniedSite,
     );
-    // Sites allowed without "Remember" are held only by the background, in
-    // memory, so it is asked for them.
+    // Sites allowed without "Remember" are held only in session storage, which
+    // the background keeps, so it is asked for them.
     renderSiteList(
         "settings-connected-sites",
         await sendMessage({ type: "AUTISTMASK_GET_CONNECTED_SITES" }),
@@ -317,12 +321,35 @@ function init(ctx) {
     networkSelect.addEventListener("change", async () => {
         const newId = networkSelect.value;
         if (newId === state.networkId) return;
+        // The screens beneath Settings show the previous network, so Back
+        // finds them as it does in a reopened popup: each is rendered again
+        // when Back lands on it, and the stack is cut at the first one that
+        // cannot be rendered from saved state, such as Send or AddToken. It
+        // is cut at AddressToken too, unless that shows the native token: any
+        // other token there was picked on the previous network. Without a
+        // wallet the stack starts at Welcome, which that cut would drop, and
+        // Welcome shows nothing from a network. The cut comes before the
+        // switch so that the switch's save keeps it for a popup closed
+        // straight after.
+        if (state.hasWallet) {
+            const tokenView = state.viewStack.indexOf("address-token");
+            if (tokenView !== -1 && state.selectedToken !== "ETH") {
+                state.viewStack = state.viewStack.slice(0, tokenView);
+            }
+            state.viewStack = restorableStack(state.viewStack, "settings");
+        }
         const net = await onChainSwitch(newId);
         // Open pages are told by the background, as after a site's approved
         // switch request.
         notify({ type: "AUTISTMASK_NETWORK_CHANGED", chainId: net.chainId });
+        resetRenderedViews();
+        // Settings itself, and the testnet banner above it, are brought up
+        // to date for the new network here.
+        markViewRendered("settings");
         $("settings-rpc").value = state.rpcUrl;
         $("settings-blockscout").value = state.blockscoutUrl;
+        renderTrackedTokens();
+        updateDebugBanner(state.currentView);
         showFlash("Switched to " + net.name + ".");
     });
 

src/popup/views/settingsAddToken.js

@@ -1,6 +1,6 @@
 const { $, showView, showFlash, escapeHtml, goBack } = require("./helpers");
 const { getTopTokens } = require("../../shared/tokenList");
-const { state, saveState } = require("../../shared/state");
+const { state, saveState, currentNetwork } = require("../../shared/state");
 const { lookupTokenInfo } = require("../../shared/balances");
 const { isScamAddress } = require("../../shared/scamlist");
 const { log } = require("../../shared/log");
@@ -75,6 +75,12 @@ function show() {
     $("settings-addtoken-address").value = "";
     $("settings-addtoken-info").textContent = "";
     $("settings-addtoken-info").style.visibility = "hidden";
+    // The bundled list holds Ethereum Mainnet contracts, which name no token
+    // on any other network.
+    $("settings-addtoken-common").classList.toggle(
+        "hidden",
+        state.networkId !== "mainnet",
+    );
     renderTop10();
     renderDropdown();
     showView("settings-addtoken");
@@ -130,6 +136,9 @@ function init(_ctx) {
         infoEl.textContent = "Looking up token...";
         infoEl.style.visibility = "visible";
         log.debugf("Looking up token contract", addr);
+        // The network the lookup asks, which Settings may switch away from
+        // before it answers, as for a transaction in confirmTx.js.
+        const chainId = currentNetwork().chainId;
         try {
             const info = await lookupTokenInfo(
                 addr,
@@ -137,6 +146,15 @@ function init(_ctx) {
                 state.networkId,
                 ctx.pageClosed,
             );
+            // A contract address names a token on one network only, so an
+            // answer after a switch is not added to the new network's list.
+            if (currentNetwork().chainId !== chainId) {
+                showFlash(
+                    "The active network changed before the lookup finished," +
+                        " so the token was not added.",
+                );
+                return;
+            }
             log.infof("Adding token", info.symbol, addr);
             state.trackedTokens.push({
                 address: addr,

src/popup/views/transactionDetail.js

@@ -18,6 +18,7 @@ const {
     copyableHtml,
     etherscanLinkHtml,
     explorerUrl,
+    endpointsByChainId,
     displaySymbol,
     goBack,
 } = require("./helpers");
@@ -48,16 +49,16 @@ function getTransactionType(tx) {
     return "Native " + nativeCurrencyByChainId(tx.chainId) + " Transfer";
 }
 
-function txAddressHtml(address, ensName, title) {
+function txAddressHtml(address, ensName, title, chainId) {
     const blockie = blockieHtml(address);
     return (
         `<div class="mb-1">${blockie}</div>` +
-        renderAddressHtml(address, { title, ensName })
+        renderAddressHtml(address, { title, ensName, chainId })
     );
 }
 
-function txHashHtml(hash) {
-    const link = explorerUrl("tx", hash);
+function txHashHtml(hash, chainId) {
+    const link = explorerUrl("tx", hash, chainId);
     const extLink = etherscanLinkHtml(link);
     return copyableHtml(hash, "break-all") + extLink;
 }
@@ -83,10 +84,11 @@ function show(tx) {
             method: tx.method || null,
             contractAddress: tx.contractAddress || null,
             // The network the history entry was read from. The type line and
-            // the fee are in its native currency, not the active network's:
-            // the active network can change, in Settings or when the user
-            // approves a site's request, before a later popup shows this
-            // screen again.
+            // the fee are in its native currency, not the active network's,
+            // the links open its explorer, and the block, network details and
+            // calldata are read from its Blockscout: the active network can
+            // change, in Settings or when the user approves a site's request,
+            // before a later popup shows this screen again.
             chainId: tx.chainId,
         },
     };
@@ -96,18 +98,24 @@ function show(tx) {
 function render() {
     const tx = state.viewData.tx;
     if (!tx) return;
-    $("tx-detail-hash").innerHTML = txHashHtml(tx.hash);
+    $("tx-detail-hash").innerHTML = txHashHtml(tx.hash, tx.chainId);
 
     const fromTitle = addressTitle(tx.from, state.wallets);
     $("tx-detail-from").innerHTML = txAddressHtml(
         tx.from,
         tx.fromEns,
         fromTitle,
+        tx.chainId,
     );
     // A contract creation has no recipient: transactions.js gives it `to: ""`.
     if (tx.to) {
         const toTitle = addressTitle(tx.to, state.wallets);
-        $("tx-detail-to").innerHTML = txAddressHtml(tx.to, tx.toEns, toTitle);
+        $("tx-detail-to").innerHTML = txAddressHtml(
+            tx.to,
+            tx.toEns,
+            toTitle,
+            tx.chainId,
+        );
     } else {
         $("tx-detail-to").innerHTML = escapeHtml(CONTRACT_CREATION_TEXT);
     }
@@ -146,7 +154,7 @@ function render() {
     if (tokenContractSection && tokenContractEl) {
         if (tx.contractAddress) {
             const dot = addressDotHtml(tx.contractAddress);
-            const link = explorerUrl("token", tx.contractAddress);
+            const link = explorerUrl("token", tx.contractAddress, tx.chainId);
             // Hand-rolled rather than renderAddressHtml() because the
             // link goes to the explorer's /token/ page, not /address/.
             // Same two-row shape though: dot and link on the strip, the
@@ -204,7 +212,11 @@ function showDetailField(sectionId, contentId, value) {
 function populateOnChainDetails(txData, chainId) {
     // Block number
     if (txData.block_number != null) {
-        const blockLink = explorerUrl("block", String(txData.block_number));
+        const blockLink = explorerUrl(
+            "block",
+            String(txData.block_number),
+            chainId,
+        );
         const blockSection = $("tx-detail-block-section");
         const blockEl = $("tx-detail-block");
         if (blockSection && blockEl) {
@@ -301,8 +313,9 @@ async function loadFullTxDetails(txHash, chainId) {
     if (!section || !actionEl || !detailsEl) return;
 
     try {
+        const { blockscoutUrl } = endpointsByChainId(chainId);
         const resp = await debugFetch(
-            state.blockscoutUrl + "/transactions/" + txHash,
+            blockscoutUrl + "/transactions/" + txHash,
         );
         if (!resp.ok) return;
         const txData = await resp.json();
@@ -316,7 +329,14 @@ async function loadFullTxDetails(txHash, chainId) {
         // Decoded against the address the transaction was sent to, as the
         // explorer reports it, not the history entry's `to`: for a token
         // transfer that is the transfer's recipient, not the token contract.
-        const decoded = decodeCalldata(inputData, txData.to?.hash || "");
+        // On the network the transaction was sent on, whose Blockscout was
+        // just asked, and from the sender it reports.
+        const decoded = decodeCalldata(
+            inputData,
+            txData.to?.hash || "",
+            chainId,
+            txData.from?.hash || "",
+        );
         if (decoded) {
             // Render decoded calldata matching approval view style
             actionEl.textContent = decoded.name;
@@ -333,9 +353,9 @@ async function loadFullTxDetails(txHash, chainId) {
                     if (tokenSymbol) {
                         detailsHtml += `<div class="font-bold">${escapeHtml(displaySymbol(tokenSymbol))}</div>`;
                     }
-                    detailsHtml += renderAddressHtml(d.address);
+                    detailsHtml += renderAddressHtml(d.address, { chainId });
                 } else if (d.address) {
-                    detailsHtml += renderAddressHtml(d.address);
+                    detailsHtml += renderAddressHtml(d.address, { chainId });
                 } else {
                     detailsHtml += `<div class="font-bold">${escapeHtml(d.value)}</div>`;
                 }

src/popup/views/txStatus.js

@@ -14,10 +14,13 @@ const {
     displaySymbol,
     clearViewStack,
     tokenLabel,
+    reviewedNetworkProvider,
 } = require("./helpers");
 const { state } = require("../../shared/state");
-const { nativeCurrencyByChainId } = require("../../shared/networks");
-const { getProvider } = require("../../shared/balances");
+const {
+    SUPPORTED_CHAIN_IDS,
+    nativeCurrencyByChainId,
+} = require("../../shared/networks");
 const { log } = require("../../shared/log");
 
 // Receipt poll cadence and the deadline after which the wait is reported as
@@ -61,21 +64,22 @@ function endWait() {
 }
 
 // A contract creation reaches these screens with `to` as "" (approval.js
-// writes `to: toAddr || ""`).
-function toAddressHtml(address) {
+// writes `to: toAddr || ""`). The links below open the explorer of the network
+// with `chainId`, or of the active network when none is given.
+function toAddressHtml(address, chainId) {
     if (!address) return escapeHtml(CONTRACT_CREATION_TEXT);
     const title = addressTitle(address, state.wallets);
-    return renderAddressHtml(address, { title });
+    return renderAddressHtml(address, { title, chainId });
 }
 
-function txHashHtml(hash) {
-    const link = explorerUrl("tx", hash);
+function txHashHtml(hash, chainId) {
+    const link = explorerUrl("tx", hash, chainId);
     return copyableHtml(hash, "break-all") + etherscanLinkHtml(link);
 }
 
-function blockNumberHtml(blockNumber) {
+function blockNumberHtml(blockNumber, chainId) {
     const num = String(blockNumber);
-    const link = explorerUrl("block", num);
+    const link = explorerUrl("block", num, chainId);
     return copyableHtml(num) + etherscanLinkHtml(link);
 }
 
@@ -91,9 +95,11 @@ function startWait(txInfo, txHash, broadcastTime, pollNow) {
     // native currency of txInfo.chainId, the network the transaction was sent
     // on, not the active network's: the active network can change, in
     // Settings or when the user approves a site's request, while this screen
-    // is open or before a later popup resumes it. A null token is a swap whose
-    // amount was not decoded (see showTxApproval() in approval.js): the amount
-    // says so, and no symbol follows it.
+    // is open or before a later popup resumes it. The links on all three
+    // screens open that network's explorer, and this screen's receipt is
+    // asked of that network's node, for the same reason. A null token is a
+    // swap whose amount was not decoded (see showTxApproval() in
+    // approval.js): the amount says so, and no symbol follows it.
     let symbol = "";
     if (txInfo.token === "ETH") {
         symbol = nativeCurrencyByChainId(txInfo.chainId);
@@ -102,8 +108,8 @@ function startWait(txInfo, txHash, broadcastTime, pollNow) {
     }
     $("wait-tx-summary").textContent =
         txInfo.amount + (symbol ? " " + symbol : "");
-    $("wait-tx-to").innerHTML = toAddressHtml(txInfo.to);
-    $("wait-tx-hash").innerHTML = txHashHtml(txHash);
+    $("wait-tx-to").innerHTML = toAddressHtml(txInfo.to, txInfo.chainId);
+    $("wait-tx-hash").innerHTML = txHashHtml(txHash, txInfo.chainId);
     attachCopyHandlers("view-wait-tx");
 
     // Persisted so closing and reopening the popup resumes this wait
@@ -128,7 +134,7 @@ function startWait(txInfo, txHash, broadcastTime, pollNow) {
         renderElapsed();
     }, 1000);
 
-    const provider = getProvider(state.rpcUrl, state.networkId);
+    const provider = reviewedNetworkProvider(txInfo);
     let consecutiveFailures = 0;
 
     async function poll() {
@@ -207,10 +213,11 @@ function showWait(txInfo, txHash) {
 // an object merely missing one of them throws a TypeError out of
 // restoreView() — which init() does not guard, skipping the rest of popup
 // init and leaving wait-tx on screen with no back control. A non-numeric
-// broadcastTime leaves an unexitable wait counting "NaNs". txInfo.token,
-// txInfo.tokenSymbol and txInfo.chainId are deliberately unchecked: they are
-// compared and coalesced rather than dereferenced, and tokenSymbol is null for
-// ETH.
+// broadcastTime leaves an unexitable wait counting "NaNs". txInfo.chainId picks
+// the node the receipt is asked of and the explorer the links open, so it has
+// to name a network. txInfo.token and txInfo.tokenSymbol are deliberately
+// unchecked: they are compared and coalesced rather than dereferenced, and
+// tokenSymbol is null for ETH.
 function restoreWait() {
     const d = state.viewData;
     if (!d || !d.pendingWait) return false;
@@ -226,6 +233,7 @@ function restoreWait() {
     // path itself created.
     if (typeof info.to !== "string") return false;
     if (typeof info.amount !== "string") return false;
+    if (!SUPPORTED_CHAIN_IDS.has(info.chainId)) return false;
     if (typeof w.broadcastTime !== "number" || !isFinite(w.broadcastTime)) {
         return false;
     }
@@ -250,12 +258,13 @@ function showSuccess(txInfo, txHash, blockNumber) {
         hash: txHash,
         blockNumber: blockNumber,
         decoded: txInfo.decoded || null,
+        chainId: txInfo.chainId,
     };
     renderSuccess();
     ctx.doRefreshAndRender();
 }
 
-function decodedDetailsHtml(decoded) {
+function decodedDetailsHtml(decoded, chainId) {
     if (!decoded || !decoded.details) return "";
     let html = `<div class="border border-border border-dashed p-2 mb-3">`;
     if (decoded.name) {
@@ -271,11 +280,11 @@ function decodedDetailsHtml(decoded) {
         html += `<div class="text-xs text-muted mb-1">${escapeHtml(d.label)}</div>`;
         if (d.address) {
             if (d.isToken) {
-                const sym = tokenLabel(d.address) || "Unknown token";
+                const sym = tokenLabel(d.address, chainId) || "Unknown token";
                 html += `<div class="font-bold">${escapeHtml(sym)}</div>`;
-                html += toAddressHtml(d.address);
+                html += toAddressHtml(d.address, chainId);
             } else {
-                html += toAddressHtml(d.address);
+                html += toAddressHtml(d.address, chainId);
             }
         } else {
             html += `<div class="font-bold">${escapeHtml(d.value)}</div>`;
@@ -304,16 +313,16 @@ function renderSuccess() {
         toSection.classList.remove("hidden");
         $("success-tx-summary").textContent =
             d.amount + (d.symbol ? " " + d.symbol : "");
-        $("success-tx-to").innerHTML = toAddressHtml(d.to);
+        $("success-tx-to").innerHTML = toAddressHtml(d.to, d.chainId);
     }
 
-    $("success-tx-block").innerHTML = blockNumberHtml(d.blockNumber);
-    $("success-tx-hash").innerHTML = txHashHtml(d.hash);
+    $("success-tx-block").innerHTML = blockNumberHtml(d.blockNumber, d.chainId);
+    $("success-tx-hash").innerHTML = txHashHtml(d.hash, d.chainId);
 
     // Show decoded calldata details if present
     const decodedEl = $("success-tx-decoded");
     if (decodedEl && hasDecoded) {
-        decodedEl.innerHTML = decodedDetailsHtml(d.decoded);
+        decodedEl.innerHTML = decodedDetailsHtml(d.decoded, d.chainId);
         decodedEl.classList.remove("hidden");
     } else if (decodedEl) {
         decodedEl.classList.add("hidden");
@@ -339,6 +348,7 @@ function showError(txInfo, txHash, message) {
         to: txInfo.to,
         hash: txHash || null,
         message: message,
+        chainId: txInfo.chainId,
     };
     renderError();
 }
@@ -348,11 +358,11 @@ function renderError() {
     if (!d || !d.message) return;
     $("error-tx-summary").textContent =
         d.amount + (d.symbol ? " " + d.symbol : "");
-    $("error-tx-to").innerHTML = toAddressHtml(d.to);
+    $("error-tx-to").innerHTML = toAddressHtml(d.to, d.chainId);
     $("error-tx-message").textContent = d.message;
 
     if (d.hash) {
-        $("error-tx-hash").innerHTML = txHashHtml(d.hash);
+        $("error-tx-hash").innerHTML = txHashHtml(d.hash, d.chainId);
         $("error-tx-hash-section").classList.remove("hidden");
         attachCopyHandlers("view-error-tx");
     } else {

src/shared/addressWarnings.js

@@ -51,12 +51,15 @@ function getLocalWarnings(address, options = {}) {
 
 /**
  * Check an address against local lists AND via RPC queries.
- * Async — performs network calls to check contract status and tx history.
+ * Async — performs network calls to check contract status, tx count and
+ * balance.
  *
  * @param {string} address - The target address to check.
  * @param {object} provider - An ethers.js provider instance.
  * @param {object} [options] - Optional context.
  * @param {string} [options.fromAddress] - Sender address (for self-send check).
+ * @param {string} [options.chainId] - Chain id of the network whose explorer
+ *   the Etherscan label check asks; the active network's when omitted.
  * @returns {Promise<Array<{type: string, message: string, severity: string}>>}
  */
 async function getFullWarnings(address, provider, options = {}) {
@@ -78,21 +81,30 @@ async function getFullWarnings(address, provider, options = {}) {
         log.errorf("contract check failed:", e.shortMessage || e.message);
     }
 
-    // Skip tx count check for contracts — they may legitimately have
-    // zero inbound EOA transactions.
+    // The transaction count is the number of transactions the address has
+    // sent, so an address that has only ever received has a count of zero.
+    // Native token it received stays in its balance until it sends a
+    // transaction, so the warning also needs a zero balance. A contract is
+    // skipped: it has its own warning above.
     if (!isContract) {
         try {
             const txCount = await provider.getTransactionCount(address);
             if (txCount === 0) {
-                warnings.push({
-                    type: "new-address",
-                    message:
-                        "This address has never sent a transaction. Double-check it is correct.",
-                    severity: "info",
-                });
+                const balance = await provider.getBalance(address);
+                if (balance === 0n) {
+                    warnings.push({
+                        type: "new-address",
+                        message:
+                            "This address has never sent a transaction and holds none of the network's native token. Double-check it is correct.",
+                        severity: "info",
+                    });
+                }
             }
         } catch (e) {
-            log.errorf("tx count check failed:", e.shortMessage || e.message);
+            log.errorf(
+                "tx count or balance check failed:",
+                e.shortMessage || e.message,
+            );
         }
     }
 
@@ -100,7 +112,10 @@ async function getFullWarnings(address, provider, options = {}) {
     // Runs for ALL addresses including contracts, since many dangerous
     // flagged addresses on Etherscan (drainers, phishing contracts) are contracts.
     try {
-        const etherscanWarning = await checkEtherscanLabel(address);
+        const etherscanWarning = await checkEtherscanLabel(
+            address,
+            options.chainId,
+        );
         if (etherscanWarning) {
             warnings.push(etherscanWarning);
         }

src/shared/browserApi.js

@@ -174,9 +174,9 @@ function notify(message) {
 // default: resolving {} would make an existing wallet read back as no wallet,
 // and resolving a no-op write would discard the user's state with nothing
 // logged. A caller that wants to degrade takes storageLocal() directly.
-function storageUnavailable(method) {
+function storageUnavailable(area, method) {
     return Promise.reject(
-        new Error("extension storage.local is not available: " + method),
+        new Error("extension storage." + area + " is not available: " + method),
     );
 }
 
@@ -187,7 +187,7 @@ function storageUnavailable(method) {
  */
 function storageGet(keys) {
     const storage = storageLocal();
-    if (!storage) return storageUnavailable("get");
+    if (!storage) return storageUnavailable("local", "get");
     return Promise.resolve(storage.get(keys));
 }
 
@@ -198,7 +198,7 @@ function storageGet(keys) {
  */
 function storageSet(items) {
     const storage = storageLocal();
-    if (!storage) return storageUnavailable("set");
+    if (!storage) return storageUnavailable("local", "set");
     return Promise.resolve(storage.set(items));
 }
 
@@ -215,7 +215,55 @@ function storageSet(items) {
  */
 function storageRemove(keys) {
     const storage = storageLocal();
-    if (!storage) return storageUnavailable("remove");
+    if (!storage) return storageUnavailable("local", "remove");
+    return Promise.resolve(storage.remove(keys));
+}
+
+// `storage.session`, the browser's session storage: what is kept there lasts
+// until the browser closes. It survives the background worker being stopped
+// and started again, which module-level variables do not (README, Background
+// scheduling). The background keeps the connections allowed without
+// "Remember" there; see src/background/index.js. Firefox has it from version
+// 115, the minimum manifest/firefox.json declares.
+//
+// The three below reject where it is absent, as the three above do where
+// `storage.local` is: a write that silently did nothing would tell a site it
+// is connected and then refuse its next request.
+function storageSession() {
+    const storage = namespaceMember("storage");
+    return (storage && storage.session) || null;
+}
+
+/**
+ * @param {string|string[]|null} keys null for every item.
+ * @returns {Promise<Object>} the stored items.
+ * @throws rejects where `storage.session` is absent.
+ */
+function sessionStorageGet(keys) {
+    const storage = storageSession();
+    if (!storage) return storageUnavailable("session", "get");
+    return Promise.resolve(storage.get(keys));
+}
+
+/**
+ * @param {Object} items
+ * @returns {Promise<void>}
+ * @throws rejects where `storage.session` is absent.
+ */
+function sessionStorageSet(items) {
+    const storage = storageSession();
+    if (!storage) return storageUnavailable("session", "set");
+    return Promise.resolve(storage.set(items));
+}
+
+/**
+ * @param {string|string[]} keys
+ * @returns {Promise<void>}
+ * @throws rejects where `storage.session` is absent.
+ */
+function sessionStorageRemove(keys) {
+    const storage = storageSession();
+    if (!storage) return storageUnavailable("session", "remove");
     return Promise.resolve(storage.remove(keys));
 }
 
@@ -307,6 +355,9 @@ module.exports = {
     notify,
     runtimeApi,
     sendMessage,
+    sessionStorageGet,
+    sessionStorageRemove,
+    sessionStorageSet,
     storageGet,
     storageLocal,
     storageRemove,

src/shared/chainSwitchFields.js

@@ -38,6 +38,16 @@ function applyChainSwitchFields(s, newNetworkId) {
         blockscoutUrl: s.blockscoutUrl,
     };
     const remembered = s.networkEndpoints[net.id] || {};
+
+    // Tracked tokens are kept per network the same way, because a contract
+    // address names a token on one network only. s.trackedTokens stays the
+    // active network's list, so nothing that reads it changes: the outgoing
+    // list is put away under its network, and the incoming network's list, or
+    // an empty one, takes its place.
+    if (!s.networkTrackedTokens) s.networkTrackedTokens = {};
+    s.networkTrackedTokens[s.networkId] = s.trackedTokens;
+    s.trackedTokens = s.networkTrackedTokens[net.id] || [];
+
     s.networkId = net.id;
     s.rpcUrl = remembered.rpcUrl || net.defaultRpcUrl;
     s.blockscoutUrl = remembered.blockscoutUrl || net.defaultBlockscoutUrl;

src/shared/etherscanLabels.js

@@ -2,6 +2,8 @@
 // Extension users make the requests directly to Etherscan — no proxy needed.
 // This is a best-effort enrichment: network failures return null silently.
 
+const { networkByChainId } = require("./networks");
+
 // Patterns in the page title that indicate a flagged address.
 // Title format: "Fake_Phishing184810 | Address: 0x... | Etherscan"
 const PHISHING_LABEL_PATTERNS = [/^Fake_Phishing/i, /^Phish:/i, /^Exploiter/i];
@@ -72,18 +74,21 @@ function parseEtherscanPage(html) {
  * Returns a warning object if the address is flagged, or null.
  * Network failures return null silently (best-effort check).
  *
- * Uses the current network's explorer URL so the lookup works on both
- * mainnet (etherscan.io) and Sepolia (sepolia.etherscan.io).
+ * Uses the explorer of the network with `chainId`, or of the active network
+ * when it is omitted: etherscan.io on mainnet, sepolia.etherscan.io on
+ * Sepolia.
  *
  * @param {string} address - Ethereum address to check.
+ * @param {string} [chainId] - Chain id of the network to look it up on.
  * @returns {Promise<{type: string, message: string, severity: string}|null>}
  */
-async function checkEtherscanLabel(address) {
+async function checkEtherscanLabel(address, chainId) {
     try {
         // Lazy require to avoid pulling in chrome.storage at module scope
         // (which breaks unit tests that only exercise parseEtherscanPage).
         const { currentNetwork } = require("./state");
-        const etherscanBase = currentNetwork().explorerUrl + "/address/";
+        const network = chainId ? networkByChainId(chainId) : currentNetwork();
+        const etherscanBase = network.explorerUrl + "/address/";
         const resp = await fetch(etherscanBase + address, {
             headers: { Accept: "text/html" },
         });

src/shared/persistedState.js

@@ -23,6 +23,11 @@ const DEFAULT_STATE = {
     hasWallet: false,
     wallets: [],
     trackedTokens: [],
+    // Tracked tokens remembered per network: { [networkId]: [token, ...] }.
+    // trackedTokens above is the active network's list; this is what the
+    // others are restored from when the active network changes. See
+    // applyChainSwitchFields().
+    networkTrackedTokens: {},
     networkId: "mainnet",
     rpcUrl: DEFAULT_RPC_URL,
     blockscoutUrl: DEFAULT_BLOCKSCOUT_URL,
@@ -289,6 +294,20 @@ function normalizePersisted(saved) {
     // profile whose wallets are perfectly fine. An empty list is a legitimate
     // value and survives.
     out.trackedTokens = structuredClone(tokenRefs(saved.trackedTokens));
+    // Each remembered list is floored like trackedTokens, because
+    // applyChainSwitchFields() puts it straight back onto trackedTokens when
+    // its network becomes the active one. A key that is not a network in
+    // networks.js is dropped, which also keeps an own "__proto__" key from
+    // reaching the plain assignment below.
+    out.networkTrackedTokens = {};
+    if (isRecord(saved.networkTrackedTokens)) {
+        for (const netId of Object.keys(saved.networkTrackedTokens)) {
+            if (!isKnownNetworkId(netId)) continue;
+            out.networkTrackedTokens[netId] = structuredClone(
+                tokenRefs(saved.networkTrackedTokens[netId]),
+            );
+        }
+    }
     // The loud refusal for an unknown id is assertStateUsable(); this is the
     // floor under it. networkId is an object KEY into networkEndpoints below,
     // so a value that is not a network in networks.js must never get that far

src/shared/prices.js

@@ -2,6 +2,7 @@
 
 const { getTopTokenPrices } = require("./tokenList");
 const { isBelowOneMillionth } = require("./amountDisplay");
+const { networkByChainId } = require("./networks");
 
 const PRICE_CACHE_TTL = 300000; // 5 minutes
 
@@ -36,10 +37,13 @@ function clearPrices() {
     lastFetchedAt = 0;
 }
 
-// Return the USD price for a symbol, or null on testnet / unknown.
-function getPrice(symbol) {
+// Return the USD price for a symbol on the network with `chainId`, or on the
+// active network when no chain id is given; null on testnet, on a chain id
+// that names no network, or for a symbol with no price.
+function getPrice(symbol, chainId) {
     const { currentNetwork } = require("./state");
-    if (currentNetwork().isTestnet) return null;
+    const network = chainId ? networkByChainId(chainId) : currentNetwork();
+    if (!network || network.isTestnet) return null;
     return prices[symbol] || null;
 }
 

src/shared/state.js

@@ -42,9 +42,11 @@ const { log } = require("./log");
 // and writes THIS object, never the proxy: the guard is for callers.
 const rawState = {
     ...DEFAULT_STATE,
-    // Its own object, not the one DEFAULT_STATE holds: applyChainSwitchFields()
-    // mutates this map in place, and a spread copies the reference.
+    // Their own objects, not the ones DEFAULT_STATE holds:
+    // applyChainSwitchFields() mutates these maps in place, and a spread copies
+    // the reference.
     networkEndpoints: {},
+    networkTrackedTokens: {},
     currentView: null,
     selectedWallet: null,
     selectedAddress: null,
@@ -438,12 +440,14 @@ function mergeNetworkEndpoints(base, ours, theirs) {
 //
 // Every other persisted field stays a whole-field diff:
 // `trackedTokens`/`fraudContracts`/`viewStack` are arrays of scalars with no
-// per-element identity to merge by; `tokenHolderCache` is a map shaped like
-// the ones above, but nothing in src/ ever writes an entry into it — it is
-// only ever reset wholesale to `{}` (applyChainSwitchFields()) — so there is
-// no in-place mutation for a whole-field diff to collide with; `viewData` is
-// this page's own UI scratch space, not data another page has any reason to
-// share membership of.
+// per-element identity to merge by; `networkTrackedTokens` is diffed whole like
+// `trackedTokens` and `networkId`, the two fields a network switch moves
+// together with it; `tokenHolderCache` is a map shaped like the ones above,
+// but nothing in src/ ever writes an entry into it — it is only ever reset
+// wholesale to `{}` (applyChainSwitchFields()) — so there is no in-place
+// mutation for a whole-field diff to collide with; `viewData` is this page's
+// own UI scratch space, not data another page has any reason to share
+// membership of.
 //
 // This does not make two pages that both change the SAME leaf concurrently
 // safe: last write wins on that one leaf, same as before. What it removes

src/shared/transactions.js

@@ -20,6 +20,7 @@ const { toDecimals } = require("./transferAmount");
 // truncation without the approval screens' nonzero floor: the transaction
 // detail view is the authoritative record and already shows exact precision.
 const { truncateAmount: formatTxValue } = require("./amountDisplay");
+const { routerRelease } = require("./uniswap");
 
 // Ethereum addresses are case-insensitive: EIP-55 mixed case is a checksum
 // over the address, not part of its identity.  Every address comparison in
@@ -51,7 +52,6 @@ function parseTx(tx, addrLower, chainId) {
         }
         // Map known DEX methods to "Swap" for cleaner display
         const SWAP_METHODS = new Set([
-            "execute",
             "swap",
             "swapExactTokensForTokens",
             "swapTokensForExactTokens",
@@ -59,9 +59,16 @@ function parseTx(tx, addrLower, chainId) {
             "swapTokensForExactETH",
             "swapExactTokensForETH",
             "swapETHForExactTokens",
-            "multicall",
         ]);
-        const label = SWAP_METHODS.has(method)
+        // Multisigs, smart accounts and many other contracts also have an
+        // `execute` or `multicall` method, so either is a swap only when sent
+        // to a Universal Router on this transaction's network: the same
+        // addresses the approval screen decodes a swap for.
+        const isSwap =
+            SWAP_METHODS.has(method) ||
+            ((method === "execute" || method === "multicall") &&
+                routerRelease(to, chainId) !== null);
+        const label = isSwap
             ? "Swap"
             : method.charAt(0).toUpperCase() + method.slice(1);
         direction = "contract";

src/shared/transferAmount.js

@@ -2,11 +2,11 @@
 // encoded with.
 //
 // A token amount is a decimal string plus a scale, and the two come from
-// different places. The confirmation screen renders the amount, the balance and
-// the symbol from the block explorer's cached metadata (see
-// fetchTokenBalances() in balances.js); the transfer used to be encoded from
-// decimals() read off the contract at signing time, and nothing compared the
-// two. A token whose on-chain scale differs from the cached one — an
+// different places. The confirmation screen renders the amount, the symbol and
+// the balance it reads from the node with the block explorer's cached metadata
+// (see fetchTokenBalances() in balances.js); the transfer used to be encoded
+// from decimals() read off the contract at signing time, and nothing compared
+// the two. A token whose on-chain scale differs from the cached one — an
 // upgradeable or proxy token, a caller-dependent one, a stale or wrong explorer
 // entry — therefore signed an amount that was never displayed, off by a power
 // of ten for every decimal place of disagreement.

src/shared/txValidation.js

@@ -111,8 +111,8 @@ function isValidAmount(amount, tokenDecimals = null) {
 
 // The most ETH a send can carry: the exact balance minus the fee reserve from
 // feeReserveWei(), as a decimal string, so validateTransfer() passes it with
-// exactly that reserve left behind. `ethBalance` is the exact decimal string
-// balances.js stores, never a rounded one. Null when the balance does not
+// exactly that reserve left behind. `ethBalance` is an exact decimal string as
+// formatEther() writes it, never a rounded one. Null when the balance does not
 // leave anything to send once the fee is paid, or when either input is
 // unusable.
 function maxEthAmount(ethBalance, feeWei) {

src/shared/walletDelete.js

@@ -14,7 +14,7 @@ function sameAddress(a, b) {
 
 // Forget every site permission held against the given addresses: the
 // remembered ones in `state`, and the connections approved without
-// "Remember", which only the background holds, in memory.
+// "Remember", which only the background holds, in session storage.
 function dropSitePermissions(state, addresses) {
     for (const addr of addresses) {
         delete state.allowedSites[addr];

tests/accountsChangedOpaqueOrigin.test.js

@@ -0,0 +1,167 @@
+// A page whose origin has no host is never told an address by accountsChanged
+// (https://git.eeqj.de/sneak/AutistMask/issues/564).
+//
+// When the user switches address, the background tells each open tab the new
+// active address if the site at the tab's URL is connected. A page at a
+// connected site's URL can still have another origin: one its server
+// sandboxes with a Content-Security-Policy has the origin "null", and every
+// request it makes is refused. Each test here switches the address in the real
+// background, takes the event it sent to a tab at the site's URL, and hands
+// that event to the real content script in a page of the given origin.
+
+const { networkById } = require("../src/shared/networks");
+const { makeStorageStub } = require("./support/storageStub");
+
+const ADDRESS = "0x66133E8ea0f5D1d612D2502a968757D1048c214a";
+const SITE = "https://dapp.example";
+
+const EXT_URL = "chrome-extension://autistmask/";
+const FROM_POPUP = { url: EXT_URL + "src/popup/index.html" };
+
+// One address, with SITE remembered as allowed for it.
+function storedProfile() {
+    const mainnet = networkById("mainnet");
+    return {
+        hasWallet: true,
+        wallets: [
+            {
+                name: "Wallet 1",
+                type: "hd",
+                addresses: [
+                    { address: ADDRESS, balance: "0", tokenBalances: [] },
+                ],
+            },
+        ],
+        activeAddress: ADDRESS,
+        networkId: "mainnet",
+        rpcUrl: mainnet.defaultRpcUrl,
+        blockscoutUrl: mainnet.defaultBlockscoutUrl,
+        allowedSites: { [ADDRESS]: [SITE] },
+        deniedSites: {},
+        trackedTokens: [],
+    };
+}
+
+async function settle() {
+    for (let i = 0; i < 50; i++) await Promise.resolve();
+}
+
+afterEach(() => {
+    delete global.chrome;
+    delete global.window;
+    jest.resetModules();
+});
+
+// The popup tells the background the active address changed, and the one
+// open tab, at SITE's URL, is sent an event. That event is returned.
+async function eventSentToSiteTab() {
+    jest.resetModules();
+    jest.doMock("../src/shared/balances", () => ({
+        getProvider: () => ({}),
+        refreshBalances: jest.fn(async () => {}),
+    }));
+    jest.doMock("../src/shared/phishingDomains", () => ({
+        isPhishingDomain: () => false,
+    }));
+    jest.doMock("../src/shared/alarms", () => ({
+        BALANCE_REFRESH_ALARM: "balance",
+        BALANCE_REFRESH_PERIOD_MINUTES: 1,
+        ensureRecurringAlarms: jest.fn(async () => {}),
+        registerAlarmHandlers: jest.fn(),
+    }));
+
+    let messageListener = null;
+    const sentToTabs = [];
+    global.chrome = {
+        storage: makeStorageStub({ autistmask: storedProfile() }),
+        runtime: {
+            getURL: (path) => EXT_URL + path,
+            onMessage: {
+                addListener: (fn) => {
+                    messageListener = fn;
+                },
+            },
+            onConnect: { addListener: () => {} },
+            getPlatformInfo: (cb) => cb({ os: "linux" }),
+            lastError: null,
+        },
+        windows: {
+            remove: (id, cb) => {
+                if (cb) cb();
+            },
+            onRemoved: { addListener: () => {} },
+        },
+        tabs: {
+            query: (q, cb) => cb([{ id: 1, url: SITE + "/app" }]),
+            sendMessage: (tabId, msg, cb) => {
+                sentToTabs.push(msg);
+                if (cb) cb();
+            },
+        },
+        action: { setPopup: () => {} },
+    };
+
+    require("../src/background/index");
+    messageListener(
+        { type: "AUTISTMASK_ACTIVE_CHANGED" },
+        FROM_POPUP,
+        () => {},
+    );
+    await settle();
+
+    expect(sentToTabs).toHaveLength(1);
+    return sentToTabs[0];
+}
+
+// The content script in a page whose origin is `pageOrigin` is handed `event`
+// from the background. What it posts to the page is returned.
+function postedToPage(event, pageOrigin) {
+    jest.resetModules();
+    let eventListener = null;
+    const posted = [];
+    global.chrome = {
+        runtime: {
+            onMessage: {
+                addListener: (fn) => {
+                    eventListener = fn;
+                },
+            },
+        },
+    };
+    global.window = {
+        origin: pageOrigin,
+        addEventListener: () => {},
+        postMessage: (data) => posted.push(data),
+    };
+
+    require("../src/content/index");
+    eventListener(event);
+
+    return posted;
+}
+
+describe("accountsChanged after an address switch, at a connected site's URL", () => {
+    test("the site's own page is told the active address", async () => {
+        const event = await eventSentToSiteTab();
+
+        expect(postedToPage(event, SITE)).toEqual([
+            {
+                type: "AUTISTMASK_EVENT",
+                eventName: "accountsChanged",
+                data: [ADDRESS],
+            },
+        ]);
+    });
+
+    test("a page whose origin has no host is told no address", async () => {
+        const event = await eventSentToSiteTab();
+
+        expect(postedToPage(event, "null")).toEqual([
+            {
+                type: "AUTISTMASK_EVENT",
+                eventName: "accountsChanged",
+                data: [],
+            },
+        ]);
+    });
+});

tests/addressKey.test.js

@@ -230,7 +230,7 @@ beforeEach(() => {
 
     addWallet.init({
         renderWalletList: () => {},
-        doRefreshAndRender: () => {},
+        startRefresh: () => {},
         pageClosed: new AbortController().signal,
     });
     confirmTx.init({});
@@ -291,7 +291,6 @@ async function confirmSend(from, selected) {
         to: RECIPIENT,
         amount: "0.5",
         token: "ETH",
-        balance: "1.0",
     });
     await settle();
     node("confirm-tx-password").value = PASSWORD;
@@ -443,11 +442,25 @@ describe("a confirmation screen whose From is not the selected address", () => {
         expect(Transaction.from(signed).from).toBe(derived(1).address);
     });
 
+    // The refusal's sentence is fixed in index.html, in a box of its own that
+    // holds its space from the first paint, so showing it moves nothing.
     test("nothing is sent when the selected wallet does not hold it", async () => {
         expect(await confirmSend(derived(5).address, 0)).toBeUndefined();
-        expect(node("confirm-tx-password-error").textContent).toBe(
-            "The selected wallet does not hold the From address above, " +
-                "so nothing was sent. Please go back and send again.",
+        expect(node("confirm-from-address-error").style.visibility).toBe(
+            "visible",
+        );
+        expect(node("confirm-tx-password-error").textContent).toBe("");
+
+        // Reviewing a send again draws the screen again, which hides it.
+        confirmTx.show({
+            from: derived(0).address,
+            to: RECIPIENT,
+            amount: "0.5",
+            token: "ETH",
+        });
+        await settle();
+        expect(node("confirm-from-address-error").style.visibility).toBe(
+            "hidden",
         );
     });
 });

tests/addressScanCancelled.test.js

@@ -94,7 +94,7 @@ describe.each([
     async function create(pageClosed) {
         addWallet.init({
             renderWalletList: () => {},
-            doRefreshAndRender: () => {},
+            startRefresh: () => {},
             pageClosed,
         });
         element("tab-" + mode).listeners.click();

tests/addressWarnings.test.js

@@ -0,0 +1,39 @@
+// The confirmation screen's warning for a recipient that has never sent a
+// transaction (https://git.eeqj.de/sneak/AutistMask/issues/528).
+//
+// The node's transaction count for an address is the number of transactions
+// it has sent, so an address that only ever receives, such as a savings
+// address or an exchange deposit address, has a count of zero. The warning
+// used to fire on that count alone. It now also needs a zero balance: ETH an
+// address received stays in its balance until it sends a transaction.
+
+"use strict";
+
+const { getFullWarnings } = require("../src/shared/addressWarnings");
+
+global.fetch = jest.fn(async () => {
+    throw new Error("tests must not perform network requests");
+});
+
+const RECIPIENT = "0x" + "b".repeat(40);
+
+// The warning types getFullWarnings() returns for RECIPIENT when the node
+// reports it as a regular address with `txCount` sent transactions and a
+// balance of `balance` wei.
+async function warningTypes(txCount, balance) {
+    const provider = {
+        getCode: async () => "0x",
+        getTransactionCount: async () => txCount,
+        getBalance: async () => balance,
+    };
+    const warnings = await getFullWarnings(RECIPIENT, provider);
+    return warnings.map((w) => w.type);
+}
+
+test("a recipient that has received 0.5 ETH and never sent a transaction gets no warning", async () => {
+    expect(await warningTypes(0, 500000000000000000n)).toEqual([]);
+});
+
+test("a recipient that has never sent a transaction and holds no ETH gets the warning", async () => {
+    expect(await warningTypes(0, 0n)).toEqual(["new-address"]);
+});

tests/approvalDisplayFloor.test.js

@@ -68,7 +68,14 @@ function swapData(amountIn, amountOutMin) {
 }
 
 function swapDetail(amountIn, amountOutMin, label) {
-    const decoded = uniswap.decode(swapData(amountIn, amountOutMin), ROUTER);
+    // Sent by the address the swap pays, so the output is the user's.
+    const decoded = uniswap.decode(
+        swapData(amountIn, amountOutMin),
+        ROUTER,
+        "0x1",
+        {},
+        RECIPIENT,
+    );
     return decoded.details.find((d) => d.label === label);
 }
 

tests/approvalTokenNetwork.test.js

@@ -0,0 +1,270 @@
+// The approval screen for a site's Sepolia token transfer while Ethereum
+// Mainnet is active.
+//
+// The screen named the token, and scaled its amount, from the active network's
+// tracked tokens and balances, so a token the wallet tracks on Sepolia read as
+// an unknown token with its amount in base units, and the screens after it
+// labelled the amount `?` (https://git.eeqj.de/sneak/AutistMask/issues/629).
+// It now uses what the wallet knows of the tokens on the network the
+// transaction is for.
+//
+// Its address links opened the active network's explorer
+// (https://git.eeqj.de/sneak/AutistMask/issues/631). They now open the
+// explorer of the network the transaction is for.
+//
+// Driven through the real approval screen, password and Confirm included,
+// against a minimal DOM stub in the shape tests/swapStatusAmount.test.js uses.
+// The vault is mocked so that no password has to be hashed.
+
+jest.mock("../src/shared/vault", () => ({
+    decryptWithPassword: jest.fn(),
+}));
+
+globalThis.chrome = {
+    storage: { local: { get: async () => ({}), set: async () => {} } },
+};
+
+const { Interface } = require("ethers");
+const { state } = require("../src/shared/state");
+const { NETWORKS } = require("../src/shared/networks");
+const { decryptWithPassword } = require("../src/shared/vault");
+const approval = require("../src/popup/views/approval");
+const txStatus = require("../src/popup/views/txStatus");
+
+// A well-known test phrase, and its first address.
+const PHRASE = "test test test test test test test test test test test junk";
+const FROM = "0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266";
+const RECIPIENT = "0x711e691962E5c054b78071C789A0C8CE657377aD";
+// A token the bundled token list does not name.
+const TOKEN = "0x74de5d4FCbf63E00296fd95d33236B9794016631";
+
+// FROM sends 1234.5 of the 6-decimal token to RECIPIENT.
+const TRANSFER_DATA = new Interface([
+    "function transfer(address to, uint256 amount)",
+]).encodeFunctionData("transfer", [RECIPIENT, 1234500000n]);
+
+function makeElement(id) {
+    const classes = new Set();
+    const el = {
+        id,
+        textContent: "",
+        value: "",
+        innerHTML: "",
+        disabled: false,
+        style: {},
+        dataset: {},
+        listeners: {},
+        classList: {
+            add: (...names) => names.forEach((n) => classes.add(n)),
+            remove: (...names) => names.forEach((n) => classes.delete(n)),
+            contains: (n) => classes.has(n),
+            toggle: (n, force) => {
+                const on = force === undefined ? !classes.has(n) : force;
+                if (on) classes.add(n);
+                else classes.delete(n);
+                return on;
+            },
+        },
+        addEventListener: (name, fn) => {
+            el.listeners[name] = el.listeners[name] || [];
+            el.listeners[name].push(fn);
+        },
+        querySelectorAll: () => [],
+        appendChild: () => {},
+    };
+    // Views reach for .parentElement to hide whole sections.
+    Object.defineProperty(el, "parentElement", {
+        get: () => node(id + "-parent"),
+    });
+    return el;
+}
+
+function makeDocument() {
+    const els = new Map();
+    return {
+        getElementById(id) {
+            // The debug banner is created on demand by helpers.js; absent
+            // is the state a non-debug, non-testnet popup is in.
+            if (id === "debug-banner") return null;
+            if (!els.has(id)) els.set(id, makeElement(id));
+            return els.get(id);
+        },
+        createElement: () => makeElement("created"),
+        body: { prepend: () => {} },
+    };
+}
+
+function node(id) {
+    return globalThis.document.getElementById(id);
+}
+
+function click(id) {
+    return Promise.all((node(id).listeners.click || []).map((fn) => fn()));
+}
+
+// One line of the decoded details: its label and what is drawn under it.
+function decodedLine(label) {
+    return node("approve-tx-decoded-details")
+        .innerHTML.split('<div class="mb-2">')
+        .find((line) =>
+            line.startsWith(`<div class="text-muted">${label}</div>`),
+        );
+}
+
+// Open the approval screen, with Ethereum Mainnet active and FROM holding
+// `tokenBalances` there, for the site's transaction sending TRANSFER_DATA to
+// the token, on Sepolia unless `chainId` names another chain. Confirm answers
+// the signed transaction with a failure, which leads to the error screen.
+async function showTokenTransfer(
+    tokenBalances = [],
+    chainId = NETWORKS.sepolia.chainId,
+) {
+    globalThis.document = makeDocument();
+    globalThis.window = { location: { search: "" }, close: () => {} };
+    globalThis.chrome.runtime = {
+        connect: () => ({ postMessage: () => {} }),
+        sendMessage: (msg, reply) => {
+            if (!reply) return;
+            if (msg.type !== "AUTISTMASK_GET_APPROVAL") {
+                return reply({
+                    error: "The transaction could not be sent.",
+                    retryable: false,
+                });
+            }
+            reply({
+                type: "tx",
+                origin: "https://dapp.example",
+                isPhishingDomain: false,
+                approvedFrom: FROM,
+                approvedTx: {
+                    type: 2,
+                    from: FROM,
+                    chainId,
+                    nonce: "0x7",
+                    gasLimit: "0x30d40",
+                    maxPriorityFeePerGas: "0x3b9aca00",
+                    maxFeePerGas: "0x77359400",
+                    to: TOKEN,
+                    value: "0x0",
+                    data: TRANSFER_DATA,
+                    accessList: [],
+                },
+            });
+        },
+    };
+    state.networkId = "mainnet";
+    state.activeAddress = FROM;
+    state.wallets = [
+        {
+            type: "hd",
+            name: "Wallet 1",
+            xpub: "xpub-wallet-1",
+            encryptedSecret: "encrypted-secret-1",
+            nextIndex: 1,
+            addresses: [
+                { address: FROM, index: 0, balance: "0", tokenBalances },
+            ],
+        },
+    ];
+    state.currentView = null;
+    txStatus.init({ doRefreshAndRender: () => {} });
+    approval.init({});
+    await approval.show(1);
+}
+
+async function confirm() {
+    decryptWithPassword.mockResolvedValue(PHRASE);
+    node("approve-tx-password").value = "any password";
+    await click("btn-approve-tx");
+}
+
+beforeEach(() => {
+    state.trackedTokens = [];
+    state.networkTrackedTokens = {};
+});
+
+describe("a token tracked on Sepolia only", () => {
+    beforeEach(() => {
+        state.networkTrackedTokens = {
+            sepolia: [{ address: TOKEN, symbol: "TDOL", decimals: 6 }],
+        };
+    });
+
+    test("is named on the Contract line and the decoded Token line, with its amount at its scale", async () => {
+        await showTokenTransfer();
+        expect(node("approve-tx-to").innerHTML).toContain(
+            '<div class="font-bold mb-1">TDOL</div>',
+        );
+        expect(decodedLine("Token")).toContain(
+            '<div class="font-bold">TDOL</div>',
+        );
+        expect(decodedLine("Amount")).toContain(
+            '<div class="font-bold">1234.5000 TDOL</div>',
+        );
+    });
+
+    test("labels the amount on the error screen that follows", async () => {
+        await showTokenTransfer();
+        await confirm();
+        expect(state.currentView).toBe("error-tx");
+        expect(node("error-tx-summary").textContent).toBe("1234.5000 TDOL");
+    });
+});
+
+// The same contract address on mainnet is another token, so what the wallet
+// tracks and holds there names nothing on Sepolia.
+test("a token tracked and held on mainnet only is not named, and its amount is in base units", async () => {
+    state.trackedTokens = [{ address: TOKEN, symbol: "MDOL", decimals: 18 }];
+    await showTokenTransfer([
+        { address: TOKEN, symbol: "MDOL", decimals: 18, balance: "1.0" },
+    ]);
+    expect(node("approve-tx-to").innerHTML).not.toContain("MDOL");
+    expect(decodedLine("Token")).toContain(
+        '<div class="font-bold">Unknown token</div>',
+    );
+    expect(decodedLine("Amount")).toContain(
+        '<div class="font-bold">1234500000 base units (decimals unknown)</div>',
+    );
+});
+
+// The From and Contract lines, and the decoded Token and Recipient lines.
+test("every address links to the Sepolia explorer", async () => {
+    await showTokenTransfer();
+    const sepolia = NETWORKS.sepolia.explorerUrl;
+    expect(node("approve-tx-from").innerHTML).toContain(
+        `href="${sepolia}/address/${FROM}"`,
+    );
+    expect(node("approve-tx-to").innerHTML).toContain(
+        `href="${sepolia}/address/${TOKEN}"`,
+    );
+    expect(decodedLine("Token")).toContain(
+        `href="${sepolia}/address/${TOKEN}"`,
+    );
+    expect(decodedLine("Recipient")).toContain(
+        `href="${sepolia}/address/${RECIPIENT}"`,
+    );
+    for (const id of [
+        "approve-tx-from",
+        "approve-tx-to",
+        "approve-tx-decoded-details",
+    ]) {
+        expect(node(id).innerHTML).not.toContain(NETWORKS.mainnet.explorerUrl);
+    }
+});
+
+// Chain id 1337 names no network here, so it has no explorer to link to.
+test("a transaction on a chain id that names no network is shown with no address links", async () => {
+    await showTokenTransfer([], "0x539");
+    expect(state.currentView).toBe("approve-tx");
+    expect(node("approve-tx-network").textContent).toBe(
+        "Unknown network (chain id 1337)",
+    );
+    expect(node("approve-tx-from").innerHTML).toContain(FROM);
+    for (const id of [
+        "approve-tx-from",
+        "approve-tx-to",
+        "approve-tx-decoded-details",
+    ]) {
+        expect(node(id).innerHTML).not.toContain("href=");
+    }
+});

tests/approvalValueUsd.test.js

@@ -0,0 +1,192 @@
+// The USD value on the approval screen's Value and Network fee lines, for a
+// site's ETH send.
+//
+// It was worked out from the four-decimal figure the line shows, at the price
+// on the active network, so the same value read a few cents different here than
+// on the confirmation screen, which prices the exact amount at the price on the
+// transaction's own network, and a transaction on another network than the
+// active one was priced at the active one's rate, its fee too
+// (https://git.eeqj.de/sneak/AutistMask/issues/614).
+//
+// Driven through the real approval screen, against a minimal DOM stub in the
+// shape tests/approvalTokenNetwork.test.js uses.
+
+globalThis.chrome = {
+    storage: { local: { get: async () => ({}), set: async () => {} } },
+};
+
+const { state } = require("../src/shared/state");
+const { NETWORKS } = require("../src/shared/networks");
+const { prices, clearPrices } = require("../src/shared/prices");
+const approval = require("../src/popup/views/approval");
+
+const FROM = "0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266";
+const RECIPIENT = "0x711e691962E5c054b78071C789A0C8CE657377aD";
+
+function makeElement(id) {
+    const classes = new Set();
+    const el = {
+        id,
+        textContent: "",
+        value: "",
+        innerHTML: "",
+        disabled: false,
+        style: {},
+        dataset: {},
+        listeners: {},
+        classList: {
+            add: (...names) => names.forEach((n) => classes.add(n)),
+            remove: (...names) => names.forEach((n) => classes.delete(n)),
+            contains: (n) => classes.has(n),
+            toggle: (n, force) => {
+                const on = force === undefined ? !classes.has(n) : force;
+                if (on) classes.add(n);
+                else classes.delete(n);
+                return on;
+            },
+        },
+        addEventListener: (name, fn) => {
+            el.listeners[name] = el.listeners[name] || [];
+            el.listeners[name].push(fn);
+        },
+        querySelectorAll: () => [],
+        appendChild: () => {},
+    };
+    // Views reach for .parentElement to hide whole sections.
+    Object.defineProperty(el, "parentElement", {
+        get: () => node(id + "-parent"),
+    });
+    return el;
+}
+
+function makeDocument() {
+    const els = new Map();
+    return {
+        getElementById(id) {
+            // The debug banner is created on demand by helpers.js; absent
+            // is the state a non-debug, non-testnet popup is in.
+            if (id === "debug-banner") return null;
+            if (!els.has(id)) els.set(id, makeElement(id));
+            return els.get(id);
+        },
+        createElement: () => makeElement("created"),
+        body: { prepend: () => {} },
+    };
+}
+
+function node(id) {
+    return globalThis.document.getElementById(id);
+}
+
+// Open the approval screen, with the network `networkId` active, for the
+// site's transaction sending 1.23414 ETH to RECIPIENT on the chain `chainId`.
+async function showEthSend(chainId, networkId) {
+    globalThis.document = makeDocument();
+    globalThis.window = { location: { search: "" }, close: () => {} };
+    globalThis.chrome.runtime = {
+        connect: () => ({ postMessage: () => {} }),
+        sendMessage: (msg, reply) => {
+            if (!reply) return;
+            reply({
+                type: "tx",
+                origin: "https://dapp.example",
+                isPhishingDomain: false,
+                approvedFrom: FROM,
+                approvedTx: {
+                    type: 2,
+                    from: FROM,
+                    chainId,
+                    nonce: "0x7",
+                    gasLimit: "0x5208",
+                    maxPriorityFeePerGas: "0x3b9aca00",
+                    maxFeePerGas: "0x77359400",
+                    to: RECIPIENT,
+                    value: "1234140000000000000",
+                    data: "0x",
+                    accessList: [],
+                },
+            });
+        },
+    };
+    state.networkId = networkId;
+    state.activeAddress = FROM;
+    state.wallets = [
+        {
+            type: "hd",
+            name: "Wallet 1",
+            xpub: "xpub-wallet-1",
+            encryptedSecret: "encrypted-secret-1",
+            nextIndex: 1,
+            addresses: [{ address: FROM, index: 0, balance: "0" }],
+        },
+    ];
+    state.trackedTokens = [];
+    state.networkTrackedTokens = {};
+    state.currentView = null;
+    approval.init({});
+    await approval.show(1);
+}
+
+beforeEach(() => {
+    prices.ETH = 2000;
+});
+
+afterEach(() => {
+    clearPrices();
+});
+
+// 1.23414 ETH reads 1.2341 ETH. At $2,000 the exact value is $2,468.28, the
+// figure the confirmation screen shows for it; the shown figure would be
+// $2,468.20.
+test.each([
+    [
+        "a mainnet transaction is priced from its exact value",
+        NETWORKS.mainnet.chainId,
+        "mainnet",
+        "1.2341 ETH ($2,468.28)",
+    ],
+    [
+        "a mainnet transaction shown with Sepolia active is priced at the mainnet price",
+        NETWORKS.mainnet.chainId,
+        "sepolia",
+        "1.2341 ETH ($2,468.28)",
+    ],
+    [
+        "a Sepolia transaction shown with mainnet active has no USD value",
+        NETWORKS.sepolia.chainId,
+        "mainnet",
+        "1.2341 SepoliaETH",
+    ],
+    // Chain id 1337 names no network here, so nothing knows its price.
+    [
+        "a transaction on a chain id that names no network has no USD value",
+        "0x539",
+        "mainnet",
+        "1.2341 ETH",
+    ],
+])("%s", async (_label, chainId, networkId, expected) => {
+    await showEthSend(chainId, networkId);
+    expect(state.currentView).toBe("approve-tx");
+    expect(node("approve-tx-value").textContent).toBe(expected);
+});
+
+// The Network fee line is priced on the transaction's network too. 21000 gas at
+// up to 2 gwei is 0.000042 ETH, $0.08 at $2,000.
+test.each([
+    [
+        "the fee of a mainnet transaction shown with Sepolia active is priced at the mainnet price",
+        NETWORKS.mainnet.chainId,
+        "sepolia",
+        "0.00004 ETH ($0.08)",
+    ],
+    [
+        "the fee of a Sepolia transaction shown with mainnet active has no USD value",
+        NETWORKS.sepolia.chainId,
+        "mainnet",
+        "0.00004 SepoliaETH",
+    ],
+])("%s", async (_label, chainId, networkId, expected) => {
+    await showEthSend(chainId, networkId);
+    expect(state.currentView).toBe("approve-tx");
+    expect(node("approve-tx-fee").textContent).toBe(expected);
+});

tests/backNavigation.test.js

@@ -154,7 +154,14 @@ describe("Back onto a view the reopened popup never rendered", () => {
 
     test("Back onto the transaction detail renders it", () => {
         reopenedOn("settings", ["main", "transaction"], {
-            viewData: { tx: { hash: "0xdead", from: ADDRESS, to: ADDRESS } },
+            viewData: {
+                tx: {
+                    hash: "0xdead",
+                    from: ADDRESS,
+                    to: ADDRESS,
+                    chainId: "0x1",
+                },
+            },
         });
         goBack();
         expect(calls).toEqual(["transactionDetail"]);

tests/backgroundApproval.test.js

@@ -321,9 +321,10 @@ function loadBackground(options) {
     require("../src/background/index");
 
     // Send a message the way the browser would, and hand back whatever the
-    // handler passed to sendResponse.
-    function send(msg, sender) {
-        const sendResponse = jest.fn();
+    // handler passed to sendResponse. `onResponse`, when given, receives the
+    // answer when the handler sends it, as the sender's callback does.
+    function send(msg, sender, onResponse) {
+        const sendResponse = jest.fn(onResponse);
         const kept = messageListener(msg, sender || {}, sendResponse);
         return { sendResponse, kept };
     }
@@ -2615,9 +2616,9 @@ async function siteAccounts(bg, origin) {
     return sendResponse.mock.calls[0][0];
 }
 
-// A site connected without "Remember" is held only in the background's memory,
-// keyed to the address it was connected to. Removing that address, or the
-// wallet holding it, must end the connection as part of the removal itself.
+// A site connected without "Remember" is held only in the background's session
+// storage, keyed to the address it was connected to. Removing that address, or
+// the wallet holding it, must end the connection as part of the removal itself.
 // The accountsChanged broadcast the views send afterwards also clears it, but
 // only when the active address moved, and nothing waits for it to arrive.
 //
@@ -2796,8 +2797,7 @@ describe("removing a site in Settings disconnects it", () => {
         const element = (id) => (lists[id] ||= fakeSiteList());
         global.document = { getElementById: element };
         global.chrome.runtime.sendMessage = (msg, callback) => {
-            const { sendResponse } = bg.send(msg, bg.fromPopup);
-            if (callback) callback(sendResponse.mock.calls[0]?.[0]);
+            bg.send(msg, bg.fromPopup, callback);
         };
         await require("../src/shared/state").loadState();
         await require("../src/popup/views/settings").renderSiteLists();

tests/coldWorkerChainSwitch.test.js

@@ -204,17 +204,21 @@ describe("a chain switch on a worker that never loaded state", () => {
         expect(after.rpcUrl).toBe(SEPOLIA.defaultRpcUrl);
 
         // And it took nothing else with it. Without the load these come back
-        // as [], {}, [] and "system" from DEFAULT_STATE — every wallet in the
+        // as [], {}, {} and "system" from DEFAULT_STATE — every wallet in the
         // extension gone, encrypted secrets included.
         expect(after.wallets).toEqual(walletFixture());
         expect(after.hasWallet).toBe(true);
         expect(after.activeAddress).toBe(ADDRESS);
         expect(after.allowedSites).toEqual({ [ADDRESS]: [CONNECTED_ORIGIN] });
-        expect(after.trackedTokens).toEqual([
-            { address: TOKEN, symbol: "DAI", decimals: 18 },
-        ]);
+        expect(after.networkTrackedTokens).toEqual({
+            mainnet: [{ address: TOKEN, symbol: "DAI", decimals: 18 }],
+        });
         expect(after.theme).toBe("dark");
 
+        // The mainnet token is tracked on mainnet only: Sepolia starts with
+        // none of its own.
+        expect(after.trackedTokens).toEqual([]);
+
         // The user's mainnet endpoint is remembered rather than replaced by
         // the public default, so switching back returns it.
         expect(after.networkEndpoints.mainnet).toEqual({
@@ -226,6 +230,9 @@ describe("a chain switch on a worker that never loaded state", () => {
         expect(bg.persisted().rpcUrl).toBe(CUSTOM_RPC);
         expect(bg.persisted().blockscoutUrl).toBe(CUSTOM_BLOCKSCOUT);
         expect(bg.persisted().wallets).toEqual(walletFixture());
+        expect(bg.persisted().trackedTokens).toEqual([
+            { address: TOKEN, symbol: "DAI", decimals: 18 },
+        ]);
     });
 
     test("compares the requested chain against the stored one, not the default", async () => {

tests/confirmTxAmount.test.js

@@ -0,0 +1,415 @@
+// The amount of the wallet's own send on the confirmation, wait, success and
+// error screens (https://git.eeqj.de/sneak/AutistMask/issues/522).
+//
+// These screens printed the text from Send's amount field as it was typed or
+// filled in: `0.5 ETH`, or `1.234147890123456789 ETH` after Max, where the
+// approval screen shows a site's send as `0.5000 ETH`. They now show it to four
+// decimal places with the nonzero floor, as the approval screen does, and the
+// transaction is still signed for the exact amount.
+//
+// Driven through the real Send screen, confirmation screen, Sign & Send and
+// wait screen, with only the node, the explorer and the DOM stubbed.
+
+"use strict";
+
+// What the stub node answers, and the signed transactions it was handed. The
+// token's own decimals() answers 6, as the explorer does.
+const mockNode = {
+    balanceWei: 0n,
+    tokenUnits: 0n,
+    tokenDecimals: 6n,
+    broadcast: [],
+    broadcastError: null,
+    receipt: null,
+};
+
+// The token rows the stub explorer reports for the address.
+const mockExplorer = { items: [] };
+
+jest.mock("ethers", () => {
+    const actual = jest.requireActual("ethers");
+    // The selector of decimals(); every other contract call is balanceOf().
+    const DECIMALS = "0x313ce567";
+    class StubProvider {
+        async getBalance() {
+            return mockNode.balanceWei;
+        }
+        async call(tx) {
+            return actual.AbiCoder.defaultAbiCoder().encode(
+                ["uint256"],
+                [
+                    tx.data.startsWith(DECIMALS)
+                        ? mockNode.tokenDecimals
+                        : mockNode.tokenUnits,
+                ],
+            );
+        }
+        async lookupAddress() {
+            return null;
+        }
+        // 20 gwei reserved per gas.
+        async getFeeData() {
+            return {
+                maxFeePerGas: 20000000000n,
+                maxPriorityFeePerGas: 1000000000n,
+                gasPrice: 10000000000n,
+            };
+        }
+        async estimateGas() {
+            return 21000n;
+        }
+        async getCode() {
+            return "0x";
+        }
+        async getTransactionCount() {
+            return 1;
+        }
+        async getNetwork() {
+            return { chainId: 1n };
+        }
+        async broadcastTransaction(signed) {
+            if (mockNode.broadcastError) throw mockNode.broadcastError;
+            mockNode.broadcast.push(signed);
+            return { hash: "0x" + "ab".repeat(32) };
+        }
+        async getTransactionReceipt() {
+            return mockNode.receipt;
+        }
+    }
+    return {
+        ...actual,
+        JsonRpcProvider: StubProvider,
+        Network: { from: () => ({}) },
+    };
+});
+
+jest.mock("../src/shared/log", () => ({
+    log: {
+        debugf: () => {},
+        infof: () => {},
+        warnf: () => {},
+        errorf: () => {},
+    },
+    // The explorer's token list, which refreshBalances() also fetches.
+    debugFetch: jest.fn(async () => ({
+        ok: true,
+        status: 200,
+        json: async () => mockExplorer.items,
+    })),
+    urlOrigin: () => "",
+    setRuntimeDebug: () => {},
+    isDebug: () => false,
+}));
+
+// The confirmation screen's Etherscan label lookup is the only fetch() these
+// screens make; it fails, as it does offline.
+global.fetch = jest.fn(() => {
+    throw new Error("tests must not perform network requests");
+});
+
+const { makeStorageStub } = require("./support/storageStub");
+global.chrome = { storage: makeStorageStub(), runtime: { sendMessage() {} } };
+
+// A stub DOM: every id resolves to a recording element.
+const elements = new Map();
+
+function makeEl(id) {
+    const handlers = new Map();
+    return {
+        id,
+        textContent: "",
+        innerHTML: "",
+        value: "",
+        disabled: false,
+        style: {},
+        dataset: {},
+        classList: {
+            add() {},
+            remove() {},
+            toggle() {},
+            contains: () => false,
+        },
+        handlers,
+        children: [],
+        addEventListener(name, fn) {
+            handlers.set(name, fn);
+        },
+        appendChild(child) {
+            this.children.push(child);
+            return child;
+        },
+        querySelectorAll: () => [],
+        querySelector: () => null,
+        remove() {},
+        focus() {},
+        // The success screen hides whole sections through .parentElement.
+        get parentElement() {
+            return global.document.getElementById(id + "-parent");
+        },
+    };
+}
+
+global.document = {
+    getElementById(id) {
+        if (!elements.has(id)) elements.set(id, makeEl(id));
+        return elements.get(id);
+    },
+    createElement: (tag) => makeEl(tag),
+    body: { prepend() {}, appendChild() {} },
+    addEventListener() {},
+};
+global.navigator = { clipboard: { writeText() {} } };
+
+const {
+    Interface,
+    Transaction,
+    Wallet,
+    getAddress,
+    parseEther,
+} = require("ethers");
+const { refreshBalances } = require("../src/shared/balances");
+const { encryptWithPassword } = require("../src/shared/vault");
+const { state } = require("../src/shared/state");
+const { clearPrices } = require("../src/shared/prices");
+const send = require("../src/popup/views/send");
+const confirmTx = require("../src/popup/views/confirmTx");
+const txStatus = require("../src/popup/views/txStatus");
+
+const PRIVATE_KEY = "0x" + "11".repeat(32);
+const HOLDER = new Wallet(PRIVATE_KEY).address;
+const RECIPIENT = "0xC0FfEE0000000000000000000000000000c0fFEe";
+const PASSWORD = "correct horse battery staple";
+
+const GWEI = 1000000000n;
+// 1.234567890123456789 ETH.
+const BALANCE_WEI = 1234567890123456789n;
+
+// A token the bundled list does not know, with enough holders to be listed,
+// at 6 decimal places.
+const TOKEN = "0x" + "d".repeat(40);
+
+const transferIface = new Interface([
+    "function transfer(address to, uint256 amount)",
+]);
+
+let encryptedSecret;
+
+// The confirmation screen Review leads to, once shown.
+let confirmed = null;
+
+function el(id) {
+    return global.document.getElementById(id);
+}
+
+function text(id) {
+    return el(id).textContent;
+}
+
+// show() reads the balance and then estimates the fee without awaiting
+// either; this lets both settle.
+async function settle() {
+    for (let i = 0; i < 10; i++) await new Promise((r) => setTimeout(r, 0));
+}
+
+// The address holds BALANCE_WEI and, when `tokenUnits` is given, that many
+// base units of TOKEN, fetched and stored where the popup stores them. Send
+// is then open for `token` ("ETH" or TOKEN) with the recipient entered.
+async function openSend(token, tokenUnits = null) {
+    mockNode.balanceWei = BALANCE_WEI;
+    mockNode.tokenUnits = tokenUnits ?? 0n;
+    mockExplorer.items =
+        tokenUnits === null
+            ? []
+            : [
+                  {
+                      value: String(tokenUnits),
+                      token: {
+                          type: "ERC-20",
+                          address_hash: TOKEN,
+                          symbol: "TOK",
+                          name: "Token",
+                          decimals: "6",
+                          holders_count: "50000",
+                      },
+                  },
+              ];
+    state.wallets = [
+        {
+            type: "key",
+            name: "Wallet 1",
+            encryptedSecret,
+            addresses: [{ address: HOLDER }],
+        },
+    ];
+    state.selectedWallet = 0;
+    state.selectedAddress = 0;
+    await refreshBalances(
+        state.wallets,
+        "https://rpc.example.invalid",
+        "https://blockscout.example/api/v2",
+        state.trackedTokens,
+        "mainnet",
+    );
+    send.init({
+        showConfirmTx: (info) => (confirmed = info),
+        pageClosed: new AbortController().signal,
+    });
+    confirmTx.init({});
+    send.resetSendValidation();
+    state.currentView = "send";
+    state.selectedToken = token;
+    el("send-to").value = RECIPIENT;
+    el("send-amount").value = "";
+}
+
+// Press Review and show the confirmation screen with its fee estimate settled.
+async function review() {
+    await el("btn-send-review").handlers.get("click")();
+    confirmTx.show(confirmed);
+    await settle();
+}
+
+async function signAndSend() {
+    el("confirm-tx-password").value = PASSWORD;
+    await el("btn-confirm-send").handlers.get("click")();
+}
+
+// The one transaction the stub node was handed.
+function broadcastTx() {
+    expect(mockNode.broadcast).toHaveLength(1);
+    return Transaction.from(mockNode.broadcast[0]);
+}
+
+beforeAll(async () => {
+    encryptedSecret = await encryptWithPassword(PRIVATE_KEY, PASSWORD);
+});
+
+beforeEach(() => {
+    elements.clear();
+    clearPrices();
+    confirmed = null;
+    state.selectedToken = null;
+    state.trackedTokens = [];
+    state.fraudContracts = [];
+    state.currentView = null;
+    mockNode.broadcast = [];
+    mockNode.broadcastError = null;
+    mockNode.receipt = null;
+    txStatus.init({
+        doRefreshAndRender() {},
+        pageClosed: new AbortController().signal,
+    });
+});
+
+afterEach(() => {
+    txStatus.endWait();
+});
+
+describe("the wallet's own send shows its amount to four decimal places", () => {
+    test("for a short amount", async () => {
+        await openSend("ETH");
+        el("send-amount").value = "0.5";
+        await review();
+        expect(text("confirm-amount")).toBe("0.5000 ETH");
+
+        await signAndSend();
+        expect(text("wait-tx-summary")).toBe("0.5000 ETH");
+        expect(broadcastTx().value).toBe(parseEther("0.5"));
+    });
+
+    // Send accepts both. The approval screen writes the same value `0.5000`.
+    test.each([".5", "00.5"])("for an amount typed as %s", async (typed) => {
+        await openSend("ETH");
+        el("send-amount").value = typed;
+        await review();
+        expect(text("confirm-amount")).toBe("0.5000 ETH");
+
+        await signAndSend();
+        expect(text("wait-tx-summary")).toBe("0.5000 ETH");
+        expect(broadcastTx().value).toBe(parseEther("0.5"));
+    });
+
+    test("for a token amount typed as .5", async () => {
+        // 100 TOK.
+        await openSend(TOKEN, 100000000n);
+        el("send-amount").value = ".5";
+        await review();
+        expect(text("confirm-amount")).toBe("0.5000 TOK");
+
+        await signAndSend();
+        expect(text("wait-tx-summary")).toBe("0.5000 TOK");
+        const [, amount] = transferIface.decodeFunctionData(
+            "transfer",
+            broadcastTx().data,
+        );
+        expect(amount).toBe(500000n);
+    });
+
+    test("for a Max amount with many decimals", async () => {
+        await openSend("ETH");
+        await el("btn-send-max").handlers.get("click")();
+        // The balance minus 21000 gas at 20 gwei.
+        expect(el("send-amount").value).toBe("1.234147890123456789");
+        await review();
+        expect(text("confirm-amount")).toBe("1.2341 ETH");
+
+        await signAndSend();
+        expect(text("wait-tx-summary")).toBe("1.2341 ETH");
+        expect(broadcastTx().value).toBe(BALANCE_WEI - 21000n * 20n * GWEI);
+    });
+
+    // Cut to four decimals it would read 0.0000, so it is shown to its first
+    // significant digit instead, and signed in full.
+    test("for a tiny nonzero amount", async () => {
+        await openSend("ETH");
+        el("send-amount").value = "0.000012345";
+        await review();
+        expect(text("confirm-amount")).toBe("0.00001 ETH");
+
+        await signAndSend();
+        expect(text("wait-tx-summary")).toBe("0.00001 ETH");
+        expect(broadcastTx().value).toBe(parseEther("0.000012345"));
+    });
+
+    test("for a token amount", async () => {
+        // 100 TOK.
+        await openSend(TOKEN, 100000000n);
+        el("send-amount").value = "12.345678";
+        await review();
+        expect(text("confirm-amount")).toBe("12.3456 TOK");
+
+        await signAndSend();
+        expect(text("wait-tx-summary")).toBe("12.3456 TOK");
+        const tx = broadcastTx();
+        expect(tx.to).toBe(getAddress(TOKEN));
+        const [to, amount] = transferIface.decodeFunctionData(
+            "transfer",
+            tx.data,
+        );
+        expect(to).toBe(RECIPIENT);
+        expect(amount).toBe(12345678n);
+    });
+
+    test("on the success screen", async () => {
+        await openSend("ETH");
+        el("send-amount").value = "0.5";
+        await review();
+        await signAndSend();
+        // A popup opened later resumes the wait, and the receipt is there.
+        mockNode.receipt = { blockNumber: 21000000 };
+        txStatus.restoreWait();
+        await settle();
+        expect(state.currentView).toBe("success-tx");
+        expect(text("success-tx-summary")).toBe("0.5000 ETH");
+    });
+
+    test("on the error screen", async () => {
+        await openSend("ETH");
+        el("send-amount").value = "0.5";
+        await review();
+        mockNode.broadcastError = new Error("the node refused it");
+        await signAndSend();
+        expect(state.currentView).toBe("error-tx");
+        expect(text("error-tx-summary")).toBe("0.5000 ETH");
+    });
+});

tests/confirmTxFeeBound.test.js

@@ -11,20 +11,115 @@
 //
 // The check is driven here with a fake connected signer rather than a real
 // one: populateTransaction() returns the fees the node would have produced,
-// and sendTransaction() records whether the send actually happened. The real
-// DOM path around it — reading the fee error into the reserved errors box — is
-// covered by the Chrome e2e suite.
+// and sendTransaction() records whether the send actually happened.
+//
+// The last test drives the real confirmation screen instead, with only the
+// node and the DOM stubbed: a gas limit over its own bound at an ordinary fee
+// is refused in the same box as a fee over the bound
+// (https://git.eeqj.de/sneak/AutistMask/issues/583). That the box moves
+// nothing on the screen is checked by the Chrome e2e suite.
 
-globalThis.chrome = {
-    storage: { local: { get: async () => ({}), set: async () => {} } },
+// What the stub node quotes for that test: a gas limit of 150,000,000 at a
+// maximum fee of 2 gwei per gas, 0.3 ETH in all. And the signed transactions
+// it was handed.
+const mockNode = {
+    gasLimit: 150000000n,
+    maxFeePerGas: 2000000000n,
+    broadcast: [],
 };
 
+jest.mock("ethers", () => {
+    const actual = jest.requireActual("ethers");
+    class StubProvider {
+        constructor(url, network) {
+            this.network = network;
+        }
+        async getNetwork() {
+            return this.network;
+        }
+        async getBalance() {
+            return actual.parseEther("5");
+        }
+        async getCode() {
+            return "0x";
+        }
+        async getTransactionCount() {
+            return 1;
+        }
+        async getFeeData() {
+            return {
+                maxFeePerGas: mockNode.maxFeePerGas,
+                maxPriorityFeePerGas: 1000000000n,
+                gasPrice: 1000000000n,
+            };
+        }
+        async estimateGas() {
+            return mockNode.gasLimit;
+        }
+        async broadcastTransaction(signed) {
+            mockNode.broadcast.push(signed);
+            return { hash: "0x" + "ab".repeat(32) };
+        }
+    }
+    return { ...actual, JsonRpcProvider: StubProvider };
+});
+
+// The screens a send that was not refused goes on to.
+jest.mock("../src/popup/views/txStatus", () => ({
+    showWait: jest.fn(),
+    showError: jest.fn(),
+}));
+
+const { makeStorageStub } = require("./support/storageStub");
+global.chrome = { storage: makeStorageStub(), runtime: { sendMessage() {} } };
+
 global.fetch = jest.fn(() => {
     throw new Error("tests must not perform network requests");
 });
 
-const { populateVerifyAndSend } = require("../src/popup/views/confirmTx");
+// A stub DOM: every id resolves to a recording element.
+const elements = new Map();
+
+function makeEl(id) {
+    const handlers = new Map();
+    return {
+        id,
+        textContent: "",
+        innerHTML: "",
+        value: "",
+        disabled: false,
+        style: {},
+        dataset: {},
+        classList: {
+            add() {},
+            remove() {},
+            toggle() {},
+            contains: () => false,
+        },
+        handlers,
+        addEventListener(name, fn) {
+            handlers.set(name, fn);
+        },
+        querySelectorAll: () => [],
+        remove() {},
+    };
+}
+
+global.document = {
+    getElementById(id) {
+        if (!elements.has(id)) elements.set(id, makeEl(id));
+        return elements.get(id);
+    },
+};
+
+const { Wallet } = require("ethers");
+const { encryptWithPassword } = require("../src/shared/vault");
+const { state, loadState } = require("../src/shared/state");
+const txStatus = require("../src/popup/views/txStatus");
+const confirmTx = require("../src/popup/views/confirmTx");
+const { populateVerifyAndSend } = confirmTx;
 const {
+    MAX_GAS_LIMIT,
     MAX_FEE_PER_GAS,
     MAX_TOTAL_FEE,
 } = require("../src/shared/approvalVerify");
@@ -98,3 +193,69 @@ describe("populateVerifyAndSend enforces the combined fee bound", () => {
         expect(signer.sent[0].gasLimit).toBe(under.gasLimit);
     });
 });
+
+describe("Sign & Send on the confirmation screen", () => {
+    const PRIVATE_KEY = "0x" + "11".repeat(32);
+    const PASSWORD = "correct horse battery staple";
+    let encryptedSecret;
+
+    beforeAll(async () => {
+        await loadState();
+        encryptedSecret = await encryptWithPassword(PRIVATE_KEY, PASSWORD);
+    });
+
+    function el(id) {
+        return global.document.getElementById(id);
+    }
+
+    function shown(id) {
+        return el(id).style.visibility === "visible";
+    }
+
+    // show() reads the balance and estimates the fee without awaiting
+    // either; this lets both finish.
+    async function settle() {
+        for (let i = 0; i < 10; i++) await new Promise((r) => setTimeout(r, 0));
+    }
+
+    test("refuses a gas limit over its bound at an ordinary fee in the box for a refused gas limit or fee, and sends nothing", async () => {
+        expect(mockNode.gasLimit).toBeGreaterThan(MAX_GAS_LIMIT);
+        expect(mockNode.gasLimit * mockNode.maxFeePerGas).toBeLessThan(
+            MAX_TOTAL_FEE,
+        );
+
+        const from = new Wallet(PRIVATE_KEY).address;
+        state.wallets = [
+            {
+                type: "key",
+                name: "Wallet 1",
+                encryptedSecret,
+                addresses: [{ address: from }],
+            },
+        ];
+        state.selectedWallet = 0;
+        state.selectedAddress = 0;
+        confirmTx.init({});
+        confirmTx.show({
+            from,
+            to: RECIPIENT,
+            ensName: null,
+            amount: "1",
+            token: "ETH",
+            tokenSymbol: null,
+            tokenDecimals: null,
+            max: false,
+        });
+        await settle();
+        expect(el("btn-confirm-send").disabled).toBe(false);
+        expect(shown("confirm-fee-bound-error")).toBe(false);
+
+        el("confirm-tx-password").value = PASSWORD;
+        await el("btn-confirm-send").handlers.get("click")();
+
+        expect(shown("confirm-fee-bound-error")).toBe(true);
+        expect(mockNode.broadcast).toEqual([]);
+        expect(txStatus.showWait).not.toHaveBeenCalled();
+        expect(txStatus.showError).not.toHaveBeenCalled();
+    });
+});

tests/confirmTxLateResult.test.js

@@ -0,0 +1,221 @@
+// A late answer for a confirmation screen the user has left changes nothing on
+// the screen shown since (https://git.eeqj.de/sneak/AutistMask/issues/575).
+//
+// The confirmation screen asks the node and the explorer about its transaction
+// without waiting for the answers: the recipient checks, which can show three
+// warning boxes, the balance read and the fee estimate. Back, a new recipient
+// and Review again show the screen for another transaction while those
+// questions may still be open. The recipient checks showed their boxes
+// whenever they answered, so a box about the first recipient could appear on
+// the second recipient's screen.
+//
+// Driven through the real confirmation screen, with only the node, the
+// explorer and the DOM stubbed. Each test holds back the first screen's answer
+// to one question, and gives it once the screen it tests is shown.
+
+"use strict";
+
+// The From address of every transaction here. The jest.mock() factory below
+// may only name outside variables whose names start with "mock".
+const mockFrom = "0x66133E8ea0f5D1d612D2502a968757D1048c214a";
+
+jest.mock("ethers", () => {
+    const actual = jest.requireActual("ethers");
+    // Every answer is a mock, so a test can hold one back. Every address has
+    // sent one transaction and has no code, and only the From address holds
+    // anything: 5 ETH.
+    class StubProvider {}
+    Object.assign(StubProvider.prototype, {
+        getBalance: jest.fn(async (address) =>
+            address === mockFrom ? actual.parseEther("5") : 0n,
+        ),
+        getCode: jest.fn(async () => "0x"),
+        getTransactionCount: jest.fn(async () => 1),
+        // 10 gwei expected, 20 gwei reserved per gas.
+        getFeeData: jest.fn(async () => ({
+            maxFeePerGas: 20000000000n,
+            maxPriorityFeePerGas: 1000000000n,
+            gasPrice: 10000000000n,
+        })),
+        estimateGas: jest.fn(async () => 21000n),
+    });
+    return { ...actual, JsonRpcProvider: StubProvider };
+});
+
+// An explorer address page whose title is `title`.
+function explorerPage(title) {
+    return { ok: true, text: async () => "<title>" + title + "</title>" };
+}
+
+// The explorer labels no address.
+global.fetch = jest.fn(async () => explorerPage("Etherscan"));
+
+const { makeStorageStub } = require("./support/storageStub");
+global.chrome = { storage: makeStorageStub(), runtime: { sendMessage() {} } };
+
+// A stub DOM: every id resolves to a recording element.
+const elements = new Map();
+
+function makeEl(id) {
+    return {
+        id,
+        textContent: "",
+        innerHTML: "",
+        value: "",
+        disabled: false,
+        style: {},
+        dataset: {},
+        classList: {
+            add() {},
+            remove() {},
+            toggle() {},
+            contains: () => false,
+        },
+        addEventListener() {},
+        querySelectorAll: () => [],
+        remove() {},
+    };
+}
+
+global.document = {
+    getElementById(id) {
+        if (!elements.has(id)) elements.set(id, makeEl(id));
+        return elements.get(id);
+    },
+};
+
+const { JsonRpcProvider, parseEther } = require("ethers");
+const { loadState } = require("../src/shared/state");
+const confirmTx = require("../src/popup/views/confirmTx");
+
+const node = JsonRpcProvider.prototype;
+const FIRST = "0xC0FfEE0000000000000000000000000000c0fFEe";
+const SECOND = "0xE2E0000000000000000000000000000000000E2e";
+
+function el(id) {
+    return global.document.getElementById(id);
+}
+
+function shown(id) {
+    return el(id).style.visibility === "visible";
+}
+
+// Show the confirmation screen for 1 ETH to `to` on mainnet, as Review on the
+// Send screen does.
+function review(to) {
+    confirmTx.show({
+        from: mockFrom,
+        to,
+        ensName: null,
+        amount: "1",
+        token: "ETH",
+        tokenSymbol: null,
+        tokenDecimals: null,
+        max: false,
+    });
+}
+
+// show() does not wait for its questions; this lets every answer not held
+// back arrive.
+async function settle() {
+    for (let i = 0; i < 10; i++) await new Promise((r) => setTimeout(r, 0));
+}
+
+// Hold back the next answer `question` gives. Returns the function that gives
+// it.
+function holdNextAnswer(question) {
+    let give;
+    question.mockImplementationOnce(() => new Promise((r) => (give = r)));
+    return (answer) => give(answer);
+}
+
+beforeAll(async () => {
+    await loadState();
+});
+
+beforeEach(() => {
+    elements.clear();
+});
+
+// The three boxes the recipient checks show, each with the question whose
+// answer shows it for FIRST, and that answer. FIRST holds no ETH, so the
+// answer that it has sent no transaction is what shows the box saying so.
+describe.each([
+    {
+        box: "confirm-contract-warning",
+        question: node.getCode,
+        answer: "0x6080604052",
+    },
+    {
+        box: "confirm-recipient-warning",
+        question: node.getTransactionCount,
+        answer: 0,
+    },
+    {
+        box: "confirm-etherscan-warning",
+        question: global.fetch,
+        answer: explorerPage(
+            "Fake_Phishing1 | Address: " + FIRST + " | Etherscan",
+        ),
+    },
+])("the $box box", ({ box, question, answer }) => {
+    test("is shown when the answer about the recipient arrives while its screen is shown", async () => {
+        const give = holdNextAnswer(question);
+        review(FIRST);
+        await settle();
+        expect(shown(box)).toBe(false);
+
+        give(answer);
+        await settle();
+        expect(shown(box)).toBe(true);
+    });
+
+    test("is not shown on the next recipient's screen when the answer about the first arrives after that screen is shown", async () => {
+        const give = holdNextAnswer(question);
+        review(FIRST);
+        await settle();
+        review(SECOND);
+        await settle();
+        expect(shown(box)).toBe(false);
+
+        give(answer);
+        await settle();
+        expect(shown(box)).toBe(false);
+    });
+});
+
+test("a balance read answered after the next screen is shown leaves that screen's balance and balance check as they are", async () => {
+    const give = holdNextAnswer(node.getBalance);
+    review(FIRST);
+    await settle();
+    review(SECOND);
+    await settle();
+    expect(el("confirm-balance").textContent).toBe("5.0000 ETH");
+
+    give(parseEther("0.5"));
+    await settle();
+    expect(el("confirm-balance").textContent).toBe("5.0000 ETH");
+    expect(shown("confirm-balance-error")).toBe(false);
+    expect(el("btn-confirm-send").disabled).toBe(false);
+});
+
+test("a fee estimate answered after the next screen is shown leaves that screen's fee as it is", async () => {
+    const give = holdNextAnswer(node.getFeeData);
+    review(FIRST);
+    await settle();
+    review(SECOND);
+    await settle();
+    expect(el("confirm-fee-amount").textContent).toBe("~0.0002 ETH");
+
+    // 100 times the fee the second screen was quoted.
+    give({
+        maxFeePerGas: 2000000000000n,
+        maxPriorityFeePerGas: 100000000000n,
+        gasPrice: 1000000000000n,
+    });
+    await settle();
+    expect(el("confirm-fee-amount").textContent).toBe("~0.0002 ETH");
+    expect(el("confirm-fee-reserve").textContent).toBe(
+        "up to 0.0004 ETH reserved",
+    );
+});

tests/confirmTxNetworkSwitch.test.js

@@ -7,25 +7,85 @@
 // reviewed on Sepolia went out as 1 ETH on mainnet once mainnet was chosen in
 // Settings in between.
 //
+// The same holds when the popup was closed after the switch and reopened, and
+// Back drew the screen again from the transaction it saved
+// (https://git.eeqj.de/sneak/AutistMask/issues/586): the screen was drawn for
+// the new network, and Sign & Send sent the reviewed transfer there. Drawn
+// again, the screen describes the transaction entirely on the network it was
+// reviewed for, because choosing that network again in Settings and pressing
+// Back only unhides it, and Sign & Send then sends from it.
+//
+// Its balance line and balance check are that network's balance, read from
+// that network's node each time the screen is drawn
+// (https://git.eeqj.de/sneak/AutistMask/issues/558), not the balance Send
+// handed over. The fee estimate after the read stays on that network when
+// the network is switched while the read runs.
+//
 // Driven through the real confirmation screen, signer and chain switch, with
-// only the node and the DOM stubbed. The stub node is on the network its
-// provider was built for, so a broadcast records the network it went to.
+// only the node, fetch and the DOM stubbed. The stub node is on the network
+// its provider was built for, so a broadcast records the network it went to,
+// and a balance read answers with that network's balance.
 
 "use strict";
 
-// The signed transactions the stub node was handed, with its network's chain id.
-const mockNode = { broadcast: [] };
+// The questions the stub node was asked for the balance, the fee and the
+// recipient checks, by method, network name and RPC URL, in order. The
+// balances it reports on each network, by network name: ETH in wei and the
+// token in its base units. The signed transactions it was handed, with its
+// network's chain id and RPC URL. And whether it quotes fees as a network
+// with no type-2 pricing does.
+const mockNode = {
+    asked: [],
+    balanceWei: {},
+    tokenUnits: {},
+    broadcast: [],
+    legacyFees: false,
+};
 
 jest.mock("ethers", () => {
     const actual = jest.requireActual("ethers");
+    // The selector of balanceOf(address).
+    const BALANCE_OF = "0x70a08231";
     class StubProvider {
         constructor(url, network) {
+            this.url = url;
             this.network = network;
         }
+        record(method) {
+            mockNode.asked.push({
+                method,
+                network: this.network.name,
+                url: this.url,
+            });
+        }
         async getNetwork() {
             return this.network;
         }
+        async getBalance() {
+            this.record("getBalance");
+            return mockNode.balanceWei[this.network.name];
+        }
+        // balanceOf() is the one contract call the screen makes before Sign
+        // & Send.
+        async call(tx) {
+            if (!tx.data.startsWith(BALANCE_OF)) {
+                throw new Error("the stub node answers only balanceOf()");
+            }
+            this.record("balanceOf");
+            return actual.AbiCoder.defaultAbiCoder().encode(
+                ["uint256"],
+                [mockNode.tokenUnits[this.network.name]],
+            );
+        }
         async getFeeData() {
+            this.record("getFeeData");
+            if (mockNode.legacyFees) {
+                return {
+                    maxFeePerGas: null,
+                    maxPriorityFeePerGas: null,
+                    gasPrice: 10000000000n,
+                };
+            }
             return {
                 maxFeePerGas: 20000000000n,
                 maxPriorityFeePerGas: 1000000000n,
@@ -36,16 +96,22 @@ jest.mock("ethers", () => {
             return 21000n;
         }
         async getCode() {
+            this.record("getCode");
             return "0x";
         }
         async getTransactionCount() {
+            this.record("getTransactionCount");
             return 1;
         }
         async lookupAddress() {
             return null;
         }
         async broadcastTransaction(signed) {
-            mockNode.broadcast.push({ chainId: this.network.chainId, signed });
+            mockNode.broadcast.push({
+                chainId: this.network.chainId,
+                url: this.url,
+                signed,
+            });
             return { hash: "0x" + "ab".repeat(32) };
         }
     }
@@ -75,6 +141,8 @@ jest.mock("../src/popup/views/txStatus", () => ({
     showError: jest.fn(),
 }));
 
+// The Etherscan label check is its only caller here: the explorer pages it
+// asks for are recorded, and nothing is fetched.
 global.fetch = jest.fn(() => {
     throw new Error("tests must not perform network requests");
 });
@@ -123,17 +191,35 @@ global.document = {
 };
 global.navigator = { clipboard: { writeText() {} } };
 
-const { BaseWallet, Transaction, Wallet } = require("ethers");
+const {
+    BaseWallet,
+    JsonRpcProvider,
+    Transaction,
+    Wallet,
+    parseEther,
+} = require("ethers");
 const { encryptWithPassword } = require("../src/shared/vault");
-const { state, loadState } = require("../src/shared/state");
+const { state, loadState, saveState } = require("../src/shared/state");
 const { onChainSwitch } = require("../src/shared/chainSwitch");
 const { NETWORKS } = require("../src/shared/networks");
+const { prices } = require("../src/shared/prices");
+const {
+    goBack,
+    pushCurrentView,
+    setBackRenderer,
+    showView,
+} = require("../src/popup/views/helpers");
+const {
+    makeBackRenderer,
+    resetRenderedViews,
+} = require("../src/popup/viewRouter");
 const txStatus = require("../src/popup/views/txStatus");
 const confirmTx = require("../src/popup/views/confirmTx");
 
 const PRIVATE_KEY = "0x" + "11".repeat(32);
 const HOLDER = new Wallet(PRIVATE_KEY).address;
 const RECIPIENT = "0xC0FfEE0000000000000000000000000000c0fFEe";
+const TOKEN = "0x7070707070707070707070707070707070707070";
 const PASSWORD = "correct horse battery staple";
 
 function el(id) {
@@ -150,7 +236,15 @@ beforeAll(async () => {
 
 beforeEach(() => {
     elements.clear();
+    mockNode.asked = [];
+    mockNode.balanceWei = {
+        mainnet: parseEther("5"),
+        sepolia: parseEther("5"),
+    };
+    mockNode.tokenUnits = { mainnet: 0n, sepolia: 0n };
     mockNode.broadcast = [];
+    mockNode.legacyFees = false;
+    global.fetch.mockClear();
     txStatus.showWait.mockClear();
     txStatus.showError.mockClear();
     signTransaction = jest.spyOn(BaseWallet.prototype, "signTransaction");
@@ -160,16 +254,22 @@ afterEach(() => {
     signTransaction.mockRestore();
 });
 
-// Show the confirmation screen for 1 of the native token on `networkId`, as
-// Review on the Send screen does, with its fee estimate settled.
-async function review(networkId) {
+// Show the confirmation screen for 1 of the native token on `networkId`, or
+// for the transfer `changes` makes of it, as Review on the Send screen does,
+// with its balance read and its fee estimate settled.
+async function review(networkId, changes = {}) {
     await onChainSwitch(networkId);
+    await reviewOnActiveNetwork(changes);
+}
+
+// review() on the network already active, without switching to it again.
+async function reviewOnActiveNetwork(changes = {}) {
     state.wallets = [
         {
             type: "key",
             name: "Wallet 1",
             encryptedSecret,
-            addresses: [{ address: HOLDER, balance: "5.0" }],
+            addresses: [{ address: HOLDER }],
         },
     ];
     state.selectedWallet = 0;
@@ -181,15 +281,108 @@ async function review(networkId) {
         ensName: null,
         amount: "1",
         token: "ETH",
-        balance: "5.0",
         tokenSymbol: null,
-        tokenBalance: null,
         tokenDecimals: null,
         max: false,
+        ...changes,
     });
+    await settle();
+}
+
+// The user's own node for a network, set in Settings.
+function ownNode(networkId) {
+    return "https://" + networkId + ".node.example.invalid";
+}
+
+// After review() on `reviewedOn`: the user's own node set for it, the Settings
+// gear, `switchedTo` chosen there, the popup closed and reopened onto
+// Settings, and Back, which draws the confirmation screen again from the
+// transaction it saved. The reopened page holds an ETH price of $2,000 and a
+// USDC price of $1 whichever network is active, so each USD value shows which
+// network it was priced for.
+async function switchReopenAndGoBack(reviewedOn, switchedTo) {
+    state.rpcUrl = ownNode(reviewedOn);
+    pushCurrentView();
+    showView("settings");
+    await onChainSwitch(switchedTo);
+
+    await loadState();
+    elements.clear();
+    resetRenderedViews();
+    setBackRenderer(makeBackRenderer(state, { confirmTx }));
+    confirmTx.init({});
+    prices.ETH = 2000;
+    prices.USDC = 1;
+    mockNode.asked = [];
+    global.fetch.mockClear();
+    goBack();
+    await settle();
+}
+
+// The USD value `text` as the screen appends it for `networkId`: nothing on a
+// testnet, which has no USD values.
+function usdOn(networkId, text) {
+    return NETWORKS[networkId].isTestnet ? "" : " (" + text + ")";
+}
+
+// The screen for the transfer review() shows by default, described on
+// `networkId`: in its native currency, priced by it, linking to its explorer.
+function expectNativeTransferOn(networkId) {
+    const { nativeCurrency: symbol, explorerUrl } = NETWORKS[networkId];
+    expect(el("confirm-type").textContent).toBe(
+        "Native " + symbol + " transfer",
+    );
+    expect(el("confirm-amount").textContent).toBe(
+        "1.0000 " + symbol + usdOn(networkId, "$2,000.00"),
+    );
+    expect(el("confirm-balance").textContent).toBe(
+        "5.0000 " + symbol + usdOn(networkId, "$10,000.00"),
+    );
+    expect(el("confirm-fee-amount").textContent).toBe(
+        "~0.0002 " + symbol + usdOn(networkId, "$0.42"),
+    );
+    expect(el("confirm-fee-reserve").textContent).toBe(
+        "up to 0.0004 " + symbol + " reserved",
+    );
+    expect(el("confirm-gas-error").textContent).toBe(
+        "You do not have enough " +
+            symbol +
+            " to pay the network fee for this transfer. Please add " +
+            symbol +
+            " to this address and try again.",
+    );
+    expect(el("confirm-recipient-warning").textContent).toContain(
+        " holds no " + symbol + ". ",
+    );
+    expect(el("confirm-contract-warning").textContent).toContain(
+        " Sending " + symbol + " or tokens ",
+    );
+    expect(el("confirm-from").innerHTML).toContain(
+        `href="${explorerUrl}/address/${HOLDER}"`,
+    );
+    expect(el("confirm-to").innerHTML).toContain(
+        `href="${explorerUrl}/address/${RECIPIENT}"`,
+    );
+}
+
+// show() reads the balance and then estimates the fee, and checks the
+// recipient, without awaiting any of them; this lets all of them finish.
+async function settle() {
     for (let i = 0; i < 10; i++) await new Promise((r) => setTimeout(r, 0));
 }
 
+function errors() {
+    return el("confirm-errors").innerHTML;
+}
+
+function shown(id) {
+    return el(id).style.visibility === "visible";
+}
+
+function sendDisabled() {
+    return el("btn-confirm-send").disabled;
+}
+
 async function signAndSend() {
     el("confirm-tx-password").value = PASSWORD;
     await el("btn-confirm-send").handlers.get("click")();
@@ -208,6 +401,25 @@ test("a transfer reviewed on Sepolia and sent goes out on Sepolia", async () =>
     expect(txStatus.showWait).toHaveBeenCalledTimes(1);
 });
 
+// Saving an RPC endpoint in Settings (src/popup/views/settings.js) sets only
+// state.rpcUrl: the endpoint remembered for the active network keeps its old
+// value until the next switch away from it.
+test("a transfer reviewed after the active network's RPC endpoint was changed in Settings asks the new endpoint", async () => {
+    const newNode = "https://new.node.example.invalid";
+    await onChainSwitch("sepolia");
+    state.rpcUrl = newNode;
+    await saveState();
+
+    await reviewOnActiveNetwork();
+
+    expect(mockNode.asked).toEqual([
+        { method: "getBalance", network: "sepolia", url: newNode },
+        { method: "getCode", network: "sepolia", url: newNode },
+        { method: "getTransactionCount", network: "sepolia", url: newNode },
+        { method: "getFeeData", network: "sepolia", url: newNode },
+    ]);
+});
+
 describe.each([
     ["sepolia", "mainnet", "SepoliaETH"],
     ["mainnet", "sepolia", "ETH"],
@@ -228,11 +440,219 @@ describe.each([
             expect(mockNode.broadcast).toEqual([]);
             expect(txStatus.showWait).not.toHaveBeenCalled();
             expect(txStatus.showError).not.toHaveBeenCalled();
-            expect(el("confirm-errors").style.visibility).toBe("visible");
-            expect(el("confirm-errors").innerHTML).toContain(
-                "The active network changed after this transaction was" +
-                    " reviewed, so it was not sent. Please go back and review" +
-                    " it again.",
+            expect(shown("confirm-network-changed-error")).toBe(true);
+            expect(shown("confirm-fee-bound-error")).toBe(false);
+        });
+    },
+);
+
+describe.each([
+    ["sepolia", "mainnet"],
+    ["mainnet", "sepolia"],
+])(
+    "a transfer reviewed on %s, with %s chosen in Settings, the popup reopened and Back pressed",
+    (reviewedOn, switchedTo) => {
+        const { nativeCurrency: symbol, explorerUrl } = NETWORKS[reviewedOn];
+
+        test("is described on the network it was reviewed for, and neither signed nor sent", async () => {
+            await review(reviewedOn);
+            await switchReopenAndGoBack(reviewedOn, switchedTo);
+
+            expect(state.currentView).toBe("confirm-tx");
+            expectNativeTransferOn(reviewedOn);
+            expect(mockNode.asked).toEqual([
+                {
+                    method: "getBalance",
+                    network: reviewedOn,
+                    url: ownNode(reviewedOn),
+                },
+                {
+                    method: "getCode",
+                    network: reviewedOn,
+                    url: ownNode(reviewedOn),
+                },
+                {
+                    method: "getTransactionCount",
+                    network: reviewedOn,
+                    url: ownNode(reviewedOn),
+                },
+                {
+                    method: "getFeeData",
+                    network: reviewedOn,
+                    url: ownNode(reviewedOn),
+                },
+            ]);
+            expect(global.fetch.mock.calls.map(([url]) => url)).toEqual([
+                explorerUrl + "/address/" + RECIPIENT,
+            ]);
+            expect(el("btn-confirm-send").disabled).toBe(false);
+
+            await signAndSend();
+
+            expect(signTransaction).not.toHaveBeenCalled();
+            expect(mockNode.broadcast).toEqual([]);
+            expect(txStatus.showWait).not.toHaveBeenCalled();
+            expect(txStatus.showError).not.toHaveBeenCalled();
+            expect(shown("confirm-network-changed-error")).toBe(true);
+        });
+
+        test("is sent on that network, as described, once it is chosen in Settings again and Back pressed", async () => {
+            await review(reviewedOn);
+            await switchReopenAndGoBack(reviewedOn, switchedTo);
+            // The Settings gear, the reviewed network chosen, and Back, which
+            // only unhides the screen as it was drawn.
+            pushCurrentView();
+            showView("settings");
+            await onChainSwitch(reviewedOn);
+            goBack();
+
+            expect(state.currentView).toBe("confirm-tx");
+            expectNativeTransferOn(reviewedOn);
+
+            await signAndSend();
+
+            const chainId = BigInt(NETWORKS[reviewedOn].chainId);
+            expect(mockNode.broadcast).toHaveLength(1);
+            expect(mockNode.broadcast[0].chainId).toBe(chainId);
+            expect(mockNode.broadcast[0].url).toBe(ownNode(reviewedOn));
+            expect(Transaction.from(mockNode.broadcast[0].signed).chainId).toBe(
+                chainId,
+            );
+            expect(txStatus.showWait).toHaveBeenCalledTimes(1);
+        });
+
+        test("for more than the balance, says so in that network's native currency", async () => {
+            await review(reviewedOn, { amount: "10" });
+            await switchReopenAndGoBack(reviewedOn, switchedTo);
+
+            expect(shown("confirm-balance-error")).toBe(true);
+            expect(el("confirm-balance-error").textContent).toBe(
+                "Your " +
+                    symbol +
+                    " balance does not cover this amount. Please go back and" +
+                    " send a smaller amount.",
+            );
+        });
+
+        test("states and checks that network's balance as it is then, which no longer covers the send", async () => {
+            await review(reviewedOn);
+            expect(sendDisabled()).toBe(false);
+            mockNode.balanceWei = {
+                [reviewedOn]: parseEther("0.5"),
+                [switchedTo]: parseEther("5"),
+            };
+            await switchReopenAndGoBack(reviewedOn, switchedTo);
+
+            expect(el("confirm-balance").textContent).toBe(
+                "0.5000 " + symbol + usdOn(reviewedOn, "$1,000.00"),
+            );
+            expect(shown("confirm-balance-error")).toBe(true);
+            expect(sendDisabled()).toBe(true);
+        });
+
+        test("states and checks that network's balance as it is then, which now covers the send, and refuses to send it", async () => {
+            mockNode.balanceWei[reviewedOn] = parseEther("0.5");
+            await review(reviewedOn);
+            expect(sendDisabled()).toBe(true);
+            mockNode.balanceWei = {
+                [reviewedOn]: parseEther("5"),
+                [switchedTo]: parseEther("0.5"),
+            };
+            await switchReopenAndGoBack(reviewedOn, switchedTo);
+
+            expect(el("confirm-balance").textContent).toBe(
+                "5.0000 " + symbol + usdOn(reviewedOn, "$10,000.00"),
+            );
+            expect(errors()).toBe("");
+            expect(shown("confirm-balance-error")).toBe(false);
+            expect(shown("confirm-amount-fee-error")).toBe(false);
+            expect(sendDisabled()).toBe(false);
+
+            await signAndSend();
+
+            expect(signTransaction).not.toHaveBeenCalled();
+            expect(mockNode.broadcast).toEqual([]);
+            expect(shown("confirm-network-changed-error")).toBe(true);
+        });
+
+        const tokenSend = {
+            token: TOKEN,
+            tokenSymbol: "TOK",
+            tokenDecimals: 6,
+        };
+
+        test("of a token, states and checks that network's token balance as it is then, which no longer covers the send", async () => {
+            mockNode.tokenUnits[reviewedOn] = 10000000n;
+            await review(reviewedOn, tokenSend);
+            expect(sendDisabled()).toBe(false);
+            mockNode.tokenUnits = {
+                [reviewedOn]: 500000n,
+                [switchedTo]: 10000000n,
+            };
+            await switchReopenAndGoBack(reviewedOn, switchedTo);
+
+            expect(el("confirm-balance").textContent).toBe("0.5000 TOK");
+            expect(shown("confirm-balance-error")).toBe(true);
+            expect(el("confirm-balance-error").textContent).toBe(
+                "Your TOK balance does not cover this amount. Please go back" +
+                    " and send a smaller amount.",
+            );
+            expect(sendDisabled()).toBe(true);
+        });
+
+        test("of a token, states and checks that network's token balance as it is then, which now covers the send, and refuses to send it", async () => {
+            await review(reviewedOn, tokenSend);
+            expect(sendDisabled()).toBe(true);
+            mockNode.tokenUnits = {
+                [reviewedOn]: 10000000n,
+                [switchedTo]: 0n,
+            };
+            await switchReopenAndGoBack(reviewedOn, switchedTo);
+
+            expect(el("confirm-balance").textContent).toBe("10.0000 TOK");
+            expect(errors()).toBe("");
+            expect(shown("confirm-balance-error")).toBe(false);
+            expect(shown("confirm-gas-error")).toBe(false);
+            expect(sendDisabled()).toBe(false);
+
+            await signAndSend();
+
+            expect(signTransaction).not.toHaveBeenCalled();
+            expect(mockNode.broadcast).toEqual([]);
+            expect(shown("confirm-network-changed-error")).toBe(true);
+        });
+
+        test("with a fee quoted by a node with no type-2 pricing, shows the fee in that network's native currency and price", async () => {
+            await review(reviewedOn);
+            mockNode.legacyFees = true;
+            await switchReopenAndGoBack(reviewedOn, switchedTo);
+
+            expect(el("confirm-fee-amount").textContent).toBe(
+                "0.0002 " + symbol + usdOn(reviewedOn, "$0.42"),
+            );
+        });
+
+        test("of an ERC-20 token, links the token contract to that network's explorer and prices the token by that network", async () => {
+            mockNode.tokenUnits[reviewedOn] = 50000000n;
+            await review(reviewedOn, {
+                token: TOKEN,
+                tokenSymbol: "USDC",
+                tokenDecimals: 6,
+                amount: "10",
+            });
+            await switchReopenAndGoBack(reviewedOn, switchedTo);
+
+            expect(el("confirm-type").textContent).toBe(
+                "ERC-20 token transfer (USDC)",
+            );
+            expect(el("confirm-token-contract").innerHTML).toContain(
+                `href="${explorerUrl}/address/${TOKEN}"`,
+            );
+            expect(el("confirm-amount").textContent).toBe(
+                "10.0000 USDC" + usdOn(reviewedOn, "$10.00"),
+            );
+            expect(el("confirm-balance").textContent).toBe(
+                "50.0000 USDC" + usdOn(reviewedOn, "$50.00"),
             );
         });
     },
@@ -257,3 +677,101 @@ test("the send is refused by a signer on another network's node", async () => {
     expect(signTransaction).not.toHaveBeenCalled();
     expect(mockNode.broadcast).toEqual([]);
 });
+
+describe("the balance read", () => {
+    test("leaves the balance line Loading... and Sign & Send disabled until it returns", async () => {
+        let answer;
+        const getBalance = jest
+            .spyOn(JsonRpcProvider.prototype, "getBalance")
+            .mockImplementationOnce(() => new Promise((r) => (answer = r)));
+        try {
+            await review("sepolia");
+        } finally {
+            getBalance.mockRestore();
+        }
+        expect(el("confirm-balance").textContent).toBe("Loading...");
+        expect(el("confirm-fee-amount").textContent).toBe("Estimating...");
+        expect(el("confirm-errors").style.visibility).toBe("hidden");
+        expect(shown("confirm-balance-error")).toBe(false);
+        expect(shown("confirm-balance-read-error")).toBe(false);
+        expect(sendDisabled()).toBe(true);
+
+        answer(parseEther("5"));
+        await settle();
+        expect(el("confirm-balance").textContent).toBe("5.0000 SepoliaETH");
+        expect(sendDisabled()).toBe(false);
+    });
+
+    // The Chrome suite measures that nothing moves; this checks the message
+    // is already written, only hidden, before the read returns.
+    test("that finds the amount not covered only makes a message written before it visible", async () => {
+        let answer;
+        const getBalance = jest
+            .spyOn(JsonRpcProvider.prototype, "getBalance")
+            .mockImplementationOnce(() => new Promise((r) => (answer = r)));
+        try {
+            await review("sepolia");
+        } finally {
+            getBalance.mockRestore();
+        }
+        const message =
+            "Your SepoliaETH balance does not cover this amount. Please go" +
+            " back and send a smaller amount.";
+        expect(el("confirm-balance-error").textContent).toBe(message);
+        expect(shown("confirm-balance-error")).toBe(false);
+
+        answer(parseEther("0.5"));
+        await settle();
+        expect(el("confirm-balance-error").textContent).toBe(message);
+        expect(shown("confirm-balance-error")).toBe(true);
+        expect(errors()).toBe("");
+        expect(sendDisabled()).toBe(true);
+    });
+
+    // The fee is estimated once the read returns, after the switch, and still
+    // asks the node of the network the screen was drawn for.
+    test("still in flight when Sepolia is chosen in Settings leaves the balance and the fee on mainnet", async () => {
+        let answer;
+        const getBalance = jest
+            .spyOn(JsonRpcProvider.prototype, "getBalance")
+            .mockImplementationOnce(() => new Promise((r) => (answer = r)));
+        try {
+            await review("mainnet");
+        } finally {
+            getBalance.mockRestore();
+        }
+        const feeAskedOn = () =>
+            mockNode.asked
+                .filter((q) => q.method === "getFeeData")
+                .map((q) => q.network);
+        expect(feeAskedOn()).toEqual([]);
+
+        await onChainSwitch("sepolia");
+        answer(parseEther("5"));
+        await settle();
+
+        expect(feeAskedOn()).toEqual(["mainnet"]);
+        expect(el("confirm-balance").textContent).toBe("5.0000 ETH");
+        // 21000 gas at 10 gwei expected, at 20 gwei reserved.
+        expect(el("confirm-fee-amount").textContent).toBe("~0.0002 ETH");
+        expect(el("confirm-fee-reserve").textContent).toBe(
+            "up to 0.0004 ETH reserved",
+        );
+    });
+
+    test("that fails states the balance as unknown, not zero, and blocks sending", async () => {
+        const getBalance = jest
+            .spyOn(JsonRpcProvider.prototype, "getBalance")
+            .mockRejectedValueOnce(new Error("the node did not answer"));
+        try {
+            await review("sepolia");
+        } finally {
+            getBalance.mockRestore();
+        }
+        expect(el("confirm-balance").textContent).toBe("unknown (SepoliaETH)");
+        expect(shown("confirm-balance-read-error")).toBe(true);
+        expect(shown("confirm-balance-error")).toBe(false);
+        expect(errors()).toBe("");
+        expect(sendDisabled()).toBe(true);
+    });
+});

tests/connectedSitesWorkerRestart.test.js

@@ -0,0 +1,354 @@
+// A site allowed without "Remember my choice for this site" stays connected
+// when the background worker is stopped and started again
+// (https://git.eeqj.de/sneak/AutistMask/issues/526).
+//
+// Chrome stops the worker after about 30 seconds idle and evaluates the
+// module afresh on the next event, so nothing held at module scope survives
+// it. Such a connection used to be held exactly there, and so lasted until the
+// first idle spell. Each test here makes the connection in one load of the
+// background, loads the module afresh over the same storage, as the browser
+// does, and asks the new one. The paths that end a connection are driven after
+// that restart, so each is shown to end what the earlier worker stored.
+
+const { networkById } = require("../src/shared/networks");
+const { makeStorageStub } = require("./support/storageStub");
+const {
+    removeAddressFromState,
+    removeWalletFromState,
+} = require("../src/shared/walletDelete");
+
+const ADDRESS = "0x66133E8ea0f5D1d612D2502a968757D1048c214a";
+const OTHER_ADDRESS = "0x70997970C51812dc3A010C7d01b50e0d17dc79C8";
+
+const SITE = "https://dapp.example";
+const OTHER_SITE = "https://other.example";
+
+const EXT_URL = "chrome-extension://autistmask/";
+const FROM_POPUP = { url: EXT_URL + "src/popup/index.html" };
+
+// One wallet with two addresses, so that one of them can be removed, and no
+// remembered sites, so that every connection here is one made without
+// "Remember".
+function storedProfile() {
+    const mainnet = networkById("mainnet");
+    return {
+        hasWallet: true,
+        wallets: [
+            {
+                name: "Wallet 1",
+                type: "hd",
+                addresses: [
+                    { address: ADDRESS, balance: "0", tokenBalances: [] },
+                    { address: OTHER_ADDRESS, balance: "0", tokenBalances: [] },
+                ],
+            },
+        ],
+        activeAddress: ADDRESS,
+        networkId: "mainnet",
+        rpcUrl: mainnet.defaultRpcUrl,
+        blockscoutUrl: mainnet.defaultBlockscoutUrl,
+        allowedSites: {},
+        deniedSites: {},
+        trackedTokens: [],
+    };
+}
+
+async function settle() {
+    for (let i = 0; i < 50; i++) await Promise.resolve();
+}
+
+afterEach(() => {
+    delete global.chrome;
+    jest.resetModules();
+});
+
+// Load the background module afresh, as the browser does when it starts the
+// worker, over `storage`. The storage stub stands in for the browser's own
+// storage, local and session, so it outlives each load.
+function startWorker(storage) {
+    jest.resetModules();
+    jest.doMock("../src/shared/balances", () => ({
+        getProvider: () => ({}),
+        refreshBalances: jest.fn(async () => {}),
+    }));
+    jest.doMock("../src/shared/phishingDomains", () => ({
+        isPhishingDomain: () => false,
+    }));
+    jest.doMock("../src/shared/alarms", () => ({
+        BALANCE_REFRESH_ALARM: "balance",
+        BALANCE_REFRESH_PERIOD_MINUTES: 1,
+        ensureRecurringAlarms: jest.fn(async () => {}),
+        registerAlarmHandlers: jest.fn(),
+    }));
+
+    let messageListener = null;
+    let connectListener = null;
+    // Every URL the toolbar popup was set to open: a site's connection prompt
+    // is shown there, so this is where its approval id appears.
+    const toolbarPopups = [];
+    const windowsCreated = [];
+    const sentToTabs = [];
+
+    global.chrome = {
+        storage,
+        runtime: {
+            getURL: (path) => EXT_URL + path,
+            onMessage: {
+                addListener: (fn) => {
+                    messageListener = fn;
+                },
+            },
+            onConnect: {
+                addListener: (fn) => {
+                    connectListener = fn;
+                },
+            },
+            getPlatformInfo: (cb) => cb({ os: "linux" }),
+            // What the popup sends reaches the worker from the extension's own
+            // page.
+            sendMessage: (msg, callback) => {
+                messageListener(msg, FROM_POPUP, callback || (() => {}));
+            },
+            lastError: null,
+        },
+        windows: {
+            getLastFocused: (cb) => cb(null),
+            create: (options, cb) => {
+                windowsCreated.push(options);
+                cb({ id: windowsCreated.length });
+            },
+            remove: (id, cb) => {
+                if (cb) cb();
+            },
+            onRemoved: { addListener: () => {} },
+        },
+        tabs: {
+            query: (q, cb) => cb([{ id: 1, url: SITE + "/app" }]),
+            sendMessage: (tabId, msg, cb) => {
+                sentToTabs.push(msg);
+                if (cb) cb();
+            },
+        },
+        action: {
+            setPopup: (o) => {
+                toolbarPopups.push(o.popup);
+            },
+            openPopup: () => Promise.resolve(),
+        },
+    };
+
+    require("../src/background/index");
+
+    // A request from a site, answered once the worker has had time to answer.
+    async function rpc(method, origin, params) {
+        let response = null;
+        messageListener(
+            { type: "AUTISTMASK_RPC", method, params: params || [] },
+            { origin },
+            (r) => {
+                response = r;
+            },
+        );
+        await settle();
+        return response;
+    }
+
+    // A message from the popup, and the worker's answer to it.
+    async function fromPopup(msg) {
+        let response;
+        messageListener(msg, FROM_POPUP, (r) => {
+            response = r;
+        });
+        await settle();
+        return response;
+    }
+
+    // The site asks to connect, and the user allows it in the prompt with
+    // "Remember my choice for this site" left unchecked.
+    async function connectWithoutRemember(origin) {
+        let response = null;
+        messageListener(
+            { type: "AUTISTMASK_RPC", method: "eth_requestAccounts" },
+            { origin },
+            (r) => {
+                response = r;
+            },
+        );
+        await settle();
+        const id = new URL(toolbarPopups.at(-1), EXT_URL).searchParams.get(
+            "approval",
+        );
+        const decisionListeners = [];
+        const port = {
+            name: "approval:" + id,
+            sender: { url: EXT_URL + "src/popup/index.html?approval=" + id },
+            onMessage: { addListener: (fn) => decisionListeners.push(fn) },
+            onDisconnect: { addListener: () => {} },
+        };
+        connectListener(port);
+        for (const fn of decisionListeners) {
+            fn(
+                {
+                    type: "AUTISTMASK_APPROVAL_DECISION",
+                    approved: true,
+                    remember: false,
+                },
+                port,
+            );
+        }
+        await settle();
+        return response;
+    }
+
+    return {
+        rpc,
+        fromPopup,
+        connectWithoutRemember,
+        windowsCreated,
+        sentToTabs,
+    };
+}
+
+// A site connected without "Remember" in one worker, and the worker started
+// again over the same storage, where the site is still connected.
+async function connectedThenRestarted() {
+    const storage = makeStorageStub({ autistmask: storedProfile() });
+    const first = startWorker(storage);
+    expect(await first.connectWithoutRemember(SITE)).toEqual({
+        result: [ADDRESS],
+    });
+    const worker = startWorker(storage);
+    expect(await worker.rpc("eth_accounts", SITE)).toEqual({
+        result: [ADDRESS],
+    });
+    return { storage, worker };
+}
+
+describe("a site allowed without Remember, after the worker restarts", () => {
+    test("is still told the address, and is not asked again", async () => {
+        const { worker } = await connectedThenRestarted();
+
+        expect(await worker.rpc("eth_accounts", SITE)).toEqual({
+            result: [ADDRESS],
+        });
+        expect(await worker.rpc("eth_requestAccounts", SITE)).toEqual({
+            result: [ADDRESS],
+        });
+    });
+
+    test("is still listed under Connected Sites in Settings", async () => {
+        const { worker } = await connectedThenRestarted();
+
+        expect(
+            await worker.fromPopup({ type: "AUTISTMASK_GET_CONNECTED_SITES" }),
+        ).toEqual([SITE]);
+    });
+
+    test("may still ask for a signature", async () => {
+        // Refused with 4100 before the fix. Allowed, it raises the signing
+        // prompt and waits on the user.
+        const { worker } = await connectedThenRestarted();
+
+        const response = await worker.rpc("personal_sign", SITE, [
+            "0x48656c6c6f",
+            ADDRESS,
+        ]);
+
+        expect(response).toBeNull();
+        expect(worker.windowsCreated).toHaveLength(1);
+    });
+
+    test("is not connected after the browser restarts", async () => {
+        // The browser empties session storage when it closes; the wallet's
+        // own storage keeps nothing of the connection.
+        const { storage } = await connectedThenRestarted();
+        const afterBrowserRestart = startWorker(
+            makeStorageStub({ autistmask: storage.read("autistmask") }),
+        );
+
+        expect(await afterBrowserRestart.rpc("eth_accounts", SITE)).toEqual({
+            result: [],
+        });
+    });
+});
+
+describe("each way a connection allowed without Remember ends, after the worker restarts", () => {
+    test("removing the site in Settings", async () => {
+        const { worker } = await connectedThenRestarted();
+        expect(await worker.connectWithoutRemember(OTHER_SITE)).toEqual({
+            result: [ADDRESS],
+        });
+
+        await worker.fromPopup({
+            type: "AUTISTMASK_REMOVE_SITE",
+            origin: SITE,
+        });
+
+        expect(await worker.rpc("eth_accounts", SITE)).toEqual({ result: [] });
+        expect(worker.sentToTabs).toEqual([
+            {
+                type: "AUTISTMASK_EVENT",
+                eventName: "accountsChanged",
+                data: [],
+            },
+        ]);
+        expect(
+            await worker.fromPopup({ type: "AUTISTMASK_GET_CONNECTED_SITES" }),
+        ).toEqual([OTHER_SITE]);
+        expect(await worker.rpc("eth_accounts", OTHER_SITE)).toEqual({
+            result: [ADDRESS],
+        });
+    });
+
+    test("switching to another address", async () => {
+        // Switched away and back again, so the answer turns on the connection
+        // having ended rather than on which address is active.
+        const { storage, worker } = await connectedThenRestarted();
+        const switched = { ...storage.read("autistmask") };
+
+        switched.activeAddress = OTHER_ADDRESS;
+        storage.write("autistmask", switched);
+        await worker.fromPopup({ type: "AUTISTMASK_ACTIVE_CHANGED" });
+        switched.activeAddress = ADDRESS;
+        storage.write("autistmask", switched);
+
+        expect(await worker.rpc("eth_accounts", SITE)).toEqual({ result: [] });
+        expect(
+            await worker.fromPopup({ type: "AUTISTMASK_GET_CONNECTED_SITES" }),
+        ).toEqual([]);
+    });
+
+    // The two below ask while storage still names the removed address as
+    // active, because the popup has not saved yet, so the answer turns on the
+    // connection alone.
+    test("removing the connected address", async () => {
+        const { storage, worker } = await connectedThenRestarted();
+
+        const popupState = storage.read("autistmask");
+        expect(removeAddressFromState(popupState, 0, 0).removed).toBe(true);
+        await settle();
+
+        expect(await worker.rpc("eth_accounts", SITE)).toEqual({ result: [] });
+    });
+
+    test("removing the wallet holding the connected address", async () => {
+        const { storage, worker } = await connectedThenRestarted();
+
+        removeWalletFromState(storage.read("autistmask"), 0);
+        await settle();
+
+        expect(await worker.rpc("eth_accounts", SITE)).toEqual({ result: [] });
+    });
+
+    test("removing a different address leaves it connected", async () => {
+        const { storage, worker } = await connectedThenRestarted();
+
+        const popupState = storage.read("autistmask");
+        expect(removeAddressFromState(popupState, 0, 1).removed).toBe(true);
+        await settle();
+
+        expect(await worker.rpc("eth_accounts", SITE)).toEqual({
+            result: [ADDRESS],
+        });
+    });
+});

tests/contractCreation.test.js

@@ -192,6 +192,7 @@ describe("the wait, success and error screens", () => {
         amount: "0.0000",
         token: "ETH",
         tokenSymbol: null,
+        chainId: "0x1",
     };
     const transfer = { ...creation, to: RECIPIENT };
 

tests/deleteWalletLostPassword.test.js

@@ -259,6 +259,36 @@ describe("reaching the screen", () => {
     });
 });
 
+// Both screens tell the user what they need to get the wallet back, and a
+// key or xprv wallet has no recovery phrase: telling its owner to rely on
+// one sends them looking for words that do not exist
+// (https://git.eeqj.de/sneak/AutistMask/issues/529).
+describe("what the screens say the wallet's backup is", () => {
+    test.each([
+        ["hd", "recovery phrase"],
+        ["key", "private key"],
+        ["xprv", "extended private key"],
+    ])(
+        "a wallet of type %s is told about its %s",
+        async (type, keyMaterial) => {
+            const { deleteWallet, state } = load();
+            state.wallets[1].type = type;
+
+            deleteWallet.show(1);
+            expect(state.currentView).toBe("delete-wallet-confirm");
+            expect(node("delete-wallet-key-material").textContent).toBe(
+                keyMaterial,
+            );
+
+            await click("btn-delete-wallet-lost-password");
+            expect(state.currentView).toBe(VIEW);
+            expect(node("delete-wallet-lost-key-material").textContent).toBe(
+                keyMaterial,
+            );
+        },
+    );
+});
+
 describe("the typed confirmation", () => {
     test("a name that is not the wallet's deletes nothing", async () => {
         const { deleteWallet, state, storage } = load();

tests/dustThreshold.test.js

@@ -101,7 +101,7 @@ describe("the flash line the message is shown in", () => {
     //
     // The line cuts a message too long for it with an ellipsis (see
     // showFlash() in src/popup/views/helpers.js). The assertions that
-    // measure that, in a real browser at the documented 360x600 popup, are
+    // measure that, in a real browser at the documented 396x600 popup, are
     // "a rejected dust threshold shifts no layout (#233)" and "an over-long
     // flash message keeps to one line (#252)" in tests/e2e/run.js, run by
     // make test-e2e. They are not in make check because REPO_POLICIES.md

tests/e2e/network.js

@@ -226,8 +226,9 @@ const RPC_RESULTS = {
 // The "latest" block, which ethers' getFeeData() reads baseFeePerGas from
 // to derive maxFeePerGas. Without it every fee is a legacy gasPrice, the
 // reserve and the estimate collapse to the same number, and the gate tests
-// stop being able to distinguish them.
-function latestBlock() {
+// stop being able to distinguish them. opts.baseFeeWei replaces its base fee,
+// read at request time like every other fixture switch.
+function latestBlock(opts) {
     return {
         hash: "0x" + "11".repeat(32),
         parentHash: "0x" + "22".repeat(32),
@@ -239,21 +240,26 @@ function latestBlock() {
         gasUsed: "0xf4240",
         miner: STUB_COUNTERPARTY,
         extraData: "0x",
-        baseFeePerGas: hex(BASE_FEE_WEI),
+        baseFeePerGas: opts.baseFeeWei || hex(BASE_FEE_WEI),
         transactions: [],
     };
 }
 
-// keccak("decimals()")[0:4], and the same for symbol() and name().
+// keccak("decimals()")[0:4], and the same for symbol(), name() and
+// balanceOf(address).
 const SELECTOR_DECIMALS = "0x313ce567";
 const SELECTOR_SYMBOL = "0x95d89b41";
 const SELECTOR_NAME = "0x06fdde03";
+const SELECTOR_BALANCE_OF = "0x70a08231";
 
-// Every eth_call still answers with a zero word except decimals(), symbol()
-// and name() on the stub token. The wallet reads decimals() back at signing
-// time to compare with the scale the confirmation screen rendered (issue
-// #305). Adding the token by its contract address reads all three (issue
-// #295); symbol() and name() answer what the explorer reports for it.
+// Every eth_call still answers with a zero word except decimals(), symbol(),
+// name() and balanceOf() on the stub token. The wallet reads decimals() back
+// at signing time to compare with the scale the confirmation screen rendered
+// (issue #305). Adding the token by its contract address reads the first three
+// (issue #295); symbol() and name() answer what the explorer reports for it.
+// The confirmation screen reads balanceOf()
+// (https://git.eeqj.de/sneak/AutistMask/issues/558), which answers the holding
+// the explorer reports, or zero when no holding is seeded.
 //
 // opts.tokenDecimalsOverride is the lying contract: set it and decimals()
 // answers something other than the value this same fixture reports through
@@ -278,6 +284,9 @@ function ethCallResult(req, opts) {
     if (data.startsWith(SELECTOR_NAME)) {
         return abi.encode(["string"], [tokenObject(opts).name]);
     }
+    if (data.startsWith(SELECTOR_BALANCE_OF) && opts.seedTokenBalance) {
+        return word(tokenBalanceItems(opts)[0].value);
+    }
     return ZERO_WORD;
 }
 
@@ -420,9 +429,10 @@ const HOLD_MAX_MS = 30000;
 
 // Hold a reply open for as long as the test asks: until opts[name] is false.
 //
-// The switch (holdGasEstimate, holdTransactionCount or holdBlockscout) is read
-// here rather than captured, so a test flips it on the same options object the
-// route was registered with — the same pattern as seedTokenTransfer. This is
+// The switch (holdBalance, holdGasEstimate, holdTransactionCount or
+// holdBlockscout) is read here rather than captured, so a test flips it on the
+// same options object the route was registered with — the same pattern as
+// seedTokenTransfer. This is
 // the only way to observe a screen while its request is genuinely in flight;
 // sampling the screen and hoping to win a race against the network would
 // assert nothing on a slow machine.
@@ -472,7 +482,7 @@ function rpcReply(req, opts, report) {
         });
     }
     if (req.method === "eth_getBlockByNumber") {
-        return Object.assign(envelope, { result: latestBlock() });
+        return Object.assign(envelope, { result: latestBlock(opts) });
     }
     // The end of the dApp transaction round trip: the raw signed transaction
     // the background hands to the node. It is recorded verbatim so a test can
@@ -557,6 +567,9 @@ async function handleRpc(route, postData, opts, report) {
         report("unstubbed request: POST " + route.request().url());
         return route.abort();
     }
+    if (batch.some((req) => req.method === "eth_getBalance")) {
+        await awaitRelease(opts, "holdBalance", report);
+    }
     if (batch.some((req) => req.method === "eth_estimateGas")) {
         await awaitRelease(opts, "holdGasEstimate", report);
     }
@@ -613,8 +626,12 @@ function traceEnabled(raw) {
  * @param {string} [opts.ethBalanceWei]  hex wei answered to eth_getBalance;
  *   defaults to zero, which is what every test that predates the funded
  *   fixture expects.
+ * @param {string} [opts.baseFeeWei]  hex wei answered as the latest block's
+ *   baseFeePerGas; defaults to BASE_FEE_WEI. Read at request time.
  * @param {boolean} [opts.failGasEstimate]  answer eth_estimateGas with a
  *   node-side refusal.
+ * @param {boolean} [opts.holdBalance]  hold every batch containing an
+ *   eth_getBalance until this is cleared again.
  * @param {boolean} [opts.holdGasEstimate]  hold every batch containing an
  *   eth_estimateGas until this is cleared again.
  * @param {boolean} [opts.holdTransactionCount]  hold every batch containing an

tests/e2e/run.js

@@ -60,6 +60,14 @@ const TEST_TIMEOUT_MS = 120000;
 // trailing drain in main().
 const TRAILING_WATCH_MS = 1500;
 
+// The popup's size, as README gives it: `body` in src/popup/styles/main.css
+// is 396px wide, and src/background/index.js opens an approval window at
+// the same 396x600. Pages in this context otherwise get Playwright's
+// 1280x720 default, where the page never scrolls sideways and a button
+// below the popup's fold is still on screen, so a layout measured there
+// passes whatever the page does.
+const POPUP_VIEWPORT = { width: 396, height: 600 };
+
 const tests = [];
 
 function test(name, fn) {
@@ -1824,13 +1832,66 @@ test("the Settings assertions above all ran (#229)", async (env) => {
     );
 });
 
-// ------------------------------------------------ dust threshold (#233)
+// ------------------------------------------------ testnet banner (#511)
 
-// The popup size README documents the UI as designed for. Pages in this
-// context otherwise get Playwright's 1280x720 default, at which the flash
-// line has room for any plausible message and never wraps — measuring
-// there would pass for every string and prove nothing.
-const POPUP_VIEWPORT = { width: 360, height: 600 };
+// This suite runs a release build, so the red banner at the top reads
+// "[TESTNET]" on Sepolia and is absent on mainnet. A network switch in
+// Settings must change it while Settings is still on screen; it used to
+// change only when the next screen came up
+// (https://git.eeqj.de/sneak/AutistMask/issues/511).
+
+// The banner's text, or null when there is none, once the switch to `net`
+// has finished. The switch's flash is the last thing its handler does, and
+// showView() clears the flash, so the banner read while that flash is up is
+// the one the switch left on the screen it was made from.
+async function bannerAfterSwitch(page, net) {
+    await page.waitForFunction(
+        (text) => document.getElementById("flash-msg").textContent === text,
+        "Switched to " + net.name + ".",
+    );
+    return page.evaluate(() => {
+        const banner = document.getElementById("debug-banner");
+        return {
+            text: banner === null ? null : banner.textContent,
+            onSettings: !document
+                .getElementById("view-settings")
+                .classList.contains("hidden"),
+        };
+    });
+}
+
+test("a network switch in Settings shows and removes the testnet banner at once (#511)", async (env) => {
+    const { mainnet, sepolia } = NETWORKS;
+    await openSettings(env.page);
+    assert(
+        (await env.page.locator("#debug-banner").count()) === 0,
+        "a banner is up on mainnet before the switch",
+    );
+
+    await env.page.selectOption("#settings-network", "sepolia");
+    let after = await bannerAfterSwitch(env.page, sepolia);
+    assert(after.onSettings, "Settings left the screen on the switch");
+    assert(
+        after.text === "[TESTNET]",
+        "after the switch to Sepolia, Settings shows the banner " +
+            JSON.stringify(after.text) +
+            ', expected "[TESTNET]"',
+    );
+
+    await env.page.selectOption("#settings-network", "mainnet");
+    after = await bannerAfterSwitch(env.page, mainnet);
+    assert(after.onSettings, "Settings left the screen on the switch back");
+    assert(
+        after.text === null,
+        "after the switch back to mainnet, Settings still shows the banner " +
+            JSON.stringify(after.text),
+    );
+
+    await env.page.click("#btn-settings-back");
+    await visible(env.page, "#view-main");
+});
+
+// ------------------------------------------------ dust threshold (#233)
 
 // Everything below the flash line that must not move when it fills, plus
 // the height of the line itself. Runs in the page.
@@ -2080,7 +2141,7 @@ test("a password error moves nothing on any screen (#297)", async (env) => {
 
 // ------------------------------------------ add wallet Import button (#493)
 
-// At 360x600 the add wallet screen's Import button already starts near the
+// At 396x600 the add wallet screen's Import button already starts near the
 // bottom of the popup, so its password error line sits beside the button
 // rather than above it. Measures the button and the line empty and again
 // filled with the longest error addWallet.js puts there. Runs in the page.
@@ -2232,7 +2293,8 @@ function feeEth(wei) {
 
 // What the confirmation screen is showing right now, read out of the DOM in
 // one pass: whether sending is allowed, which reason it is giving, what the
-// fee block says, and how tall the whole view is.
+// fee block says, how tall the whole view is, and where the password field and
+// Sign & Send sit in it.
 async function confirmState(page) {
     return page.evaluate(() => {
         const el = (id) => document.getElementById(id);
@@ -2245,6 +2307,12 @@ async function confirmState(page) {
         };
         return {
             height: el("view-confirm-tx").getBoundingClientRect().height,
+            passwordTop:
+                el("confirm-tx-password").getBoundingClientRect().top -
+                el("view-confirm-tx").getBoundingClientRect().top,
+            sendTop:
+                el("btn-confirm-send").getBoundingClientRect().top -
+                el("view-confirm-tx").getBoundingClientRect().top,
             type: el("confirm-type").textContent.trim(),
             balance: el("confirm-balance").textContent.trim(),
             fee: el("confirm-fee-amount").textContent.trim(),
@@ -2253,9 +2321,18 @@ async function confirmState(page) {
             errors: shown("confirm-errors")
                 ? el("confirm-errors").textContent.trim()
                 : "",
+            balanceError: shown("confirm-balance-error")
+                ? el("confirm-balance-error").textContent.trim()
+                : "",
             amountFeeError: shown("confirm-amount-fee-error"),
             gasError: shown("confirm-gas-error"),
             feeUnknownError: shown("confirm-fee-unknown-error"),
+            // Its sentence is wrapped across lines in index.html.
+            feeBoundError: shown("confirm-fee-bound-error")
+                ? el("confirm-fee-bound-error")
+                      .textContent.replace(/\s+/g, " ")
+                      .trim()
+                : "",
             sendDisabled: el("btn-confirm-send").disabled,
         };
     });
@@ -2271,6 +2348,16 @@ async function waitForEstimate(page) {
     );
 }
 
+async function waitForBalance(page) {
+    await page.waitForFunction(
+        () =>
+            document.getElementById("confirm-balance").textContent.trim() !==
+            "Loading...",
+        null,
+        { timeout: 60000 },
+    );
+}
+
 async function backToAddress(page) {
     if (await page.isVisible("#view-confirm-tx")) {
         await page.click("#btn-confirm-back");
@@ -2282,13 +2369,14 @@ async function backToAddress(page) {
     await openAddressDetail(page);
 }
 
-// Drive the popup to the confirmation screen for one send.
+// Drive the popup to the confirmation screen for one send, and return as soon
+// as the screen is shown, its balance read still in flight.
 //
 // It waits for the send screen to be showing `balance`, the fixture's balance
 // as that screen displays it, before filling anything in. Waiting for it —
 // rather than for a refresh to have probably landed — is what keeps every
 // assertion below deterministic after a fixture change.
-async function goToConfirm(page, { token, balance, amount }) {
+async function openConfirm(page, { token, balance, amount }) {
     await backToAddress(page);
     await page.click("#btn-send");
     await visible(page, "#view-send");
@@ -2303,6 +2391,14 @@ async function goToConfirm(page, { token, balance, amount }) {
     await page.fill("#send-amount", amount);
     await page.click("#btn-send-review");
     await visible(page, "#view-confirm-tx");
+}
+
+// The same, returning once the screen has read the balance. It reads it
+// before it estimates the fee, so every state below is read with the balance
+// in place, the pending fee included.
+async function goToConfirm(page, send) {
+    await openConfirm(page, send);
+    await waitForBalance(page);
     await assertAddressesFit(page, "the confirmation screen");
 }
 
@@ -2378,7 +2474,10 @@ test("ConfirmTx blocks sending while the fee estimate is pending (#238)", async
         "the estimate-failed message is shown for an estimate that is merely pending",
     );
     assert(
-        !st.amountFeeError && !st.gasError && st.errors === "",
+        !st.amountFeeError &&
+            !st.gasError &&
+            st.errors === "" &&
+            st.balanceError === "",
         "a balance message is shown before the fee is known",
     );
 });
@@ -2409,6 +2508,7 @@ test("ConfirmTx enables Send once the estimate lands, quoting both numbers (#238
     );
     assert(
         st.errors === "" &&
+            st.balanceError === "" &&
             !st.amountFeeError &&
             !st.gasError &&
             !st.feeUnknownError,
@@ -2475,30 +2575,54 @@ test("ConfirmTx gates on the fee RESERVE, not the displayed estimate (#238)", as
     );
 });
 
-test("ConfirmTx refuses a send that exceeds the balance outright (#238)", async (env) => {
-    await goToConfirm(env.page, {
-        token: "ETH",
-        balance: FUNDED_ETH_TEXT + " ETH",
-        amount: OVER_BALANCE_AMOUNT,
-    });
+// The screen is first measured with its balance read held, so the message the
+// read brings must already hold its space when the read returns (#558).
+test("ConfirmTx refuses a send that exceeds the balance outright, and nothing moves when the balance arrives (#238)", async (env) => {
+    env.routeOpts.holdBalance = true;
+    let reading;
+    try {
+        await openConfirm(env.page, {
+            token: "ETH",
+            balance: FUNDED_ETH_TEXT + " ETH",
+            amount: OVER_BALANCE_AMOUNT,
+        });
+        reading = await confirmState(env.page);
+    } finally {
+        env.routeOpts.holdBalance = false;
+    }
+    assert(
+        reading.balance === "Loading...",
+        "the balance read was not held: " + JSON.stringify(reading.balance),
+    );
+    await waitForBalance(env.page);
     await waitForEstimate(env.page);
 
     const st = await confirmState(env.page);
-    const want =
-        "Insufficient balance. You have " +
-        FUNDED_ETH_TEXT +
-        " ETH but are trying to send " +
-        OVER_BALANCE_AMOUNT +
-        " ETH.";
     assert(
-        st.errors === want,
-        "wrong over-balance message: " + JSON.stringify(st.errors),
+        st.balance === FUNDED_ETH_TEXT + " ETH",
+        "the confirmation screen shows the wrong balance: " +
+            JSON.stringify(st.balance),
+    );
+    const want =
+        "Your ETH balance does not cover this amount. Please go back and" +
+        " send a smaller amount.";
+    assert(
+        st.balanceError === want,
+        "wrong over-balance message: " + JSON.stringify(st.balanceError),
     );
     assert(st.sendDisabled, "Send is enabled for a send that exceeds balance");
     assert(
         !st.amountFeeError,
         "the amount-plus-fee message is shown for an amount that alone exceeds the balance",
     );
+    assert(
+        st.sendTop === reading.sendTop,
+        "Sign & Send moved when the balance read returned: " +
+            reading.sendTop +
+            "px -> " +
+            st.sendTop +
+            "px",
+    );
 });
 
 test("ConfirmTx refuses to send when the fee estimate fails, with its own message (#238)", async (env) => {
@@ -2542,7 +2666,10 @@ test("ConfirmTx refuses to send when the fee estimate fails, with its own messag
             "the estimate-failed message is not shown after a failed estimate",
         );
         assert(
-            !st.amountFeeError && !st.gasError && st.errors === "",
+            !st.amountFeeError &&
+                !st.gasError &&
+                st.errors === "" &&
+                st.balanceError === "",
             "a balance message is shown for an estimate that simply failed",
         );
         assert(
@@ -2633,21 +2760,19 @@ test("ConfirmTx refuses an ERC-20 send that exceeds the token balance (#238)", a
     await waitForEstimate(env.page);
 
     const st = await confirmState(env.page);
-    const want =
-        "Insufficient " +
-        STUB_TOKEN.symbol +
-        " balance. You have " +
-        TOKEN_BALANCE_TEXT +
-        " " +
-        STUB_TOKEN.symbol +
-        " but are trying to send " +
-        OVER_TOKEN_AMOUNT +
-        " " +
-        STUB_TOKEN.symbol +
-        ".";
     assert(
-        st.errors === want,
-        "wrong over-token-balance message: " + JSON.stringify(st.errors),
+        st.balance === TOKEN_BALANCE_TEXT + " " + STUB_TOKEN.symbol,
+        "the confirmation screen shows the wrong token balance: " +
+            JSON.stringify(st.balance),
+    );
+    const want =
+        "Your " +
+        STUB_TOKEN.symbol +
+        " balance does not cover this amount. Please go back and send a" +
+        " smaller amount.";
+    assert(
+        st.balanceError === want,
+        "wrong over-token-balance message: " + JSON.stringify(st.balanceError),
     );
     assert(
         st.sendDisabled,
@@ -2703,9 +2828,9 @@ test("ConfirmTx gates the ERC-20 fee on the RESERVE, with the ERC-20 message (#2
         "the native-ETH over-budget message is shown on an ERC-20 transfer",
     );
     assert(
-        st.errors === "",
+        st.errors === "" && st.balanceError === "",
         "a token-balance message is shown for a transfer the token balance covers: " +
-            JSON.stringify(st.errors),
+            JSON.stringify(st.errors + st.balanceError),
     );
     assert(
         st.height === env.erc20PendingHeight,
@@ -2851,9 +2976,10 @@ async function goToTokenConfirm(env) {
         amount: TOKEN_AMOUNT,
     });
     await waitForEstimate(env.page);
+    // TOKEN_AMOUNT to four decimal places (README.md, Display Consistency).
     const shown = await shownAmount(env.page);
     assert(
-        shown === TOKEN_AMOUNT + " " + STUB_TOKEN.symbol,
+        shown === "0.2500 " + STUB_TOKEN.symbol,
         "the confirmation screen is not showing the amount that was entered: " +
             JSON.stringify(shown),
     );
@@ -3003,6 +3129,210 @@ test("a token that lies about decimals() at signing time broadcasts nothing (#30
     }
 });
 
+// ------------------------- a send Sign & Send refuses moves nothing (#583)
+//
+// README, No Layout Shift. Sign & Send refuses a send on the confirmation
+// screen when the active network changed since review and when its gas limit
+// or fee is over its bound, and each refusal's sentence sits in a box that held
+// its space from the first paint. This drives the total fee refusal, the longer
+// of the two sentences.
+
+// The base fee the stub node quotes once Sign & Send is pressed. ethers asks
+// twice it plus the 1 gwei priority fee per gas, 50,001 gwei, so the 21,000-gas
+// send would allow a fee of about 1.05 ETH, over the 1 ETH this wallet signs
+// for (MAX_TOTAL_FEE in src/shared/approvalVerify.js).
+const OVER_BOUND_BASE_FEE_WEI = 25000n * 10n ** 9n;
+
+test("a send refused for its fee leaves the password field and Sign & Send where they were (#583)", async (env) => {
+    env.errors.expect("confirmTx logging the refused send", /send refused/);
+    try {
+        await goToConfirm(env.page, {
+            token: "ETH",
+            balance: FUNDED_ETH_TEXT + " ETH",
+            amount: COMFORTABLE_AMOUNT,
+        });
+        await waitForEstimate(env.page);
+        const before = await confirmState(env.page);
+        assert(
+            !before.sendDisabled && before.feeBoundError === "",
+            "the screen is not ready to send: " + JSON.stringify(before),
+        );
+
+        // Only now, with the screen drawn and its fee estimated, does the
+        // node quote a fee over the bound.
+        env.routeOpts.baseFeeWei = toHexWei(OVER_BOUND_BASE_FEE_WEI);
+        const sent = env.routeOpts.broadcastTransactions.length;
+        await fillPasswordAndSend(env.page);
+        await env.page.waitForFunction(
+            () =>
+                getComputedStyle(
+                    document.getElementById("confirm-fee-bound-error"),
+                ).visibility === "visible",
+            null,
+            { timeout: 60000 },
+        );
+        const after = await confirmState(env.page);
+
+        // Printed pass or fail, as the dust threshold test does.
+        console.log(
+            "# refused send: password field top " +
+                before.passwordTop +
+                " -> " +
+                after.passwordTop +
+                "px, Sign & Send top " +
+                before.sendTop +
+                " -> " +
+                after.sendTop +
+                "px",
+        );
+        assert(
+            env.routeOpts.broadcastTransactions.length === sent,
+            "a send over the fee bound reached the RPC",
+        );
+        assert(
+            after.feeBoundError ===
+                "The gas limit or fee the RPC endpoint quoted for this" +
+                    " transaction is more than this wallet will sign for, so" +
+                    " it was not sent. Please go back and try again.",
+            "wrong fee refusal: " + JSON.stringify(after.feeBoundError),
+        );
+        assert(
+            after.passwordTop === before.passwordTop,
+            "the password field moved " +
+                (after.passwordTop - before.passwordTop) +
+                "px when the send was refused",
+        );
+        assert(
+            after.sendTop === before.sendTop,
+            "Sign & Send moved " +
+                (after.sendTop - before.sendTop) +
+                "px when the send was refused",
+        );
+    } finally {
+        env.routeOpts.baseFeeWei = undefined;
+        await backToAddress(env.page);
+    }
+});
+
+// --------- a send from an address the selected wallet does not hold (#609)
+//
+// The selection is saved apart from the confirmation screen, so the popup can
+// reopen onto the screen with a wallet selected that does not hold its From
+// address, and Sign & Send then refuses the send. Another popup selecting the
+// key wallet would save that selection; here it is written into storage, and
+// the popup reopened.
+
+test("a send from an address the selected wallet does not hold leaves the password field and Sign & Send where they were (#609)", async (env) => {
+    try {
+        // From the HD wallet's address.
+        await goToConfirm(env.page, {
+            token: "ETH",
+            balance: FUNDED_ETH_TEXT + " ETH",
+            amount: COMFORTABLE_AMOUNT,
+        });
+        // The screen's own save lands first, so it cannot write over the
+        // selection below.
+        await waitForPersisted(
+            env.page,
+            "currentView",
+            "confirm-tx",
+            "before selecting the key wallet",
+        );
+        await env.page.evaluate(
+            () =>
+                new Promise((resolve) => {
+                    chrome.storage.local.get("autistmask", (r) => {
+                        const record = {
+                            ...r.autistmask,
+                            selectedWallet: 1,
+                            selectedAddress: 0,
+                        };
+                        chrome.storage.local.set(
+                            { autistmask: record },
+                            resolve,
+                        );
+                    });
+                }),
+        );
+        await reopenPopup(env, "confirm-tx");
+        await waitForEstimate(env.page);
+        // The refusal shown anywhere on the screen, not only in its own box:
+        // shown on the password error line instead, the test fails on the
+        // moves checked below rather than on the wait for it.
+        const refusal = env.page
+            .locator("#view-confirm-tx")
+            .getByText("does not hold the From address above")
+            .filter({ visible: true });
+        const before = await confirmState(env.page);
+        assert(
+            !before.sendDisabled && (await refusal.count()) === 0,
+            "the screen is not ready to send: " + JSON.stringify(before),
+        );
+
+        const sent = env.routeOpts.broadcastTransactions.length;
+        await fillPasswordAndSend(env.page);
+        await refusal.waitFor({ timeout: 60000 });
+        const after = await confirmState(env.page);
+
+        // Printed pass or fail, as the dust threshold test does.
+        console.log(
+            "# refused From address: password field top " +
+                before.passwordTop +
+                " -> " +
+                after.passwordTop +
+                "px, Sign & Send top " +
+                before.sendTop +
+                " -> " +
+                after.sendTop +
+                "px",
+        );
+        assert(
+            env.routeOpts.broadcastTransactions.length === sent,
+            "a send from an address the selected wallet does not hold" +
+                " reached the RPC",
+        );
+        assert(
+            after.passwordTop === before.passwordTop,
+            "the password field moved " +
+                (after.passwordTop - before.passwordTop) +
+                "px when the send was refused",
+        );
+        assert(
+            after.sendTop === before.sendTop,
+            "Sign & Send moved " +
+                (after.sendTop - before.sendTop) +
+                "px when the send was refused",
+        );
+        // Only now, where the refusal is shown. Its sentence is wrapped across
+        // lines in index.html.
+        const shownIn = await refusal.evaluate((el) => ({
+            id: el.id,
+            text: el.textContent.replace(/\s+/g, " ").trim(),
+        }));
+        assert(
+            shownIn.id === "confirm-from-address-error" &&
+                shownIn.text ===
+                    "The selected wallet does not hold the From address above," +
+                        " so nothing was sent. Please go back and send again.",
+            "wrong From address refusal: " + JSON.stringify(shownIn),
+        );
+    } finally {
+        // A reopened popup restores no Send screen beneath this one, so Back
+        // lands on the selected address. Then Home, and the HD wallet's
+        // address, which the later tests send from.
+        if (await env.page.isVisible("#view-confirm-tx")) {
+            await env.page.click("#btn-confirm-back");
+        }
+        if (await env.page.isVisible("#view-send")) {
+            await env.page.click("#btn-send-back");
+        }
+        await visible(env.page, "#view-address");
+        await env.page.click("#btn-address-back");
+        await visible(env.page, "#view-main");
+        await openAddressDetail(env.page);
+    }
+});
+
 // ------------------------------ the wait for a receipt ending in error (#315)
 //
 // README.md (WaitTx) documents two ways the wait ends on the error screen: a
@@ -3103,10 +3433,14 @@ test("six failed receipt lookups in a row end on the unreachable-network message
 // timeout ("<iframe id=\"pwn\"> intercepts pointer events") rather than as
 // anything that names the defect.
 
-// Verbatim from the issue's reproduction.
+// The issue's reproduction, with the frame sized to the popup.
 const HOSTILE_SYMBOL =
     '<iframe id="pwn" src="https://dapp.e2e.test/" ' +
-    'style="position:fixed;left:0;top:0;width:360px;height:600px;z-index:99999"></iframe>';
+    'style="position:fixed;left:0;top:0;width:' +
+    POPUP_VIEWPORT.width +
+    "px;height:" +
+    POPUP_VIEWPORT.height +
+    'px;z-index:99999"></iframe>';
 
 // What a correctly escaped and capped render of it reads as: the first
 // MAX_SYMBOL_LENGTH-1 characters and an ellipsis. Spelled out rather than
@@ -3861,10 +4195,8 @@ test("eth_requestAccounts approved returns the selected address (#183)", async (
         // all; this measures that the whole address is visible (#517).
         await assertAddressesFit(popup, "the connection prompt");
 
-        // Remembered, so the connection survives a background worker that MV3
-        // terminates after 30 seconds idle. The in-memory connectedSites map
-        // does not, and the sign and transaction tests below all require the
-        // origin to still be authorized.
+        // Remembered, because the sign and transaction tests below all
+        // require the origin to still be authorized.
         await popup.check("#approve-remember");
         await clickAndClose(popup, "#btn-approve");
 
@@ -4700,8 +5032,20 @@ function addressRowReport(page) {
     });
 }
 
+// Measured at the popup's 396x600 (POPUP_VIEWPORT). Every page in this
+// context, approval windows included, is otherwise 1280x720 whatever size
+// the extension asks for, and a page that wide never scrolls sideways. The
+// page is then put back to the size it had, so the size a later step runs at
+// does not depend on whether this one ran.
 async function assertAddressesFit(page, where) {
-    const report = await addressRowReport(page);
+    const sizeBefore = page.viewportSize();
+    await page.setViewportSize(POPUP_VIEWPORT);
+    let report;
+    try {
+        report = await addressRowReport(page);
+    } finally {
+        await page.setViewportSize(sizeBefore);
+    }
     assert(
         report.rows.length > 0,
         where + ": no address rows were rendered, so nothing was measured",
@@ -4861,6 +5205,9 @@ async function main() {
         seedTokenBalance: false,
         ethBalanceWei: null,
         failGasEstimate: false,
+        // Whether a JSON-RPC batch asking for a balance is held unanswered:
+        // the confirmation screen's own balance read (#558).
+        holdBalance: false,
         holdGasEstimate: false,
         // Whether a JSON-RPC batch asking for a transaction count is held
         // unanswered: the address scan after creating a wallet (#475).

tests/e2e/slowApproval.js

@@ -22,6 +22,11 @@
 // Before the approvals are raised it watches the worker stop on its own, so a
 // run in which something else keeps the worker running cannot pass.
 //
+// The site is connected without "Remember", and once the worker has stopped
+// the program requires the site still to be told the address: such a
+// connection used to be held in the worker's memory and ended with it
+// (https://git.eeqj.de/sneak/AutistMask/issues/526).
+//
 // The dApp page and the stub node are the loopback ones the Firefox suite also
 // uses (tests/e2e/dapp.js). The site is connected and the node chosen
 // through the extension's own screens, so nothing is written to its storage
@@ -311,8 +316,8 @@ async function main() {
         );
         await send("Target.closeTarget", { targetId: popup.targetId });
 
-        // The site, connected through the real prompt with "Remember", so
-        // the connection is stored rather than held by the worker.
+        // The site, connected through the real prompt without "Remember", so
+        // the connection is one that has to outlive the worker stopping below.
         const dapp = await openPage(node.url);
         await until("the injected provider", () =>
             dapp.evaluate("!!window.ethereum && !!window.__dapp"),
@@ -329,7 +334,7 @@ async function main() {
             inPrompt(shows("view-approve-site")),
         );
         await inPrompt(
-            "document.getElementById('approve-remember').checked = true",
+            "document.getElementById('approve-remember').checked = false",
         );
         // The prompt closes itself on the click.
         await inPrompt(click("btn-approve")).catch(() => {});
@@ -365,6 +370,20 @@ async function main() {
                 "s",
         );
 
+        // The site's request starts the worker again, and the new worker still
+        // has the connection allowed without "Remember"
+        // (https://git.eeqj.de/sneak/AutistMask/issues/526).
+        const stillConnected = await dapp.evaluate(
+            "window.ethereum.request({ method: 'eth_accounts' })",
+        );
+        check(
+            "a site allowed without Remember is still connected after the worker stopped",
+            Array.isArray(stillConnected) &&
+                stillConnected.length === 1 &&
+                getAddress(stillConnected[0]) === address,
+            "eth_accounts answered " + JSON.stringify(stillConnected),
+        );
+
         // A transaction approval and a signature approval, both open at once.
         await dapp.evaluate(
             "window.__dapp.start('tx', 'eth_sendTransaction', [" +

tests/fabricatedDecimals.test.js

@@ -136,7 +136,7 @@ function erc20AmountLine(data, tokenAddress) {
 }
 
 function swapAmountLine(data) {
-    return decodeCalldata(data, ROUTER).details.find(
+    return decodeCalldata(data, ROUTER, "0x1").details.find(
         (d) => d.label === "Amount",
     ).value;
 }

tests/firstWalletRefresh.test.js

@@ -0,0 +1,135 @@
+// A popup that opened with no wallet never started the ten-second refresh, so
+// after the first wallet was added Home went on showing the balance it had then
+// until the popup was reopened
+// (https://git.eeqj.de/sneak/AutistMask/issues/530). Each test boots the real
+// popup, adds wallets through AddWallet, and runs the intervals the popup set
+// with tick(). The balance stand-in writes what the chain holds onto every
+// address, as the real refreshBalances() does.
+
+const { HDNodeWallet, Mnemonic } = require("ethers");
+
+const {
+    bootPopup,
+    cleanupPopup,
+    unversionedValidProfile,
+    ADDRESS,
+} = require("./support/popupBoot");
+
+const PHRASE =
+    "abandon abandon abandon abandon abandon abandon " +
+    "abandon abandon abandon abandon abandon about";
+const PRIVATE_KEY = "0x" + "11".repeat(32);
+const XPRV = HDNodeWallet.fromSeed(
+    Mnemonic.fromPhrase(PHRASE).computeSeed(),
+).extendedKey;
+const PASSWORD = "correct horse battery staple";
+
+const TABS = [
+    { tab: "tab-mnemonic", field: "wallet-mnemonic", secret: PHRASE },
+    { tab: "tab-privkey", field: "import-private-key", secret: PRIVATE_KEY },
+    { tab: "tab-xprv", field: "import-xprv-key", secret: XPRV },
+];
+
+// A record this build cannot read: its wallets are a string.
+const UNREADABLE = {
+    hasWallet: true,
+    wallets: ADDRESS,
+    activeAddress: ADDRESS,
+};
+
+// The ETH balance the chain holds for every address, in ether.
+let chainBalance = "0.0";
+
+// Boots the popup over `stored`, with the balance stand-in reading the chain.
+async function boot(stored) {
+    const page = await bootPopup(stored);
+    const { refreshBalances } = require("../src/shared/balances");
+    refreshBalances.mockImplementation(async (wallets) => {
+        for (const wallet of wallets) {
+            for (const addr of wallet.addresses) addr.balance = chainBalance;
+        }
+    });
+    return { page, refreshBalances };
+}
+
+// Fills in the open AddWallet screen and presses "Import".
+async function importOn(page, { tab, field, secret }) {
+    await page.click(tab);
+    page.node(field).value = secret;
+    page.node("add-wallet-password").value = PASSWORD;
+    page.node("add-wallet-password-confirm").value = PASSWORD;
+    await page.click("btn-add-wallet-confirm");
+}
+
+beforeEach(() => {
+    chainBalance = "0.0";
+});
+
+afterEach(() => {
+    cleanupPopup();
+});
+
+describe("a popup that opened on Welcome", () => {
+    test.each(TABS)(
+        "after the first wallet is added from $tab, funds that arrive show on Home",
+        async (entry) => {
+            const { page } = await boot(undefined);
+            expect(page.pageErrors).toEqual([]);
+            await page.click("btn-welcome-add");
+            await importOn(page, entry);
+            expect(page.visibleViews()).toEqual(["main"]);
+            expect(page.text("total-value")).toBe("0.0000 ETH");
+
+            chainBalance = "2.0";
+            await page.tick();
+
+            expect(page.text("total-value")).toBe("2.0000 ETH");
+        },
+    );
+
+    test("a second wallet starts no second refresh", async () => {
+        const { page, refreshBalances } = await boot(undefined);
+        await page.click("btn-welcome-add");
+        await importOn(page, TABS[1]);
+        await page.click("btn-add-wallet-bottom");
+        await importOn(page, TABS[0]);
+        const calls = refreshBalances.mock.calls.length;
+
+        await page.tick();
+
+        expect(refreshBalances).toHaveBeenCalledTimes(calls + 1);
+    });
+
+    test("a wallet added as the recovery screen goes up starts no refresh", async () => {
+        const { page, refreshBalances } = await boot(undefined);
+        // The stored record becomes unreadable during the address scan that
+        // follows the import, and a save finds it.
+        const { scanForAddresses } = require("../src/shared/balances");
+        const { saveState } = require("../src/shared/state");
+        scanForAddresses.mockImplementationOnce(async () => {
+            page.storage.write("autistmask", UNREADABLE);
+            await saveState().catch(() => {});
+            return { addresses: [], nextIndex: 1 };
+        });
+        await page.click("btn-welcome-add");
+        await importOn(page, TABS[0]);
+        expect(page.visibleViews()).toEqual(["state-recovery"]);
+
+        await page.tick();
+
+        expect(refreshBalances).not.toHaveBeenCalled();
+    });
+});
+
+describe("a popup that opened with a wallet", () => {
+    test("adding a wallet starts no second refresh", async () => {
+        const { page, refreshBalances } = await boot(unversionedValidProfile());
+        await page.click("btn-add-wallet-bottom");
+        await importOn(page, TABS[1]);
+        const calls = refreshBalances.mock.calls.length;
+
+        await page.tick();
+
+        expect(refreshBalances).toHaveBeenCalledTimes(calls + 1);
+    });
+});

tests/flashLine.test.js

@@ -80,6 +80,7 @@ describe.each([
         jest.doMock("../src/shared/state", () => ({
             state: { trackedTokens: [] },
             saveState,
+            currentNetwork: () => ({ chainId: 1 }),
         }));
         jest.doMock("../src/popup/views/helpers", () => ({
             $: element,

tests/nativeCurrency.test.js

@@ -17,6 +17,10 @@ jest.mock("ethers", () => {
         async lookupAddress() {
             return null;
         }
+        // The 1.5 of the native token the address holds on either network.
+        async getBalance() {
+            return 1500000000000000000n;
+        }
         // 10 gwei expected, 20 gwei reserved per gas.
         async getFeeData() {
             return { maxFeePerGas: 20000000000n, gasPrice: 10000000000n };
@@ -241,7 +245,7 @@ describe.each([
     test("the value", async () => {
         await confirmSend("0.1");
         expect(text("confirm-type")).toBe("Native " + symbol + " transfer");
-        expect(text("confirm-amount")).toBe("0.1 " + symbol);
+        expect(text("confirm-amount")).toBe("0.1000 " + symbol);
         await approveTx(NETWORKS[networkId].chainId);
         expect(text("approve-tx-value")).toBe("0.0100 " + symbol);
     });
@@ -267,6 +271,13 @@ describe.each([
         );
     });
 
+    test("the warning for a recipient that has never sent a transaction", async () => {
+        await confirmSend("0.1");
+        expect(text("confirm-recipient-warning")).toContain(
+            "has never sent a transaction and holds no " + symbol + ".",
+        );
+    });
+
     // A token reports whatever symbol it likes. One reporting the label the
     // wallet shows its native token under, on this network or any other, is
     // a fake, exactly as one reporting `ETH` always was.
@@ -332,14 +343,11 @@ describe.each([
 
     test("the insufficient-balance error", async () => {
         await confirmSend("2");
-        expect(
-            global.document.getElementById("confirm-errors").innerHTML,
-        ).toContain(
-            "You have 1.5000 " +
+        expect(text("confirm-balance-error")).toBe(
+            "Your " +
                 symbol +
-                " but are trying to send 2 " +
-                symbol +
-                ".",
+                " balance does not cover this amount. Please go back and send" +
+                " a smaller amount.",
         );
     });
 });
@@ -421,10 +429,10 @@ describe.each([
             await global.document
                 .getElementById("btn-confirm-send")
                 .handlers.get("click")();
-            expect(text("wait-tx-summary")).toBe("0.1 " + symbol);
+            expect(text("wait-tx-summary")).toBe("0.1000 " + symbol);
             state.networkId = activeNetworkId;
             txStatus.restoreWait();
-            expect(text("wait-tx-summary")).toBe("0.1 " + symbol);
+            expect(text("wait-tx-summary")).toBe("0.1000 " + symbol);
         });
 
         test("the transaction detail screen's type line and fee", async () => {

tests/persistedFieldContract.test.js

@@ -97,6 +97,7 @@ const {
     normalizePersisted,
 } = require("../src/shared/persistedState");
 const { stateProblem } = require("../src/shared/stateSchema");
+const { isKnownNetworkId } = require("../src/shared/networks");
 const { RESTORABLE_VIEWS } = require("../src/shared/restorableViews");
 const {
     bootPopup,
@@ -193,6 +194,29 @@ const CONTRACT = [
         floorOnly: [[1, 2], [null], [{}], [[TOKEN_ADDRESS]]],
         holds: (v) => everyEntry(v, (t) => isRecord(t) && isText(t.address)),
     },
+    {
+        field: "networkTrackedTokens",
+        kind: KIND.ENTRIES,
+        hostile: [42, "notarecord", { sepolia: "notalist" }],
+        floorOnly: [
+            [1, 2],
+            { sepolia: [1, 2] },
+            { mainnet: [null, {}, [TOKEN_ADDRESS]] },
+            { notanetwork: [{ address: TOKEN_ADDRESS }] },
+            JSON.parse('{"__proto__":[{"address":"0xabc"}]}'),
+        ],
+        // Each list is put straight back onto trackedTokens by
+        // applyChainSwitchFields() when its network becomes the active one, so
+        // it is floored the same way; a key that names no network is dropped.
+        holds: (v) =>
+            isRecord(v) &&
+            Object.getPrototypeOf(v) === Object.prototype &&
+            Object.keys(v).every(
+                (id) =>
+                    isKnownNetworkId(id) &&
+                    everyEntry(v[id], (t) => isRecord(t) && isText(t.address)),
+            ),
+    },
     {
         field: "allowedSites",
         kind: KIND.ENTRIES,
@@ -417,6 +441,17 @@ const CONTRACT = [
                 views: ["error-tx"],
                 restored: false,
             },
+            // A chain id naming no network has no explorer to link to.
+            {
+                value: { hash: "0x1", to: ADDRESS, chainId: "0x5" },
+                views: ["success-tx"],
+                restored: false,
+            },
+            {
+                value: { message: "boom", to: ADDRESS, chainId: "0x5" },
+                views: ["error-tx"],
+                restored: false,
+            },
             // transaction passes on `data.tx`.
             {
                 value: { tx: { hash: "0x1" } },
@@ -430,6 +465,26 @@ const CONTRACT = [
                         from: ADDRESS,
                         to: ADDRESS,
                         contractAddress: 42,
+                        chainId: "0x1",
+                    },
+                },
+                views: ["transaction"],
+                restored: false,
+            },
+            // A transaction whose chain id is missing or names no network has
+            // no explorer to link to and no Blockscout to be read from.
+            {
+                value: { tx: { hash: "0x1", from: ADDRESS, to: ADDRESS } },
+                views: ["transaction"],
+                restored: false,
+            },
+            {
+                value: {
+                    tx: {
+                        hash: "0x1",
+                        from: ADDRESS,
+                        to: ADDRESS,
+                        chainId: "0x5",
                     },
                 },
                 views: ["transaction"],
@@ -453,6 +508,33 @@ const CONTRACT = [
                 views: ["confirm-tx"],
                 restored: false,
             },
+            // The amount line splits the amount to cut it to four decimals.
+            {
+                value: {
+                    pendingTx: {
+                        token: "ETH",
+                        from: ADDRESS,
+                        to: ADDRESS,
+                        amount: 42,
+                    },
+                },
+                views: ["confirm-tx"],
+                restored: false,
+            },
+            // A chain id naming no network has no explorer to link to.
+            {
+                value: {
+                    pendingTx: {
+                        token: "ETH",
+                        from: ADDRESS,
+                        to: ADDRESS,
+                        amount: "1",
+                        chainId: "0x5",
+                    },
+                },
+                views: ["confirm-tx"],
+                restored: false,
+            },
             // wait-tx passes on `pendingWait.hash`; restoreWait() has checked
             // the fields below it since it was written, and this is the
             // regression guard.
@@ -761,17 +843,22 @@ const WELL_FORMED_DATA = {
     message: "boom",
     to: ADDRESS,
     decoded: { details: [{ address: TOKEN_ADDRESS }] },
-    tx: { hash: "0x1", from: ADDRESS, to: ADDRESS, contractAddress: null },
+    tx: {
+        hash: "0x1",
+        from: ADDRESS,
+        to: ADDRESS,
+        contractAddress: null,
+        chainId: "0x1",
+    },
     pendingTx: {
         token: "ETH",
         from: ADDRESS,
         to: ADDRESS,
         amount: "1",
-        balance: "2",
     },
     pendingWait: {
         hash: "0x1",
-        txInfo: { to: ADDRESS, amount: "1" },
+        txInfo: { to: ADDRESS, amount: "1", chainId: "0x1" },
         broadcastTime: BROADCAST_TIME,
     },
 };

tests/popupBoot.test.js

@@ -0,0 +1,87 @@
+// A timer the popup started and that fires after cleanupPopup() has removed
+// the page throws "document is not defined", and the throw fails whatever test
+// the jest worker is running by then, in this file or another
+// (https://git.eeqj.de/sneak/AutistMask/issues/578). The flash message's
+// timer is the one that did it. A throw from a timer during a test fails that
+// test, so each test here passes only if nothing throws.
+
+const {
+    bootPopup,
+    cleanupPopup,
+    unversionedValidProfile,
+    ADDRESS,
+} = require("./support/popupBoot");
+
+const FLASH_MS = 10;
+
+function wait(ms) {
+    return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+afterEach(() => {
+    cleanupPopup();
+});
+
+test("a flash message clears while the page is up", async () => {
+    const page = await bootPopup(unversionedValidProfile());
+    const { showFlash } = require("../src/popup/views/helpers");
+    showFlash("Copied.", FLASH_MS);
+    expect(page.text("flash-msg")).toBe("Copied.");
+
+    await wait(FLASH_MS * 5);
+
+    expect(page.text("flash-msg")).toBe("");
+});
+
+test("a flash message's timer does not fire after cleanupPopup()", async () => {
+    await bootPopup(unversionedValidProfile());
+    const { showFlash } = require("../src/popup/views/helpers");
+    showFlash("Copied.", FLASH_MS);
+    cleanupPopup();
+
+    await wait(FLASH_MS * 5);
+});
+
+// A boot onto a screen that sends a request no mocked module answers: that
+// request reaches the boot's fetch() stub, never the internet
+// (https://git.eeqj.de/sneak/AutistMask/issues/559).
+function restoringOnto(view, viewData) {
+    return unversionedValidProfile({
+        currentView: view,
+        selectedWallet: 0,
+        selectedAddress: 0,
+        viewStack: ["main"],
+        viewData,
+    });
+}
+
+test("the transaction screen's Blockscout request reaches the stub", async () => {
+    const page = await bootPopup(
+        restoringOnto("transaction", {
+            tx: { hash: "0x1", from: ADDRESS, to: ADDRESS, chainId: "0x1" },
+        }),
+    );
+
+    expect(page.visibleViews()).toEqual(["transaction"]);
+    expect(globalThis.fetch.mock.calls.map((call) => call[0])).toEqual([
+        "https://eth.blockscout.com/api/v2/transactions/0x1",
+    ]);
+});
+
+test("the confirmation screen's Etherscan lookup reaches the stub", async () => {
+    const page = await bootPopup(
+        restoringOnto("confirm-tx", {
+            pendingTx: {
+                token: "ETH",
+                from: ADDRESS,
+                to: ADDRESS,
+                amount: "1",
+            },
+        }),
+    );
+
+    expect(page.visibleViews()).toEqual(["confirm-tx"]);
+    expect(globalThis.fetch.mock.calls.map((call) => call[0])).toEqual([
+        "https://etherscan.io/address/" + ADDRESS,
+    ]);
+});

tests/rpcErrorLog.test.js

@@ -74,7 +74,7 @@ test("ethers puts the URL in the error message, not in the short message", async
 test("the recipient checks before a send", async () => {
     await getFullWarnings(ADDRESS, getProvider(RPC_URL, "mainnet"));
     expectFailureLoggedWithoutKey("contract check failed");
-    expectFailureLoggedWithoutKey("tx count check failed");
+    expectFailureLoggedWithoutKey("tx count or balance check failed");
 });
 
 test("the ENS reverse lookup", async () => {

tests/sendAmountRule.test.js

@@ -23,7 +23,10 @@ jest.mock("../src/shared/log", () => ({
     isDebug: () => false,
 }));
 
-// What the confirmation screen asks the node for.
+const { AbiCoder } = require("ethers");
+
+// What the confirmation screen asks the node for. The address holds the 1 ETH
+// and 250 TOK the wallet below records.
 const mockProvider = {
     getFeeData: async () => ({
         maxFeePerGas: 2000000000n,
@@ -32,7 +35,11 @@ const mockProvider = {
     estimateGas: async () => 21000n,
     getCode: async () => "0x",
     getTransactionCount: async () => 1,
-    getBalance: async () => 0n,
+    getBalance: async () => 1000000000000000000n,
+    // The one contract call the screen makes, balanceOf(), answered at the
+    // token's 6 decimal places.
+    call: async () =>
+        AbiCoder.defaultAbiCoder().encode(["uint256"], [250000000n]),
 };
 
 jest.mock("../src/shared/balances", () => {

tests/sendDisplayFloor.test.js

@@ -18,6 +18,7 @@
 // What the stub node answers. Each test sets what it needs.
 const mockNode = {
     balanceWei: 0n,
+    tokenUnits: 0n,
     feeData: { maxFeePerGas: 1n, gasPrice: 1n },
 };
 
@@ -30,6 +31,13 @@ jest.mock("ethers", () => {
         async getBalance() {
             return mockNode.balanceWei;
         }
+        // balanceOf(), the one contract call these screens make.
+        async call() {
+            return actual.AbiCoder.defaultAbiCoder().encode(
+                ["uint256"],
+                [mockNode.tokenUnits],
+            );
+        }
         async lookupAddress() {
             return null;
         }
@@ -195,10 +203,19 @@ function errors() {
     return global.document.getElementById("confirm-errors").innerHTML;
 }
 
+// The message for an amount the balance does not cover, while it is shown.
+function balanceError() {
+    const box = global.document.getElementById("confirm-balance-error");
+    return box.style.visibility === "visible" ? box.textContent : "";
+}
+
 // The ETH balance the node reports and the token rows the explorer reports,
-// fetched and stored exactly where the popup stores them.
+// fetched and stored exactly where the popup stores them. The node reports the
+// token holding the explorer does.
 async function refreshWith(balanceWei, tokenItems = []) {
     mockNode.balanceWei = balanceWei;
+    mockNode.tokenUnits =
+        tokenItems.length > 0 ? BigInt(tokenItems[0].value) : 0n;
     mockExplorer.items = tokenItems;
     state.wallets = [{ name: "Wallet 1", addresses: [{ address: HOLDER }] }];
     state.selectedWallet = 0;
@@ -300,9 +317,10 @@ describe("a tracked token holding below 0.000001 never renders as zero", () => {
         await confirmSend("0.0000005", TOKEN);
         expect(text("confirm-balance")).toBe("0.0000005 TOK");
         expect(errors()).toBe("");
+        expect(balanceError()).toBe("");
         await confirmSend("0.0000006", TOKEN);
-        expect(errors()).toContain(
-            "You have 0.0000005 TOK but are trying to send 0.0000006 TOK.",
+        expect(balanceError()).toContain(
+            "Your TOK balance does not cover this amount.",
         );
     });
 
@@ -316,6 +334,7 @@ describe("a tracked token holding below 0.000001 never renders as zero", () => {
         await confirmSend("1.5", TOKEN);
         expect(text("confirm-balance")).toBe("1.5000 TOK");
         expect(errors()).toBe("");
+        expect(balanceError()).toBe("");
     });
 
     test("with more than 18 decimals and a holding below 10^-18", async () => {
@@ -329,9 +348,8 @@ describe("a tracked token holding below 0.000001 never renders as zero", () => {
         );
         await confirmSend("0.000000000000000001", TOKEN);
         expect(text("confirm-balance")).toBe("0.000000000000000000000001 TOK");
-        expect(errors()).toContain(
-            "You have 0.000000000000000000000001 TOK but are trying to send" +
-                " 0.000000000000000001 TOK.",
+        expect(balanceError()).toContain(
+            "Your TOK balance does not cover this amount.",
         );
     });
 });
@@ -356,9 +374,10 @@ describe("an untracked token holding below 0.000001 never renders as zero", () =
         await confirmSend("0.0000005", TOKEN);
         expect(text("confirm-balance")).toBe("0.0000005 TOK");
         expect(errors()).toBe("");
+        expect(balanceError()).toBe("");
         await confirmSend("0.0000006", TOKEN);
-        expect(errors()).toContain(
-            "You have 0.0000005 TOK but are trying to send 0.0000006 TOK.",
+        expect(balanceError()).toContain(
+            "Your TOK balance does not cover this amount.",
         );
     });
 });

tests/sendMax.test.js

@@ -17,6 +17,7 @@
 // What the stub node answers, and the signed transactions it was handed.
 const mockNode = {
     balanceWei: 0n,
+    tokenUnits: 0n,
     feeData: null,
     broadcast: [],
 };
@@ -30,6 +31,14 @@ jest.mock("ethers", () => {
         async getBalance() {
             return mockNode.balanceWei;
         }
+        // balanceOf(), the one contract call these screens make before Sign
+        // & Send.
+        async call() {
+            return actual.AbiCoder.defaultAbiCoder().encode(
+                ["uint256"],
+                [mockNode.tokenUnits],
+            );
+        }
         async lookupAddress() {
             return null;
         }
@@ -187,9 +196,12 @@ function text(id) {
 }
 
 // The ETH balance the node reports and the token rows the explorer reports,
-// fetched and stored exactly where the popup stores them.
+// fetched and stored exactly where the popup stores them. The node reports the
+// token holding the explorer does.
 async function refreshWith(balanceWei, tokenItems = []) {
     mockNode.balanceWei = balanceWei;
+    mockNode.tokenUnits =
+        tokenItems.length > 0 ? BigInt(tokenItems[0].value) : 0n;
     mockExplorer.items = tokenItems;
     state.wallets = [
         {
@@ -294,7 +306,8 @@ describe("Max on an ETH send", () => {
         openSend();
         await pressMax();
         await review();
-        expect(text("confirm-amount")).toBe(maxAfter(20n * GWEI) + " ETH");
+        expect(confirmed.amount).toBe(maxAfter(20n * GWEI));
+        expect(text("confirm-amount")).toBe("1.2341 ETH");
         expect(el("confirm-errors").innerHTML).toBe("");
         expect(el("confirm-amount-fee-error").style.visibility).toBe("hidden");
         expect(canSend()).toBe(true);
@@ -310,14 +323,16 @@ describe("Max on an ETH send", () => {
         // Kept, the Send screen's amount would be refused for want of funds.
         mockNode.feeData = fees(30n * GWEI);
         await review();
-        expect(text("confirm-amount")).toBe(maxAfter(30n * GWEI) + " ETH");
+        expect(confirmed.amount).toBe(maxAfter(30n * GWEI));
+        expect(text("confirm-amount")).toBe("1.2339 ETH");
         expect(canSend()).toBe(true);
 
         // And falls when the screen is shown again, as on reopening the popup.
         mockNode.feeData = fees(10n * GWEI);
         confirmTx.restore();
         await settle();
-        expect(text("confirm-amount")).toBe(maxAfter(10n * GWEI) + " ETH");
+        expect(confirmed.amount).toBe(maxAfter(10n * GWEI));
+        expect(text("confirm-amount")).toBe("1.2343 ETH");
         expect(canSend()).toBe(true);
     });
 
@@ -514,7 +529,8 @@ describe("Max on an ETH send", () => {
         el("send-amount").handlers.get("input")();
         mockNode.feeData = fees(30n * GWEI);
         await review();
-        expect(text("confirm-amount")).toBe("0.5 ETH");
+        expect(confirmed.amount).toBe("0.5");
+        expect(text("confirm-amount")).toBe("0.5000 ETH");
     });
 });
 
@@ -528,7 +544,8 @@ describe("Max on a token send", () => {
         await pressMax();
         expect(el("send-amount").value).toBe("1234.567890123456789012");
         await review();
-        expect(text("confirm-amount")).toBe("1234.567890123456789012 TOK");
+        expect(confirmed.amount).toBe("1234.567890123456789012");
+        expect(text("confirm-amount")).toBe("1234.5678 TOK");
         expect(canSend()).toBe(true);
     });
 
@@ -541,7 +558,8 @@ describe("Max on a token send", () => {
         await pressMax();
         expect(el("send-amount").value).toBe("1234.567890123456789012");
         await review();
-        expect(text("confirm-amount")).toBe("1234.567890123456789012 TOK");
+        expect(confirmed.amount).toBe("1234.567890123456789012");
+        expect(text("confirm-amount")).toBe("1234.5678 TOK");
         expect(canSend()).toBe(true);
     });
 

tests/stateRecovery.test.js

@@ -225,7 +225,12 @@ describe("a popup already open when the stored profile becomes unreadable", () =
                 viewData: {
                     pendingWait: {
                         hash: "0x1",
-                        txInfo: { to: ADDRESS, amount: "1", token: "ETH" },
+                        txInfo: {
+                            to: ADDRESS,
+                            amount: "1",
+                            token: "ETH",
+                            chainId: "0x1",
+                        },
                         broadcastTime: Date.now(),
                     },
                 },

tests/support/popupBoot.js

@@ -43,6 +43,13 @@ jest.doMock("ethereum-blockies-base64", () => makeBlockie);
 // Taken before any boot replaces them; see bootPopup().
 const realSetInterval = globalThis.setInterval;
 const realClearInterval = globalThis.clearInterval;
+const realSetTimeout = globalThis.setTimeout;
+const realClearTimeout = globalThis.clearTimeout;
+const realFetch = globalThis.fetch;
+
+// Every timeout set since the last cleanupPopup() that has neither fired nor
+// been cleared. cleanupPopup() clears them all.
+const pendingTimeouts = new Set();
 
 const POPUP_HTML = fs.readFileSync(
     path.join(__dirname, "..", "..", "src", "popup", "index.html"),
@@ -254,8 +261,14 @@ async function settle() {
 async function bootPopup(stored, options) {
     jest.resetModules();
 
-    // The three modules that reach the network. None is on the path under
-    // test; all would make the suite hit the internet.
+    // The RPC requests made through src/shared/balances.js go through Node's
+    // own http and https modules, not fetch(), so the fetch() stub below would
+    // not stop them, which is why that module stays mocked.
+    // src/shared/prices.js and src/shared/transactions.js send their requests
+    // through fetch(), and their mocks answer with no prices and no
+    // transactions. Every request the page still sends, such as the
+    // transaction screen's Blockscout lookup and the Etherscan lookup in
+    // src/shared/etherscanLabels.js, meets the fetch() stub.
     jest.doMock("../../src/shared/prices", () => ({
         prices: {},
         refreshPrices: jest.fn(async () => {}),
@@ -328,6 +341,12 @@ async function bootPopup(stored, options) {
             windowListeners[name].push(fn);
         },
     };
+    // Every fetch() the page makes fails, as it does elsewhere in the suite,
+    // instead of reaching the internet. A new stub per boot, so the calls it
+    // records start with that boot. Put back by cleanupPopup().
+    globalThis.fetch = jest.fn(() => {
+        throw new Error("tests must not perform network requests");
+    });
     // The ten-second refresh init() starts, and a transaction wait's timers,
     // would outlive the test. So every interval is recorded rather than
     // started, clearInterval() removes it as a browser would, and tick() below
@@ -342,6 +361,24 @@ async function bootPopup(stored, options) {
     globalThis.clearInterval = (id) => {
         intervals.delete(id);
     };
+    // Timeouts, such as the one that clears a flash message, run for real, but
+    // each is recorded until it fires or is cleared, so cleanupPopup() can
+    // clear the ones still pending. One that fired after the page was removed
+    // would throw "document is not defined" into whatever test the worker runs
+    // by then. jest.useFakeTimers() in a test does not reach them. Put back by
+    // cleanupPopup().
+    globalThis.setTimeout = (fn, ms, ...args) => {
+        const timer = realSetTimeout(() => {
+            pendingTimeouts.delete(timer);
+            fn(...args);
+        }, ms);
+        pendingTimeouts.add(timer);
+        return timer;
+    };
+    globalThis.clearTimeout = (timer) => {
+        pendingTimeouts.delete(timer);
+        realClearTimeout(timer);
+    };
 
     require("../../src/popup/index");
 
@@ -407,6 +444,11 @@ function cleanupPopup() {
     delete globalThis.window;
     globalThis.setInterval = realSetInterval;
     globalThis.clearInterval = realClearInterval;
+    for (const timer of pendingTimeouts) realClearTimeout(timer);
+    pendingTimeouts.clear();
+    globalThis.setTimeout = realSetTimeout;
+    globalThis.clearTimeout = realClearTimeout;
+    globalThis.fetch = realFetch;
 }
 
 module.exports = {

tests/support/storageStub.js

@@ -1,4 +1,4 @@
-// A chrome.storage.local stub that behaves like the real one.
+// A chrome.storage stub that behaves like the real one.
 //
 // The real extension storage API is a serialization boundary: `set` writes a
 // structured clone of what it is given, and `get` hands back a structured
@@ -17,13 +17,8 @@
 // So every test that drives real persistence uses this, and nothing rebuilds
 // a storage stub by hand.
 
-// `initial` is the starting contents, keyed as storage is: { autistmask: {...} }.
-// `onOp` runs before each operation, for a test that needs to advance a clock
-// or count round trips.
-function makeStorageStub(initial, onOp) {
-    const store = initial ? structuredClone(initial) : {};
-    const tick = onOp || (() => {});
-
+// One storage area: get, set and remove over its own store, cloning both ways.
+function makeArea(store, tick) {
     const get = jest.fn(async (key) => {
         tick();
         if (key === undefined || key === null) return structuredClone(store);
@@ -49,15 +44,28 @@ function makeStorageStub(initial, onOp) {
         for (const k of Array.isArray(key) ? key : [key]) delete store[k];
     });
 
+    return { get, set, remove };
+}
+
+// `initial` is the starting contents of `storage.local`, keyed as storage is:
+// { autistmask: {...} }. `storage.session` starts empty.
+// `onOp` runs before each operation on either area, for a test that needs to
+// advance a clock or count round trips.
+function makeStorageStub(initial, onOp) {
+    const store = initial ? structuredClone(initial) : {};
+    const tick = onOp || (() => {});
+    const local = makeArea(store, tick);
+
     return {
         // Drop this straight in as chrome.storage.
-        local: { get, set, remove },
-        get,
-        set,
-        remove,
-        // What is stored, cloned on the way out: a test can neither observe a
-        // later write through an object it read nor reach into the store by
-        // mutating one.
+        local,
+        session: makeArea({}, tick),
+        get: local.get,
+        set: local.set,
+        remove: local.remove,
+        // What is stored in `storage.local`, cloned on the way out: a test can
+        // neither observe a later write through an object it read nor reach
+        // into the store by mutating one.
         read: (key) =>
             key === undefined
                 ? structuredClone(store)

tests/tokenTransferDetail.test.js

@@ -8,6 +8,14 @@
 // tracks. It decodes against the address the explorer reports the transaction
 // was sent to.
 //
+// Its links open the explorer of the network the transaction was sent on,
+// whichever network is active
+// (https://git.eeqj.de/sneak/AutistMask/issues/584), and the transaction is
+// read from that network's Blockscout, the one Settings has for it
+// (https://git.eeqj.de/sneak/AutistMask/issues/623). Its decoded details name
+// the token, and scale its amount, from what the wallet knows of that
+// network's tokens (https://git.eeqj.de/sneak/AutistMask/issues/629).
+//
 // The row is the one the real history parser makes from the explorer's answer,
 // opened through transactionDetail.show(), which is what a click on the row
 // calls. Driven against a minimal DOM stub in the shape
@@ -22,10 +30,10 @@ jest.mock("../src/shared/log", () => ({
         warnf: () => {},
         errorf: () => {},
     },
-    debugFetch: async (url) => ({
-        ok: true,
-        json: async () => mockExplorerAnswer(url),
-    }),
+    debugFetch: async (url) => {
+        mockAsked.push(url);
+        return { ok: true, json: async () => mockExplorerAnswer(url) };
+    },
     setRuntimeDebug: () => {},
     isDebug: () => false,
 }));
@@ -35,10 +43,13 @@ globalThis.chrome = {
 };
 
 const { state } = require("../src/shared/state");
+const { NETWORKS } = require("../src/shared/networks");
 const { fetchRecentTransactions } = require("../src/shared/transactions");
 const transactionDetail = require("../src/popup/views/transactionDetail");
 
 const EXPLORER = "https://explorer.example/api/v2";
+// A Blockscout that knows nothing of the transaction.
+const OTHER_EXPLORER = "https://other-explorer.example/api/v2";
 const HOLDER = "0x0000000000000000000000000000000000000a11";
 const RECIPIENT = "0x711e691962E5c054b78071C789A0C8CE657377aD";
 // A token the wallet tracks and the bundled token list does not name.
@@ -51,6 +62,9 @@ const TRANSFER_DATA = new Interface([
     "function transfer(address to, uint256 amount)",
 ]).encodeFunctionData("transfer", [RECIPIENT, 1234500000n]);
 
+// Every URL asked of a Blockscout, in order.
+const mockAsked = [];
+
 // The explorer's answers: the transfer in HOLDER's token transfers, and the
 // transaction itself, sent to the token contract.
 function mockExplorerAnswer(url) {
@@ -77,7 +91,11 @@ function mockExplorerAnswer(url) {
         };
     }
     if (url === EXPLORER + "/transactions/" + TX_HASH) {
-        return { to: { hash: TOKEN }, raw_input: TRANSFER_DATA };
+        return {
+            to: { hash: TOKEN },
+            raw_input: TRANSFER_DATA,
+            block_number: 100,
+        };
     }
     return { items: [] };
 }
@@ -140,6 +158,7 @@ beforeEach(() => {
     globalThis.document = makeDocument();
     globalThis.window = { location: { search: "" } };
     state.blockscoutUrl = EXPLORER;
+    state.networkEndpoints = {};
     state.wallets = [
         {
             name: "Main",
@@ -148,13 +167,18 @@ beforeEach(() => {
         },
     ];
     state.trackedTokens = [{ address: TOKEN, symbol: "TDOL", decimals: 6 }];
+    state.networkTrackedTokens = {};
     state.viewData = {};
     state.viewStack = [];
     state.currentView = null;
 });
 
 test("a token transfer's decoded details name the token contract and the amount at its scale", async () => {
-    const [row] = await fetchRecentTransactions(HOLDER, EXPLORER, 1);
+    const [row] = await fetchRecentTransactions(
+        HOLDER,
+        EXPLORER,
+        NETWORKS.mainnet.chainId,
+    );
     expect(row.to).toBe(RECIPIENT);
     expect(row.contractAddress).toBe(TOKEN.toLowerCase());
 
@@ -174,3 +198,96 @@ test("a token transfer's decoded details name the token contract and the amount
         '<div class="font-bold">1234.5000 TDOL</div>',
     );
 });
+
+// Mainnet is active, and its Blockscout knows nothing of the transaction. The
+// row was read from the Blockscout Settings remembers for Sepolia, and the
+// screen reads the transaction from there too, so every link on it is drawn.
+test("with mainnet active, a Sepolia transaction is read from Sepolia's Blockscout and its links open the Sepolia explorer", async () => {
+    state.networkId = "mainnet";
+    state.blockscoutUrl = OTHER_EXPLORER;
+    state.networkEndpoints = { sepolia: { blockscoutUrl: EXPLORER } };
+    const [row] = await fetchRecentTransactions(
+        HOLDER,
+        EXPLORER,
+        NETWORKS.sepolia.chainId,
+    );
+
+    transactionDetail.show(row);
+    for (let i = 0; i < 10; i++) await new Promise((r) => setTimeout(r, 0));
+
+    const sepolia = "https://sepolia.etherscan.io";
+    const links = (id) =>
+        [...node(id).innerHTML.matchAll(/href="([^"]*)"/g)].map((m) => m[1]);
+    expect(links("tx-detail-hash")).toEqual([`${sepolia}/tx/${TX_HASH}`]);
+    expect(links("tx-detail-from")).toEqual([`${sepolia}/address/${HOLDER}`]);
+    expect(links("tx-detail-to")).toEqual([`${sepolia}/address/${RECIPIENT}`]);
+    expect(links("tx-detail-token-contract")).toEqual([
+        `${sepolia}/token/${TOKEN.toLowerCase()}`,
+    ]);
+    expect(links("tx-detail-block")).toEqual([`${sepolia}/block/100`]);
+    expect(links("tx-detail-calldata-details")).toEqual([
+        `${sepolia}/address/${TOKEN}`,
+        `${sepolia}/address/${RECIPIENT}`,
+    ]);
+});
+
+test("with mainnet active and no Blockscout remembered for Sepolia, a Sepolia transaction is asked of Sepolia's default Blockscout", async () => {
+    state.networkId = "mainnet";
+    state.blockscoutUrl = OTHER_EXPLORER;
+    const [row] = await fetchRecentTransactions(
+        HOLDER,
+        EXPLORER,
+        NETWORKS.sepolia.chainId,
+    );
+    mockAsked.length = 0;
+
+    transactionDetail.show(row);
+    for (let i = 0; i < 10; i++) await new Promise((r) => setTimeout(r, 0));
+
+    expect(mockAsked).toEqual([
+        NETWORKS.sepolia.defaultBlockscoutUrl + "/transactions/" + TX_HASH,
+    ]);
+});
+
+// Open the Sepolia transfer's detail screen with mainnet active, and wait for
+// its decoded details.
+async function showSepoliaTransferWithMainnetActive() {
+    state.networkId = "mainnet";
+    state.blockscoutUrl = OTHER_EXPLORER;
+    state.networkEndpoints = { sepolia: { blockscoutUrl: EXPLORER } };
+    const [row] = await fetchRecentTransactions(
+        HOLDER,
+        EXPLORER,
+        NETWORKS.sepolia.chainId,
+    );
+    transactionDetail.show(row);
+    for (let i = 0; i < 10; i++) await new Promise((r) => setTimeout(r, 0));
+}
+
+test("with mainnet active, a Sepolia token transfer's decoded details name the token tracked on Sepolia and its amount at its scale", async () => {
+    state.trackedTokens = [];
+    state.networkTrackedTokens = {
+        sepolia: [{ address: TOKEN, symbol: "TDOL", decimals: 6 }],
+    };
+    await showSepoliaTransferWithMainnetActive();
+
+    expect(decodedLine("Token")).toContain('<div class="font-bold">TDOL</div>');
+    expect(decodedLine("Amount")).toContain(
+        '<div class="font-bold">1234.5000 TDOL</div>',
+    );
+});
+
+// The same contract address on mainnet is another token, so what the wallet
+// tracks and holds there names nothing on Sepolia.
+test("with mainnet active, a Sepolia token transfer's decoded details take nothing from mainnet's tracked tokens or balances", async () => {
+    state.trackedTokens = [{ address: TOKEN, symbol: "MDOL", decimals: 18 }];
+    state.wallets[0].addresses[0].tokenBalances = [
+        { address: TOKEN, symbol: "MDOL", decimals: 18, balance: "1.0" },
+    ];
+    await showSepoliaTransferWithMainnetActive();
+
+    expect(decodedLine("Token")).not.toContain("MDOL");
+    expect(decodedLine("Amount")).toContain(
+        '<div class="font-bold">1234500000 base units (decimals unknown)</div>',
+    );
+});

tests/trackedTokensPerNetwork.test.js

@@ -0,0 +1,372 @@
+// Tracked tokens are kept per network, and the two add-token screens offer the
+// bundled token list, which holds Ethereum Mainnet contracts, on Ethereum
+// Mainnet only (https://git.eeqj.de/sneak/AutistMask/issues/523), including on
+// the screen "Back" lands on after a switch made from the Settings gear and for
+// a contract lookup that answers after one. Driven through the real popup over
+// a stored profile; the same switch made by the background is in
+// tests/coldWorkerChainSwitch.test.js.
+
+const {
+    bootPopup,
+    cleanupPopup,
+    unversionedValidProfile,
+    ADDRESS,
+    TOKEN_ADDRESS,
+} = require("./support/popupBoot");
+const { NETWORKS } = require("../src/shared/networks");
+
+const SEPOLIA_TOKEN = {
+    address: TOKEN_ADDRESS,
+    symbol: "TST",
+    decimals: 18,
+    name: "Test Token",
+};
+const MAINNET_TOKEN = {
+    address: "0x6B175474E89094C44Da98b954EedeAC495271d0F",
+    symbol: "DAI",
+    decimals: 18,
+    name: "Dai Stablecoin",
+};
+// Tracked on neither network.
+const NEW_TOKEN_ADDRESS = "0xBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
+const NETWORK_CHANGED_FLASH =
+    "The active network changed before the lookup finished, so the token was" +
+    " not added.";
+
+afterEach(() => {
+    cleanupPopup();
+});
+
+// The popup reopened onto SettingsAddToken, on `networkId`.
+function bootOnAddToken(networkId, extra) {
+    return bootPopup(
+        unversionedValidProfile({
+            networkId,
+            currentView: "settings-addtoken",
+            ...extra,
+        }),
+    );
+}
+
+// The popup reopened onto AddressDetail on Ethereum Mainnet, with DAI tracked
+// there and TST tracked on Sepolia.
+function bootOnAddress() {
+    return bootPopup(
+        unversionedValidProfile({
+            currentView: "address",
+            selectedWallet: 0,
+            selectedAddress: 0,
+            trackedTokens: [MAINNET_TOKEN],
+            networkTrackedTokens: { sepolia: [SEPOLIA_TOKEN] },
+        }),
+    );
+}
+
+// The popup reopened onto AddressToken for `token`, with AddressDetail beneath
+// it, over the same tracked tokens as bootOnAddress().
+function bootOnToken(token) {
+    return bootPopup(
+        unversionedValidProfile({
+            currentView: "address-token",
+            viewStack: ["main", "address"],
+            selectedWallet: 0,
+            selectedAddress: 0,
+            selectedToken: token,
+            trackedTokens: [MAINNET_TOKEN],
+            networkTrackedTokens: { sepolia: [SEPOLIA_TOKEN] },
+        }),
+    );
+}
+
+// AddressToken for `token` opened from AddressDetail, as tapping the token's
+// row there does.
+async function openToken(boot, token) {
+    const { state } = require("../src/shared/state");
+    state.selectedToken = token;
+    require("../src/popup/views/helpers").pushCurrentView();
+    require("../src/popup/views/addressToken").show();
+    await boot.settle();
+}
+
+// Presses `addButton` with a contract lookup that answers only after the
+// Settings gear and a switch to `networkId`.
+async function addAcrossSwitch(boot, addButton, networkId) {
+    const { lookupTokenInfo } = require("../src/shared/balances");
+    let answer;
+    lookupTokenInfo.mockImplementationOnce(
+        () =>
+            new Promise((resolve) => {
+                answer = resolve;
+            }),
+    );
+    const adding = boot.click(addButton);
+    await boot.click("btn-settings");
+    await chooseNetwork(boot, networkId);
+    answer({ symbol: "NEW", decimals: 18, name: "New Token" });
+    await adding;
+}
+
+// Picks `networkId` in the Settings network selector, as the user does.
+async function chooseNetwork(boot, networkId) {
+    const select = boot.node("settings-network");
+    select.value = networkId;
+    for (const fn of select.listeners.change) await fn();
+    await boot.settle();
+}
+
+// The Settings gear, a switch to Sepolia, and Back.
+async function gearSwitchBack(boot) {
+    await boot.click("btn-settings");
+    expect(boot.visibleViews()).toEqual(["settings"]);
+    await chooseNetwork(boot, "sepolia");
+    await boot.click("btn-settings-back");
+}
+
+describe.each([
+    ["mainnet", false],
+    ["sepolia", true],
+])("on %s", (networkId, hidden) => {
+    test(`the common tokens are hidden: ${hidden}`, async () => {
+        const boot = await bootOnAddToken(networkId);
+        expect(boot.pageErrors).toEqual([]);
+        expect(boot.visibleViews()).toEqual(["settings-addtoken"]);
+        expect(boot.hidden("settings-addtoken-common")).toBe(hidden);
+
+        require("../src/popup/views/addToken").show();
+        expect(boot.visibleViews()).toEqual(["add-token"]);
+        expect(boot.hidden("add-token-common")).toBe(hidden);
+    });
+});
+
+test("a token added by contract address on Sepolia is tracked on Sepolia only", async () => {
+    const boot = await bootOnAddToken("sepolia", {
+        networkTrackedTokens: { mainnet: [MAINNET_TOKEN] },
+    });
+    const stored = () => boot.storage.read("autistmask");
+    const { lookupTokenInfo } = require("../src/shared/balances");
+    lookupTokenInfo.mockResolvedValueOnce({
+        symbol: SEPOLIA_TOKEN.symbol,
+        decimals: SEPOLIA_TOKEN.decimals,
+        name: SEPOLIA_TOKEN.name,
+    });
+
+    boot.node("settings-addtoken-address").value = TOKEN_ADDRESS;
+    await boot.click("btn-settings-addtoken-manual");
+
+    expect(lookupTokenInfo).toHaveBeenCalledWith(
+        TOKEN_ADDRESS,
+        expect.any(String),
+        "sepolia",
+        expect.anything(),
+    );
+    expect(stored().trackedTokens).toEqual([SEPOLIA_TOKEN]);
+
+    await chooseNetwork(boot, "mainnet");
+    expect(stored().networkId).toBe("mainnet");
+    expect(stored().trackedTokens).toEqual([MAINNET_TOKEN]);
+    const onMainnet = boot.node("settings-tracked-tokens").innerHTML;
+    expect(onMainnet).toContain("DAI");
+    expect(onMainnet).not.toContain("TST");
+
+    await chooseNetwork(boot, "sepolia");
+    expect(stored().networkId).toBe("sepolia");
+    expect(stored().trackedTokens).toEqual([SEPOLIA_TOKEN]);
+    const onSepolia = boot.node("settings-tracked-tokens").innerHTML;
+    expect(onSepolia).toContain("TST");
+    expect(onSepolia).not.toContain("DAI");
+});
+
+describe("Back after a switch from the Settings gear", () => {
+    test("SettingsAddToken no longer offers the common tokens", async () => {
+        const boot = await bootOnAddToken("mainnet");
+        expect(boot.hidden("settings-addtoken-common")).toBe(false);
+
+        await gearSwitchBack(boot);
+        expect(boot.visibleViews()).toEqual(["settings-addtoken"]);
+        expect(boot.hidden("settings-addtoken-common")).toBe(true);
+    });
+
+    test("AddressDetail lists the new network's tracked tokens", async () => {
+        const boot = await bootOnAddress();
+        expect(boot.node("address-balances").innerHTML).toContain("DAI");
+
+        await gearSwitchBack(boot);
+        expect(boot.visibleViews()).toEqual(["address"]);
+        const balances = boot.node("address-balances").innerHTML;
+        expect(balances).toContain("TST");
+        expect(balances).not.toContain("DAI");
+    });
+
+    // Neither can be rendered from saved state, so neither is landed on.
+    test.each([
+        ["btn-add-token", "add-token"],
+        ["btn-send", "send"],
+    ])("from over %s, it lands on AddressDetail", async (button, view) => {
+        const boot = await bootOnAddress();
+        await boot.click(button);
+        expect(boot.visibleViews()).toEqual([view]);
+
+        await gearSwitchBack(boot);
+        expect(boot.visibleViews()).toEqual(["address"]);
+        expect(boot.node("address-balances").innerHTML).not.toContain("DAI");
+    });
+
+    // DAI was picked on Ethereum Mainnet, where alone it is tracked.
+    test.each([
+        [
+            "opened from AddressDetail",
+            async () => {
+                const boot = await bootOnAddress();
+                await openToken(boot, MAINNET_TOKEN.address);
+                return boot;
+            },
+        ],
+        ["in a reopened popup", () => bootOnToken(MAINNET_TOKEN.address)],
+    ])(
+        "from AddressToken for DAI %s, it lands on AddressDetail",
+        async (_how, open) => {
+            const boot = await open();
+            expect(boot.visibleViews()).toEqual(["address-token"]);
+            expect(boot.text("address-token-title")).toContain("DAI");
+
+            await gearSwitchBack(boot);
+            expect(boot.visibleViews()).toEqual(["address"]);
+            const balances = boot.node("address-balances").innerHTML;
+            expect(balances).toContain("TST");
+            expect(balances).not.toContain("DAI");
+        },
+    );
+
+    // The stack is saved cut with the switch, so a popup closed straight after
+    // it and reopened onto Settings lands where this one would. Loading a
+    // saved stack cuts it at AddToken and Send as well, but not at
+    // AddressToken.
+    test.each([
+        [
+            "AddressToken for DAI",
+            (boot) => openToken(boot, MAINNET_TOKEN.address),
+        ],
+        ["AddToken", (boot) => boot.click("btn-add-token")],
+        ["Send", (boot) => boot.click("btn-send")],
+    ])(
+        "from %s, a popup reopened after the switch lands on AddressDetail",
+        async (_view, open) => {
+            const boot = await bootOnAddress();
+            await open(boot);
+            await boot.click("btn-settings");
+            await chooseNetwork(boot, "sepolia");
+
+            const reopened = await bootPopup(boot.storage.read("autistmask"));
+            expect(reopened.visibleViews()).toEqual(["settings"]);
+            await reopened.click("btn-settings-back");
+            expect(reopened.visibleViews()).toEqual(["address"]);
+            const balances = reopened.node("address-balances").innerHTML;
+            expect(balances).toContain("TST");
+            expect(balances).not.toContain("DAI");
+        },
+    );
+
+    test("AddressToken for the native token is drawn again for the new network", async () => {
+        const boot = await bootOnToken("ETH");
+        expect(boot.visibleViews()).toEqual(["address-token"]);
+
+        await gearSwitchBack(boot);
+        expect(boot.visibleViews()).toEqual(["address-token"]);
+        expect(boot.text("address-token-title")).toContain("SepoliaETH");
+    });
+
+    // A popup reopened onto ConfirmTx has no Send beneath it, so "Back" draws
+    // ConfirmTx again from the saved transaction. It is drawn for the network
+    // the transaction was reviewed on, and Sign & Send refuses it on the new
+    // one.
+    test("ConfirmTx reviewed on Sepolia is not sent on Ethereum Mainnet", async () => {
+        const boot = await bootPopup(
+            unversionedValidProfile({
+                networkId: "sepolia",
+                currentView: "confirm-tx",
+                selectedWallet: 0,
+                selectedAddress: 0,
+                viewData: {
+                    pendingTx: {
+                        token: "ETH",
+                        from: ADDRESS,
+                        to: ADDRESS,
+                        amount: "1",
+                        chainId: NETWORKS.sepolia.chainId,
+                    },
+                },
+            }),
+        );
+        expect(boot.visibleViews()).toEqual(["confirm-tx"]);
+
+        await boot.click("btn-settings");
+        await chooseNetwork(boot, "mainnet");
+        globalThis.fetch.mockClear();
+        await boot.click("btn-settings-back");
+        expect(boot.visibleViews()).toEqual(["confirm-tx"]);
+        // Drawn again: its Etherscan label check asks Sepolia's explorer.
+        expect(globalThis.fetch.mock.calls.map((call) => call[0])).toEqual([
+            NETWORKS.sepolia.explorerUrl + "/address/" + ADDRESS,
+        ]);
+        expect(boot.text("confirm-type")).toBe("Native SepoliaETH transfer");
+
+        boot.node("confirm-tx-password").value = "any password";
+        await boot.click("btn-confirm-send");
+        expect(boot.visibleViews()).toEqual(["confirm-tx"]);
+        expect(
+            boot.node("confirm-network-changed-error").style.visibility,
+        ).toBe("visible");
+        // Refused before the password is even tried.
+        expect(boot.text("confirm-tx-password-error")).toBe("");
+    });
+
+    test("without a wallet, it lands on Welcome", async () => {
+        const boot = await bootPopup(undefined);
+        expect(boot.visibleViews()).toEqual(["welcome"]);
+
+        await gearSwitchBack(boot);
+        expect(boot.visibleViews()).toEqual(["welcome"]);
+    });
+
+    test("a later Back onto Settings keeps what was typed there", async () => {
+        const boot = await bootOnAddress();
+        await boot.click("btn-settings");
+        await chooseNetwork(boot, "sepolia");
+        boot.node("settings-rpc").value = "https://typed.example";
+
+        await boot.click("btn-settings-add-token");
+        expect(boot.visibleViews()).toEqual(["settings-addtoken"]);
+        await boot.click("btn-settings-addtoken-back");
+        expect(boot.visibleViews()).toEqual(["settings"]);
+        expect(boot.value("settings-rpc")).toBe("https://typed.example");
+    });
+});
+
+describe("a contract lookup that answers after a switch adds nothing", () => {
+    test("from SettingsAddToken", async () => {
+        const boot = await bootOnAddToken("sepolia", {
+            networkTrackedTokens: { mainnet: [MAINNET_TOKEN] },
+        });
+        const stored = () => boot.storage.read("autistmask");
+        boot.node("settings-addtoken-address").value = NEW_TOKEN_ADDRESS;
+
+        await addAcrossSwitch(boot, "btn-settings-addtoken-manual", "mainnet");
+        expect(boot.visibleViews()).toEqual(["settings"]);
+        expect(boot.text("flash-msg")).toBe(NETWORK_CHANGED_FLASH);
+        expect(stored().trackedTokens).toEqual([MAINNET_TOKEN]);
+        expect(stored().networkTrackedTokens.sepolia).toEqual([]);
+    });
+
+    test("from AddToken", async () => {
+        const boot = await bootOnAddress();
+        const stored = () => boot.storage.read("autistmask");
+        await boot.click("btn-add-token");
+        boot.node("add-token-address").value = NEW_TOKEN_ADDRESS;
+
+        await addAcrossSwitch(boot, "btn-add-token-confirm", "sepolia");
+        expect(boot.visibleViews()).toEqual(["settings"]);
+        expect(boot.text("flash-msg")).toBe(NETWORK_CHANGED_FLASH);
+        expect(stored().trackedTokens).toEqual([SEPOLIA_TOKEN]);
+        expect(stored().networkTrackedTokens.mainnet).toEqual([MAINNET_TOKEN]);
+    });
+});

tests/txStatus.test.js

@@ -29,8 +29,13 @@ jest.mock("../src/shared/log", () => ({
 }));
 
 const mockReceiptLookup = jest.fn();
+// The RPC URL and network of every node a wait was given.
+const mockNodes = [];
 jest.mock("../src/shared/balances", () => ({
-    getProvider: () => ({ getTransactionReceipt: mockReceiptLookup }),
+    getProvider: (rpcUrl, networkId) => {
+        mockNodes.push({ rpcUrl, networkId });
+        return { getTransactionReceipt: mockReceiptLookup };
+    },
     refreshBalances: jest.fn(),
 }));
 
@@ -107,6 +112,7 @@ global.chrome = { storage };
 
 const txStatus = require("../src/popup/views/txStatus");
 const { state } = require("../src/shared/state");
+const { NETWORKS } = require("../src/shared/networks");
 const { RESTORABLE_VIEWS } = require("../src/shared/restorableViews");
 const { log } = require("../src/shared/log");
 
@@ -118,6 +124,7 @@ const TX_INFO = {
     amount: "0.0050",
     token: "ETH",
     tokenSymbol: null,
+    chainId: NETWORKS.mainnet.chainId,
 };
 
 // True when a view element is not hidden.
@@ -137,8 +144,14 @@ beforeEach(() => {
     jest.setSystemTime(new Date("2026-08-11T12:00:00Z"));
     elements.clear();
     mockReceiptLookup.mockReset();
+    mockNodes.length = 0;
     log.errorf.mockClear();
+    state.networkId = "mainnet";
+    state.rpcUrl = NETWORKS.mainnet.defaultRpcUrl;
+    state.networkEndpoints = {};
     state.wallets = [];
+    state.trackedTokens = [];
+    state.networkTrackedTokens = {};
     state.viewData = {};
     state.viewStack = [];
     state.currentView = null;
@@ -349,14 +362,14 @@ describe("WaitTx persistence across popup close", () => {
             // out of restoreView().
             {
                 hash: TX_HASH,
-                txInfo: { to: 42, amount: "0.0050" },
+                txInfo: { ...TX_INFO, to: 42 },
                 broadcastTime: Date.now(),
             },
             // Otherwise complete but an array: only Array.isArray() rejects
             // it, since typeof [] is "object" and the fields are present.
             {
                 hash: TX_HASH,
-                txInfo: Object.assign([], { to: RECIPIENT, amount: "0.0050" }),
+                txInfo: Object.assign([], TX_INFO),
                 broadcastTime: Date.now(),
             },
             {
@@ -364,6 +377,18 @@ describe("WaitTx persistence across popup close", () => {
                 txInfo: { to: RECIPIENT },
                 broadcastTime: Date.now(),
             },
+            // Otherwise complete but for a chain id naming no network: there
+            // is no node to ask for the receipt, and no explorer to link to.
+            {
+                hash: TX_HASH,
+                txInfo: { ...TX_INFO, chainId: undefined },
+                broadcastTime: Date.now(),
+            },
+            {
+                hash: TX_HASH,
+                txInfo: { ...TX_INFO, chainId: "0x5" },
+                broadcastTime: Date.now(),
+            },
         ]) {
             state.viewData = { pendingWait: bad };
             expect(txStatus.restoreWait()).toBe(false);
@@ -499,6 +524,154 @@ describe("WaitTx when the popup closes", () => {
     });
 });
 
+// The popup can reopen onto WaitTx after Settings switched the network. The
+// wait asked the active network's node for the receipt, never found it, and
+// reported a timeout, and its links went to the active network's explorer
+// (https://git.eeqj.de/sneak/AutistMask/issues/584).
+describe("WaitTx for a Sepolia transaction with mainnet active", () => {
+    const SEPOLIA_NODE = "https://sepolia.node.example.invalid";
+    const sepoliaTx = { ...TX_INFO, chainId: NETWORKS.sepolia.chainId };
+
+    beforeEach(() => {
+        state.rpcUrl = "https://mainnet.node.example.invalid";
+        state.networkEndpoints = { sepolia: { rpcUrl: SEPOLIA_NODE } };
+    });
+
+    test("the receipt is asked of the Sepolia node Settings has", async () => {
+        mockReceiptLookup.mockResolvedValue({ blockNumber: 21000000 });
+        state.viewData = {
+            pendingWait: {
+                txInfo: sepoliaTx,
+                hash: TX_HASH,
+                broadcastTime: Date.now(),
+            },
+        };
+        expect(txStatus.restoreWait()).toBe(true);
+        await jest.advanceTimersByTimeAsync(0);
+
+        expect(mockNodes).toEqual([
+            { rpcUrl: SEPOLIA_NODE, networkId: "sepolia" },
+        ]);
+        expect(state.currentView).toBe("success-tx");
+    });
+
+    test("the recipient and hash link to the Sepolia explorer", () => {
+        mockReceiptLookup.mockResolvedValue(null);
+        txStatus.showWait(sepoliaTx, TX_HASH);
+
+        expect(getElement("wait-tx-to").innerHTML).toContain(
+            `href="https://sepolia.etherscan.io/address/${RECIPIENT}"`,
+        );
+        expect(getElement("wait-tx-hash").innerHTML).toContain(
+            `href="https://sepolia.etherscan.io/tx/${TX_HASH}"`,
+        );
+    });
+});
+
+// SuccessTx and ErrorTx follow WaitTx and describe the same transaction, but
+// their links went to the active network's explorer
+// (https://git.eeqj.de/sneak/AutistMask/issues/622). Each test checks the
+// screen again after rendering it from its stored view data alone, as a
+// reopened popup does.
+describe("SuccessTx and ErrorTx for a Sepolia transaction with mainnet active", () => {
+    const SEPOLIA_EXPLORER = "https://sepolia.etherscan.io";
+    const TOKEN = "0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238";
+    const sepoliaTx = { ...TX_INFO, chainId: NETWORKS.sepolia.chainId };
+
+    test("the recipient, block and hash on SuccessTx link to the Sepolia explorer", async () => {
+        function expectSepoliaLinks() {
+            expect(getElement("success-tx-to").innerHTML).toContain(
+                `href="${SEPOLIA_EXPLORER}/address/${RECIPIENT}"`,
+            );
+            expect(getElement("success-tx-block").innerHTML).toContain(
+                `href="${SEPOLIA_EXPLORER}/block/21000000"`,
+            );
+            expect(getElement("success-tx-hash").innerHTML).toContain(
+                `href="${SEPOLIA_EXPLORER}/tx/${TX_HASH}"`,
+            );
+        }
+        mockReceiptLookup.mockResolvedValue({ blockNumber: 21000000 });
+        txStatus.showWait(sepoliaTx, TX_HASH);
+        await jest.advanceTimersByTimeAsync(10000);
+        expect(state.currentView).toBe("success-tx");
+        expectSepoliaLinks();
+
+        elements.clear();
+        txStatus.renderSuccess();
+        expectSepoliaLinks();
+    });
+
+    test("the addresses in SuccessTx's decoded action link to the Sepolia explorer", async () => {
+        function expectSepoliaLinks() {
+            const html = getElement("success-tx-decoded").innerHTML;
+            expect(html).toContain(
+                `href="${SEPOLIA_EXPLORER}/address/${TOKEN}"`,
+            );
+            expect(html).toContain(
+                `href="${SEPOLIA_EXPLORER}/address/${RECIPIENT}"`,
+            );
+        }
+        const decoded = {
+            name: "Transfer",
+            details: [
+                { label: "Token", address: TOKEN, isToken: true },
+                { label: "Recipient", address: RECIPIENT },
+            ],
+        };
+        mockReceiptLookup.mockResolvedValue({ blockNumber: 21000000 });
+        txStatus.showWait({ ...sepoliaTx, decoded }, TX_HASH);
+        await jest.advanceTimersByTimeAsync(10000);
+        expect(state.currentView).toBe("success-tx");
+        expectSepoliaLinks();
+
+        elements.clear();
+        txStatus.renderSuccess();
+        expectSepoliaLinks();
+    });
+
+    // https://git.eeqj.de/sneak/AutistMask/issues/629
+    test("SuccessTx's decoded action names the token from the tokens tracked on Sepolia", async () => {
+        function expectTokenNamed() {
+            expect(getElement("success-tx-decoded").innerHTML).toContain(
+                '<div class="font-bold">TDOL</div>',
+            );
+        }
+        state.networkTrackedTokens = {
+            sepolia: [{ address: TOKEN, symbol: "TDOL", decimals: 6 }],
+        };
+        const decoded = {
+            name: "Transfer",
+            details: [{ label: "Token", address: TOKEN, isToken: true }],
+        };
+        mockReceiptLookup.mockResolvedValue({ blockNumber: 21000000 });
+        txStatus.showWait({ ...sepoliaTx, decoded }, TX_HASH);
+        await jest.advanceTimersByTimeAsync(10000);
+        expect(state.currentView).toBe("success-tx");
+        expectTokenNamed();
+
+        elements.clear();
+        txStatus.renderSuccess();
+        expectTokenNamed();
+    });
+
+    test("the recipient and hash on ErrorTx link to the Sepolia explorer", () => {
+        function expectSepoliaLinks() {
+            expect(getElement("error-tx-to").innerHTML).toContain(
+                `href="${SEPOLIA_EXPLORER}/address/${RECIPIENT}"`,
+            );
+            expect(getElement("error-tx-hash").innerHTML).toContain(
+                `href="${SEPOLIA_EXPLORER}/tx/${TX_HASH}"`,
+            );
+        }
+        txStatus.showError(sepoliaTx, TX_HASH, "The transaction failed.");
+        expectSepoliaLinks();
+
+        elements.clear();
+        txStatus.renderError();
+        expectSepoliaLinks();
+    });
+});
+
 describe("wait-tx is a view the popup may reopen onto", () => {
     // The resume feature is wired through RESTORABLE_VIEWS: restoreView()
     // refuses any view not in the set, so dropping "wait-tx" from it kills

tests/uniswapRouterAddress.test.js

@@ -0,0 +1,381 @@
+// Which transactions are shown as a swap through the Uniswap Universal Router
+// (https://git.eeqj.de/sneak/AutistMask/issues/520).
+//
+// The decoder used to recognise the router's execute() call by its selector
+// alone, so the same calldata sent to an ordinary address was shown as a swap
+// through the router, with that address as its Protocol. It is now decoded
+// only when the transaction is sent to a Universal Router deployment on the
+// network it is for; anywhere else it is left to the raw data.
+//
+// The transaction history labelled any call named `execute` or `multicall` a
+// Swap, whatever address it went to
+// (https://git.eeqj.de/sneak/AutistMask/issues/580). It now does so only for
+// such a call sent to a Universal Router deployment on the network the
+// transaction is on; any other is labelled by its method name.
+//
+// The transaction detail screen and the approval screen are driven against a
+// minimal DOM stub in the shape tests/tokenTransferDetail.test.js uses, the
+// approval screen opened the way tests/swapStatusAmount.test.js opens it.
+
+const { AbiCoder, Interface, getAddress, solidityPacked } = require("ethers");
+
+jest.mock("../src/shared/log", () => ({
+    log: {
+        debugf: () => {},
+        infof: () => {},
+        warnf: () => {},
+        errorf: () => {},
+    },
+    debugFetch: async (url) => ({
+        ok: true,
+        json: async () => mockExplorerAnswer(url),
+    }),
+    setRuntimeDebug: () => {},
+    isDebug: () => false,
+}));
+
+globalThis.chrome = {
+    storage: { local: { get: async () => ({}), set: async () => {} } },
+};
+
+const { state } = require("../src/shared/state");
+const { fetchRecentTransactions } = require("../src/shared/transactions");
+const approval = require("../src/popup/views/approval");
+const { decodeCalldata } = approval;
+const transactionDetail = require("../src/popup/views/transactionDetail");
+
+const MAINNET = "0x1";
+const SEPOLIA = "0xaa36a7";
+
+// From Uniswap's deployment files: one router on Ethereum Mainnet only, one on
+// Sepolia only, and one at the same address on both.
+const MAINNET_ROUTER = "0x66a9893cc07d91d95644aedd05d03f95e1dba8af";
+const SEPOLIA_ROUTER = "0x3a9d48ab9751398bbfa63ad67599bb04e4bdf98b";
+const ROUTER_ON_BOTH = "0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD";
+// The address with no code from the issue.
+const ORDINARY = "0x0b0050Da68435b3EcBC236c40F16dB2070bCD79A";
+// A contract that is not a router, such as a multisig.
+const OTHER_CONTRACT = "0x5afe000000000000000000000000000000005afe";
+
+const RECIPIENT = "0xC0FfEE0000000000000000000000000000c0fFEe";
+const SEPOLIA_WETH = "0xfFf9976782d46CC05630D1f6eBAb18b2324d6B14";
+const TOKEN = "0xE2E0000000000000000000000000000000000E2e";
+const HUNDREDTH_ETH = 10000000000000000n;
+
+const coder = AbiCoder.defaultAbiCoder();
+const routerIface = new Interface([
+    "function execute(bytes commands, bytes[] inputs, uint256 deadline)",
+]);
+
+// The calldata from the issue: wrap 0.01 ETH, then a V3 swap of it into a
+// token.
+const SWAP_DATA = routerIface.encodeFunctionData("execute", [
+    solidityPacked(["uint8", "uint8"], [0x0b, 0x00]),
+    [
+        coder.encode(["address", "uint256"], [RECIPIENT, HUNDREDTH_ETH]),
+        coder.encode(
+            ["address", "uint256", "uint256", "bytes", "bool"],
+            [
+                RECIPIENT,
+                HUNDREDTH_ETH,
+                1n,
+                solidityPacked(
+                    ["address", "uint24", "address"],
+                    [SEPOLIA_WETH, 3000, TOKEN],
+                ),
+                false,
+            ],
+        ),
+    ],
+    9999999999n,
+]);
+
+beforeEach(() => {
+    state.trackedTokens = [];
+    state.wallets = [];
+});
+
+describe("execute() calldata on the approval screen's decoder", () => {
+    test("sent to a router on the transaction's network, it is a swap", () => {
+        const onMainnet = decodeCalldata(SWAP_DATA, MAINNET_ROUTER, MAINNET);
+        expect(onMainnet.description).toBe("Swap via Uniswap Universal Router");
+        expect(onMainnet.details[0]).toMatchObject({
+            label: "Protocol",
+            address: MAINNET_ROUTER,
+        });
+        expect(
+            decodeCalldata(SWAP_DATA, SEPOLIA_ROUTER, SEPOLIA).description,
+        ).toBe("Swap via Uniswap Universal Router");
+    });
+
+    test("sent to an ordinary address, it is not decoded", () => {
+        expect(decodeCalldata(SWAP_DATA, ORDINARY, MAINNET)).toBeNull();
+        expect(decodeCalldata(SWAP_DATA, ORDINARY, SEPOLIA)).toBeNull();
+    });
+
+    test("sent to a router of the other network only, it is not decoded", () => {
+        expect(decodeCalldata(SWAP_DATA, SEPOLIA_ROUTER, MAINNET)).toBeNull();
+        expect(decodeCalldata(SWAP_DATA, MAINNET_ROUTER, SEPOLIA)).toBeNull();
+    });
+
+    test("a router deployed at the same address on both networks is one on each", () => {
+        expect(
+            decodeCalldata(SWAP_DATA, ROUTER_ON_BOTH, MAINNET),
+        ).not.toBeNull();
+        expect(
+            decodeCalldata(SWAP_DATA, ROUTER_ON_BOTH, SEPOLIA),
+        ).not.toBeNull();
+    });
+
+    test("the router address matches in any letter case", () => {
+        const upper = "0x" + MAINNET_ROUTER.slice(2).toUpperCase();
+        for (const address of [getAddress(MAINNET_ROUTER), upper]) {
+            expect(decodeCalldata(SWAP_DATA, address, MAINNET)).not.toBeNull();
+        }
+    });
+});
+
+// The transaction the explorer reports: SWAP_DATA, sent to `mockSentTo`.
+const TX_HASH = "0x" + "5".repeat(64);
+let mockSentTo = null;
+// The transactions the explorer reports for RECIPIENT's history.
+let mockHistory = [];
+
+function mockExplorerAnswer(url) {
+    if (url.endsWith("/addresses/" + RECIPIENT + "/transactions")) {
+        return { items: mockHistory };
+    }
+    if (url.endsWith("/transactions/" + TX_HASH)) {
+        return {
+            to: { hash: mockSentTo },
+            raw_input: SWAP_DATA,
+            method: "execute",
+        };
+    }
+    return {};
+}
+
+function makeElement(id) {
+    const classes = new Set();
+    const el = {
+        id,
+        textContent: "",
+        value: "",
+        innerHTML: "",
+        style: {},
+        dataset: {},
+        classList: {
+            add: (...names) => names.forEach((n) => classes.add(n)),
+            remove: (...names) => names.forEach((n) => classes.delete(n)),
+            contains: (n) => classes.has(n),
+            toggle: () => false,
+        },
+        addEventListener: () => {},
+        querySelectorAll: () => [],
+        appendChild: () => {},
+    };
+    // Views reach for .parentElement to hide whole sections.
+    Object.defineProperty(el, "parentElement", {
+        get: () => node(id + "-parent"),
+    });
+    return el;
+}
+
+function makeDocument() {
+    const els = new Map();
+    return {
+        getElementById(id) {
+            // The debug banner is created on demand by helpers.js; absent
+            // is the state a non-debug popup is in.
+            if (id === "debug-banner") return null;
+            if (!els.has(id)) els.set(id, makeElement(id));
+            return els.get(id);
+        },
+        createElement: () => makeElement("created"),
+        body: { prepend: () => {} },
+    };
+}
+
+function node(id) {
+    return globalThis.document.getElementById(id);
+}
+
+// Open the transaction detail screen with `activeNetworkId` active, for the
+// history row `row`, and wait for its decoded details.
+async function showDetail(row, activeNetworkId) {
+    mockSentTo = row.to;
+    globalThis.document = makeDocument();
+    globalThis.window = { location: { search: "" } };
+    state.networkId = activeNetworkId;
+    state.blockscoutUrl = "https://explorer.example/api/v2";
+    state.viewData = {};
+    state.viewStack = [];
+    state.currentView = null;
+    transactionDetail.show(row);
+    for (let i = 0; i < 10; i++) await new Promise((r) => setTimeout(r, 0));
+}
+
+// Open the transaction detail screen with `activeNetworkId` active, for the
+// Sepolia transaction the explorer reports sent to `sentTo`, and wait for its
+// decoded details.
+async function showDetailSentTo(sentTo, activeNetworkId) {
+    await showDetail(
+        {
+            hash: TX_HASH,
+            from: RECIPIENT,
+            to: sentTo,
+            value: "",
+            symbol: "SepoliaETH",
+            timestamp: 1790000000,
+            isError: false,
+            direction: "contract",
+            directionLabel: "Swap",
+            method: "execute",
+            chainId: SEPOLIA,
+        },
+        activeNetworkId,
+    );
+}
+
+describe("execute() calldata on the transaction detail screen", () => {
+    test("sent to a router on the active network, it is a swap", async () => {
+        await showDetailSentTo(SEPOLIA_ROUTER, "sepolia");
+        expect(node("tx-detail-calldata-details").innerHTML).toContain(
+            "Swap via Uniswap Universal Router",
+        );
+    });
+
+    // https://git.eeqj.de/sneak/AutistMask/issues/623
+    test("sent to a router on its network, with the other network active, it is a swap", async () => {
+        await showDetailSentTo(SEPOLIA_ROUTER, "mainnet");
+        expect(node("tx-detail-calldata-details").innerHTML).toContain(
+            "Swap via Uniswap Universal Router",
+        );
+    });
+
+    test("sent to an ordinary address, it is not decoded", async () => {
+        await showDetailSentTo(ORDINARY, "sepolia");
+        expect(node("tx-detail-calldata-action").textContent).toBe("execute");
+        expect(node("tx-detail-calldata-details").innerHTML).toBe("");
+        expect(node("tx-detail-rawdata").innerHTML).toContain(SWAP_DATA);
+    });
+
+    test("sent to a router of the other network only, it is not decoded", async () => {
+        await showDetailSentTo(MAINNET_ROUTER, "sepolia");
+        expect(node("tx-detail-calldata-action").textContent).toBe("execute");
+        expect(node("tx-detail-calldata-details").innerHTML).toBe("");
+        expect(node("tx-detail-rawdata").innerHTML).toContain(SWAP_DATA);
+    });
+});
+
+// The history row made from the explorer's answer for RECIPIENT's `method`
+// call sent to the contract `sentTo` on the network with `chainId`. The
+// explorer gives the address in checksummed form.
+async function historyRow(method, sentTo, chainId) {
+    mockHistory = [
+        {
+            hash: TX_HASH,
+            block_number: 7000000,
+            timestamp: "2026-09-01T00:00:00Z",
+            from: { hash: RECIPIENT },
+            to: { hash: getAddress(sentTo), is_contract: true },
+            value: "0",
+            method,
+            status: "ok",
+        },
+    ];
+    const rows = await fetchRecentTransactions(
+        RECIPIENT,
+        "https://explorer.example/api/v2",
+        chainId,
+    );
+    return rows[0];
+}
+
+// The history row's label and TransactionDetail's Type line, for a Sepolia
+// transaction. The active network does not decide either.
+describe.each([
+    ["execute", "Execute"],
+    ["multicall", "Multicall"],
+])("a %s() call in the history", (method, methodLabel) => {
+    test("sent to a router on its network, it is a Swap", async () => {
+        const row = await historyRow(method, SEPOLIA_ROUTER, SEPOLIA);
+        expect(row.directionLabel).toBe("Swap");
+        await showDetail(row, "mainnet");
+        expect(node("tx-detail-type").textContent).toBe("Swap");
+    });
+
+    test("sent to another contract, it is labelled by its method name", async () => {
+        const row = await historyRow(method, OTHER_CONTRACT, SEPOLIA);
+        expect(row.directionLabel).toBe(methodLabel);
+        await showDetail(row, "sepolia");
+        expect(node("tx-detail-type").textContent).toBe("Contract Call");
+    });
+
+    test("sent to a router of the other network only, it is labelled by its method name", async () => {
+        const row = await historyRow(method, MAINNET_ROUTER, SEPOLIA);
+        expect(row.directionLabel).toBe(methodLabel);
+        await showDetail(row, "mainnet");
+        expect(node("tx-detail-type").textContent).toBe("Contract Call");
+    });
+});
+
+// Open the approval screen with Ethereum Mainnet active, for a site's Sepolia
+// transaction that sends SWAP_DATA to `sentTo`.
+async function showApprovalSentTo(sentTo) {
+    globalThis.document = makeDocument();
+    globalThis.window = { location: { search: "" }, close: () => {} };
+    globalThis.chrome.runtime = {
+        connect: () => ({ postMessage: () => {} }),
+        sendMessage: (_msg, reply) =>
+            reply({
+                type: "tx",
+                origin: "https://dapp.example",
+                isPhishingDomain: false,
+                approvedFrom: RECIPIENT,
+                approvedTx: {
+                    type: 2,
+                    from: RECIPIENT,
+                    chainId: SEPOLIA,
+                    nonce: "0x7",
+                    gasLimit: "0x30d40",
+                    maxPriorityFeePerGas: "0x3b9aca00",
+                    maxFeePerGas: "0x77359400",
+                    to: sentTo,
+                    value: "0x" + HUNDREDTH_ETH.toString(16),
+                    data: SWAP_DATA,
+                    accessList: [],
+                },
+            }),
+    };
+    state.networkId = "mainnet";
+    state.currentView = null;
+    await approval.show(1);
+}
+
+// The router is on Sepolia's list only, so the swap is shown only if the
+// screen decodes for the transaction's network: on Ethereum Mainnet, the
+// active network, that address is not a router.
+describe("execute() calldata on the approval screen, for a Sepolia transaction while Ethereum Mainnet is active", () => {
+    test("sent to a router on Sepolia, it is a swap", async () => {
+        await showApprovalSentTo(SEPOLIA_ROUTER);
+        expect(node("approve-tx-decoded").classList.contains("hidden")).toBe(
+            false,
+        );
+        expect(node("approve-tx-decoded-details").innerHTML).toContain(
+            "Swap via Uniswap Universal Router",
+        );
+    });
+
+    test("sent to an ordinary address, it is shown as raw data", async () => {
+        await showApprovalSentTo(ORDINARY);
+        expect(node("approve-tx-decoded").classList.contains("hidden")).toBe(
+            true,
+        );
+        expect(node("approve-tx-decoded-details").innerHTML).toBe("");
+        expect(node("approve-tx-data").textContent).toBe(SWAP_DATA);
+        expect(
+            node("approve-tx-data-section").classList.contains("hidden"),
+        ).toBe(false);
+    });
+});

tests/uniswapTokenOut.test.js

@@ -53,7 +53,14 @@ function unwrapData() {
 }
 
 function detail(data, label, sources) {
-    const decoded = uniswap.decode(data, ROUTER, sources || {});
+    // Sent by the address the swap pays, so the output is the user's.
+    const decoded = uniswap.decode(
+        data,
+        ROUTER,
+        "0x1",
+        sources || {},
+        RECIPIENT,
+    );
     return decoded.details.find((d) => d.label === label);
 }
 

tests/uniswapUndeterminedTokenIn.test.js

@@ -71,6 +71,8 @@ function exactInParams(currencyIn, path, amountIn, amountOutMin) {
 
 // BALANCE_CHECK_ERC20 (command 0x0e): (address owner, address token,
 // uint256 minBalance). It names the output token and nothing about the input.
+// Its owner is USER, the transaction's sender: a check of any other address
+// names no output token.
 function balanceCheck(token, minBalance) {
     return coder.encode(
         ["address", "address", "uint256"],
@@ -78,8 +80,13 @@ function balanceCheck(token, minBalance) {
     );
 }
 
+// A transaction from USER.
+function decode(data) {
+    return uniswap.decode(data, ROUTER, "0x1", {}, USER);
+}
+
 function detail(data, label) {
-    const decoded = uniswap.decode(data, ROUTER, {});
+    const decoded = decode(data);
     expect(decoded).not.toBeNull();
     return decoded.details.find((d) => d.label === label);
 }
@@ -87,7 +94,7 @@ function detail(data, label) {
 describe("an execute() whose input currency never decoded", () => {
     // A V4_SWAP whose sub-action params do not decode — an action encoding
     // this decoder does not know — leaves every V4 token null. The
-    // BALANCE_CHECK still names the output, so the screen has a Min. received
+    // BALANCE_CHECK still names the output, so the screen has a minimum
     // figure and a Token Out, and previously claimed the user was paying ETH
     // for them.
     const data = () =>
@@ -113,7 +120,7 @@ describe("an execute() whose input currency never decoded", () => {
     });
 
     test("does not name ETH in the swap title either", () => {
-        expect(uniswap.decode(data(), ROUTER, {}).name).toBe("Uniswap Swap");
+        expect(decode(data()).name).toBe("Uniswap Swap");
     });
 });
 
@@ -123,12 +130,13 @@ describe("an execute() that names only an output token", () => {
 
     test("refuses the input rather than defaulting it to ETH", () => {
         expect(detail(data(), "Token In").value).toBe(REFUSAL);
-        expect(uniswap.decode(data(), ROUTER, {}).name).toBe("Uniswap Swap");
+        expect(decode(data()).name).toBe("Uniswap Swap");
     });
 
     test("still states the output it did establish", () => {
         expect(detail(data(), "Token Out").value).toContain("USDT");
-        expect(detail(data(), "Min. received").value).toBe("2.0000 USDT");
+        // No step pays anyone, so the minimum is not said to be received.
+        expect(detail(data(), "Min. paid out").value).toBe("2.0000 USDT");
     });
 });
 
@@ -170,7 +178,7 @@ describe("native ETH in, which V4 spells as the zero address", () => {
 
         expect(detail(data, "Token In").value).toBe("ETH (native)");
         expect(detail(data, "Amount").value).toBe("1.0000 ETH");
-        expect(uniswap.decode(data, ROUTER, {}).name).toBe("Swap ETH → USDT");
+        expect(decode(data).name).toBe("Swap ETH → USDT");
     });
 
     test("WRAP_ETH is still ETH at 18 decimals", () => {

tests/uniswapUndeterminedTokenOut.test.js

@@ -105,7 +105,7 @@ function v3ExactIn(tokenIn, tokenOut, amountIn, amountOutMin) {
 }
 
 function detail(data, label) {
-    const decoded = uniswap.decode(data, ROUTER, {});
+    const decoded = uniswap.decode(data, ROUTER, "0x1", {}, USER);
     expect(decoded).not.toBeNull();
     return decoded.details.find((d) => d.label === label);
 }
@@ -134,13 +134,15 @@ describe("a V4 step that states a Min. received but no output currency", () => {
     });
 
     test("refuses to scale Min. received rather than assuming 18", () => {
-        expect(detail(data(), "Min. received").value).toBe(
+        // With no TAKE, no step pays the user either, so the line is not
+        // labelled received.
+        expect(detail(data(), "Min. paid out").value).toBe(
             unknownDecimalsAmount(MIN_OUT),
         );
     });
 
     test("does not name ETH in the swap title either", () => {
-        const decoded = uniswap.decode(data(), ROUTER, {});
+        const decoded = uniswap.decode(data(), ROUTER, "0x1", {});
         expect(decoded.name).toBe("Uniswap Swap");
     });
 });
@@ -206,6 +208,8 @@ describe("native ETH out, which V4 spells as the zero address", () => {
     test("is still named ETH and still scaled at 18 decimals", () => {
         expect(detail(data(), "Token Out").value).toBe("ETH");
         expect(detail(data(), "Min. received").value).toBe("0.5000 ETH");
-        expect(uniswap.decode(data(), ROUTER, {}).name).toBe("Swap USDT → ETH");
+        expect(uniswap.decode(data(), ROUTER, "0x1", {}).name).toBe(
+            "Swap USDT → ETH",
+        );
     });
 });

tests/uniswapUnknownDecimals.test.js

@@ -82,7 +82,8 @@ function walletsHolding(token, decimals) {
 // decodeCalldata() rather than uniswap.decode() directly, because the scale
 // sources the screen supplies are part of what is under test.
 function swapDetail(data, label) {
-    const decoded = decodeCalldata(data, ROUTER);
+    // Sent by the address the swap pays, so the output is the user's.
+    const decoded = decodeCalldata(data, ROUTER, "0x1", RECIPIENT);
     return decoded.details.find((d) => d.label === label);
 }
 

tests/unknownScaleSend.test.js

@@ -39,7 +39,8 @@ jest.mock("../src/shared/log", () => ({
 
 // Everything the confirmation screen would reach the network for. The gas
 // estimate is the point: with a usable scale it must succeed, so that a failure
-// in these tests is a failure of the scale and not of the stub.
+// in these tests is a failure of the scale and not of the stub. The address
+// holds the 1 ETH the wallets below record, and `tokenUnits` of the token.
 const mockProvider = {
     getFeeData: async () => ({
         maxFeePerGas: 2000000000n,
@@ -48,7 +49,14 @@ const mockProvider = {
     estimateGas: async () => 21000n,
     getCode: async () => "0x",
     getTransactionCount: async () => 1,
-    getBalance: async () => 0n,
+    getBalance: async () => 1000000000000000000n,
+    tokenUnits: 0n,
+    // The one contract call the screen makes, balanceOf().
+    call: async () =>
+        AbiCoder.defaultAbiCoder().encode(
+            ["uint256"],
+            [mockProvider.tokenUnits],
+        ),
 };
 
 jest.mock("../src/shared/balances", () => {
@@ -114,7 +122,7 @@ global.document = {
 };
 global.navigator = { clipboard: { writeText() {} } };
 
-const { parseUnits } = require("ethers");
+const { AbiCoder, parseUnits } = require("ethers");
 const { fetchTokenBalances } = require("../src/shared/balances");
 const { debugFetch } = require("../src/shared/log");
 const { state } = require("../src/shared/state");
@@ -155,8 +163,9 @@ function row(token = {}, value = FIVE_WETH) {
 }
 
 // Fetch the explorer's rows through the real fetcher and put them exactly where
-// refreshBalances() puts them.
+// refreshBalances() puts them. The node reports the holding the explorer does.
 async function fetchOnto(items) {
+    mockProvider.tokenUnits = BigInt(items[0].value);
     debugFetch.mockImplementation(async () => ({
         ok: true,
         status: 200,
@@ -181,6 +190,7 @@ async function fetchOnto(items) {
 // is from the first. Two addresses is what it takes to reach
 // explorerDecimals()'s disagreement check, which is only reachable across rows.
 async function fetchOntoBoth(itemsA, itemsB) {
+    mockProvider.tokenUnits = BigInt(itemsA[0].value);
     debugFetch.mockImplementation(async () => ({
         ok: true,
         status: 200,
@@ -239,6 +249,12 @@ function errors() {
     return el("confirm-errors").innerHTML;
 }
 
+// The message for an amount the balance does not cover, while it is shown.
+function balanceError() {
+    const box = el("confirm-balance-error");
+    return box.style.visibility === "visible" ? box.textContent : "";
+}
+
 function sendDisabled() {
     return el("btn-confirm-send").disabled;
 }
@@ -270,7 +286,6 @@ describe("the Send screen resolves the scale rather than reading the stored one"
         const txInfo = await reviewSend(WETH, "1.5");
         expect(txInfo.tokenDecimals).toBe(18);
         expect(txInfo.tokenDecimals).not.toBe(balances[0].decimals);
-        expect(txInfo.tokenBalance).toBe("5.0");
     });
 
     test("that scale estimates a fee and leaves Send enabled", async () => {
@@ -307,11 +322,10 @@ describe("the Send screen resolves the scale rather than reading the stored one"
         // No fallback was introduced: resolution answers null here, and the
         // null is what goes forward.
         expect(txInfo.tokenDecimals).toBeNull();
-        expect(txInfo.tokenBalance).toBeNull();
         confirmTx.show(txInfo);
         await settle();
         expect(text("confirm-balance")).toBe("unknown (NOVEL)");
-        expect(errors()).toContain("This token's balance is unknown");
+        expect(balanceError()).toContain("This token's balance is unknown");
         expect(sendDisabled()).toBe(true);
     });
 });
@@ -355,7 +369,8 @@ describe("a scale the explorer's own rows disagree about", () => {
         const txInfo = await reviewSend(NOVEL, "1.5");
         expect(txInfo.tokenDecimals).toBeNull();
         // The regression this closes: null scale alongside a non-null balance.
-        expect(txInfo.tokenBalance).toBeNull();
+        send.updateSendBalance();
+        expect(text("send-balance")).toBe("Current balance: unknown (NOVEL)");
     });
 
     test("so the user is told the balance is unknown, not only that the fee failed", async () => {
@@ -367,8 +382,7 @@ describe("a scale the explorer's own rows disagree about", () => {
         // confirm-fee-unknown-error — "the network fee could not be
         // estimated... please go back and try again" — as the only explanation
         // for a screen that can never proceed.
-        expect(errors()).not.toBe("");
-        expect(errors()).toContain("This token's balance is unknown");
+        expect(balanceError()).toContain("This token's balance is unknown");
         expect(text("confirm-balance")).toBe("unknown (NOVEL)");
         expect(sendDisabled()).toBe(true);
         // The fee line still reports the estimate as unavailable, because it
@@ -434,31 +448,20 @@ describe("a scale the explorer's own rows disagree about", () => {
         expect(text("send-balance")).toBe("Current balance: 5.0000 NOVEL");
         const txInfo = await reviewSend(NOVEL, "1.5");
         expect(txInfo.tokenDecimals).toBe(6);
-        expect(txInfo.tokenBalance).toBe("5.0");
         confirmTx.show(txInfo);
         await settle();
         expect(text("confirm-balance")).toBe("5.0000 NOVEL");
         expect(errors()).toBe("");
+        expect(balanceError()).toBe("");
         expect(sendDisabled()).toBe(false);
     });
 });
 
 describe("the confirmation screen tells an unknown balance from a zero one", () => {
-    function txInfo(tokenBalance) {
-        return {
-            from: HOLDER,
-            to: RECIPIENT,
-            ensName: null,
-            amount: "1.5",
-            token: NOVEL,
-            balance: "1.0",
-            tokenSymbol: "NOVEL",
-            tokenBalance,
-            tokenDecimals: tokenBalance === null ? null : 18,
-        };
-    }
-
-    async function render(tokenBalance) {
+    // A send of 1.5 NOVEL from an address the node reports none of, with the
+    // token's scale `tokenDecimals`, or null for a scale nobody knows.
+    async function render(tokenDecimals) {
+        mockProvider.tokenUnits = 0n;
         state.wallets = [
             {
                 name: "Wallet 1",
@@ -469,30 +472,40 @@ describe("the confirmation screen tells an unknown balance from a zero one", ()
         ];
         state.selectedWallet = 0;
         state.selectedAddress = 0;
-        confirmTx.show(txInfo(tokenBalance));
+        confirmTx.show({
+            from: HOLDER,
+            to: RECIPIENT,
+            ensName: null,
+            amount: "1.5",
+            token: NOVEL,
+            tokenSymbol: "NOVEL",
+            tokenDecimals,
+        });
         await settle();
-        return { balance: text("confirm-balance"), errors: errors() };
+        return { balance: text("confirm-balance"), message: balanceError() };
     }
 
     test("the balance line states unknown rather than a quantity of zero", async () => {
         const unknown = await render(null);
-        const zero = await render("0.0");
+        const zero = await render(18);
         expect(unknown.balance).not.toBe(zero.balance);
         expect(unknown.balance).toBe("unknown (NOVEL)");
         expect(zero.balance).toBe("0.0000 NOVEL");
     });
 
     // Both hit INSUFFICIENT_TOKEN — an unknown balance is treated as nothing to
-    // spend from, which is the fail-closed side — but "you have 0.0" is a claim
-    // about the holding, and this one has no established quantity to claim.
-    test("the insufficient-balance message names the reason, not a figure", async () => {
+    // spend from, which is the fail-closed side — but "your balance does not
+    // cover this amount" is a claim about the holding, and this one has no
+    // established quantity to claim.
+    test("the insufficient-balance message names the reason, not a shortfall", async () => {
         const unknown = await render(null);
-        const zero = await render("0.0");
-        expect(unknown.errors).not.toBe(zero.errors);
-        expect(unknown.errors).toContain("This token's balance is unknown");
-        expect(unknown.errors).not.toContain("You have");
-        expect(zero.errors).toContain("You have 0.0000 NOVEL");
-        expect(zero.errors).not.toContain("balance is unknown");
+        const zero = await render(18);
+        expect(unknown.message).toContain("This token's balance is unknown");
+        expect(unknown.message).not.toContain("does not cover");
+        expect(zero.message).toBe(
+            "Your NOVEL balance does not cover this amount. Please go back and" +
+                " send a smaller amount.",
+        );
     });
 });
 

tests/walletDefects.test.js

@@ -475,7 +475,7 @@ describe("every way to a signature or the private key refuses a defective wallet
                 to: RECIPIENT,
                 value: "0x0",
                 data: "0x",
-                chainId: 1,
+                chainId: "0x1",
                 nonce: 0,
                 gasLimit: "21000",
                 maxFeePerGas: "1000000000",