fix: the address screen shows a token just added at its fetched balance, not 0.0000 (closes #516)

A balance refresh that returns now draws the balances on AddressDetail or
AddressToken again when that screen is up, not only the wallet list; their
transaction lists are left alone. Every add path on AddToken and
SettingsAddToken tracks a token through one step, trackToken(), which also
lists it in the new stored field tokensNotFetched: its line reads `quantity
unknown` instead of 0.0000 until a refresh that started with it tracked has
fetched every address's token balances, even if the popup closes first. To
tell an address whose token balances the explorer did not return, the refresh
takes them off its copy of the wallets before fetching.

Model: opus-5-5

README.md

@@ -461,13 +461,15 @@ address, the transaction assertions run against the raw signed transaction
 captured at `eth_sendRawTransaction` rather than against anything the extension
 reported, rejecting each prompt is required to return a rejection to the page
 rather than hang or resolve, a network switch request is required to leave the
-stored network unchanged and send no `chainChanged` until it is approved, a
+stored network unchanged and send no `chainChanged` until it is approved, the
-network switch in Settings is required to send the page `chainChanged` with the
+popup open all along is required to show the `[TESTNET]` banner once a switch to
-new chain id, a prompt raised while another approval window has focus is
+Sepolia is approved and to drop it once the switch back is, a network switch in
-required to open a window of its own, and the password is required to be absent
+Settings is required to send the page `chainChanged` with the new chain id, a
-from every message the approval window sends to the background — with the
+prompt raised while another approval window has focus is required to open a
-message that would carry it required to be present, so that check cannot pass by
+window of its own, and the password is required to be absent from every message
-observing nothing. That last one is the standing floor under
+the approval window sends to the background — with the message that would carry
+it required to be present, so that check cannot pass by observing nothing. That
+last one is the standing floor under
 [#157](https://git.eeqj.de/sneak/AutistMask/issues/157).
 
 The limits of that coverage and of the rest of the Chrome suite, none of them
@@ -603,9 +605,10 @@ suite), wallet creation through the UI, the Add Token screen, and the dApp round
 trips — `eth_requestAccounts`, `personal_sign`, `wallet_switchEthereumChain`
 rejected and then approved, `eth_sendTransaction`, and a closed approval window
 rejecting with EIP-1193 4001 — driven through the real content script,
-background page and approval windows. The `personal_sign` prompt is also
+background page and approval windows. The popup open all along is required to
-required to fit its window without scrolling sideways, with the extension's
+show the `[TESTNET]` banner once the switch to Sepolia is approved and to drop
-pages at 170% zoom.
+it once the switch back is. The `personal_sign` prompt is also required to fit
+its window without scrolling sideways, with the extension's pages at 170% zoom.
 
 The suite lives in `tests/e2e/firefox/`. Its WebDriver client (`driver.js`) has
 **no npm dependencies at all**: it is built on global `fetch` and
@@ -1129,13 +1132,15 @@ 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`
+(`src/popup/views/approval.js`) and the swap's `Amount`, `Min. received`,
-lines (`src/shared/uniswap.js`). The token permission warning on the signature
+`Moved from the sender` and `Permit2 allowance` lines and the `Paid to` line of
-screen takes the same rule for its amounts. An unbounded allowance or permit
+a move into the router (`src/shared/uniswap.js`). The token permission warning
-needs no scale to describe and is still shown as `Unlimited`. A source's answer
+on the signature screen takes the same rule for its amounts. An unbounded
-counts only if it is a whole number from 0 to 80: `decimals()` returns a
+allowance or permit needs no scale to describe and is still shown as
-`uint8`, but `formatUnits()` cannot format more than 80 decimal places, so a
+`Unlimited`. A source's answer counts only if it is a whole number from 0 to 80:
-token that reports 81 to 255 is shown as one whose scale nothing knows.
+`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
@@ -1168,8 +1173,8 @@ 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; `Min. received` reads `Min. paid out` unless
-only the user is paid, see Transaction Decoding), do not always read as a
+only the user is paid and no allowance goes to a spender other than the router,
-number. They can read:
+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.
@@ -1391,7 +1396,9 @@ lists, the send-screen token selector, the address total and the remove-address
 warning (`isBelowOneMillionth()` in `src/shared/amountDisplay.js`). The Send and
 confirmation screens show it when its token is the one being sent. Tracked
 tokens with a zero balance are listed as well while "Show tracked tokens with
-zero balance" is on.
+zero balance" is on; a token just added on AddToken or SettingsAddToken whose
+balance no refresh has fetched yet is listed there as `quantity unknown` (see
+AddToken).
 
 #### Stored state and its version
 
@@ -1562,20 +1569,36 @@ 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
+The popup refreshes balances every ten seconds while it is open
-previous network, so after it "Back" behaves as in a reopened popup: every
+(`doRefreshAndRender()` in `src/popup/index.js`). Each refresh that returns
-screen on the stack counts as not yet rendered, and the stack is cut at the
+draws the wallet list again and, when AddressDetail or AddressToken is up, that
-first screen that cannot be rendered from saved state, such as Send or AddToken,
+screen's USD total and balance lines; its transaction list is left alone. No
-or at AddressToken for any token but the native one, because that token was
+other screen is drawn again by a refresh, DeleteAddress and its balance lines
-picked on the previous network. The cut stack is saved with the switch, so a
+included.
-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
+A network switch leaves every screen on the page showing the previous network.
-anything typed there and not saved, which belonged to the previous network, is
+The user makes it in Settings, or approves a site's request and the background
-dropped. ConfirmTx, WaitTx, SuccessTx, ErrorTx and TransactionDetail are
+saves it. Any other popup open meanwhile takes the switch from the stored
-rendered instead for the network of the transaction they show: the network it
+record, even one saved while it was opening, and never switches the network
-was reviewed on for ConfirmTx, and the network it was sent on for the others.
+itself. A switch the user picks in its Settings while it takes one is made after
-Without a wallet the stack is not cut, because it starts at Welcome, which shows
+it, not overwritten by it. An approval window does not take the switch. After
-nothing from a network.
+the switch, whichever way the page got 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 and is no longer selected. The cut
+stack is saved with the popup's new network, so a popup closed straight after
+and reopened lands in the same place. The screen on top is drawn again for the
+new network: Settings in place, and any other screen as a reopened popup draws
+it, so Home takes the place of one that cannot be rendered from saved state or
+of AddressToken for a token no longer selected. "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 and
+only Settings is drawn again, because the stack starts at Welcome, and Welcome
+and AddWallet show 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
@@ -2064,7 +2087,14 @@ view would leave a wallet one click from deletion.
     - "Add" button
 - **Transitions**:
     - "Add" (valid contract) → tracks the token, pops the stack, and re-renders
-      **AddressDetail**
+      **AddressDetail**. The token's balance is not known until a balance
+      refresh that started with it tracked has fetched every address's token
+      balances; until then its balance line reads `quantity unknown`, never
+      `0.0000`, unless the explorer had already listed a holding of it. That
+      holds after the popup is closed and opened again, as the tokens still
+      waiting for a fetch are stored with the profile. A refresh that returns
+      draws AddressDetail's balances again (see Navigation), so the fetched
+      balance shows without the screen being reopened
     - "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
@@ -2092,8 +2122,11 @@ view would leave a wallet one click from deletion.
       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
+      network only. Switching also clears every address's balances. A balance
-      sends nothing
+      refresh, by the popup or the background, stores what it fetched only if
+      the stored network is still the one it fetched on when it returns, so the
+      previous network's balances never reach the new one. 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
@@ -2338,7 +2371,9 @@ view would leave a wallet one click from deletion.
       add path
 - **Transitions**:
     - Any of the add paths shown, on success → adds the token and shows an
-      "Added SYMBOL" flash message (no screen change)
+      "Added SYMBOL" flash message (no screen change). Until its balance is
+      fetched, its balance line reads `quantity unknown`, as after "Add" on
+      AddToken
     - 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
@@ -2422,10 +2457,12 @@ view would leave a wallet one click from deletion.
       transaction"
     - Decoded action (if calldata is recognized): action name, token details,
       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
+      what each `PERMIT2_TRANSFER_FROM` moves and where to, what each
-      unless a swap pays only the From address, a `Paid to` line for each other
+      `PERMIT2_PERMIT` whose amount is not the `Amount` figure, and each
-      address it pays, or saying that a token stays in the router or who it pays
+      `PERMIT2_PERMIT_BATCH`, lets its spender take, steps, deadline, and unless
-      is unknown (see Transaction Decoding)
+      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
@@ -3178,8 +3215,9 @@ Currently supported:
   `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
+  TransactionDetail), no `Paid to` line is shown, and no permit or batch grants
-  `Token Out` name each other address paid; one reads
+  an allowance to a spender other than the router (see below). `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)`
@@ -3214,38 +3252,57 @@ Currently supported:
   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
+  no `Amount` line. A `PERMIT2_PERMIT` names `Token In` only when its amount,
-  decoder reads, when there is one. Its amount, `Unlimited` included, stands as
+  `Unlimited` included, stands as the `Amount` figure in place of the total,
-  the `Amount` figure in place of the total only in the plain shape of Uniswap's
+  which it does only in the plain shape of Uniswap's own routes: it comes before
-  own routes: it is the only `PERMIT2_PERMIT`, its spender is the router, the
+  the step that sets the input side, it is the only `PERMIT2_PERMIT` in the
-  router may not let it fail, no step before it takes its token or a token the
+  transaction and there is no `PERMIT2_PERMIT_BATCH`, its spender is the router,
-  decoder does not know, and the decoder reads every step after it in full.
+  the router may not let it fail, no step before it takes its token, a
-  Permit2 then lets the router take no more of the token than that amount, so
+  `PERMIT2_TRANSFER_FROM` of it included, or a token the decoder does not know,
-  the permit covers every take of it. A step the decoder does not read in full
+  and the decoder reads every step after it in full. Permit2 then lets the
-  may raise what Permit2 lets the router take, as a `PERMIT2_PERMIT_BATCH` can:
+  router take no more of the token than that amount, so the permit covers every
-  a command the decoder does not read (listed at the end of this section), a
+  take of it. A step before the permit takes under whatever allowance the router
-  step whose input it cannot read, in whole or in part, and a step it fails on.
+  already had, so it may take more than the permit's amount, which would then
-  In any other case the line gives the total, as with no permit. When the step
+  read lower than what leaves the user's wallet: a `PERMIT2_TRANSFER_FROM` of
-  that sets the input side spends a token other than the permit's, or one the
+  2,000 USDT into the router, then a permit of 600 USDT to the router and a V3
-  decoder does not know, its amount gets lines of its own, unless it states no
+  exact-in of 2,000 USDT paid from the router, read `Amount 2000.0000 USDT`. A
-  amount and the user pays it none of its input token, and the total has no
+  later permit or batch may raise what Permit2 lets the router take, and so may
-  figure to start from: unless the permit's amount stands there is no `Amount`
+  a step the decoder does not read in full: a command the decoder does not read
-  line, and each take of the permit's token gets lines of its own. Each take the
+  (listed at the end of this section), a step whose input it cannot read, in
-  total does not count gives three lines after the `Amount` line (after
+  whole or in part, and a step it fails on. Every other `PERMIT2_PERMIT`, before
-  `Token In` when there is none): one of a token other than `Token In`; one of
+  the step that sets the input side or after it, leaves `Token In` and the
-  `Token In` after an amount that is not a quantity (a V4 open delta,
+  `Amount` line as they read with no permit, unless it lets a spender other than
-  `ALREADY_PAID`, which keep their wording on the `Amount` line, or no stated
+  the router take `Token In` (see below): a permit of 5,000 DAI to another
-  amount, as of a V4 exact-out step); and one whose amount the decoder does not
+  address and then a V3 exact-in of 600 USDT read `Swap USDT → USDC` with
-  know. When the step that sets the input side states no amount, the user pays
+  `Amount 600.0000 USDT`, and so do that exact-in and then a permit of 5,000 DAI
-  it some of its input token, and there is no `Amount` line, that step gets them
+  to the router. When a permit's amount stands and the step that sets the input
-  too whenever another take's lines give a figure, or a `PERMIT2_TRANSFER_FROM`
+  side spends a token other than the permit's, or one the decoder does not know,
-  of its token gives one, on the lines below or, into the router, on its
+  that step's amount gets lines of its own, unless it states no amount and the
-  `Paid to` line, so that figure cannot read as all that leaves. When it states
+  user pays it none of its input token. Each take the total does not count gives
-  no amount and the user pays it none of its input token, as when the router
+  three lines after the `Amount` line (after `Token In` when there is none): one
-  pays it, that step takes none of that token from the user's wallet and never
+  of a token other than `Token In`; one of `Token In` after an amount that is
-  gets them, with a permit or without. They come in step order, the step that
+  not a quantity (a V4 open delta, `ALREADY_PAID`, which keep their wording on
-  sets the input side first when it has them: `Moved from the sender`, its
+  the `Amount` line, or no stated amount, as of a V4 exact-out step); and one
-  amount, worded as the `Amount` line words one, or
+  whose amount the decoder does not know. When there is no `Amount` line, each
+  take the total counts gets them too, so that every amount the decoder reads is
+  shown: the amount the step that sets the input side states, when it is a
+  quantity and the user pays that step (a V2 or V3 step whose `payerIsUser` is
+  true, a V4 step the user pays some of its input token, or a `WRAP_ETH`, whose
+  ETH comes from the transaction's value), and each later take of `Token In`
+  added to it. A step that sets the input side and is paid from the router takes
+  nothing from the user's wallet and gets none. A `PERMIT2_PERMIT` the decoder
+  cannot read, then V3 exact-ins of 600 USDT and 400 DAI paid by the user, give
+  lines for both amounts. 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,
+  except that the step that sets the input side comes first when it has them,
+  followed, when there is no `Amount` line, by the other takes the total counts:
+  `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
@@ -3268,11 +3325,34 @@ Currently supported:
   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
+  where it goes, and so its amount is shown once. Every `PERMIT2_PERMIT` whose
-  `Paid to` lines nor the minimum's label. A step goes unread when its recipient
+  amount does not stand as the `Amount` figure, before the step that sets the
-  does not decode as an address, when it is a V3 swap step whose path is shorter
+  input side or after it, gives three lines, in step order, after those for each
-  than one token address or has bytes after its last hop, or when it is a
+  `PERMIT2_TRANSFER_FROM`: `Permit2 allowance`, its amount, for example
-  command the decoder does not read: every command other than `PERMIT2_PERMIT`,
+  `5000.0000 DAI`, or `Unlimited` for Permit2's maximum; `Allowance token`,
+  giving the token's address as the `Token In` line does; and
+  `Allowance spender`, the address it lets take the token. Only a permit whose
+  amount stands gives none: the `Amount` line gives its amount, `Token In` its
+  token, and its spender is the router. Each allowance a `PERMIT2_PERMIT_BATCH`
+  grants, one for each token it names, all for its one spender, gives the same
+  three lines, in step order with those of each `PERMIT2_PERMIT`. A
+  `PERMIT2_PERMIT` or `PERMIT2_PERMIT_BATCH` whose input the decoder cannot
+  read, such as one whose token or spender word has a nonzero top byte, may let
+  any spender take any amount of any token: it gives one `Permit2 allowance`
+  line alone, reading `Unknown (could not be decoded)`. These lines change no
+  `Paid to` line: a permit or batch pays nobody. But code that a step runs, such
+  as a V4 pool's hook or a token's own code, can call a spender other than the
+  router, which can then take up to its allowance from the user's wallet before
+  the transaction ends. So an allowance to any spender but the router, or a
+  permit or batch the decoder cannot read, makes the minimum read
+  `Min. paid out`, and when its token is `Token In`, or the decoder does not
+  know its token or `Token In`, it leaves no `Amount` line, whose figure might
+  be too low: a permit of 5,000 USDT to another address and then a V3 exact-in
+  of 600 USDT read with no `Amount` line, and the 600 USDT gets lines of its
+  own. 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_PERMIT_BATCH`,
   `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`,

src/background/index.js

@@ -1379,6 +1379,13 @@ const RECENT_BALANCE_REFRESH_MS = Math.floor(BALANCE_REFRESH_PERIOD_MS / 2);
 // balances that came back — by address, onto whatever storage holds NOW.
 // Applying by address rather than writing the array back is what keeps a
 // wallet or address added, renamed or deleted during the round trip.
+//
+// Nothing is applied when the network stored NOW is not the one the refresh
+// ran on. A network switch during the round trip cleared every address's
+// balances (applyChainSwitchFields()), and the previous network's must not come
+// back over them (https://git.eeqj.de/sneak/AutistMask/issues/577).
+// lastBalanceRefresh is left as the switch set it, so the next tick refreshes
+// the new network.
 async function backgroundRefresh() {
     const s = await getState();
     const now = Date.now();
@@ -1402,6 +1409,7 @@ async function backgroundRefresh() {
     }
 
     await updateState((fresh) => {
+        if (fresh.networkId !== s.networkId) return;
         for (const wallet of fresh.wallets) {
             for (const addr of wallet.addresses || []) {
                 const got = refreshed.get(String(addr.address).toLowerCase());

src/popup/index.js

@@ -5,12 +5,14 @@ const {
     state,
     saveState,
     onSaveFailure,
+    takeStoredNetwork,
     loadState,
 } = require("../shared/state");
 const { StateUnusableError } = require("../shared/stateSchema");
 const { log, setRuntimeDebug } = require("../shared/log");
 const { refreshPrices } = require("../shared/prices");
 const { refreshBalances } = require("../shared/balances");
+const { clearPopupCaches } = require("../shared/chainSwitch");
 const {
     $,
     showView,
@@ -22,6 +24,7 @@ const {
 } = require("./views/helpers");
 const { applyTheme } = require("./theme");
 const {
+    onStorageChanged,
     tabsGetCurrent,
     tabsGetZoom,
     windowsGetCurrent,
@@ -68,24 +71,83 @@ let refreshInFlight = false;
 // the recovery screen: there is no profile left to refresh.
 let refreshTimer = null;
 
+// The refresh writes into a copy of the wallets. Inside the save, under the
+// lock, its results are copied onto the address records in `state` only if the
+// network it ran on is still the active one, on this page and in the stored
+// record; the background's switch, after the user approves a site's request,
+// reaches this page only after the stored record (followNetworkSwitch() below).
+// A switch while the refresh ran cleared every address's balances
+// (applyChainSwitchFields() in src/shared/chainSwitchFields.js), and the
+// previous network's must not come back over them
+// (https://git.eeqj.de/sneak/AutistMask/issues/577). A dropped refresh is not
+// recorded as done. Results are copied by address, so an address added or
+// removed meanwhile is left as it is.
+//
+// Once the save is done, the wallet list is drawn again, and so are the
+// balances on AddressDetail or AddressToken when that is the screen up. No
+// other screen is drawn again, DeleteAddress and its balance lines included.
 async function doRefreshAndRender() {
     if (refreshInFlight) return;
     refreshInFlight = true;
     try {
+        const networkId = state.networkId;
+        // The tracked tokens this refresh asks the explorer about. A token
+        // added on AddToken after this point is not among them, so this
+        // refresh does not count as having fetched it.
+        const tokens = state.trackedTokens.map((t) => t.address.toLowerCase());
+        const wallets = structuredClone(state.wallets);
+        // Taken off the copy, so that an address whose token balances the
+        // explorer did not return comes back without any and keeps its
+        // stored ones.
+        for (const wallet of wallets) {
+            for (const addr of wallet.addresses) delete addr.tokenBalances;
+        }
         await Promise.all([
             refreshPrices(),
             refreshBalances(
-                state.wallets,
+                wallets,
                 state.rpcUrl,
                 state.blockscoutUrl,
                 state.trackedTokens,
-                state.networkId,
+                networkId,
                 pageClosed.signal,
             ),
         ]);
-        state.lastBalanceRefresh = Date.now();
+        const refreshed = new Map();
-        await saveState();
+        let allTokenBalancesFetched = true;
+        for (const wallet of wallets) {
+            for (const addr of wallet.addresses) {
+                refreshed.set(addr.address, addr);
+                if (addr.tokenBalances === undefined) {
+                    allTokenBalancesFetched = false;
+                }
+            }
+        }
+        await saveState((stored) => {
+            if (state.networkId !== networkId) return false;
+            if (stored.networkId !== networkId) return false;
+            for (const wallet of state.wallets) {
+                for (const addr of wallet.addresses) {
+                    const got = refreshed.get(addr.address);
+                    if (!got) continue;
+                    for (const key of ["balance", "ensName", "tokenBalances"]) {
+                        if (got[key] !== undefined) addr[key] = got[key];
+                    }
+                }
+            }
+            // Each token this refresh asked about is now fetched for every
+            // address.
+            if (allTokenBalancesFetched) {
+                state.tokensNotFetched = state.tokensNotFetched.filter(
+                    (token) => !tokens.includes(token),
+                );
+            }
+            state.lastBalanceRefresh = Date.now();
+            return true;
+        });
         renderWalletList();
+        if (state.currentView === "address") addressDetail.renderBalances();
+        if (state.currentView === "address-token") addressToken.renderBalance();
     } catch (e) {
         // Every call site fires this and walks away — the boot below, the ten
         // second interval, and eight views through ctx — so it must never
@@ -116,6 +178,7 @@ const ctx = {
     renderWalletList,
     doRefreshAndRender,
     startRefresh,
+    restoreView,
     pageClosed: pageClosed.signal,
     showAddWalletView: () => {
         pushCurrentView();
@@ -183,6 +246,28 @@ function fallbackView() {
     showView("main");
 }
 
+// When the background saves a network switch, once the user approves a site's
+// request, or another popup page saves one, this page follows the stored
+// record. It takes the network the record names as a save reads it, holding
+// the lock, so no later save of this page writes the previous network back, and
+// then leaves the page as a switch in Settings leaves it. This page's own
+// switch in Settings is made under the lock as well (onChainSwitch() in
+// src/shared/chainSwitch.js), so a record naming a network other than this
+// page's always holds a switch saved elsewhere, and a switch the user picks
+// here while this waits for the lock is made after it.
+async function followNetworkSwitch() {
+    let switched = false;
+    // A failed save is reported by saveState() itself: see onSaveFailure().
+    await saveState((stored) => {
+        if (stored.networkId === state.networkId) return false;
+        settings.cutViewStack();
+        takeStoredNetwork(stored);
+        clearPopupCaches();
+        switched = true;
+    }).catch(() => {});
+    if (switched) settings.showNewNetwork();
+}
+
 // The background opens the approval window as wide as the page, but the
 // browser counts the window's frame in that width, and a screen taller than
 // the window takes a vertical scrollbar out of it too. So once the screen is
@@ -327,6 +412,17 @@ async function init() {
     settingsAddToken.init(ctx);
     deleteAddress.init(ctx);
 
+    // Only a record naming a network other than this page's is followed: the
+    // one this page's own switch in Settings saves names the network it
+    // already has, and a record naming none is no switch.
+    onStorageChanged((changes) => {
+        const written = changes.autistmask && changes.autistmask.newValue;
+        if (!written || !written.networkId) return;
+        if (written.networkId !== state.networkId) followNetworkSwitch();
+    });
+    // A switch saved since loadState() above, before there was a listener.
+    followNetworkSwitch();
+
     if (!state.hasWallet) {
         showView("welcome");
     } else {

src/popup/viewRouter.js

@@ -39,8 +39,8 @@ function markViewRendered(view) {
 }
 
 // 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
+// asks for one after a network switch, because every screen then on the page
-// then on the page shows the previous network (views/settings.js); the
+// shows the previous network (showNewNetwork() in views/settings.js); the
 // unit tests, which simulate several page loads against one module
 // instance, ask for one too.
 function resetRenderedViews() {

src/popup/views/addToken.js

@@ -1,4 +1,11 @@
-const { $, showView, showFlash, escapeHtml, goBack } = require("./helpers");
+const {
+    $,
+    showView,
+    showFlash,
+    escapeHtml,
+    goBack,
+    trackToken,
+} = require("./helpers");
 const { getTopTokens } = require("../../shared/tokenList");
 const { state, saveState, currentNetwork } = require("../../shared/state");
 const { lookupTokenInfo } = require("../../shared/balances");
@@ -72,7 +79,7 @@ function init(ctx) {
                 return;
             }
             log.infof("Adding token", info.symbol, contractAddr);
-            state.trackedTokens.push({
+            trackToken({
                 address: contractAddr,
                 symbol: info.symbol,
                 decimals: info.decimals,

src/popup/views/addressDetail.js

@@ -65,11 +65,25 @@ function show() {
     });
     $("address-line").dataset.full = addr.address;
     attachCopyHandlers($("address-line"));
-    const usdTotal = formatAddressTotal(getAddressValue(addr));
-    $("address-usd-total").innerHTML = escapeHtml(usdTotal) || " ";
     const ensEl = $("address-ens");
     // ENS is now shown inside renderAddressHtml, hide the separate element
     ensEl.classList.add("hidden");
+    renderBalances();
+    renderSendTokenSelect(addr);
+    $("tx-list").innerHTML =
+        '<div class="text-muted text-xs py-1">Loading...</div>';
+    showView("address");
+    loadTransactions(addr.address);
+}
+
+// The USD total and the balance list. Drawn again by each balance refresh
+// that returns while this screen is up (doRefreshAndRender() in
+// src/popup/index.js), which leaves the rest of the screen as it is.
+function renderBalances() {
+    const addr =
+        state.wallets[state.selectedWallet].addresses[state.selectedAddress];
+    const usdTotal = formatAddressTotal(getAddressValue(addr));
+    $("address-usd-total").innerHTML = escapeHtml(usdTotal) || "&nbsp;";
     $("address-balances").innerHTML = balanceLinesForAddress(
         addr,
         state.trackedTokens,
@@ -83,11 +97,6 @@ function show() {
                 ctx.showAddressToken();
             });
         });
-    renderSendTokenSelect(addr);
-    $("tx-list").innerHTML =
-        '<div class="text-muted text-xs py-1">Loading...</div>';
-    showView("address");
-    loadTransactions(addr.address);
 }
 
 let loadedTxs = [];
@@ -280,4 +289,4 @@ function init(_ctx) {
     exportPrivkey.init();
 }
 
-module.exports = { init, show };
+module.exports = { init, show, renderBalances };

src/popup/views/addressToken.js

@@ -48,37 +48,18 @@ function show() {
     const addr = wallet.addresses[state.selectedAddress];
     const ai = state.selectedAddress;
     const tokenId = state.selectedToken;
-
-    // Determine token symbol and balance
-    let symbol, amount, price;
     const knownToken = TOKEN_BY_ADDRESS.get(tokenId.toLowerCase());
-    if (tokenId === "ETH") {
+    currentSymbol =
-        symbol = nativeCurrency();
+        tokenId === "ETH"
-        amount = parseFloat(addr.balance || "0");
+            ? nativeCurrency()
-        price = getPrice("ETH");
+            : resolveSymbol(tokenId, addr.tokenBalances, state.trackedTokens);
-    } else {
-        const tb = (addr.tokenBalances || []).find(
-            (t) => t.address.toLowerCase() === tokenId.toLowerCase(),
-        );
-        symbol = resolveSymbol(
-            tokenId,
-            addr.tokenBalances,
-            state.trackedTokens,
-        );
-        // null when the scale is unknown: no quantity to show, and none to
-        // price. balanceLine() states that rather than printing 0.0000.
-        amount = tb ? unknownableAmount(tb.balance) : 0;
-        price = getPrice(symbol);
-    }
-
-    currentSymbol = symbol;
 
     $("address-token-title").textContent =
         wallet.name +
         " \u2014 Address " +
         (ai + 1) +
         " \u2014 " +
-        displaySymbol(symbol);
+        displaySymbol(currentSymbol);
 
     // Blockie
     const blockieEl = $("address-token-jazzicon");
@@ -100,13 +81,7 @@ function show() {
     $("address-token-line").dataset.full = addr.address;
     attachCopyHandlers($("address-token-line"));
 
-    // USD total for this token only
+    renderBalance();
-    const usdVal = price && amount !== null ? amount * price : null;
-    const usdStr = formatUsd(usdVal);
-    $("address-token-usd-total").innerHTML = escapeHtml(usdStr) || " ";
-
-    // Single token balance line (no tokenId — not clickable here)
-    $("address-token-balance").innerHTML = balanceLine(symbol, amount, price);
 
     // Token contract details (ERC-20 only)
     const contractInfo = $("address-token-contract-info");
@@ -168,6 +143,44 @@ function show() {
     loadTransactions(addr.address, tokenId);
 }
 
+// The USD total and the balance line of the selected token. Drawn again by
+// each balance refresh that returns while this screen is up
+// (doRefreshAndRender() in src/popup/index.js), which leaves the rest of the
+// screen as it is.
+function renderBalance() {
+    const addr =
+        state.wallets[state.selectedWallet].addresses[state.selectedAddress];
+    const tokenId = state.selectedToken;
+    let amount, price;
+    if (tokenId === "ETH") {
+        amount = parseFloat(addr.balance || "0");
+        price = getPrice("ETH");
+    } else {
+        const id = tokenId.toLowerCase();
+        const tb = (addr.tokenBalances || []).find(
+            (t) => t.address.toLowerCase() === id,
+        );
+        // null when the scale is unknown, or when no refresh has fetched a
+        // token just added: no quantity to show, and none to price.
+        // balanceLine() states that rather than printing 0.0000.
+        if (tb) amount = unknownableAmount(tb.balance);
+        else amount = state.tokensNotFetched.includes(id) ? null : 0;
+        price = getPrice(currentSymbol);
+    }
+
+    // USD total for this token only
+    const usdVal = price && amount !== null ? amount * price : null;
+    const usdStr = formatUsd(usdVal);
+    $("address-token-usd-total").innerHTML = escapeHtml(usdStr) || " ";
+
+    // Single token balance line (no tokenId — not clickable here)
+    $("address-token-balance").innerHTML = balanceLine(
+        currentSymbol,
+        amount,
+        price,
+    );
+}
+
 async function loadTransactions(address, tokenId) {
     try {
         const rawTxs = await fetchRecentTransactions(
@@ -343,4 +356,4 @@ function init(_ctx) {
     });
 }
 
-module.exports = { init, show };
+module.exports = { init, show, renderBalance };

src/popup/views/helpers.js

@@ -380,6 +380,18 @@ function balanceLine(symbol, amount, price, tokenId) {
     );
 }
 
+// Tracks `token` on the active network, as every add path on AddToken and
+// SettingsAddToken does, and lists it in `state.tokensNotFetched`: no refresh
+// has fetched its balance yet. An address with no balance row for it has no
+// known balance of it, so its line says the quantity is unknown rather than
+// 0.0000. doRefreshAndRender() in src/popup/index.js takes it off once a
+// refresh that started with it tracked has fetched every address's token
+// balances (https://git.eeqj.de/sneak/AutistMask/issues/516).
+function trackToken(token) {
+    state.trackedTokens.push(token);
+    state.tokensNotFetched.push(token.address.toLowerCase());
+}
+
 function balanceLinesForAddress(addr, trackedTokens, showZero) {
     let html = balanceLine(
         nativeCurrency(),
@@ -409,12 +421,13 @@ function balanceLinesForAddress(addr, trackedTokens, showZero) {
     }
     if (showZero && trackedTokens) {
         for (const t of trackedTokens) {
-            if (seen.has(t.address.toLowerCase())) continue;
+            const id = t.address.toLowerCase();
+            if (seen.has(id)) continue;
             html += balanceLine(
                 t.symbol,
-                0,
+                state.tokensNotFetched.includes(id) ? null : 0,
                 getPrice(t.symbol),
-                t.address.toLowerCase(),
+                id,
             );
         }
     }
@@ -786,6 +799,7 @@ module.exports = {
     flashCopyFeedback,
     balanceLine,
     balanceLinesForAddress,
+    trackToken,
     addressHoldsFunds,
     keyMaterialName,
     unknownableAmount,

src/popup/views/settings.js

@@ -38,6 +38,8 @@ const {
 
 const { notify, sendMessage } = require("../../shared/browserApi");
 
+let ctx;
+
 let versionClickCount = 0;
 let versionClickTimer = null;
 
@@ -243,7 +245,51 @@ async function renderSiteLists() {
     );
 }
 
-function init(ctx) {
+// A network switch, made by the user here or saved by the background once the
+// user approved a site's request (src/popup/index.js), leaves every screen on
+// the page showing the previous network. These two leave the page as README's
+// Screen Map describes, the first before the switch is saved, so that save
+// keeps the cut for a popup closed straight after, the second once `state`
+// holds the new network.
+//
+// The stack is cut at the first screen that cannot be rendered from saved
+// state, such as Send or AddToken, and at AddressToken unless it shows the
+// native token: any other token there was picked on the previous network, so
+// it is no longer selected either. Without a wallet the stack starts at
+// Welcome, which that cut would drop, and Welcome shows nothing from a network.
+function cutViewStack() {
+    if (!state.hasWallet) return;
+    if (state.selectedToken !== "ETH") {
+        const tokenView = state.viewStack.indexOf("address-token");
+        if (tokenView !== -1) {
+            state.viewStack = state.viewStack.slice(0, tokenView);
+        }
+        state.selectedToken = null;
+    }
+    state.viewStack = restorableStack(state.viewStack, state.currentView);
+}
+
+// Every screen counts as not yet rendered, so "Back" renders the one it lands
+// on for the new network. Settings on top is brought up to date in place;
+// any other screen is drawn again as a reopened popup draws it, which is Home
+// for one that cannot be rendered from saved state. Without a wallet any other
+// screen is Welcome or AddWallet, which show nothing from a network.
+function showNewNetwork() {
+    resetRenderedViews();
+    if (state.currentView === "settings") {
+        markViewRendered("settings");
+        $("settings-network").value = state.networkId;
+        $("settings-rpc").value = state.rpcUrl;
+        $("settings-blockscout").value = state.blockscoutUrl;
+        renderTrackedTokens();
+    } else if (state.hasWallet) {
+        ctx.restoreView();
+    }
+    updateDebugBanner(state.currentView);
+}
+
+function init(_ctx) {
+    ctx = _ctx;
     deleteWallet.init(ctx);
     showPhrase.init();
 
@@ -319,37 +365,18 @@ function init(ctx) {
 
     const networkSelect = $("settings-network");
     networkSelect.addEventListener("change", async () => {
+        // Whether `state` already has the network picked is asked only once
+        // the switch holds the lock: while an earlier pick waits for it,
+        // `state` still has the network before that pick, and a pick back to
+        // that network must still be made.
         const newId = networkSelect.value;
-        if (newId === state.networkId) return;
+        cutViewStack();
-        // 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);
+        if (!net) return;
         // Open pages are told by the background, as after a site's approved
         // switch request.
         notify({ type: "AUTISTMASK_NETWORK_CHANGED", chainId: net.chainId });
-        resetRenderedViews();
+        showNewNetwork();
-        // 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 + ".");
     });
 
@@ -484,4 +511,10 @@ function init(ctx) {
     });
 }
 
-module.exports = { init, show, renderSiteLists };
+module.exports = {
+    init,
+    show,
+    renderSiteLists,
+    cutViewStack,
+    showNewNetwork,
+};

src/popup/views/settingsAddToken.js

@@ -1,4 +1,11 @@
-const { $, showView, showFlash, escapeHtml, goBack } = require("./helpers");
+const {
+    $,
+    showView,
+    showFlash,
+    escapeHtml,
+    goBack,
+    trackToken,
+} = require("./helpers");
 const { getTopTokens } = require("../../shared/tokenList");
 const { state, saveState, currentNetwork } = require("../../shared/state");
 const { lookupTokenInfo } = require("../../shared/balances");
@@ -43,7 +50,7 @@ function renderTop10() {
                     decimals: parseInt(btn.dataset.decimals, 10),
                     name: btn.dataset.name || btn.dataset.symbol,
                 };
-                state.trackedTokens.push(token);
+                trackToken(token);
                 await saveState();
                 showFlash("Added " + token.symbol);
                 renderTop10();
@@ -110,7 +117,7 @@ function init(_ctx) {
             decimals: parseInt(opt.dataset.decimals, 10),
             name: opt.dataset.name || opt.dataset.symbol,
         };
-        state.trackedTokens.push(token);
+        trackToken(token);
         await saveState();
         showFlash("Added " + token.symbol);
         renderTop10();
@@ -156,7 +163,7 @@ function init(_ctx) {
                 return;
             }
             log.infof("Adding token", info.symbol, addr);
-            state.trackedTokens.push({
+            trackToken({
                 address: addr,
                 symbol: info.symbol,
                 decimals: info.decimals,

src/shared/browserApi.js

@@ -224,6 +224,19 @@ function storageRemove(keys) {
     return Promise.resolve(storage.remove(keys));
 }
 
+/**
+ * Call `listener` after every write to `storage.local`, whether this page,
+ * another page or the background made it, with what the write changed, as the
+ * browser reports it: `{ [key]: { oldValue, newValue } }`.
+ *
+ * @param {function(Object): void} listener
+ */
+function onStorageChanged(listener) {
+    namespaceMember("storage").onChanged.addListener((changes, areaName) => {
+        if (areaName === "local") listener(changes);
+    });
+}
+
 /**
  * Run `fn` while holding the browser's lock called `name`
  * (`navigator.locks`), and settle as `fn` settles. Every page of the extension
@@ -385,6 +398,7 @@ module.exports = {
     getPlatformInfo,
     hasBrowserNamespace,
     notify,
+    onStorageChanged,
     runtimeApi,
     sendMessage,
     sessionStorageGet,

src/shared/chainSwitch.js

@@ -1,8 +1,18 @@
-// Consolidated chain-switch handler for the popup.
+// The popup's network switch.
 //
-// Every state change required when the active network changes is
+// A network switch reaches the popup's `state` in one of two ways:
-// performed here so that callers (settings UI, future chain additions) all go
+//
-// through a single code path.
+// - onChainSwitch() below makes the switch the user picks in Settings, with
+//   applyChainSwitchFields() (chainSwitchFields.js).
+// - followNetworkSwitch() in src/popup/index.js takes a switch the background
+//   or another popup page saved, from the stored record, with
+//   takeStoredNetwork() (state.js), which copies it with
+//   copyChainSwitchFields() (chainSwitchFields.js).
+//
+// Both change `state` inside a save, holding the lock, and both reset the
+// popup's own caches through clearPopupCaches(), so a reset added there
+// reaches both. A field applyChainSwitchFields() sets has to be copied by
+// copyChainSwitchFields() too.
 //
 // Adding a new chain (e.g. ETC) requires only a new entry in
 // networks.js — no per-caller wiring is needed.
@@ -20,22 +30,32 @@
 const { applyChainSwitchFields } = require("./chainSwitchFields");
 const { clearPrices } = require("./prices");
 
+// The popup's own caches a network switch resets. Prices are chain-specific
+// (testnet tokens are worthless, ETC has different pricing, etc.). In-memory
+// and per bundle, so this is the popup's own cache — the only context that
+// ever fills it.
+function clearPopupCaches() {
+    clearPrices();
+}
+
 // Switch the active chain and reset all chain-specific cached state.
-// Returns the network configuration object for the new chain.
+// Returns the network configuration object for the new chain, or null when
+// `state` already has that network once the save holds the lock, and nothing
+// is switched.
+//
+// `state` is switched inside the save that stores the switch, holding the
+// lock, so it is never switched while a follow of a switch saved elsewhere
+// waits for the lock (followNetworkSwitch() in src/popup/index.js): that
+// follow runs first, and this switch is made after it.
 async function onChainSwitch(newNetworkId) {
     const { state, saveState } = require("./state");
-
+    let net = null;
-    const net = applyChainSwitchFields(state, newNetworkId);
+    await saveState(() => {
-
+        if (state.networkId === newNetworkId) return false;
-    // --- price cache ---
+        net = applyChainSwitchFields(state, newNetworkId);
-    // Prices are chain-specific (testnet tokens are worthless,
+        clearPopupCaches();
-    // ETC has different pricing, etc.). In-memory and per bundle, so this is
+    });
-    // the popup's own cache — the only context that ever fills it.
-    clearPrices();
-
-    await saveState();
-
     return net;
 }
 
-module.exports = { onChainSwitch };
+module.exports = { onChainSwitch, clearPopupCaches };

src/shared/chainSwitchFields.js

@@ -7,7 +7,7 @@
 // the singleton and saves; the background applies it to the detached record of
 // its own read-modify-write (src/background/state.js).
 //
-// Everything here is synchronous and touches nothing but the object it is
+// Everything here is synchronous and touches nothing but the objects it is
 // given: no storage, no caches, no imports beyond the network table. That is
 // what makes it usable on a record that has been read fresh from storage
 // microseconds earlier and is about to be written back.
@@ -76,4 +76,33 @@ function applyChainSwitchFields(s, newNetworkId) {
     return net;
 }
 
-module.exports = { applyChainSwitchFields };
+// Give `s` every field applyChainSwitchFields() sets, as `switched` holds it:
+// the popup takes a switch the background saved from the stored record this
+// way, rather than performing it again (takeStoredNetwork() in
+// src/shared/state.js). Balances are taken by address, and an address
+// `switched` does not have keeps none.
+function copyChainSwitchFields(s, switched) {
+    s.networkEndpoints = switched.networkEndpoints;
+    s.networkTrackedTokens = switched.networkTrackedTokens;
+    s.trackedTokens = switched.trackedTokens;
+    s.networkId = switched.networkId;
+    s.rpcUrl = switched.rpcUrl;
+    s.blockscoutUrl = switched.blockscoutUrl;
+    s.lastBalanceRefresh = switched.lastBalanceRefresh;
+    s.tokenHolderCache = switched.tokenHolderCache;
+    s.fraudContracts = switched.fraudContracts;
+
+    const stored = new Map();
+    for (const wallet of switched.wallets) {
+        for (const addr of wallet.addresses) stored.set(addr.address, addr);
+    }
+    for (const wallet of s.wallets) {
+        for (const addr of wallet.addresses) {
+            const got = stored.get(addr.address);
+            addr.balance = got ? got.balance : "0";
+            addr.tokenBalances = got ? got.tokenBalances : [];
+        }
+    }
+}
+
+module.exports = { applyChainSwitchFields, copyChainSwitchFields };

src/shared/persistedState.js

@@ -28,6 +28,13 @@ const DEFAULT_STATE = {
     // others are restored from when the active network changes. See
     // applyChainSwitchFields().
     networkTrackedTokens: {},
+    // Contract addresses, lowercased, of the tokens the user added that no
+    // balance refresh has fetched yet. trackToken() in
+    // src/popup/views/helpers.js adds one, and doRefreshAndRender() in
+    // src/popup/index.js takes it off. Stored, so a token added just before
+    // the popup closed still reads `quantity unknown` when it opens again
+    // (https://git.eeqj.de/sneak/AutistMask/issues/516).
+    tokensNotFetched: [],
     networkId: "mainnet",
     rpcUrl: DEFAULT_RPC_URL,
     blockscoutUrl: DEFAULT_BLOCKSCOUT_URL,
@@ -412,6 +419,8 @@ function normalizePersisted(saved) {
     // so a stored string walks through the `|| []` and a stored number walks
     // through an Array.isArray().
     out.fraudContracts = textList(saved.fraudContracts);
+    // Contract addresses too, read with `includes()` and `filter()`.
+    out.tokensNotFetched = textList(saved.tokensNotFetched);
     out.tokenHolderCache = structuredClone(saved.tokenHolderCache || {});
     out.theme = saved.theme || "system";
     out.debugMode = saved.debugMode !== undefined ? saved.debugMode : false;

src/shared/state.js

@@ -23,6 +23,7 @@
 // guarantee.
 
 const { networkById } = require("./networks");
+const { copyChainSwitchFields } = require("./chainSwitchFields");
 const {
     DEFAULT_STATE,
     PERSISTED_FIELDS,
@@ -125,8 +126,10 @@ function currentNetwork() {
 }
 
 // The persisted fields as this page held them when its last loadState()
-// finished, or when its last successful saveState() began. saveState() diffs
+// finished, or when its last successful saveState() began, with any network
-// the live state against this to find only the fields THIS page changed since.
+// switch saved elsewhere that this page has taken since (takeStoredNetwork()).
+// saveState() diffs the live state against this to find only the fields THIS
+// page changed since.
 //
 // Deep-cloned, not a reference: callers mutate persisted objects and arrays
 // in place (state.wallets.push(...)), and a reference baseline would mutate
@@ -466,12 +469,10 @@ function mergeNetworkEndpoints(base, ours, theirs) {
 // exists to remove, just delayed and confined to one page instead of two
 // (caught by tests/txStatus.test.js). A page's live picture of a field it
 // does not own goes on being whatever its last loadState() saw, same as
-// before this fix; only the persisted record is guaranteed current.
+// before this fix; only the persisted record is guaranteed current. The
-async function saveStateOnce() {
+// network is the exception: the popup takes a switch another context saved
-    // A copy, so what this save compares and writes is the page's state as it
+// through `beforeWrite` (followNetworkSwitch() in src/popup/index.js).
-    // stood when the save began. A change made while it waits on storage is
+async function saveStateOnce(beforeWrite) {
-    // left for the next save, which compares against this copy.
-    const current = structuredClone(snapshotPersisted());
     const result = await storageGet("autistmask");
     // The record in storage right now is about to be merged into and written
     // back, so it is validated exactly like a load validates it. Without this,
@@ -485,6 +486,12 @@ async function saveStateOnce() {
     // come from storage in its loaded (self-healed) shape. See
     // normalizePersisted() in persistedState.js.
     const fresh = normalizePersisted(result.autistmask);
+    if (beforeWrite && beforeWrite(fresh) === false) return;
+
+    // A copy, so what this save compares and writes is the page's state as it
+    // stood once the stored record was read. A change made while it waits on
+    // the write is left for the next save, which compares against this copy.
+    const current = structuredClone(snapshotPersisted());
 
     const merged = { ...fresh };
     for (const key of PERSISTED_FIELDS) {
@@ -579,10 +586,15 @@ function reportSaveFailure(err) {
 // The same lock orders this page's own saves. showView() calls saveState() on
 // every navigation without awaiting it, so two saves from one page can be
 // asked for at once; they take the lock in the order they were asked, and each
-// compares the page's state as it stands when its turn begins against the
+// compares the page's state, as it stands once the stored record has been read
-// baseline the save before it left.
+// and `beforeWrite` has run, against the baseline the save before it left.
-function saveState() {
+//
-    const turn = withLock("autistmask", saveStateOnce);
+// `beforeWrite`, when given, is called inside the lock with the stored record
+// as just read, before this page's state is compared against it. It may change
+// `state`, and this save writes that change. When it returns false, nothing is
+// written; any other return lets the save go ahead.
+function saveState(beforeWrite) {
+    const turn = withLock("autistmask", () => saveStateOnce(beforeWrite));
     // Every failed save is reported, whether or not the caller awaited this
     // one. The returned promise still rejects, so a caller that DOES await
     // keeps its own error handling.
@@ -590,6 +602,17 @@ function saveState() {
     return turn;
 }
 
+// Give this page the network switch held by `stored`, a record a save of this
+// page has just read (followNetworkSwitch() in src/popup/index.js calls this
+// from `beforeWrite`), in `state` and in `baseline` alike, as loadState() does
+// with a whole record. The switch is then not this page's own change, even when
+// that save fails to write: a later switch back to the previous network still
+// differs from `baseline`, and is stored.
+function takeStoredNetwork(stored) {
+    copyChainSwitchFields(rawState, stored);
+    copyChainSwitchFields(baseline, structuredClone(stored));
+}
+
 // Rejects with StateUnusableError for a stored record this build cannot make
 // sense of. Nothing is assigned and `loaded` stays false in that case, so a
 // caller that ignores the rejection gets StateNotLoadedError on the first
@@ -635,6 +658,7 @@ module.exports = {
     state,
     saveState,
     onSaveFailure,
+    takeStoredNetwork,
     loadState,
     currentAddress,
     currentNetwork,

src/shared/uniswap.js

@@ -336,7 +336,8 @@ const UNNAMED_CURRENCY = "Unknown (not named in the calldata)";
 // currencies, and those commands may name one, so saying the calldata did not
 // name it would be false. The Paid to line uses it too, when a step may pay an
 // address this decoder did not read, and so do the lines for what a step
-// takes from the sender, when this decoder does not know it.
+// takes from the sender, when this decoder does not know it, and for what a
+// permit it could not read allows.
 const UNDECODED_CURRENCY = "Unknown (could not be decoded)";
 
 // The Paid to line for each token paid to the router, the swap's output or
@@ -494,8 +495,9 @@ function amountText(raw, info) {
     };
 }
 
-// The line giving a moved token under `label`, in the shape of the Token In
+// The line giving a moved token, or the token of a permit, under `label`, in
-// line, so the screens show it as they show that one. ETH has no address.
+// the shape of the Token In line, so the screens show it as they show that
+// one. ETH has no address.
 function tokenMovedLine(label, token, sources) {
     const info = tokenInfo(token, sources);
     if (!present(info.address)) {
@@ -527,6 +529,32 @@ function decodePermit2(input) {
     }
 }
 
+// Decode PERMIT2_PERMIT_BATCH (command 0x03) input bytes into the allowances
+// it grants, one for each token it names, all for its one spender, in the
+// shape decodePermit2() returns. Each release's
+// `contracts/base/Dispatcher.sol`, at the commit linked for it above, hands
+// Permit2 the batch in this shape.
+// ABI: (((address token, uint160 amount, uint48 expiration, uint48 nonce)[],
+//        address spender, uint256 sigDeadline), bytes signature)
+function decodePermit2Batch(input) {
+    try {
+        const d = coder.decode(
+            [
+                "tuple(tuple(address,uint160,uint48,uint48)[],address,uint256)",
+                "bytes",
+            ],
+            input,
+        );
+        return d[0][0].map((details) => ({
+            token: details[0],
+            amount: details[1],
+            spender: d[0][1],
+        }));
+    } catch {
+        return null;
+    }
+}
+
 // Decode BALANCE_CHECK_ERC20 (command 0x0e) input bytes. The router passes the
 // check when `owner` holds at least `minBalance` of `token`, and reads `owner`
 // as written, without map(), on every release that has the command:
@@ -596,12 +624,14 @@ function decodeV2SwapExactOut(input) {
 // token(20) ...), or null when it is not one token followed by whole hops of
 // a fee and a token (40 hex digits, then 46 per hop). The router reads only
 // whole hops and ignores any bytes after the last one, so the last 20 bytes
-// of such a path are not the token it reads there.
+// of such a path are not the token it reads there. Both are checksummed, as
+// the ABI decoder gives every other address, so a token reads the same on
+// every line.
 function decodeV3Path(pathHex) {
     const hex = pathHex.startsWith("0x") ? pathHex.slice(2) : pathHex;
     if (hex.length < 40 || (hex.length - 40) % 46 !== 0) return null;
-    const first = "0x" + hex.slice(0, 40);
+    const first = getAddress("0x" + hex.slice(0, 40));
-    const last = "0x" + hex.slice(-40);
+    const last = getAddress("0x" + hex.slice(-40));
     return { first, last };
 }
 
@@ -1204,13 +1234,22 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         let inputToken = null;
         let inputAmount = null;
         let inputEstablished = false;
-        // Whether the user pays the V4 step that set the input side any of
+        // Whether the user pays the step that set the input side: a V2 or V3
-        // its input currency (see decodeV4Swap()). Only a V4 step can set the
+        // swap step with `payerIsUser` true, a V4 step the user pays some of
-        // input side with no amount, the one case in which this is read.
+        // its input currency (see decodeV4Swap()), or a WRAP_ETH, whose ETH
+        // comes from the transaction's value. A step paid from the router
+        // takes nothing from the sender.
         let inputPaidByUser = false;
-        // The last PERMIT2_PERMIT this decoder read, or null (see
+        // The last PERMIT2_PERMIT this decoder read before a step set the
-        // permitStands after the loop).
+        // input side, or null (see permitStands after the loop).
         let permit = null;
+        // Every allowance a PERMIT2_PERMIT or PERMIT2_PERMIT_BATCH grants,
+        // before a step set the input side or after, in step order, as
+        // { token, amount, spender, step }. A permit or batch whose input
+        // this decoder cannot read is one with a null token, amount and
+        // spender. Each but a permit whose amount is the Amount figure gets
+        // lines of its own (see after the PERMIT2_TRANSFER_FROM lines).
+        const permits = [];
         // The index of each step this decoder did not read in full: a
         // command it does not read, a step whose input it cannot read, in
         // whole or in part, and one it fails on (see permitStands).
@@ -1268,8 +1307,9 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         // when no earlier hop set it. A half the establishing hop did not
         // state stays null and the line says so, rather than being filled in
         // from a different hop. A PERMIT2_PERMIT sets no side here: after the
-        // loop, the last one read names Token In, and the Amount line is
+        // loop, one whose amount stands as the Amount figure names Token In,
-        // formed there, in one place (see permitStands).
+        // and the Amount line is formed there, in one place (see
+        // permitStands).
         const setInput = (token, amount) => {
             inputToken = present(token) ? token : null;
             inputAmount = present(amount) ? amount : null;
@@ -1313,6 +1353,15 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         const spentUnread = () => {
             userPaid.push({ token: null, amount: null });
         };
+        // A PERMIT2_PERMIT or PERMIT2_PERMIT_BATCH at `step` whose input this
+        // decoder cannot read may let any spender take any amount of any
+        // token: one line says so, there is no Amount line, whose figure may
+        // then be too low, and the minimum reads Min. paid out (see
+        // toAnotherSpender).
+        const permitUnread = (step) => {
+            permits.push({ token: null, amount: null, spender: null, step });
+            stepsUnread.push(step);
+        };
 
         // Who the steps pay, in whichever step and of whatever token.
         // MSG_SENDER is the sender. The router itself, as ADDRESS_THIS or by
@@ -1465,24 +1514,44 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                 } else if (command === "PERMIT2_PERMIT") {
                     const p = decodePermit2(inputs[i]);
                     if (p) {
+                        permits.push({ ...p, step: i });
+                        keepsRouterWeth = true;
+                    } else {
+                        permitUnread(i);
+                    }
+                    // Only a permit whose amount stands as the Amount figure
+                    // names Token In (see permitStands). Every other permit,
+                    // before the step that sets the input side or after it,
+                    // leaves Token In and Amount as they read with no permit
+                    // and gets lines of its own. One after a step set the input
+                    // side never stands, so only one before it is kept here.
+                    if (p && !inputEstablished) {
                         // Whether a step before it took its token, or may
-                        // have: the step that set the input side or one in
+                        // have: one in `userPaid`, `movedIntoRouter` or
-                        // `userPaid`, when its token is the permit's or not
+                        // `movedFromSender`, when its token is the permit's
-                        // known.
+                        // or not known. No step has set the input side yet.
                         const mayBeItsToken = (token) =>
                             !present(token) || sameAddress(token, p.token);
-                        const tookBefore =
+                        const tookBefore = [
-                            (inputEstablished && mayBeItsToken(inputToken)) ||
+                            ...userPaid,
-                            userPaid.some((t) => mayBeItsToken(t.token));
+                            ...movedIntoRouter,
+                            ...movedFromSender,
+                        ].some((t) => mayBeItsToken(t.token));
                         permit = {
                             ...p,
                             step: i,
                             allowedToFail,
                             beforeEveryTake: !tookBefore,
                         };
-                        keepsRouterWeth = true;
+                    }
+                } else if (command === "PERMIT2_PERMIT_BATCH") {
+                    // Each allowance it grants gets the lines of a permit
+                    // whose amount does not stand. It pays nobody.
+                    const batch = decodePermit2Batch(inputs[i]);
+                    if (batch) {
+                        permits.push(...batch.map((p) => ({ ...p, step: i })));
                     } else {
-                        stepsUnread.push(i);
+                        permitUnread(i);
                     }
                 } else if (command === "PERMIT2_TRANSFER_FROM") {
                     const p = decodePermit2TransferFrom(inputs[i]);
@@ -1556,6 +1625,7 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                     if (s) {
                         if (!inputEstablished) {
                             setInputOnce(s.tokenIn, s.amountIn);
+                            inputPaidByUser = s.payerIsUser;
                         } else if (s.payerIsUser) {
                             addUserPaid(s.tokenIn, s.amountIn);
                         }
@@ -1579,6 +1649,7 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                     if (s) {
                         if (!inputEstablished) {
                             setInputOnce(s.tokenIn, s.amountIn);
+                            inputPaidByUser = s.payerIsUser;
                         } else if (s.payerIsUser) {
                             addUserPaid(s.tokenIn, s.amountIn);
                         }
@@ -1610,6 +1681,7 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                     if (s) {
                         if (!inputEstablished) {
                             setInputOnce(s.tokenIn, s.amountInMax);
+                            inputPaidByUser = s.payerIsUser;
                         } else if (s.payerIsUser) {
                             addUserPaid(s.tokenIn, s.amountInMax);
                         }
@@ -1705,10 +1777,13 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                 } else if (command === "WRAP_ETH") {
                     const w = decodeWrapEth(inputs[i]);
                     if (w) {
-                        setInputOnce(
+                        if (!inputEstablished) {
-                            "0x0000000000000000000000000000000000000000",
+                            setInputOnce(
-                            w.amount,
+                                "0x0000000000000000000000000000000000000000",
-                        );
+                                w.amount,
+                            );
+                            inputPaidByUser = true;
+                        }
                         addPayee(w.recipient);
                         // CONTRACT_BALANCE wraps all the router's ETH.
                         if (w.amount === CONTRACT_BALANCE) {
@@ -1892,8 +1967,8 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                     }
                 } else {
                     // Any other step may pay an address this decoder does not
-                    // read: PERMIT2_PERMIT_BATCH and the NFT commands among
+                    // read: the NFT commands among them, and a type the
-                    // them, and a type the release names no command for.
+                    // release names no command for.
                     payeeUnread = true;
                     stepsUnread.push(i);
                 }
@@ -1939,18 +2014,26 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         // lines of its own. One whose amount is not known also leaves the
         // total unknown, with no figure.
         //
-        // The last PERMIT2_PERMIT read names Token In. Its amount stands as
+        // A PERMIT2_PERMIT names Token In only when its amount stands as the
-        // the Amount figure in place of the total only in the plain shape of
+        // Amount figure in place of the total, which it does only in the
-        // Uniswap's own routes: it is the only PERMIT2_PERMIT, its spender is
+        // plain shape of Uniswap's own routes: it comes before the step that
+        // set the input side, it is the only PERMIT2_PERMIT in the
+        // transaction and there is no PERMIT2_PERMIT_BATCH, its spender is
         // the router, the router may not let it fail, no step before it took
-        // its token or one not known, and this decoder read every step after
+        // its token or one not known (a PERMIT2_TRANSFER_FROM of its token
-        // it in full (see stepsUnread). Permit2 then lets the router take no
+        // included), and this decoder read every step after it in full (see
-        // more of the token than that amount, so the permit covers every take
+        // stepsUnread). Permit2 then lets the router take no more of the token
-        // of it. A later step this decoder did not read may raise what Permit2
+        // than that amount, so the permit covers every take of it. A step
-        // lets the router take, as a PERMIT2_PERMIT_BATCH can. A step that
+        // before it takes under whatever allowance the router already had, so
-        // may take from the sender what this decoder did not read leaves no
+        // it may take more. A later permit or batch, or a later step this
-        // figure, permit or not (see spentUnread()), and an EXECUTE_SUB_PLAN
+        // decoder did not read, may raise what Permit2 lets the router take.
-        // step leaves both sides unknown (below).
+        // Every other PERMIT2_PERMIT leaves Token In and the Amount line as
+        // they read with no permit, and gets lines of its own below. A step
+        // that may take from the sender what this decoder did not read leaves
+        // no figure, permit or not (see spentUnread()), and so do a permit
+        // or batch whose input it cannot read (see permitUnread()) and an
+        // allowance of Token In to another spender (see toAnotherSpender). An
+        // EXECUTE_SUB_PLAN step leaves both sides unknown (below).
         const stepCommands = Array.from(
             commandsBytes,
             (b) => commands[b & commandTypeMask],
@@ -1958,6 +2041,7 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         const permitStands =
             permit !== null &&
             stepCommands.filter((c) => c === "PERMIT2_PERMIT").length === 1 &&
+            !stepCommands.includes("PERMIT2_PERMIT_BATCH") &&
             sameAddress(permit.spender, toAddress) &&
             !permit.allowedToFail &&
             permit.beforeEveryTake &&
@@ -1967,6 +2051,11 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         // (see spentUnread()), or a token it does not know.
         const spentFromSender = [];
         let total = null;
+        // The takes from the sender that `total` adds up, each a quantity, as
+        // { token, amount }. When there is no Amount line, each gets lines of
+        // its own (see below). The amount of a step that set the input side
+        // and is paid from the router counts in `total` but is not among them.
+        const inTotal = [];
         // Whether the step that set the input side counts as a take from the
         // sender, which may get lines of its own. The amount it stated counts
         // whoever pays it. Stating none, it counts only when the user pays it
@@ -1977,17 +2066,20 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         // The take of the step that set the input side, when the total
         // starts from it and it stated no amount (see below), or null.
         let firstTakeUnstated = null;
-        if (permit === null || sameAddress(inputToken, permit.token)) {
+        if (!permitStands || sameAddress(inputToken, permit.token)) {
             total = inputAmount;
+            if (typeof inputAmount === "bigint" && inputPaidByUser) {
+                inTotal.push({ token: inputToken, amount: inputAmount });
+            }
             if (hasFirstTake && !present(inputAmount)) {
                 firstTakeUnstated = { token: inputToken, amount: null };
             }
         } else if (hasFirstTake) {
             // The step that set the input side spent a token other than the
-            // permit's, or one not known, so the total starts with no figure.
+            // permit's, or one not known, so its amount gets lines of its own.
             spentFromSender.push({ token: inputToken, amount: inputAmount });
         }
-        if (permit !== null) inputToken = permit.token;
+        if (permitStands) inputToken = permit.token;
         for (const t of userPaid) {
             const ofTokenIn = sameAddress(t.token, inputToken);
             if (ofTokenIn && permitStands) continue;
@@ -1997,6 +2089,7 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                 typeof t.amount === "bigint"
             ) {
                 total += t.amount;
+                inTotal.push(t);
                 continue;
             }
             spentFromSender.push(t);
@@ -2020,10 +2113,9 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         }
 
         // The commands of an EXECUTE_SUB_PLAN step may spend the user's tokens
-        // or pay the user, before or after any other step, and a permit among
+        // or pay the user, before or after any other step. What the other
-        // them would name Token In. What the other steps state is
+        // steps state is then not the whole swap, so both sides are set
-        // then not the whole swap, so both sides are set unknown, with no
+        // unknown, with no figure, wherever the step stands.
-        // figure, wherever the step stands.
         if (hasSubPlan) {
             inputToken = null;
             inputAmount = null;
@@ -2126,12 +2218,30 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
             return amountText(amount, info);
         };
 
+        // Each allowance to a spender other than the router. Code that a step
+        // runs, such as a V4 pool's hook or a token's own code, can call that
+        // spender, which can then take up to the allowance from the sender
+        // before the transaction ends. A permit or batch this decoder could
+        // not read may be to any spender, of any token.
+        const toAnotherSpender = permits.filter(
+            (p) => !sameAddress(p.spender, toAddress),
+        );
+
         // A null token in `spentFromSender`, a step this decoder did not read
-        // or a token it does not know, leaves no Amount figure, which may
+        // or a token it does not know, and an allowance to another spender
-        // then be too low.
+        // that may be of Token In, leave no Amount figure, which may then be
+        // too low. With no Amount line, each take the total adds up gets
+        // lines of its own, first, so that every amount this decoder read is
+        // shown.
         if (
             present(inputAmount) &&
-            spentFromSender.every((s) => present(s.token))
+            spentFromSender.every((s) => present(s.token)) &&
+            toAnotherSpender.every(
+                (p) =>
+                    present(p.token) &&
+                    present(inputToken) &&
+                    !sameAddress(p.token, inputToken),
+            )
         ) {
             const amount = spentText(inputAmount, inInfo);
             details.push({
@@ -2139,6 +2249,8 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                 value: amount.display,
                 rawValue: amount.raw,
             });
+        } else {
+            spentFromSender.unshift(...inTotal);
         }
 
         // What steps take from the sender beyond the Amount line, in the shape
@@ -2181,6 +2293,40 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
             );
         }
 
+        // What each allowance of a PERMIT2_PERMIT or PERMIT2_PERMIT_BATCH lets
+        // its spender take: its amount, its token and the spender, an address
+        // on a line of its own. Permit2's maximum is unbounded. Only a permit
+        // whose amount stands as the Amount figure (see permitStands) gets
+        // none: that line already gives its amount and Token In its token,
+        // and its spender is the router. Every other allowance, one after the
+        // step that set the input side included, gets these lines, so nothing
+        // it lets anyone take goes unstated. A permit or batch this decoder
+        // could not read gets one line saying so.
+        for (const p of permits) {
+            if (permitStands && p.step === permit.step) continue;
+            if (!present(p.token)) {
+                details.push({
+                    label: "Permit2 allowance",
+                    value: UNDECODED_CURRENCY,
+                });
+                continue;
+            }
+            details.push({
+                label: "Permit2 allowance",
+                value:
+                    p.amount >= MAX_UINT160
+                        ? "Unlimited"
+                        : amountText(p.amount, tokenInfo(p.token, sources))
+                              .display,
+            });
+            details.push(tokenMovedLine("Allowance token", p.token, sources));
+            details.push({
+                label: "Allowance spender",
+                value: p.spender,
+                address: p.spender,
+            });
+        }
+
         // Keyed on the address, not the symbol: a token absent from the
         // bundled list has no symbol, and gating the line on one dropped it
         // entirely, leaving a Min. received figure with nothing saying what is
@@ -2216,9 +2362,10 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         // step pays the bridge, when one moves the sender's tokens into the
         // router, when a token stays in the router, and when a payout could
         // not be read. The output is received by the sender only when some
-        // step pays the sender and there is no such line. When no step names
+        // step pays the sender, there is no such line, and no allowance goes
-        // anyone paid, one line says so. `paidTo` holds these lines and the
+        // to another spender (see toAnotherSpender). When no step names anyone
-        // token line after each line about a token in the router.
+        // paid, one line says so. `paidTo` holds these lines and the token
+        // line after each line about a token in the router.
         const outputHeld =
             present(outputToken) && heldByRouter.has(outputToken.toLowerCase());
         const paidTo = paidElsewhere.map((address) => ({
@@ -2265,7 +2412,10 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         if (payeeUnread) {
             paidTo.push({ label: "Paid to", value: UNDECODED_CURRENCY });
         }
-        const received = paidToSender && paidTo.length === 0;
+        const received =
+            paidToSender &&
+            paidTo.length === 0 &&
+            toAnotherSpender.length === 0;
         if (!paidToSender && paidTo.length === 0) {
             paidTo.push({ label: "Paid to", value: UNNAMED_CURRENCY });
         }

tests/addedTokenBalance.test.js

@@ -0,0 +1,273 @@
+// After "Add" on AddToken, AddressDetail lists the new token, and its line reads
+// `quantity unknown`, not 0.0000, until a balance refresh that asked the
+// explorer about the token has returned for every address, the popup closing
+// and opening again meanwhile included; so does a token added on
+// SettingsAddToken, wherever it is listed. A refresh that returns draws the
+// balances on AddressDetail or AddressToken again, so the fetched balance shows
+// without the screen being reopened
+// (https://git.eeqj.de/sneak/AutistMask/issues/516). Driven through the real
+// popup over a stored profile on Ethereum Mainnet, with "Show tracked tokens
+// with zero balance" on, as it is by default.
+
+const {
+    bootPopup,
+    cleanupPopup,
+    unversionedValidProfile,
+} = require("./support/popupBoot");
+
+// Tracked by nobody until a test adds it.
+const NEW_TOKEN = "0xBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
+
+// The explorer's row for a holding of a million NEW_TOKEN, in the shape
+// fetchTokenBalances() stores it.
+const MILLION = {
+    address: NEW_TOKEN,
+    name: "New Token",
+    symbol: "NEW",
+    decimals: 18,
+    balance: "1000000.0",
+    holders: 3,
+};
+
+afterEach(() => {
+    cleanupPopup();
+});
+
+// The popup reopened onto AddressDetail for the one address.
+function bootOnAddress() {
+    return bootPopup(
+        unversionedValidProfile({
+            currentView: "address",
+            selectedWallet: 0,
+            selectedAddress: 0,
+        }),
+    );
+}
+
+// Holds the next balance refresh open. The returned function lets it finish
+// with the address's ETH balance at 2 and `tokenBalances` as the explorer's
+// rows for it, or with no token balances at all when given null: an explorer
+// that did not answer, which the real refreshBalances() leaves unwritten.
+function holdNextRefresh(page) {
+    const { refreshBalances } = require("../src/shared/balances");
+    let release;
+    refreshBalances.mockImplementationOnce(async (wallets) => {
+        const tokenBalances = await new Promise((resolve) => {
+            release = resolve;
+        });
+        wallets[0].addresses[0].balance = "2.0";
+        if (tokenBalances !== null) {
+            wallets[0].addresses[0].tokenBalances = tokenBalances;
+        }
+    });
+    return async (tokenBalances) => {
+        release(tokenBalances);
+        await page.settle();
+    };
+}
+
+// "+ Token", NEW_TOKEN typed in, and "Add", with the contract lookup
+// answering at once.
+async function addNewToken(page) {
+    const { lookupTokenInfo } = require("../src/shared/balances");
+    lookupTokenInfo.mockResolvedValueOnce({
+        symbol: "NEW",
+        decimals: 18,
+        name: "New Token",
+    });
+    await page.click("btn-add-token");
+    page.node("add-token-address").value = NEW_TOKEN;
+    await page.click("btn-add-token-confirm");
+}
+
+// NEW_TOKEN's row in the balance list in element `id`, AddressDetail's unless
+// another is named, as markup.
+function newTokenRow(page, id = "address-balances") {
+    return page
+        .node(id)
+        .innerHTML.split("<div ")
+        .find((row) =>
+            row.includes('data-token="' + NEW_TOKEN.toLowerCase() + '"'),
+        );
+}
+
+// AddressDetail for the one address opened from Home, as its `[info]` button
+// does.
+async function openAddress(page) {
+    const { state } = require("../src/shared/state");
+    state.selectedWallet = 0;
+    state.selectedAddress = 0;
+    require("../src/popup/views/helpers").pushCurrentView();
+    require("../src/popup/views/addressDetail").show();
+    await page.settle();
+}
+
+// AddressToken for `token` opened from AddressDetail, as tapping the token's
+// row there does.
+async function openToken(page, token) {
+    const { state } = require("../src/shared/state");
+    state.selectedToken = token;
+    require("../src/popup/views/helpers").pushCurrentView();
+    require("../src/popup/views/addressToken").show();
+    await page.settle();
+}
+
+test("until the refresh Add started returns, the new token's line reads quantity unknown", async () => {
+    const page = await bootOnAddress();
+    expect(page.pageErrors).toEqual([]);
+    const finish = holdNextRefresh(page);
+
+    await addNewToken(page);
+
+    expect(page.visibleViews()).toEqual(["address"]);
+    const row = newTokenRow(page);
+    expect(row).toContain("quantity unknown");
+    expect(row).not.toContain("0.0000");
+    await finish([MILLION]);
+});
+
+test("once that refresh returns, AddressDetail shows the fetched balance without being reopened", async () => {
+    const page = await bootOnAddress();
+    const finish = holdNextRefresh(page);
+    await addNewToken(page);
+    // Stands for the transactions on the screen, which only show() replaces.
+    page.node("tx-list").innerHTML = "transactions on the screen";
+
+    await finish([MILLION]);
+
+    expect(page.visibleViews()).toEqual(["address"]);
+    expect(newTokenRow(page)).toContain("1000000.0000");
+    // Only the balances are drawn again, not the transaction list.
+    expect(page.node("tx-list").innerHTML).toBe("transactions on the screen");
+});
+
+test("a refresh already running when the token is added does not count as fetching it", async () => {
+    const page = await bootOnAddress();
+    const finishRunning = holdNextRefresh(page);
+    const ticking = page.tick();
+    await page.settle();
+
+    await addNewToken(page);
+    await finishRunning([]);
+    await ticking;
+
+    expect(newTokenRow(page)).toContain("quantity unknown");
+
+    // The next one asks the explorer about the token, which lists no holding
+    // of it: a fetched zero.
+    const finishNext = holdNextRefresh(page);
+    const next = page.tick();
+    await page.settle();
+    await finishNext([]);
+    await next;
+
+    expect(newTokenRow(page)).toContain("0.0000");
+});
+
+test("closed and opened again before any refresh has fetched it, the new token's line still reads quantity unknown", async () => {
+    const closed = await bootOnAddress();
+    holdNextRefresh(closed);
+    await addNewToken(closed);
+    cleanupPopup();
+
+    // The refresh this boot starts gets no token balances back: the boot's
+    // stub of refreshBalances() writes none.
+    const page = await bootPopup(undefined, { storage: closed.storage });
+    expect(page.visibleViews()).toEqual(["address"]);
+    const row = newTokenRow(page);
+    expect(row).toContain("quantity unknown");
+    expect(row).not.toContain("0.0000");
+
+    const finish = holdNextRefresh(page);
+    const ticking = page.tick();
+    await page.settle();
+    await finish([MILLION]);
+    await ticking;
+
+    expect(newTokenRow(page)).toContain("1000000.0000");
+});
+
+test("a refresh in which the explorer did not answer leaves the new token's line quantity unknown", async () => {
+    const page = await bootOnAddress();
+    const finish = holdNextRefresh(page);
+    await addNewToken(page);
+
+    await finish(null);
+
+    // Drawn again: the ETH balance it fetched is shown.
+    expect(page.node("address-balances").innerHTML).toContain("2.0000");
+    expect(newTokenRow(page)).toContain("quantity unknown");
+});
+
+test("AddressToken for the new token reads quantity unknown until the refresh returns, then the fetched balance", async () => {
+    const page = await bootOnAddress();
+    const finish = holdNextRefresh(page);
+    await addNewToken(page);
+
+    await openToken(page, NEW_TOKEN.toLowerCase());
+
+    expect(page.visibleViews()).toEqual(["address-token"]);
+    const before = page.node("address-token-balance").innerHTML;
+    expect(before).toContain("quantity unknown");
+    expect(before).not.toContain("0.0000");
+
+    await finish([MILLION]);
+
+    expect(page.node("address-token-balance").innerHTML).toContain(
+        "1000000.0000",
+    );
+});
+
+test("a token added by contract address on SettingsAddToken reads quantity unknown until the refresh returns", async () => {
+    const page = await bootPopup(unversionedValidProfile());
+    expect(page.visibleViews()).toEqual(["main"]);
+    const finish = holdNextRefresh(page);
+    const { lookupTokenInfo } = require("../src/shared/balances");
+    lookupTokenInfo.mockResolvedValueOnce({
+        symbol: "NEW",
+        decimals: 18,
+        name: "New Token",
+    });
+
+    await page.click("btn-settings");
+    await page.click("btn-settings-add-token");
+    page.node("settings-addtoken-address").value = NEW_TOKEN;
+    await page.click("btn-settings-addtoken-manual");
+    await page.click("btn-settings-addtoken-back");
+    await page.click("btn-settings-back");
+    expect(page.visibleViews()).toEqual(["main"]);
+    const onHome = newTokenRow(page, "wallet-list");
+    expect(onHome).toContain("quantity unknown");
+    expect(onHome).not.toContain("0.0000");
+
+    await openAddress(page);
+    const onAddress = newTokenRow(page);
+    expect(onAddress).toContain("quantity unknown");
+    expect(onAddress).not.toContain("0.0000");
+
+    await finish([MILLION]);
+
+    expect(newTokenRow(page)).toContain("1000000.0000");
+});
+
+test("a refresh that returns while AddressToken is up draws its balance again", async () => {
+    const page = await bootPopup(
+        unversionedValidProfile({
+            currentView: "address-token",
+            viewStack: ["main", "address"],
+            selectedWallet: 0,
+            selectedAddress: 0,
+            selectedToken: "ETH",
+        }),
+    );
+    expect(page.visibleViews()).toEqual(["address-token"]);
+    expect(page.node("address-token-balance").innerHTML).toContain("1.5000");
+    const finish = holdNextRefresh(page);
+    const ticking = page.tick();
+    await page.settle();
+
+    await finish(null);
+    await ticking;
+
+    expect(page.node("address-token-balance").innerHTML).toContain("2.0000");
+});

tests/backgroundStateIsolation.test.js

@@ -19,7 +19,10 @@
 //     that followed persisted the pre-refresh values — while still stamping
 //     lastBalanceRefresh, suppressing the redo.
 //
-// Both use the real persistence path over a cloning storage stub. Nothing here
+// A network switch landing inside a balance refresh's round trip is covered at
+// the end (https://git.eeqj.de/sneak/AutistMask/issues/577).
+//
+// All use the real persistence path over a cloning storage stub. Nothing here
 // asserts the absence of a loadState() call; each asserts the OUTCOME, so it
 // holds against any implementation that gets the outcome right.
 
@@ -395,3 +398,48 @@ describe("a balance refresh under another handler's state read", () => {
         expect(after.wallets[0].addresses[0].balance).toBe(REFRESHED_BALANCE);
     });
 });
+
+describe("a balance refresh under a network switch", () => {
+    // https://git.eeqj.de/sneak/AutistMask/issues/577. The switch clears every
+    // address's balances, and a refresh that started on the previous network
+    // must not write that network's back over them when it returns. The same
+    // refresh in the popup is in tests/balanceRefreshNetworkSwitch.test.js.
+    test("a refresh that returns after a switch writes nothing, and the next one runs on the new network", async () => {
+        const roundTrip = deferred();
+        const reachedNetwork = deferred();
+        const ranOn = [];
+
+        const bg = loadWorker("sepolia", {
+            refreshBalances: async (wallets, rpcUrl, explorer, tokens, id) => {
+                ranOn.push(id);
+                reachedNetwork.resolve();
+                await roundTrip.promise;
+                wallets[0].addresses[0].balance = REFRESHED_BALANCE;
+            },
+        });
+
+        const refresh = bg.fireBalanceAlarm();
+        await reachedNetwork.promise;
+
+        // The user switches to Ethereum Mainnet in Settings while the round
+        // trip is out.
+        const during = bg.persisted();
+        applyChainSwitchFields(during, MAINNET.id);
+        global.chrome.storage.write("autistmask", during);
+
+        roundTrip.resolve();
+        await refresh;
+
+        const after = bg.persisted();
+        expect(after.networkId).toBe("mainnet");
+        expect(after.wallets[0].addresses[0].balance).toBe("0");
+        expect(after.lastBalanceRefresh).toBe(0);
+
+        await bg.fireBalanceAlarm();
+
+        expect(ranOn).toEqual(["sepolia", "mainnet"]);
+        expect(bg.persisted().wallets[0].addresses[0].balance).toBe(
+            REFRESHED_BALANCE,
+        );
+    });
+});

tests/balanceRefreshNetworkSwitch.test.js

@@ -0,0 +1,161 @@
+// A balance refresh the popup started on one network, and that returns after
+// the network was switched to another, writes nothing: the switch cleared every
+// address's balances, and the previous network's must not come back over them
+// (https://git.eeqj.de/sneak/AutistMask/issues/577). The switch is made either
+// by the user in this popup's Settings, or by the background after the user
+// approved a site's request, which changes only the stored record. Driven
+// through the real popup over a stored profile on Ethereum Mainnet. The same
+// refresh in the background is in tests/backgroundStateIsolation.test.js.
+
+const {
+    bootPopup,
+    cleanupPopup,
+    unversionedValidProfile,
+    TOKEN_ADDRESS,
+} = require("./support/popupBoot");
+const { applyChainSwitchFields } = require("../src/shared/chainSwitchFields");
+
+afterEach(() => {
+    cleanupPopup();
+});
+
+// Starts the ten-second refresh and holds it open. The balance stand-in writes
+// Ethereum Mainnet's balances in place, on the records handed in, as the real
+// refreshBalances() does, once the returned function is called. Resolves with
+// that function and the refresh still running.
+async function holdRefresh(page) {
+    const { refreshBalances } = require("../src/shared/balances");
+    let answer;
+    refreshBalances.mockImplementationOnce(async (wallets) => {
+        await new Promise((resolve) => {
+            answer = resolve;
+        });
+        wallets[0].addresses[0].balance = "7.0";
+        wallets[0].addresses[0].tokenBalances = [
+            {
+                address: TOKEN_ADDRESS,
+                name: "Test Token",
+                symbol: "TST",
+                decimals: 18,
+                balance: "5.0",
+                holders: null,
+            },
+        ];
+    });
+    const ticking = page.tick();
+    await page.settle();
+    return {
+        finish: async () => {
+            answer();
+            await ticking;
+        },
+    };
+}
+
+// Picks `networkId` in the Settings network selector, as the user does.
+async function chooseNetwork(page, networkId) {
+    const select = page.node("settings-network");
+    select.value = networkId;
+    for (const fn of select.listeners.change) await fn();
+    await page.settle();
+}
+
+// The stored record holds none of Ethereum Mainnet's balances, and no refresh
+// recorded as done.
+function expectNothingStored(page) {
+    const stored = page.storage.read("autistmask");
+    expect(stored.networkId).toBe("sepolia");
+    expect(stored.wallets[0].addresses[0].balance).toBe("0");
+    expect(stored.wallets[0].addresses[0].tokenBalances).toEqual([]);
+    expect(stored.lastBalanceRefresh).toBe(0);
+}
+
+test("a refresh that returns after a switch in Settings writes nothing, and the next one runs on the new network", async () => {
+    const page = await bootPopup(unversionedValidProfile());
+    expect(page.pageErrors).toEqual([]);
+    const { refreshBalances } = require("../src/shared/balances");
+    const { state } = require("../src/shared/state");
+
+    const refresh = await holdRefresh(page);
+    await page.click("btn-settings");
+    await chooseNetwork(page, "sepolia");
+    await refresh.finish();
+
+    expect(state.wallets[0].addresses[0].balance).toBe("0");
+    expect(state.wallets[0].addresses[0].tokenBalances).toEqual([]);
+    expectNothingStored(page);
+
+    await page.click("btn-settings-back");
+    expect(page.visibleViews()).toEqual(["main"]);
+    expect(page.text("total-value")).toBe("0.0000 SepoliaETH");
+
+    await page.tick();
+
+    expect(refreshBalances.mock.lastCall[4]).toBe("sepolia");
+    expect(page.storage.read("autistmask").lastBalanceRefresh).toBeGreaterThan(
+        0,
+    );
+});
+
+// The switch is made only once the refresh's save, holding the lock, has
+// written Ethereum Mainnet's balances, and the switch then clears them.
+test("a refresh whose save is reading the stored record when the user switches in Settings leaves none of its balances stored", async () => {
+    const page = await bootPopup(unversionedValidProfile());
+    expect(page.pageErrors).toEqual([]);
+    const { state } = require("../src/shared/state");
+
+    const refresh = await holdRefresh(page);
+    await page.click("btn-settings");
+
+    // The next read of the stored record, the refresh's save's, is held.
+    const get = page.storage.local.get;
+    const read = get.getMockImplementation();
+    let releaseRead;
+    get.mockImplementationOnce(async (key) => {
+        await new Promise((resolve) => {
+            releaseRead = resolve;
+        });
+        return read(key);
+    });
+    const finishing = refresh.finish();
+    await page.settle();
+
+    // The user picks Sepolia meanwhile; the switch's own save waits for the
+    // refresh's save to let the lock go.
+    const select = page.node("settings-network");
+    select.value = "sepolia";
+    const switching = Promise.all(select.listeners.change.map((fn) => fn()));
+    await page.settle();
+
+    releaseRead();
+    await finishing;
+    await switching;
+    await page.settle();
+
+    expect(state.networkId).toBe("sepolia");
+    expect(state.wallets[0].addresses[0].balance).toBe("0");
+    expect(state.wallets[0].addresses[0].tokenBalances).toEqual([]);
+    expectNothingStored(page);
+});
+
+test("a refresh that returns after the background switched the network writes nothing", async () => {
+    const page = await bootPopup(unversionedValidProfile());
+    expect(page.pageErrors).toEqual([]);
+    const { saveState } = require("../src/shared/state");
+
+    const refresh = await holdRefresh(page);
+    // The background writes the switch to Sepolia, as its updateState() does
+    // once the user approves a site's request. This page is not told of it
+    // yet.
+    const record = page.storage.read("autistmask");
+    applyChainSwitchFields(record, "sepolia");
+    page.storage.write("autistmask", record);
+    await refresh.finish();
+
+    expectNothingStored(page);
+
+    // Nor does a later save by this page, such as every navigation makes.
+    await saveState();
+
+    expectNothingStored(page);
+});

tests/chainSwitchGate.test.js

@@ -446,7 +446,10 @@ describe("switching the network in Settings tells every open tab", () => {
         global.chrome.runtime.sendMessage = (msg) => {
             bg.send(msg, POPUP);
         };
-        await require("../src/shared/state").loadState();
+        const { state, loadState } = require("../src/shared/state");
+        await loadState();
+        // Set by showView(), which is mocked above.
+        state.currentView = "settings";
         require("../src/popup/views/settings").init({
             pageClosed: new AbortController().signal,
         });

tests/e2e/firefox/run.js

@@ -867,6 +867,14 @@ step(
             "the page was not told of the approved switch: " +
                 JSON.stringify(events),
         );
+        // The popup, open all along, shows the new network
+        // (https://git.eeqj.de/sneak/AutistMask/issues/650).
+        await d.switchToWindow(env.popupWindow);
+        await d.waitFor(
+            "the open popup to show the testnet banner",
+            `const banner = document.getElementById("debug-banner");
+             return banner !== null && banner.textContent === "[TESTNET]";`,
+        );
 
         await openNetworkPrompt(env, "switch-restore", sepolia, mainnet);
         await d.click("#btn-approve-network");
@@ -881,6 +889,10 @@ step(
             isDeepStrictEqual(await storedNetwork(env), before),
             "switching back did not restore the mainnet network and endpoints",
         );
+        await d.waitFor(
+            "the open popup to drop the testnet banner",
+            `return document.getElementById("debug-banner") === null;`,
+        );
         await d.switchToWindow(env.dappWindow);
     },
 );

tests/e2e/run.js

@@ -651,7 +651,8 @@ test("a token added by its contract address is listed on the address screen (#15
     await visible(env.page, "#view-address");
 
     // No wait: the confirm renders the balance list before it shows the
-    // screen, and nothing renders the list again while the screen is up.
+    // screen. The refresh it starts draws the list again, with the row still
+    // in it.
     const row = env.page.locator(
         '#address-balances [data-token="' + STUB_TOKEN.address + '"]',
         { hasText: STUB_TOKEN.symbol },
@@ -4865,6 +4866,12 @@ test("a site's network switch changes nothing until the user approves it (#408)"
         "the page was not told of the approved switch: " +
             JSON.stringify(events),
     );
+    // The popup, open all along, shows the new network
+    // (https://git.eeqj.de/sneak/AutistMask/issues/650).
+    await env.page.waitForFunction(() => {
+        const banner = document.getElementById("debug-banner");
+        return banner !== null && banner.textContent === "[TESTNET]";
+    });
 
     const restored = await openNetworkPrompt(
         env,
@@ -4886,6 +4893,9 @@ test("a site's network switch changes nothing until the user approves it (#408)"
         isDeepStrictEqual(await storedNetwork(env.page), before),
         "switching back did not restore the mainnet network and endpoints",
     );
+    await env.page.waitForFunction(
+        () => document.getElementById("debug-banner") === null,
+    );
 });
 
 // Switching the network in Settings tells the page too, as an approved site

tests/flashLine.test.js

@@ -88,6 +88,7 @@ describe.each([
             showFlash: (msg) => flashes.push(msg),
             escapeHtml: (s) => s,
             goBack: () => {},
+            trackToken: () => {},
         }));
 
         require("../src/popup/views/" + view).init({

tests/persistedFieldContract.test.js

@@ -248,6 +248,13 @@ const CONTRACT = [
         floorOnly: [[42], [null], [{}], [[TOKEN_ADDRESS]]],
         holds: (v) => everyEntry(v, isText),
     },
+    {
+        field: "tokensNotFetched",
+        kind: KIND.ENTRIES,
+        hostile: [42, "notalist", { a: 1 }],
+        floorOnly: [[42], [null], [{}], [[TOKEN_ADDRESS]]],
+        holds: (v) => everyEntry(v, isText),
+    },
     {
         field: "viewStack",
         kind: KIND.ENTRIES,

tests/popupFollowsNetworkSwitch.test.js

@@ -0,0 +1,300 @@
+// An open popup follows a network switch the background saves once the user
+// approves a site's request: it takes the new network from the stored record
+// and draws the screen it is on for it, as a switch in Settings does
+// (https://git.eeqj.de/sneak/AutistMask/issues/650). Driven through the real
+// popup over a stored profile on Ethereum Mainnet. The background's write is
+// the storage stub's set, which the stub reports to the page as the browser
+// does.
+
+const {
+    bootPopup,
+    cleanupPopup,
+    unversionedValidProfile,
+    TOKEN_ADDRESS,
+} = require("./support/popupBoot");
+const { makeStorageStub } = require("./support/storageStub");
+const {
+    applyChainSwitchFields,
+    copyChainSwitchFields,
+} = require("../src/shared/chainSwitchFields");
+const { NETWORKS } = require("../src/shared/networks");
+const { STATE_SCHEMA_VERSION } = require("../src/shared/stateSchema");
+
+afterEach(() => {
+    cleanupPopup();
+});
+
+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",
+};
+
+// A profile on Ethereum Mainnet that reopens the popup onto AddressDetail,
+// with DAI tracked there and TST tracked on Sepolia.
+function profileOnAddress() {
+    return unversionedValidProfile({
+        currentView: "address",
+        viewStack: ["main"],
+        selectedWallet: 0,
+        selectedAddress: 0,
+        trackedTokens: [MAINNET_TOKEN],
+        networkTrackedTokens: { sepolia: [SEPOLIA_TOKEN] },
+    });
+}
+
+// The popup reopened onto it.
+function bootOnAddress() {
+    return bootPopup(profileOnAddress());
+}
+
+// The background saves a switch to `networkId`, as its updateState() does
+// once the user approves a site's request.
+async function backgroundSwitch(page, networkId) {
+    const record = page.storage.read("autistmask");
+    applyChainSwitchFields(record, networkId);
+    await page.storage.local.set({ autistmask: record });
+    await page.settle();
+    await page.settle();
+}
+
+test("the popup open on AddressDetail shows the new network and its balances", async () => {
+    const page = await bootOnAddress();
+    expect(page.pageErrors).toEqual([]);
+    expect(page.visibleViews()).toEqual(["address"]);
+    expect(page.node("address-balances").innerHTML).toContain("DAI");
+    expect(page.node("debug-banner")).toBeNull();
+
+    await backgroundSwitch(page, "sepolia");
+
+    const { state } = require("../src/shared/state");
+    expect(state.networkId).toBe("sepolia");
+    expect(state.rpcUrl).toBe(NETWORKS.sepolia.defaultRpcUrl);
+    expect(page.visibleViews()).toEqual(["address"]);
+    const balances = page.node("address-balances").innerHTML;
+    expect(balances).toContain("TST");
+    expect(balances).toContain("SepoliaETH");
+    expect(balances).not.toContain("DAI");
+    expect(page.text("debug-banner")).toBe("[TESTNET]");
+
+    // Its next refresh runs on Sepolia, and what it fetched is stored.
+    await page.tick();
+    const { refreshBalances } = require("../src/shared/balances");
+    expect(refreshBalances.mock.lastCall[4]).toBe("sepolia");
+    const stored = page.storage.read("autistmask");
+    expect(stored.networkId).toBe("sepolia");
+    expect(stored.lastBalanceRefresh).toBeGreaterThan(0);
+});
+
+test("the popup open on Settings shows the new network, and Back draws the screen beneath for it", async () => {
+    const page = await bootOnAddress();
+    await page.click("btn-settings");
+    expect(page.visibleViews()).toEqual(["settings"]);
+
+    await backgroundSwitch(page, "sepolia");
+
+    expect(page.visibleViews()).toEqual(["settings"]);
+    expect(page.value("settings-network")).toBe("sepolia");
+    expect(page.value("settings-rpc")).toBe(NETWORKS.sepolia.defaultRpcUrl);
+    expect(page.node("settings-tracked-tokens").innerHTML).toContain("TST");
+    expect(page.text("debug-banner")).toBe("[TESTNET]");
+
+    await page.click("btn-settings-back");
+    expect(page.visibleViews()).toEqual(["address"]);
+    expect(page.node("address-balances").innerHTML).not.toContain("DAI");
+});
+
+// Neither can be drawn again for the new network: Send cannot be rendered from
+// saved state, and DAI was picked on Ethereum Mainnet, where alone it is
+// tracked. A reopened popup goes to Home in their place.
+test.each([
+    ["Send", (page) => page.click("btn-send")],
+    [
+        "AddressToken for DAI",
+        async (page) => {
+            const { state } = require("../src/shared/state");
+            state.selectedToken = MAINNET_TOKEN.address;
+            require("../src/popup/views/helpers").pushCurrentView();
+            require("../src/popup/views/addressToken").show();
+            await page.settle();
+        },
+    ],
+])("the popup open on %s goes to Home", async (_view, open) => {
+    const page = await bootOnAddress();
+    await open(page);
+    expect(page.visibleViews()).not.toEqual(["address"]);
+
+    await backgroundSwitch(page, "sepolia");
+
+    expect(page.visibleViews()).toEqual(["main"]);
+    expect(page.text("total-value")).toBe("0.0000 SepoliaETH");
+});
+
+// The report of the switch's own save names the network the page already has.
+test("a switch in Settings is not taken a second time when its save is reported", async () => {
+    const page = await bootOnAddress();
+    await page.click("btn-settings");
+    const { get, set } = page.storage.local;
+    const reads = get.mock.calls.length;
+    const writes = set.mock.calls.length;
+
+    const select = page.node("settings-network");
+    select.value = "sepolia";
+    for (const fn of select.listeners.change) await fn();
+    await page.settle();
+    await page.settle();
+
+    expect(get).toHaveBeenCalledTimes(reads + 1);
+    expect(set).toHaveBeenCalledTimes(writes + 1);
+    expect(page.text("flash-msg")).toBe("Switched to Sepolia Testnet.");
+});
+
+// The background saves the switch once the popup has read the stored record
+// and before it listens for changes to it, so the browser tells the page
+// nothing of it. Nor is any later write reported here: Chrome reports none
+// that leaves the record as it was, such as the popup's own save at start-up.
+test("a switch saved while the popup opens, before it listens for one, is followed", async () => {
+    const storage = makeStorageStub({ autistmask: profileOnAddress() });
+    storage.onChanged = { addListener: () => {} };
+    const read = storage.local.get.getMockImplementation();
+    storage.local.get.mockImplementationOnce(async (key) => {
+        const loaded = await read(key);
+        const record = storage.read("autistmask");
+        applyChainSwitchFields(record, "sepolia");
+        storage.write("autistmask", record);
+        return loaded;
+    });
+    const page = await bootPopup(undefined, { storage });
+    await page.settle();
+
+    const { state } = require("../src/shared/state");
+    expect(page.pageErrors).toEqual([]);
+    expect(state.networkId).toBe("sepolia");
+    expect(page.visibleViews()).toEqual(["address"]);
+    expect(page.node("address-balances").innerHTML).toContain("SepoliaETH");
+    expect(page.text("debug-banner")).toBe("[TESTNET]");
+});
+
+// While the popup's follow of the background's switch to Sepolia waits for the
+// lock, the user picks Sepolia in Settings and then Ethereum Mainnet again. The
+// last pick is the network stored, and the last one sites are told of.
+test("a switch in Settings made while a follow waits for the lock is not overwritten by it", async () => {
+    const page = await bootOnAddress();
+    await page.click("btn-settings");
+
+    // Another write holds the lock, so every save of the page waits for it.
+    let releaseLock;
+    const lockHeld = navigator.locks.request(
+        "autistmask",
+        () =>
+            new Promise((resolve) => {
+                releaseLock = resolve;
+            }),
+    );
+    await backgroundSwitch(page, "sepolia");
+    const select = page.node("settings-network");
+    const picks = [];
+    for (const networkId of ["sepolia", "mainnet"]) {
+        select.value = networkId;
+        for (const fn of select.listeners.change) picks.push(fn());
+    }
+    releaseLock();
+    await lockHeld;
+    await Promise.all(picks);
+    await page.settle();
+
+    const { state } = require("../src/shared/state");
+    expect(state.networkId).toBe("mainnet");
+    expect(page.storage.read("autistmask").networkId).toBe("mainnet");
+    expect(page.value("settings-network")).toBe("mainnet");
+    const told = globalThis.chrome.runtime.sendMessage.mock.calls
+        .map(([message]) => message)
+        .filter((message) => message.type === "AUTISTMASK_NETWORK_CHANGED");
+    expect(told.at(-1).chainId).toBe(NETWORKS.mainnet.chainId);
+});
+
+// The popup follows the background's switch to Sepolia, but its own write in
+// that save fails. The user then picks Ethereum Mainnet in Settings, the
+// network the popup was on before: that switch is stored, and only then
+// flashed and sent to sites.
+test("a switch back in Settings after a follow whose write failed is stored", async () => {
+    const page = await bootOnAddress();
+    await page.click("btn-settings");
+    const { set } = page.storage.local;
+    const write = set.getMockImplementation();
+    // The background's write lands; the next, the follow's, fails.
+    set.mockImplementationOnce(write).mockRejectedValueOnce(
+        new Error("quota exceeded"),
+    );
+    await backgroundSwitch(page, "sepolia");
+    const { state } = require("../src/shared/state");
+    expect(state.networkId).toBe("sepolia");
+
+    const select = page.node("settings-network");
+    select.value = "mainnet";
+    for (const fn of select.listeners.change) await fn();
+    await page.settle();
+
+    const stored = page.storage.read("autistmask");
+    expect(stored.networkId).toBe("mainnet");
+    expect(stored.rpcUrl).toBe(NETWORKS.mainnet.defaultRpcUrl);
+    expect(stored.trackedTokens).toEqual([MAINNET_TOKEN]);
+    expect(page.text("flash-msg")).toBe("Switched to Ethereum Mainnet.");
+    const told = globalThis.chrome.runtime.sendMessage.mock.calls
+        .map(([message]) => message)
+        .filter((message) => message.type === "AUTISTMASK_NETWORK_CHANGED");
+    expect(told.at(-1).chainId).toBe(NETWORKS.mainnet.chainId);
+});
+
+// Such as one a newer build wrote, which this build cannot read. Nothing reads
+// or writes the stored record for it: the popup's next save finds it, as
+// before.
+test("a record that names no network is not followed", async () => {
+    const page = await bootOnAddress();
+    const { get, set } = page.storage.local;
+    const reads = get.mock.calls.length;
+
+    await set({
+        autistmask: {
+            schemaVersion: STATE_SCHEMA_VERSION + 1,
+            wallets: [{ type: "hd", name: "Main", addresses: [] }],
+        },
+    });
+    await page.settle();
+
+    expect(get).toHaveBeenCalledTimes(reads);
+    expect(page.visibleViews()).toEqual(["address"]);
+});
+
+// A record that takes the switch from the switched record ends up as that
+// record, balances the background fetched since included.
+test("copyChainSwitchFields() takes every field applyChainSwitchFields() sets", () => {
+    const before = unversionedValidProfile({
+        trackedTokens: [MAINNET_TOKEN],
+        networkTrackedTokens: { sepolia: [SEPOLIA_TOKEN] },
+        networkEndpoints: {
+            sepolia: {
+                rpcUrl: "http://127.0.0.1:8545",
+                blockscoutUrl: "http://127.0.0.1:4000/api/v2",
+            },
+        },
+        lastBalanceRefresh: 1,
+        tokenHolderCache: { [MAINNET_TOKEN.address]: 5000 },
+        fraudContracts: ["0x1111111111111111111111111111111111111111"],
+    });
+    const switched = structuredClone(before);
+    applyChainSwitchFields(switched, "sepolia");
+    switched.wallets[0].addresses[0].balance = "2.0";
+
+    const follower = structuredClone(before);
+    copyChainSwitchFields(follower, switched);
+
+    expect(follower).toEqual(switched);
+});

tests/support/popupBoot.js

@@ -311,7 +311,7 @@ async function bootPopup(stored, options) {
     const windowListeners = {};
 
     globalThis.chrome = {
-        storage: { local: storage.local },
+        storage: { local: storage.local, onChanged: storage.onChanged },
         runtime: {
             sendMessage: jest.fn(async () => ({})),
             getURL: (p) => "chrome-extension://autistmask/" + p,

tests/support/storageStub.js

@@ -18,7 +18,9 @@
 // a storage stub by hand.
 
 // One storage area: get, set and remove over its own store, cloning both ways.
-function makeArea(store, tick) {
+// `changed` is handed what each set or remove changed, in the shape
+// storage.onChanged reports it.
+function makeArea(store, tick, changed) {
     const get = jest.fn(async (key) => {
         tick();
         if (key === undefined || key === null) return structuredClone(store);
@@ -34,14 +36,25 @@ function makeArea(store, tick) {
 
     const set = jest.fn(async (items) => {
         tick();
+        const changes = {};
         for (const k of Object.keys(items)) {
+            changes[k] = structuredClone({
+                oldValue: store[k],
+                newValue: items[k],
+            });
             store[k] = structuredClone(items[k]);
         }
+        changed(changes);
     });
 
     const remove = jest.fn(async (key) => {
         tick();
-        for (const k of Array.isArray(key) ? key : [key]) delete store[k];
+        const changes = {};
+        for (const k of Array.isArray(key) ? key : [key]) {
+            changes[k] = { oldValue: store[k] };
+            delete store[k];
+        }
+        changed(changes);
     });
 
     return { get, set, remove };
@@ -54,12 +67,22 @@ function makeArea(store, tick) {
 function makeStorageStub(initial, onOp) {
     const store = initial ? structuredClone(initial) : {};
     const tick = onOp || (() => {});
-    const local = makeArea(store, tick);
+    // storage.onChanged: after a set or remove has finished, every listener is
+    // called with what it changed and the area's name, as the browser calls
+    // them for a write by any page or the background.
+    const listeners = [];
+    const announce = (areaName) => (changes) => {
+        Promise.resolve().then(() => {
+            for (const fn of listeners) fn(structuredClone(changes), areaName);
+        });
+    };
+    const local = makeArea(store, tick, announce("local"));
 
     return {
         // Drop this straight in as chrome.storage.
         local,
-        session: makeArea({}, tick),
+        session: makeArea({}, tick, announce("session")),
+        onChanged: { addListener: (fn) => listeners.push(fn) },
         get: local.get,
         set: local.set,
         remove: local.remove,
@@ -71,7 +94,9 @@ function makeStorageStub(initial, onOp) {
                 ? structuredClone(store)
                 : structuredClone(store[key]),
         // Seed or replace a record without going through the module under
-        // test — for standing in as "another page wrote this".
+        // test — for standing in as "another page wrote this". Nothing is
+        // announced to storage.onChanged, so it also stands in for the time
+        // before the browser tells this page of such a write.
         write: (key, value) => {
             store[key] = structuredClone(value);
         },

tests/trackedTokensPerNetwork.test.js

@@ -161,6 +161,7 @@ test("a token added by contract address on Sepolia is tracked on Sepolia only",
     );
     expect(stored().trackedTokens).toEqual([SEPOLIA_TOKEN]);
 
+    await boot.click("btn-settings");
     await chooseNetwork(boot, "mainnet");
     expect(stored().networkId).toBe("mainnet");
     expect(stored().trackedTokens).toEqual([MAINNET_TOKEN]);

tests/uniswapRecipient.test.js

@@ -1439,8 +1439,17 @@ describe("any token left in the router is not received", () => {
             "Token In",
             // A later step whose SETTLE or SETTLE_ALL the decoder cannot read
             // may take anything from the sender: one line says so, in place
-            // of the Amount line (https://git.eeqj.de/sneak/AutistMask/issues/625).
+            // of the Amount line (https://git.eeqj.de/sneak/AutistMask/issues/625),
-            unread ? "Moved from the sender" : "Amount",
+            // after the lines the WRAP_ETH's 1 ETH then gets
+            // (https://git.eeqj.de/sneak/AutistMask/issues/659).
+            ...(unread
+                ? [
+                      "Moved from the sender",
+                      "Token moved",
+                      "Moved to",
+                      "Moved from the sender",
+                  ]
+                : ["Amount"]),
             // A later swap step the user pays for spends `spent` of a token
             // other than Token In.
             ...(spent
@@ -1457,9 +1466,11 @@ describe("any token left in the router is not received", () => {
             expect(detail(result, "Moved from the sender").value).toBe(spent);
         }
         if (unread) {
-            expect(detail(result, "Moved from the sender").value).toBe(
+            expect(
-                UNDECODED,
+                result.details
-            );
+                    .filter((d) => d.label === "Moved from the sender")
+                    .map((d) => d.value),
+            ).toEqual(["1.0000 ETH", UNDECODED]);
         }
         expect(paidTo(result)).toEqual([STAYS_IN_ROUTER]);
         expect(detail(result, "Token moved into the router")).toEqual(left);
@@ -2791,26 +2802,37 @@ describe("the allow-revert flag", () => {
     });
 
     // Only the routers from UniversalRouterV2 on let a PERMIT2_PERMIT fail.
+    // The permit's spender is the router at ROUTER, which on every other
+    // router is an allowance to another spender, so the minimum reads
+    // Min. paid out there.
     test.each([
-        { router: "UniversalRouterV1", address: ROUTER_V1, mark: "" },
+        {
+            router: "UniversalRouterV1",
+            address: ROUTER_V1,
+            mark: "",
+            minimum: "Min. paid out",
+        },
         {
             router: "UniversalRouterV1_2_V2Support",
             address: ROUTER_V1_2,
             mark: "",
+            minimum: "Min. paid out",
         },
         {
             router: "UniversalRouterV2",
             address: ROUTER,
             mark: " (allowed to fail)",
+            minimum: "Min. received",
         },
         {
             router: "UniversalRouterV2_1_2",
             address: ROUTER_V2_1_2,
             mark: " (allowed to fail)",
+            minimum: "Min. paid out",
         },
     ])(
-        "on $router, a PERMIT2_PERMIT with the flag is listed as 'Permit2 Permit$mark', and the swap reads as without the flag",
+        "on $router, a PERMIT2_PERMIT with the flag is listed as 'Permit2 Permit$mark', and the swap's lines read as without the flag",
-        ({ address, mark }) => {
+        ({ address, mark, minimum }) => {
             const steps = [
                 permit2Permit(USDT, USDT_2000),
                 swapToWeth(MSG_SENDER),
@@ -2824,10 +2846,25 @@ describe("the allow-revert flag", () => {
             expect(detail(withFlag, "Steps").value).toBe(
                 "Permit2 Permit" + mark + " → V3 Swap (Exact In)",
             );
-            const withoutSteps = (r) =>
+            // The permit names the router at ROUTER as its spender, so its
-                r.details.filter((d) => d.label !== "Steps");
+            // amount stands as the Amount figure only there, and only without
-            expect(withoutSteps(withFlag)).toEqual(withoutSteps(plain));
+            // the flag. With the flag it stands on no router and gets lines
-            expect(detail(withFlag, "Min. received").value).toBe("1.0000 WETH");
+            // of its own, and the swap step names Token In: the same token,
+            // its address written the same way.
+            const permitLines = [
+                "Permit2 allowance",
+                "Allowance token",
+                "Allowance spender",
+            ];
+            const swapLines = (r) =>
+                r.details.filter(
+                    (d) => !["Steps", ...permitLines].includes(d.label),
+                );
+            expect(swapLines(withFlag)).toEqual(swapLines(plain));
+            expect(
+                labels(withFlag).filter((l) => permitLines.includes(l)),
+            ).toEqual(permitLines);
+            expect(detail(withFlag, minimum).value).toBe("1.0000 WETH");
         },
     );