fix: a save merges this page's tracked token change into the stored list (closes #717)

A save wrote `trackedTokens` whole, so two pages on one network dropped each
other's adds and brought back each other's removals.

A save that keeps the network now merges this page's change into the stored
list by contract address. A save that switches networks is unchanged.

`mergeTrackedTokens()` does that merge, and the two other merges of tracked
tokens now call it. It keeps one record per contract address, this page's for
a token both lists hold, so a token held twice no longer multiplies.

Model: opus-5-5

docs/README.md

@@ -17,7 +17,7 @@ Firefox. This guide explains how to install it and how to use it.
 
 It does nothing else. It has:
 
-- no swap screen;
+- no swap screen (a swap exchanges one token for another);
 - no portfolio view;
 - no NFT gallery (an NFT is a non-fungible token, such as a collectible);
 - no advertising;
@@ -30,8 +30,10 @@ named below sees your IP address, as any website you visit does.
 
 By default the wallet talks to one service: the Ethereum RPC endpoint. The RPC
 endpoint is the server that the wallet asks about the blockchain and sends your
-transactions through. Usually it is a node, a computer running the Ethereum
-software. A new install uses a public one,
+transactions through. The blockchain is the shared record of all Ethereum
+transactions. It grows in blocks; a block is a batch of transactions that the
+network adds together. Usually the endpoint is a node, a computer running the
+Ethereum software. A new install uses a public one,
 `https://ethereum-rpc.publicnode.com`. You can change it in Settings.
 
 The RPC endpoint sees every address that the wallet asks about and every
@@ -40,29 +42,29 @@ balances every 10 seconds. While it is closed, it asks every 60 seconds. If you
 want privacy, point the Ethereum RPC setting at a node of your own.
 
 On Ethereum Mainnet, the main Ethereum network, the wallet reads USD prices
-through the RPC endpoint, from Chainlink price feed contracts. No price service
-is contacted. A token with no Chainlink price feed shows no USD value.
+through the RPC endpoint, from Chainlink price feeds. A Chainlink price feed is
+a contract that publishes an exchange rate on Ethereum. No price service is
+contacted. A token with no Chainlink price feed shows no USD value.
 
 Two more services get your data only after you turn on a setting. Both settings
 are off in a new install. The first screen and Settings both offer the two
 settings.
 
 - "Use Blockscout". Blockscout is an open-source block explorer, a service that
-  indexes the blockchain and answers questions about it. With the setting on,
-  the wallet sends Blockscout your addresses on each refresh, and the hash of
-  each transaction you open. A hash is the id of a transaction. In return the
-  wallet shows your transaction history, transaction details and the tokens you
-  have not added yourself. You can point the setting at a Blockscout server of
-  your own.
+  reads the whole blockchain and answers questions about it. With the setting
+  on, the wallet sends Blockscout your addresses each time it refreshes your
+  balances, and the hash of each transaction you open. A hash is the id of a
+  transaction. In return the wallet shows your transaction history, transaction
+  details and the tokens you have not added yourself. You can change the
+  Blockscout URL in Settings to a server of your own.
 - "Check recipients on Etherscan". Etherscan is a block explorer website. With
   the setting on, the wallet fetches the recipient's Etherscan page each time
   you review a send. The wallet warns when Etherscan labels the address as
-  phishing, scam or exploiter. Only the recipient's address is sent. The
-  Etherscan server cannot be changed.
+  phishing, scam, exploiter or wallet drainer. Only the recipient's address is
+  sent. The Etherscan server cannot be changed.
 
-Each time a site's request opens an approval screen, the wallet checks the site
-against a phishing list built into the extension. That check sends nothing
-anywhere.
+Each time a site's request opens a window, the wallet checks the site against a
+phishing list built into the extension. That check sends nothing anywhere.
 
 These stay in your browser and never leave it:
 
@@ -70,7 +72,7 @@ These stay in your browser and never leave it:
   your password;
 - your wallet names and your settings;
 - which sites you have allowed or denied;
-- the list of fraud contracts that the wallet has seen.
+- the list of contracts that the wallet has caught issuing fake tokens.
 
 The Etherscan links on the screens are ordinary links. They contact nothing
 until you click them.
@@ -114,8 +116,8 @@ restore the wallet on any device without the password. The password protects
 only the copy stored in this browser.
 
 While a phrase wallet is in this browser, `[recovery phrase]` in Settings shows
-its phrase after your password. Once this browser's copy is gone too, the wallet
-is lost.
+its phrase after your password. If you lose the written phrase and this
+browser's copy is gone, the wallet is lost.
 
 The wallet asks for the password when you:
 
@@ -165,13 +167,14 @@ The Add Wallet screen has three tabs:
   path. Most wallets use the same rule, so the same phrase gives the same
   addresses here and elsewhere.
 - "From Key": paste one private key. The wallet gets one address.
-- "From xprv": paste an extended private key. It must be the master key, the
-  root of the key tree, not a key computed from the root. The wallet behaves
-  like a phrase wallet but has no phrase to show.
+- "From xprv": paste an extended private key; `xprv` is the usual short name for
+  one. It must be the master key, the one that every other key of the wallet is
+  computed from, not a key computed from it. The wallet behaves like a phrase
+  wallet but has no phrase to show.
 
 All three tabs ask for the same password fields. "Import" finishes the job.
 
-After a phrase or xprv import the wallet looks for addresses that have been
+After a phrase or `xprv` import the wallet looks for addresses that have been
 used. The scan counts an address as used when it holds ETH or has sent a
 transaction. An address that only received tokens is not found. The scan checks
 addresses through the RPC endpoint, five at a time, and stops after five unused
@@ -195,21 +198,23 @@ sequence of addresses. Each address is labelled "Address N".
 
 One address is the active address. The home screen shows it at the top, with its
 ETH balance and its USD value. "Send" and "Receive" on the home screen act on
-the active address. Connected sites see the active address and no other. Tap any
-address row on the home screen to make that address active.
+the active address. Connected sites see the active address and no other. Click
+any address row on the home screen to make that address active.
 
 ### Removing an address
 
-Each address of a phrase or xprv wallet with more than one address has an `[x]`
-button on the home screen. The confirmation screen explains what removing does.
-Nothing is destroyed: the address stays yours, and any funds at it stay where
-they are. The wallet stops listing the address and forgets the sites allowed or
-denied for it.
+Each address of a phrase or `xprv` wallet with more than one address has an
+`[x]` button on the home screen. The confirmation screen explains what removing
+does. Nothing is destroyed: the address stays yours, and any funds at it stay
+where they are. The wallet stops listing the address and forgets the sites
+allowed or denied for it.
 
-Getting the address back is not easy. "+" computes an address that this wallet
-has never listed, so never the removed one. The way back is to delete the whole
-wallet and import its backup again. The scan after the import finds the address
-only if it holds ETH or has sent a transaction.
+Getting the address back is not easy. "+" computes only addresses that this
+wallet has never listed. The removed address was listed once, so "+" skips it.
+The way back is to delete the whole wallet and import its backup again. After
+the import, the scan lists the address again if it holds ETH or has sent a
+transaction. Otherwise "+" may reach it again, because the new wallet has never
+listed it.
 
 ### Deleting a wallet
 
@@ -235,14 +240,14 @@ not "Use Blockscout" is on.
 
 Other tokens appear only while "Use Blockscout" is on. Blockscout reports every
 token that an address holds. The wallet lists such a token only when it is on
-the bundled list of well-known tokens or has at least 1,000 holders. Everything
+the built-in list of well-known tokens or has at least 1,000 holders. Everything
 else is treated as spam and hidden. Turning "Use Blockscout" off removes every
 untracked token from the lists at once.
 
-The balance list and the send screen hide a token that uses a well-known symbol
-from another contract, `ETH` included. A token you track yourself is still
-listed at zero while "Show tracked tokens with zero balance" is on. See Scam
-protection.
+The balance list and the send screen hide a token that carries a well-known
+symbol, `ETH` included, but comes from another contract. A token that fakes a
+known symbol cannot be tracked ("Not added: this token fakes a known symbol."),
+and is never listed at zero. See Scam protection.
 
 ### Tracking a token
 
@@ -258,6 +263,9 @@ From Settings, under Tracked Tokens, click "+ Add token". That screen offers the
 top 10 tokens as buttons, the top 100 in a dropdown, and a contract address
 field. The two lists are offered on Ethereum Mainnet only.
 
+A line for the new token reads `quantity unknown` until a refresh has read its
+balance.
+
 A token is tracked on the network that it was added on. Settings lists the
 tracked tokens of the active network, each with an `[x]` button that stops
 tracking it.
@@ -275,7 +283,7 @@ On an address's screen, click any balance row. The token screen shows:
 - the token's balance;
 - its contract address;
 - its name, symbol and decimals (the number of decimal places its amounts have);
-- its holder count, when known;
+- how many addresses hold it, when known;
 - its website, when known;
 - the token's own transaction history.
 
@@ -290,9 +298,10 @@ On an address's screen, click any balance row. The token screen shows:
 4. Enter the amount, or click "Max".
 5. Click "Review".
 
-"Max" fills in a token's whole balance. For ETH it fills in the balance minus
-the network fee that the confirmation screen will reserve, so enter the
-recipient first. A message says why when there is nothing to fill in.
+"Max" fills in a token's whole balance. For ETH it fills in your balance minus
+the largest network fee the send can cost. The network fee is the price the
+network charges to process a transaction. It depends on the recipient, so enter
+the recipient first. A message says why when there is nothing to fill in.
 
 An amount must be a number above zero, written as digits with at most one
 decimal point. ETH has 18 decimal places. A token has as many as it declares, up
@@ -306,16 +315,16 @@ address instead.
 
 The screen shows:
 
-- the type: a native ETH transfer or an ERC-20 token transfer;
+- the type: "Native ETH transfer", or "ERC-20 token transfer" with the token's
+  symbol. Native means that ETH is built into the network and needs no contract;
 - the token's contract address, for a token;
 - the From and To addresses, each in full, with an identicon (a small pixel
   picture made from the address) and an Etherscan link;
 - the amount, with its USD value;
 - your balance on this network;
-- the network fee, the price the network charges to process the transaction. The
-  screen shows what the transfer is expected to cost, and under it the larger
-  amount reserved until the transaction confirms. The network refunds the
-  difference.
+- the network fee. The screen shows what the transfer is expected to cost, and
+  under it the larger amount reserved until the network has processed the
+  transaction. The network refunds the difference.
 
 It warns when the recipient is:
 
@@ -324,10 +333,10 @@ It warns when the recipient is:
 - the address you are sending from;
 - a contract rather than a person's address;
 - an address that has never sent a transaction and holds no ETH;
-- labelled as phishing, scam or exploiter on Etherscan, while "Check recipients
-  on Etherscan" is on. A lookup that fails shows no warning, so no warning does
-  not prove the address was checked. While the setting is off, a line says the
-  address was not checked.
+- labelled as phishing, scam, exploiter or wallet drainer on Etherscan, while
+  "Check recipients on Etherscan" is on. A failed lookup shows no warning. A
+  missing warning therefore does not prove that Etherscan was asked. While the
+  setting is off, a line says the address was not checked.
 
 It refuses to send, and says why, when:
 
@@ -339,10 +348,10 @@ It refuses to send, and says why, when:
 - your balance could not be read.
 
 Enter your password and click "Sign & Send". The wallet signs the transaction
-and broadcasts it to the network. Before signing, it refuses when:
+and sends it to the network. Before signing, it refuses when:
 
 - the network was switched since you reviewed the send;
-- the wallet shown no longer holds the From address;
+- the selected wallet no longer holds the From address;
 - the fee or gas limit that the network quotes is above the wallet's limits,
   which allow a total fee of at most 1 ETH. Gas is the unit Ethereum measures
   work in, and the gas limit is the most gas the transaction may use;
@@ -359,8 +368,8 @@ the wallet. Then:
 - a receipt opens the success screen, with the block number, the hash and
   Etherscan links;
 - no receipt after 60 seconds opens the error screen with a timeout message. A
-  timeout does not mean the transaction failed. It may still confirm; check the
-  hash on Etherscan;
+  timeout does not mean the transaction failed. It may still be included later;
+  check the hash on Etherscan;
 - six failed lookups in a row open the error screen with a message saying the
   network could not be reached. Check the Ethereum RPC setting.
 
@@ -393,21 +402,31 @@ the setting is off, each history list shows one line saying so.
 
 Each row shows:
 
-- the age and the direction, "Sent" or "Received". A row for a call to a
-  contract shows the name of the call instead, such as "Approve", and a symbol
-  without an amount;
-- the amount;
-- the other party's address, in full. A swap row shows your own address here.
+- the age and the direction, "Sent" or "Received". A transaction can also ask a
+  contract to do something; that is a contract call. A row for a contract call
+  shows the call's name instead, such as "Approve" or "Swap";
+- the amount. A contract call row shows an amount only when the call moved a
+  token. A swap row shows the amount received, or the amount paid in when no
+  token came back. A row with no amount shows only a symbol, such as `USDC` or
+  `ETH`;
+- the other party's address, in full. A swap row shows your own address here. On
+  a token's screen, every contract call row shows your own address.
 
 The scam filters below hide fake transfers and dust from these lists. Dust is a
 tiny amount of ETH.
 
-Tap a row to open the transaction. The transaction screen shows:
+Click a row to open the transaction. The transaction screen shows:
 
 - the hash;
-- the type: native ETH transfer, ERC-20 token transfer, swap, token approval,
-  contract call or contract creation;
-- the status;
+- the type, one of:
+    - "Native ETH Transfer";
+    - "ERC-20 Token Transfer";
+    - "Swap";
+    - "Token Approval", a call that lets a contract move your tokens;
+    - "Contract Call", any other call to a contract;
+    - "Contract Creation", a transaction that puts a new contract on the
+      network;
+- the status, "Success" or "Failed";
 - the From and To addresses, in full;
 - the time, as a date and time and as an age;
 - the exact amount, and under it the amount in the token's smallest unit;
@@ -419,7 +438,7 @@ Tap a row to open the transaction. The transaction screen shows:
     - what the transaction did, when the wallet can read it;
     - the raw data, the bytes the transaction carried.
 
-Tapping the hash, an address, the amount or a detail copies it. Each address,
+Clicking the hash, an address, the amount or a detail copies it. Each address,
 hash and block has an Etherscan link.
 
 ## Connecting to web3 sites
@@ -431,17 +450,18 @@ wallet opens a connection request.
 
 ### Connection requests
 
-The request shows the site's origin: its address up to the first slash, for
-example `https://app.example`. The origin includes the scheme (`https`), the
-host and the port. The request also shows the address that will be shared, which
-is the active address. Click "Allow" or "Deny".
+The request shows the site's origin, for example `https://app.example`. The
+origin is the start of the site's web address, before any path. It holds the
+scheme (`https` or `http`), the host name (`app.example`) and a port number,
+which most addresses leave out. The request also shows the address that will be
+shared, which is the active address. Click "Allow" or "Deny".
 
 "Remember my choice for this site" starts ticked. The box stays as you last left
 it. While it is ticked, the wallet keeps your answer, and the site is not asked
 again. The answer applies to that exact origin and to the active address. A
 choice remembered for `https://app.example` does not cover `http://app.example`
-or another port of the same host. A choice remembered for one address does not
-cover another.
+or another port of the same host name. A choice remembered for one address does
+not cover another.
 
 Without "Remember", an allowed site stays connected until:
 
@@ -462,9 +482,10 @@ The window shows:
 - the site's origin;
 - what the transaction does, when the wallet can read it:
     - a token transfer;
-    - a token approval, which lets a contract move your tokens;
-    - a swap, an exchange of one token for another, through the Uniswap
-      Universal Router, step by step;
+    - a token approval;
+    - a swap through the Uniswap Universal Router, step by step. Uniswap is a
+      token exchange made of contracts on Ethereum, and the Universal Router is
+      its contract that carries out a swap in steps;
 - the From address and the contract or recipient, in full;
 - the value in ETH and its USD value;
 - the largest network fee the transaction can cost, with the gas limit and the
@@ -472,10 +493,9 @@ The window shows:
 - the network and the nonce;
 - the raw data.
 
-Enter your password and click "Confirm". The wallet signs exactly the
-transaction shown, and checks the signed transaction against every value on the
-screen before it broadcasts anything. What you read is what goes out, or nothing
-does. "Reject" tells the site you refused.
+Enter your password and click "Confirm". Before sending, the wallet checks the
+signed transaction against the request you approved, field by field. If any
+field differs, nothing is sent. "Reject" tells the site you refused.
 
 One transaction request is open at a time, across all sites. While one is open,
 the wallet refuses any other, and the site is asked to send it again later.
@@ -490,27 +510,35 @@ in a window of its own. The window shows:
 - the From address;
 - what will be signed.
 
-A plain message is shown as text, left to right in the order it was written, so
-right-to-left characters cannot reorder it. An invisible character, such as a
-zero-width space, is shown as its code in a small box, for example `U+200B`. The
-message is also shown as hex, that is as the hexadecimal digits of its bytes.
+A site sends a message as hex, the hexadecimal digits of its bytes. The window
+shows the hex. When the bytes are text, it also shows the text, left to right in
+the order of its bytes, so right-to-left characters cannot reorder it. An
+invisible character, such as a zero-width space, is shown as its code in a small
+box, for example `U+200B`.
 
 Typed data is shown as its fields. Fields that the site added but that are not
-signed are listed apart, under "Not part of the signature". A token permission
-is a `Permit` or a Permit2 permission. Permit2 is Uniswap's contract for token
-allowances, that is for permissions to move tokens. For a token permission, a
-red warning names the spender and each token and amount that the spender may
-take.
+signed are listed apart, under "Not part of the signature".
 
-"Sign" is disabled, and the screen says why, when:
+Some typed data is a token permission: a signature that lets a spender take your
+tokens later without asking you again. The spender is the contract or address
+that the permission names. The wallet recognises two kinds:
+
+- `Permit`, a signed permission that a token's own contract accepts;
+- a Permit2 permission. Permit2 is Uniswap's contract for token allowances, that
+  is for permissions to move tokens.
+
+For a token permission, a red warning names the spender and each token and
+amount that the spender may take.
+
+"Sign" is disabled, and the window says why, when:
 
 - the typed data cannot be signed as shown;
 - the typed data names a different network than the active one;
-- a message is not hex.
+- the site sent the message as plain text instead of hex.
 
-A request made with the older `eth_sign` method shows a warning that names the
-method. Enter your password and click "Sign" to sign. "Reject" tells the site
-you refused.
+A request made with `eth_sign`, an older way of asking for a signature, shows a
+warning. The warning says the data will be signed as a personal message. Enter
+your password and click "Sign" to sign. "Reject" tells the site you refused.
 
 ### Network switch requests
 
@@ -544,29 +572,32 @@ Settings lists the sites under three headings:
 it has no address. `[x]` beside a denied site forgets the refusal.
 
 Making another address active disconnects every site allowed without "Remember",
-and rejects every request still waiting for an answer. A site remembered for the
-old address only is not told the new one.
+and rejects every request still waiting for an answer. A site whose remembered
+choice covers only the old address is not told the new one.
 
 ## Scam protection
 
-Address poisoning is a scam. The scammer gets an address that resembles one you
-have dealt with into your history, hoping that you copy it later instead of the
-real one. Five defenses against this and related scams are on in a new install.
+Address poisoning is a scam. The scammer makes an address that looks like one
+you have dealt with. The scammer then puts that address in your history, hoping
+you copy it later by mistake. Five defenses guard against this and related
+scams. The list of known scam addresses is always on. Settings has a switch for
+each of the other four, and all four are on in a new install.
 
 Fake tokens. Scammers issue tokens from their own contracts under a well-known
 symbol, such as `USDT` or `ETH`. The wallet knows which contracts may carry each
-symbol on its bundled list. The balance list and the send screen hide a token
-that carries one of those symbols from any other contract. `ETH` and the test
-network's `SepoliaETH` belong to no contract at all, so every token that claims
-them is hidden. In the history, the rule applies while "Hide fake tokens
-impersonating a known symbol" is on. A token you track yourself is still listed
-at zero while "Show tracked tokens with zero balance" is on.
+symbol on its built-in list. The balance list and the send screen hide a token
+that carries one of those symbols but comes from another contract. The built-in
+list's symbols are checked on Ethereum Mainnet only. `ETH` and `SepoliaETH` are
+checked on every network. `ETH` and the test network's `SepoliaETH` belong to no
+contract at all, so every token that claims them is hidden. In the history, the
+rule applies while "Hide fake tokens impersonating a known symbol" is on. A
+token that fakes a known symbol cannot be tracked, and is never listed at zero.
 
 Tokens with few holders. Real tokens have many holders; tokens made for address
 poisoning have almost none. While "Hide tokens with fewer than 1,000 holders" is
 on, the history and the send screen hide a token with fewer than 1,000 reported
 holders. The balance list has its own rule: an untracked token appears only when
-it is on the bundled list or has at least 1,000 reported holders. When
+it is on the built-in list or has at least 1,000 reported holders. When
 Blockscout reports no holder count for a token, the history and the send screen
 still show it. While "Use Blockscout" is off, no holder count is known.
 
@@ -584,11 +615,12 @@ the threshold are hidden from the history. A gwei is a billionth of an ETH. The
 threshold starts at 100,000 gwei, which is 0.0001 ETH. A threshold of 0 hides
 nothing.
 
-Known scam addresses. The wallet ships a list of addresses used for fraud, for
-phishing and for wallet drainers, contracts that empty a wallet once given
-permission. Sending to one of them raises a warning on the confirmation screen,
-and such an address cannot be tracked as a token. The list holds only addresses
-involved in fraud; it is not a sanctions list.
+Known scam addresses. The wallet ships a list of addresses known for fraud,
+including phishing addresses and wallet drainers. A wallet drainer is a contract
+that empties a wallet once given permission. Sending to a listed address raises
+a warning on the confirmation screen, and a listed address cannot be tracked as
+a token. The list holds only addresses involved in fraud; it is not a sanctions
+list.
 
 Addresses and hashes are shown in full, because address poisoning relies on
 shortened ones. The only shortened address is the label of a token with no known
@@ -596,9 +628,9 @@ symbol: the first 10 characters of its contract address and "…". That label
 appears on the send screen, on the token screen, and on the confirmation and
 result screens of a send.
 
-The wallet also warns about phishing sites. The list of phishing domains is
-built into the extension and checked in your browser, so nobody learns which
-sites you visit. The list is as current as the AutistMask build you run.
+The wallet also warns about phishing sites. The list of phishing sites is built
+into the extension and checked in your browser, so nobody learns which sites you
+visit. The list is as current as the AutistMask build you run.
 
 ## Networks
 
@@ -613,6 +645,7 @@ Switching:
   or that network's defaults;
 - shows the tokens tracked on that network;
 - reloads every balance and history for the new network;
+- empties the list of fraud contracts;
 - tells every open site about the new network.
 
 On Sepolia, a red `[TESTNET]` banner sits at the top of the wallet, and no USD
@@ -622,7 +655,7 @@ values are shown.
 
 Click the gear in the title bar.
 
-- Wallets: your wallets. Tap a name to rename it. `[recovery phrase]` shows a
+- Wallets: your wallets. Click a name to rename it. `[recovery phrase]` shows a
   phrase wallet's recovery phrase, after your password. `[x]` deletes a wallet.
   "+ Add wallet" adds one.
 - Passwords: "Allow weak passwords" lets you choose a password shorter than 12
@@ -631,25 +664,31 @@ Click the gear in the title bar.
   "+ Add token".
 - Display:
     - "Show tracked tokens with zero balance";
-    - "UTC Timestamps"; otherwise times are shown in your local time;
+    - "UTC Timestamps": times are shown in UTC, the world reference time,
+      instead of your local time;
     - the theme: System, Light or Dark.
 - Network: Ethereum Mainnet or Sepolia Testnet.
 - Ethereum RPC: the RPC endpoint URL. "Save" checks that the URL answers for the
   shown network before storing it.
-- Blockscout API: the "Use Blockscout" checkbox and the Blockscout URL. "Save"
-  checks that the URL answers before storing it. That check sends no data of
-  yours and runs whether or not the checkbox is ticked.
+- Blockscout API: the "Use Blockscout" checkbox and the Blockscout URL. The API
+  is the address at which a program, here the wallet, asks Blockscout its
+  questions. "Save" checks that the URL answers before storing it. That check
+  sends no data of yours and runs whether or not the checkbox is ticked.
 - Etherscan: the "Check recipients on Etherscan" checkbox.
-- Token Spam Protection: the four filters described under Scam protection, and
-  the dust threshold in gwei.
+- Token Spam Protection, the four switches described under Scam protection:
+    - "Hide fake tokens impersonating a known symbol";
+    - "Hide tokens with fewer than 1,000 holders";
+    - "Hide transactions from detected fraud contracts";
+    - "Hide dust transactions below N gwei", with the threshold N as a field.
 - Allowed Sites, Connected Sites, Denied Sites: see Managing sites.
 - About:
     - the project link;
     - the license and the author;
     - the version and the release date;
-    - the commit the build came from.
-- Debug: hidden until you click the version ten times. It holds a checkbox that
-  turns on a red banner and more detailed logging in the browser console.
+    - the source code revision (the commit) the build came from.
+- Debug: hidden until you click the version ten times. It holds the checkbox
+  "Enable debug mode". That checkbox turns on a red banner and more detailed
+  logging in the browser console, the browser's own log for developers.
 
 The URLs you save are remembered per network.
 
@@ -704,8 +743,9 @@ the rule `m/44'/60'/0'/0`.
 **What happens when a transaction times out?**
 
 After 60 seconds without a receipt the wallet shows the error screen. A timeout
-does not mean the transaction failed. It may still confirm; check the hash on
-Etherscan. Congestion or a low fee can delay confirmation past 60 seconds.
+does not mean the transaction failed. It may still be included later; check the
+hash on Etherscan. A busy network or a low fee can delay a transaction past 60
+seconds.
 
 ## License
 

docs/RELEASE.md

@@ -1,87 +1,225 @@
 # Releasing AutistMask
 
-This is the procedure that turns a green `main` into a tagged, packaged release.
-It gathers into one place what is otherwise spread across the `Makefile` and
-three `README.md` sections, so the person cutting a release does not have to
-reconstruct the order from them.
+A release is a tagged commit on the `main` branch and the two archives that
+`make package` writes from that commit. This file is the procedure, in order.
 
-There is one version, declared in three files (`package.json`,
-`manifest/chrome.json`, `manifest/firefox.json`), and `make package` builds and
-packages but publishes nothing. `make build` and `make package` can be run by
-anyone; tagging, signing, packing a CRX and any upload need credentials only the
-owner ([@sneak](https://sneak.berlin)) holds and are marked **owner-only**
-below. Releases are tagged from `main` (see the Workflow section of `TODO.md`),
-so the "release commit" throughout is the `main` commit the milestone PR merged.
+Only the owner ([@sneak](https://sneak.berlin)):
+
+- decides whether and when a release is tagged;
+- creates, moves or deletes a tag;
+- decides where the archives are published.
+
+Anyone can run steps 1 to 4. No script in this repository uploads or publishes
+the archives. None signs them, and none packs a CRX (Chrome's packaged extension
+file).
+
+## Terms
+
+- The tracker is the repository's Gitea site (Gitea is the software that hosts
+  the repository): https://git.eeqj.de/sneak/AutistMask. The tracker's Actions
+  page, https://git.eeqj.de/sneak/AutistMask/actions, lists the workflow runs.
+- A workflow is a file under `.gitea/workflows/` that lists jobs. The tracker
+  runs every workflow on each push. Each job runs one script on the tracker's
+  runner (the machine that runs jobs).
+- The release commit is a commit on `main`. Releases are tagged from `main` only
+  (`TODO.md`, Workflow).
+- A clean checkout is a working tree (the checked-out files) at the release
+  commit where `git status --porcelain` prints nothing. The build stamps the
+  commit hash (the commit's id) into the extension and appends `-dirty` when the
+  tree has local changes.
+- A tag is a name that git attaches to one commit. Release tags read `vX.Y.Z`,
+  such as `v0.1.0`.
+- A digest is the sha256 hash of a file (a fixed-length fingerprint of its
+  bytes), written as 64 hexadecimal characters.
+
+## What you need
+
+- A clean checkout of the release commit.
+- `make`.
+- Docker (a tool that runs programs in containers), for `script/cibuild` in
+  step 1. `make package` needs no Docker.
+- Node and yarn, on the `PATH`. `make package` runs both directly.
+  `script/bootstrap` can install both through nvm (a Node version manager), but
+  it leaves them off the `PATH`.
 
 ## Procedure
 
-1. **Confirm `main` is green in CI.** The `check` workflow
-   (`.gitea/workflows/check.yml`) runs `script/cibuild`, which runs
-   `script/check` and then builds the image uncached, so a green `check` run is
-   a green `make check`. Find the run for the exact release commit on the
-   tracker's Actions view. _Check:_ that commit's `check` run succeeded; running
-   `make check` on a clean checkout of the commit reproduces it and exits 0.
+### 1. Confirm the release commit is green
 
-2. **Confirm the version matches the intended tag.** `package.json`,
-   `manifest/chrome.json` and `manifest/firefox.json` must all declare the same
-   `X.Y.Z`. `make build` fails when they disagree, but nothing checks that they
-   equal the tag you mean to create — that is this manual step. _Check:_ all
-   three files read the same `X.Y.Z`, and it is the version you intend to tag
-   `vX.Y.Z`.
+The `check` workflow (`.gitea/workflows/check.yml`) runs `script/cibuild` on
+every push. `script/cibuild` runs:
 
-3. **Build and package from a clean checkout of that commit.** From a fresh
-   clone, or a working tree with no local modifications (`git status` clean),
-   checked out at the release commit: run `make setup`, then `make package`.
-   `make package` runs `make build` first, so the archives can only be made from
-   a `dist/` verified against that build's own receipt as a release (not debug)
-   build. It writes three files into `release/`:
-   `autistmask-chrome-<version>.zip`, `autistmask-firefox-<version>.xpi`, and
-   `SHA256SUMS`. _Check:_ those three files exist and `<version>` in the archive
-   names is the version confirmed in step 2. The Firefox `.xpi` is **unsigned**
-   (see step 6 and "Installing on Firefox" in `README.md`).
+- `script/bootstrap`, which installs the dependencies;
+- `script/check`, which is what `make check` runs;
+- the Docker image build (an image is Docker's packaged form of a program).
 
-4. **Verify `SHA256SUMS`.** The archives are deterministic — sorted entries,
-   fixed timestamps, fixed compression — so a second `make package` from another
-   clean checkout of the same commit produces byte-identical files. Verify the
-   recorded digests against the files with `sha256sum -c SHA256SUMS`, run from
-   `release/`. To confirm reproducibility, run `make package` again on a
-   separate clean checkout and compare the digests. _Check:_ `sha256sum -c`
-   reports `OK` for every file, and an independent build's digests match.
+`script/check` runs:
 
-5. **Tag the release commit.** _(owner-only)_ Create an annotated tag `vX.Y.Z`
-   on the release commit and push it: `git tag -a vX.Y.Z` (with a message), then
-   `git push origin vX.Y.Z`. _Check:_ `git tag` lists `vX.Y.Z`, and
-   `git rev-parse vX.Y.Z^{commit}` resolves to the release commit.
+- `script/test`: the tests, in Docker;
+- `script/lint`, which runs three checks in Docker:
+    - ESLint, a code checker;
+    - `prettier --check .`, the formatting check;
+    - `script/check-censored`, which fails when the name that `RULES.md` bars
+      appears outside its allowed places;
+- `script/fmt-check`: `prettier --check .` again, on the host.
 
-6. **Distribute per browser.** _(owner-only; pending the owner's choice on
-   https://git.eeqj.de/sneak/AutistMask/issues/386)_ How 1.0.0 is distributed on
-   each browser is not yet decided; it is the open question on that issue, and
-   the concrete steps cannot be written until the owner records a choice there.
-   These steps need credentials only the owner holds. The options under
-   consideration are:
-    - **Firefox** — the packaged `.xpi` is unsigned, and release Firefox and ESR
-      refuse an unsigned add-on:
-        - (a) AMO self-distribution signing (unlisted): submit the `.xpi` to AMO
-          with the owner's credentials; AMO returns a signed `.xpi` installable
-          on every Firefox, with nothing listed publicly.
-        - (b) AMO listed: as (a), plus a public AMO listing and review.
-        - (c) Ship the unsigned `.xpi` and state that Firefox support means
-          Developer Edition, Nightly, or an Unbranded build with
-          `xpinstall.signatures.required` set to `false`.
-    - **Chrome** — the repo packs no CRX and publishes nothing; the extension id
-      is fixed by the `key` in `manifest/chrome.json`:
-        - (a) Chrome Web Store (unlisted): upload the `.zip` with the owner's
-          developer account; the store delivers installs and updates.
-        - (b) Self-hosted CRX signed with the private key the owner holds
-          (`chrome --pack-extension=dist/chrome --pack-extension-key=<path to the .pem>`),
-          installable only via enterprise policy on Windows and macOS, so
-          realistically Linux-only.
-        - (c) "Load unpacked" from `dist/chrome/` only, as today.
+The `e2e` workflow (`.gitea/workflows/e2e.yml`) has two jobs. One runs
+`script/test-e2e`, the browser tests in Chrome. The other runs
+`script/test-e2e-firefox`, the browser tests in Firefox. A red `e2e` job does
+not fail the `check` run.
 
-    Once the owner decides, the chosen steps — including which credentials they
-    need and who holds them — are written into this section and `README.md`'s
-    installation sections are updated to match, which is part of the definition
-    of done of https://git.eeqj.de/sneak/AutistMask/issues/386. _Check:_ for a
-    store or AMO route, the artifact installs from the store or AMO on a clean
-    browser profile; for the CRX or unpacked route, the documented load succeeds
-    and Chrome reports the extension id `gipbhkogfopeahplcjhipkgpcimdpkip`.
+Run `script/cibuild` on the clean checkout. `script/cibuild` runs the same steps
+as the `check` run, and must exit 0.
+
+Check: on the Actions page, the `check` run for the release commit succeeded,
+and both `e2e` jobs for that commit succeeded. `script/cibuild` exited 0 on the
+clean checkout.
+
+### 2. Confirm the version
+
+Three files declare the version:
+
+- `package.json`;
+- `manifest/chrome.json`;
+- `manifest/firefox.json`.
+
+`script/lib/version.js` fails the build when the three disagree.
+`tests/version.test.js` fails when the version is not three numbers separated by
+dots. Nothing compares the version with a tag. That comparison is this step.
+
+Check: all three files read the same `X.Y.Z`, and `vX.Y.Z` is the tag that the
+owner creates in step 5.
+
+### 3. Build and package
+
+On the clean checkout, run:
+
+```bash
+make setup
+make package
+```
+
+`make setup` installs two things:
+
+- the dependencies, from the lockfile `yarn.lock`, which pins each one's
+  version;
+- the git pre-commit hook, a script that git runs before each commit. Here the
+  hook runs `script/check`.
+
+`make package` runs `make build`, then `script/lib/package.js`.
+
+`make build`:
+
+- runs `build.js`. `build.js` writes `dist/chrome/`, `dist/firefox/` and a build
+  receipt. The receipt lists every file that `build.js` wrote, with each file's
+  digest. The receipt lives outside the repository and is deleted when the build
+  ends;
+- runs `script/verify-build --expect release` against the receipt. The check
+  fails when:
+    - `dist/` differs from the receipt;
+    - a bundle (one JavaScript file built from many source files) was compiled
+      with the build-time constant `DEBUG` on;
+    - any file carries the test recovery phrase, which a debug build gives every
+      new wallet;
+- runs `script/check-censored --require-dist` against the built files;
+- removes `dist/` when any of those steps fails.
+
+`script/lib/package.js`:
+
+- empties `release/`;
+- refuses a symbolic link (a file that points at another file) under `dist/`;
+- checks that the browser's directory (`dist/chrome/` or `dist/firefox/`) holds
+  every file named in `manifest.json` or in the popup's HTML page.
+  `manifest.json` is the file that describes the extension to the browser. The
+  popup is the window that the toolbar button opens;
+- checks that the `version` in each `manifest.json` is the version from step 2;
+- writes one archive per browser;
+- reads each archive back;
+- compares every member (a file inside the archive) with `dist/` byte for byte;
+- writes `SHA256SUMS`, with one line per archive:
+    - the digest;
+    - two spaces;
+    - the file name.
+
+`make package` writes three files:
+
+```
+release/autistmask-chrome-<version>.zip
+release/autistmask-firefox-<version>.xpi
+release/SHA256SUMS
+```
+
+The `.xpi` is Firefox's add-on package file (an add-on is Firefox's word for an
+extension). The `.xpi` is not signed.
+
+`make package` prints a line that starts `Not shipped` and names `styles.css`.
+This is expected: each archive holds its own copy of the stylesheet.
+
+Check: `release/` holds those three files, and `<version>` in their names is the
+version from step 2.
+
+### 4. Verify the digests
+
+From `release/`, run `sha256sum -c SHA256SUMS`.
+
+The archives are deterministic for a given `dist/`: the same `dist/` always
+gives the same bytes. `script/lib/zip.js`:
+
+- sorts the members;
+- sets every member's timestamp (its recorded date) to 1980-01-01;
+- compresses each member the same way every time.
+
+`dist/` itself carries the build date. `build.js` compiles the build date, a UTC
+(universal time) day, into the extension. So two builds of the same commit on
+the same UTC day give byte-identical archives. Builds on different days differ.
+
+Check: `sha256sum -c` prints `OK` for both archives. On the same UTC day, a
+second `make package` from another clean checkout of the same commit gives the
+same `SHA256SUMS`.
+
+### 5. Tag the release commit
+
+Owner only. Only the owner decides whether and when a release is tagged. Only
+the owner creates, moves or deletes a tag. On the release commit, the owner
+runs:
+
+```bash
+git tag -a vX.Y.Z -m "AutistMask X.Y.Z"
+git push origin vX.Y.Z
+```
+
+`-a` makes an annotated tag: a tag that carries a message and records who made
+the tag and when. `v0.1.0` is one.
+
+Once the tag exists, `git describe --tags` on the release commit prints
+`vX.Y.Z`. `script/cibuild` and `script/docker` pass that value to the Docker
+image build as `VERSION`.
+
+Check: `git rev-parse vX.Y.Z^{commit}` prints the release commit's hash, and the
+tag is listed at https://git.eeqj.de/sneak/AutistMask/tags.
+
+### 6. Publish the archives
+
+Owner only. The owner decides where the archives are published. No script in
+this repository uploads or publishes them.
+
+Whoever receives an archive installs it as follows.
+
+Chrome loads the extension from a directory:
+
+- unzip the archive into a new, empty directory, for example
+  `unzip autistmask-chrome-0.1.0.zip -d autistmask-chrome`;
+- open `chrome://extensions/` and turn on "Developer mode";
+- click "Load unpacked" and pick that directory.
+
+Chrome then reports the extension id `gipbhkogfopeahplcjhipkgpcimdpkip`. The id
+is the fixed string that identifies the extension to Chrome; the `key` in
+`manifest/chrome.json` sets the id.
+
+Release builds of Firefox refuse to install an unsigned add-on. Desktop Firefox
+115 or newer, in any edition, loads the `.xpi` as a temporary add-on from the
+`about:debugging` page. Firefox unloads a temporary add-on when Firefox exits.
+The section "Installing on Firefox" in `README.md` has the details.
+
+Check: each archive installs on a fresh browser profile (a new, empty set of
+browser data) by the route above.

src/popup/index.js

@@ -6,6 +6,7 @@ const {
     saveState,
     onSaveFailure,
     takeStoredNetwork,
+    clearBalanceNotFetched,
     loadState,
 } = require("../shared/state");
 const { StateUnusableError } = require("../shared/stateSchema");
@@ -95,6 +96,17 @@ let refreshTimer = null;
 // removed meanwhile is left as it is. Blockscout may have answered before the
 // user turned "Use Blockscout" off. So the save drops every token the user has
 // not tracked if the stored setting is off by then.
+//
+// The save also deletes `balanceNotFetched` from each tracked token whose
+// balance this refresh read at every address. trackToken() in
+// src/popup/views/helpers.js sets that field. The save takes the field off the
+// matching tokens of the stored record (clearBalanceNotFetched() in
+// src/shared/state.js). The rest of the stored tracked token list stays as it
+// is.
+//
+// Once the save is done, the wallet list is drawn again. So are the balances
+// on AddressDetail or AddressToken when that screen is up. No other screen is
+// drawn again, DeleteAddress and its balance lines included.
 async function doRefreshAndRender() {
     if (refreshInFlight) {
         refreshAgain = true;
@@ -105,7 +117,7 @@ async function doRefreshAndRender() {
         await followStoredSettings();
         const networkId = state.networkId;
         const wallets = structuredClone(state.wallets);
-        await Promise.all([
+        const [, readTokens] = await Promise.all([
             refreshPrices(pageClosed.signal),
             refreshBalances(
                 wallets,
@@ -137,10 +149,13 @@ async function doRefreshAndRender() {
             if (!stored.useBlockscout) {
                 dropUntrackedTokens(state.wallets, stored.trackedTokens);
             }
+            clearBalanceNotFetched(stored, readTokens);
             state.lastBalanceRefresh = Date.now();
             return true;
         });
         renderWalletList();
+        if (state.currentView === "address") addressDetail.renderBalances();
+        if (state.currentView === "address-token") addressToken.renderBalance();
     } catch (e) {
         // No caller waits for this function, so it must never reject. An
         // unhandled rejection reports nothing. The save inside it reports its

src/popup/views/addToken.js

@@ -1,8 +1,16 @@
-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");
 const { isScamAddress } = require("../../shared/scamlist");
+const { isSpoofedSymbol } = require("../../shared/symbolSpoof");
 const { log } = require("../../shared/log");
 
 // Counts the times AddToken has opened. A contract lookup started before
@@ -77,8 +85,17 @@ function init(ctx) {
                 );
                 return;
             }
+            // The balance list never shows a token that the spoof rule
+            // refuses, so such a token is not tracked.
+            if (isSpoofedSymbol(info.symbol, contractAddr, chainId)) {
+                showFlash("Not added: this token fakes a known symbol.");
+                if (addTokenScreenOpenings !== opening) return;
+                infoEl.textContent = "";
+                infoEl.style.visibility = "hidden";
+                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

@@ -22,6 +22,7 @@ const {
     filterTransactions,
 } = require("../../shared/transactions");
 const { resolveEnsNames } = require("../../shared/ens");
+const { storedNetworkIs } = require("../../shared/storedSettings");
 const {
     updateSendBalance,
     renderSendTokenSelect,
@@ -66,11 +67,27 @@ 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();
+    // Only Blockscout reports the tokens the user has not tracked.
+    $("address-tokens-note").classList.toggle("hidden", !!state.useBlockscout);
+    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,
@@ -84,13 +101,6 @@ function show() {
                 ctx.showAddressToken();
             });
         });
-    // Only Blockscout reports the tokens the user has not tracked.
-    $("address-tokens-note").classList.toggle("hidden", !!state.useBlockscout);
-    renderSendTokenSelect(addr);
-    $("tx-list").innerHTML =
-        '<div class="text-muted text-xs py-1">Loading...</div>';
-    showView("address");
-    loadTransactions(addr.address);
 }
 
 let loadedTxs = [];
@@ -98,6 +108,7 @@ let loadedTxs = [];
 let ensNameMap = new Map();
 
 async function loadTransactions(address) {
+    const networkId = state.networkId;
     try {
         const rawTxs = await fetchRecentTransactions(
             address,
@@ -114,43 +125,74 @@ async function loadTransactions(address) {
         });
         const txs = result.transactions;
 
-        // Persist any newly discovered fraud contracts
-        if (result.newFraudContracts.length > 0) {
-            for (const addr of result.newFraudContracts) {
-                if (!state.fraudContracts.includes(addr)) {
-                    state.fraudContracts.push(addr);
-                }
-            }
-            await saveState();
-        }
-
-        loadedTxs = txs;
-
         // Collect ALL unique addresses (from + to) for ENS resolution so
         // that reverse lookups work for every displayed address, not just
         // the ones that were originally entered as ENS names.
         const counterparties = [
             ...new Set(txs.flatMap((tx) => [tx.from, tx.to].filter(Boolean))),
         ];
+        let names = new Map();
         if (counterparties.length > 0) {
             try {
-                ensNameMap = await resolveEnsNames(
+                names = await resolveEnsNames(
                     counterparties,
                     state.rpcUrl,
                     state.networkId,
                     ctx.pageClosed,
                 );
             } catch {
-                ensNameMap = new Map();
+                // The rows then show no ENS names.
             }
         }
 
+        // If the network changed during the lookups above, or the screen now
+        // shows another address, nothing is saved or drawn. See
+        // src/shared/storedSettings.js.
+        if (
+            state.networkId !== networkId ||
+            !(await storedNetworkIs(networkId)) ||
+            $("address-line").dataset.full !== address
+        ) {
+            return;
+        }
+
+        // Persist any newly discovered fraud contracts, inside the save and
+        // holding the lock. Nothing is added unless this page and the stored
+        // record both still name the request's network.
+        if (result.newFraudContracts.length > 0) {
+            let saved = false;
+            await saveState((stored) => {
+                if (state.networkId !== networkId) return false;
+                if (stored.networkId !== networkId) return false;
+                for (const addr of result.newFraudContracts) {
+                    if (!state.fraudContracts.includes(addr)) {
+                        state.fraudContracts.push(addr);
+                    }
+                }
+                saved = true;
+            });
+            // If the network changed while the save waited for the lock,
+            // nothing is drawn.
+            if (!saved) return;
+        }
+
+        loadedTxs = txs;
+        ensNameMap = names;
         renderTransactions(txs);
     } catch (e) {
         // Cancelled by the popup closing, not failed: see pageClosed in
         // src/popup/index.js.
         if (ctx.pageClosed.aborted) return;
         log.errorf("loadTransactions failed:", e.message);
+        // If the network changed, or the screen now shows another address,
+        // the failure is not shown.
+        if (
+            state.networkId !== networkId ||
+            !(await storedNetworkIs(networkId)) ||
+            $("address-line").dataset.full !== address
+        ) {
+            return;
+        }
         $("tx-list").innerHTML =
             '<div class="text-muted text-xs py-1">Failed to load transactions.</div>';
     }
@@ -287,4 +329,4 @@ function init(_ctx) {
     exportPrivkey.init();
 }
 
-module.exports = { init, show };
+module.exports = { init, show, renderBalances };

src/popup/views/addressToken.js

@@ -22,13 +22,14 @@ const {
     timeAgo,
 } = require("./helpers");
 const { state, saveState, currentNetwork } = require("../../shared/state");
-const { TOKEN_BY_ADDRESS, resolveSymbol } = require("../../shared/tokenList");
+const { bundledToken, resolveSymbol } = require("../../shared/tokenList");
 const { formatUsd, getPrice } = require("../../shared/prices");
 const {
     fetchRecentTransactions,
     filterTransactions,
 } = require("../../shared/transactions");
 const { resolveEnsNames } = require("../../shared/ens");
+const { storedNetworkIs } = require("../../shared/storedSettings");
 const {
     updateSendBalance,
     renderSendTokenSelect,
@@ -49,37 +50,24 @@ 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") {
-        symbol = nativeCurrency();
-        amount = parseFloat(addr.balance || "0");
-        price = getPrice("ETH");
-    } 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(tokenId);
-    }
-
-    currentSymbol = symbol;
+    const chainId = currentNetwork().chainId;
+    const knownToken = bundledToken(tokenId, chainId);
+    currentSymbol =
+        tokenId === "ETH"
+            ? nativeCurrency()
+            : resolveSymbol(
+                  tokenId,
+                  addr.tokenBalances,
+                  state.trackedTokens,
+                  chainId,
+              );
 
     $("address-token-title").textContent =
         wallet.name +
         " \u2014 Address " +
         (ai + 1) +
         " \u2014 " +
-        displaySymbol(symbol);
+        displaySymbol(currentSymbol);
 
     // Blockie
     const blockieEl = $("address-token-jazzicon");
@@ -101,13 +89,7 @@ function show() {
     $("address-token-line").dataset.full = addr.address;
     attachCopyHandlers($("address-token-line"));
 
-    // 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(symbol, amount, price);
+    renderBalance();
 
     // Token contract details (ERC-20 only)
     const contractInfo = $("address-token-contract-info");
@@ -169,7 +151,49 @@ 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,
+        );
+        const tracked = state.trackedTokens.find(
+            (t) => t.address.toLowerCase() === id,
+        );
+        // null when the scale is unknown, or when no refresh has read the
+        // balance of 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 = tracked && tracked.balanceNotFetched ? null : 0;
+        price = getPrice(tokenId);
+    }
+
+    // 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) {
+    const networkId = state.networkId;
     try {
         const rawTxs = await fetchRecentTransactions(
             address,
@@ -186,16 +210,6 @@ async function loadTransactions(address, tokenId) {
         });
         let txs = result.transactions;
 
-        // Persist any newly discovered fraud contracts
-        if (result.newFraudContracts.length > 0) {
-            for (const addr of result.newFraudContracts) {
-                if (!state.fraudContracts.includes(addr)) {
-                    state.fraudContracts.push(addr);
-                }
-            }
-            await saveState();
-        }
-
         // Filter to this token only
         if (tokenId === "ETH") {
             txs = txs.filter((tx) => tx.contractAddress === null);
@@ -207,32 +221,75 @@ async function loadTransactions(address, tokenId) {
             );
         }
 
-        loadedTxs = txs;
-
         // Collect ALL unique addresses for ENS resolution so reverse
         // lookups work for every displayed address.
         const counterparties = [
             ...new Set(txs.flatMap((tx) => [tx.from, tx.to].filter(Boolean))),
         ];
+        let names = new Map();
         if (counterparties.length > 0) {
             try {
-                ensNameMap = await resolveEnsNames(
+                names = await resolveEnsNames(
                     counterparties,
                     state.rpcUrl,
                     state.networkId,
                     ctx.pageClosed,
                 );
             } catch {
-                ensNameMap = new Map();
+                // The rows then show no ENS names.
             }
         }
 
+        // If the network changed during the lookups above, or the screen now
+        // shows another address or token, nothing is saved or drawn. See
+        // src/shared/storedSettings.js.
+        if (
+            state.networkId !== networkId ||
+            !(await storedNetworkIs(networkId)) ||
+            $("address-token-line").dataset.full !== address ||
+            state.selectedToken !== tokenId
+        ) {
+            return;
+        }
+
+        // Persist any newly discovered fraud contracts, inside the save and
+        // holding the lock. Nothing is added unless this page and the stored
+        // record both still name the request's network.
+        if (result.newFraudContracts.length > 0) {
+            let saved = false;
+            await saveState((stored) => {
+                if (state.networkId !== networkId) return false;
+                if (stored.networkId !== networkId) return false;
+                for (const addr of result.newFraudContracts) {
+                    if (!state.fraudContracts.includes(addr)) {
+                        state.fraudContracts.push(addr);
+                    }
+                }
+                saved = true;
+            });
+            // If the network changed while the save waited for the lock,
+            // nothing is drawn.
+            if (!saved) return;
+        }
+
+        loadedTxs = txs;
+        ensNameMap = names;
         renderTransactions(txs);
     } catch (e) {
         // Cancelled by the popup closing, not failed: see pageClosed in
         // src/popup/index.js.
         if (ctx.pageClosed.aborted) return;
         log.errorf("loadTransactions failed:", e.message);
+        // If the network changed, or the screen now shows another address or
+        // token, the failure is not shown.
+        if (
+            state.networkId !== networkId ||
+            !(await storedNetworkIs(networkId)) ||
+            $("address-token-line").dataset.full !== address ||
+            state.selectedToken !== tokenId
+        ) {
+            return;
+        }
         $("address-token-tx-list").innerHTML =
             '<div class="text-muted text-xs py-1">Failed to load transactions.</div>';
     }
@@ -348,4 +405,4 @@ function init(_ctx) {
     });
 }
 
-module.exports = { init, show };
+module.exports = { init, show, renderBalance };

src/popup/views/helpers.js

@@ -33,6 +33,7 @@ const { networkByChainId } = require("../../shared/networks");
 const { formatUsd, getPrice } = require("../../shared/prices");
 const { state, saveState, currentNetwork } = require("../../shared/state");
 const { displaySymbol } = require("../../shared/symbolDisplay");
+const { isSpoofedSymbol } = require("../../shared/symbolSpoof");
 const { walletHasRecoveryPhrase } = require("../../shared/wallet");
 const { markViewRendered } = require("../viewRouter");
 
@@ -313,14 +314,17 @@ function nativeCurrency() {
 // The wallets' balances hold what Blockscout reported for each token. So the
 // wallets are returned only while "Use Blockscout" is on.
 function tokenSourcesByChainId(chainId) {
-    const net = chainId ? networkByChainId(chainId) : currentNetwork();
+    const chainIdOrActive = chainId || currentNetwork().chainId;
+    const net = networkByChainId(chainIdOrActive);
     if (net && net.id === state.networkId) {
         return {
+            chainId: chainIdOrActive,
             trackedTokens: state.trackedTokens,
             wallets: state.useBlockscout ? state.wallets : [],
         };
     }
     return {
+        chainId: chainIdOrActive,
         trackedTokens: (net && state.networkTrackedTokens[net.id]) || [],
         wallets: [],
     };
@@ -351,7 +355,7 @@ function blockscoutOffTokenNoteHtml(token, chainId) {
 
 // The symbol shown for a token line, from these sources in order:
 //
-// - the bundled list
+// - the bundled list, for a token on Ethereum Mainnet
 // - the tokens the user tracks
 // - the explorer's report, while "Use Blockscout" is on
 //
@@ -417,6 +421,15 @@ function balanceLine(symbol, amount, price, tokenId) {
     );
 }
 
+// Tracks `token` on the active network, as every add path on AddToken and
+// SettingsAddToken does. The tracked record carries `balanceNotFetched: true`
+// until a balance refresh has read the token's balance at every address
+// (doRefreshAndRender() in src/popup/index.js). Until then, an address with no
+// balance row for the token shows `quantity unknown` for it, not 0.0000.
+function trackToken(token) {
+    state.trackedTokens.push({ ...token, balanceNotFetched: true });
+}
+
 function balanceLinesForAddress(addr, trackedTokens, showZero) {
     let html = balanceLine(
         nativeCurrency(),
@@ -447,9 +460,16 @@ function balanceLinesForAddress(addr, trackedTokens, showZero) {
     if (showZero && trackedTokens) {
         for (const t of trackedTokens) {
             if (seen.has(t.address.toLowerCase())) continue;
+            // A token that the spoof rule refuses has no stored balance, and
+            // gets no zero row either.
+            if (
+                isSpoofedSymbol(t.symbol, t.address, currentNetwork().chainId)
+            ) {
+                continue;
+            }
             html += balanceLine(
                 t.symbol,
-                0,
+                t.balanceNotFetched ? null : 0,
                 getPrice(t.address),
                 t.address.toLowerCase(),
             );
@@ -829,6 +849,7 @@ module.exports = {
     flashCopyFeedback,
     balanceLine,
     balanceLinesForAddress,
+    trackToken,
     addressHoldsFunds,
     keyMaterialName,
     unknownableAmount,

src/popup/views/home.js

@@ -44,6 +44,7 @@ const {
     fetchRecentTransactions,
     filterTransactions,
 } = require("../../shared/transactions");
+const { storedNetworkIs } = require("../../shared/storedSettings");
 const { log } = require("../../shared/log");
 
 function findActiveAddr() {
@@ -183,6 +184,7 @@ async function loadHomeTxs(ctx) {
     }
     if (allAddresses.length === 0) return;
 
+    const networkId = state.networkId;
     const filters = {
         hideSpoofedSymbols: state.hideSpoofedSymbols,
         hideLowHolderTokens: state.hideLowHolderTokens,
@@ -202,6 +204,15 @@ async function loadHomeTxs(ctx) {
         );
         const results = await Promise.all(fetches);
 
+        // If the network changed during the lookups, nothing is saved or
+        // drawn. See src/shared/storedSettings.js.
+        if (
+            state.networkId !== networkId ||
+            !(await storedNetworkIs(networkId))
+        ) {
+            return;
+        }
+
         // Merge, deduplicate by hash, filter, sort, take 25
         const seen = new Set();
         let merged = [];
@@ -215,14 +226,24 @@ async function loadHomeTxs(ctx) {
 
         const filtered = filterTransactions(merged, filters);
 
-        // Persist any newly discovered fraud contracts
+        // Persist any newly discovered fraud contracts, inside the save and
+        // holding the lock. Nothing is added unless this page and the stored
+        // record both still name the request's network.
         if (filtered.newFraudContracts.length > 0) {
-            for (const addr of filtered.newFraudContracts) {
-                if (!state.fraudContracts.includes(addr)) {
-                    state.fraudContracts.push(addr);
+            let saved = false;
+            await saveState((stored) => {
+                if (state.networkId !== networkId) return false;
+                if (stored.networkId !== networkId) return false;
+                for (const addr of filtered.newFraudContracts) {
+                    if (!state.fraudContracts.includes(addr)) {
+                        state.fraudContracts.push(addr);
+                    }
                 }
-            }
-            await saveState();
+                saved = true;
+            });
+            // If the network changed while the save waited for the lock,
+            // nothing is drawn.
+            if (!saved) return;
         }
 
         merged = filtered.transactions;
@@ -234,6 +255,13 @@ async function loadHomeTxs(ctx) {
         // src/popup/index.js.
         if (ctx.pageClosed.aborted) return;
         log.errorf("loadHomeTxs failed:", e.message);
+        // If the network changed, the failure is not shown.
+        if (
+            state.networkId !== networkId ||
+            !(await storedNetworkIs(networkId))
+        ) {
+            return;
+        }
         const list = $("home-tx-list");
         if (list) {
             list.innerHTML =

src/popup/views/send.js

@@ -12,7 +12,7 @@ const {
     goBack,
     tokenSourcesByChainId,
 } = require("./helpers");
-const { state, currentAddress } = require("../../shared/state");
+const { state, currentAddress, currentNetwork } = require("../../shared/state");
 let ctx;
 const { getProvider } = require("../../shared/balances");
 const { resolveTokenDecimals } = require("../../shared/approvalAmount");
@@ -154,7 +154,9 @@ function renderSendTokenSelect(addr) {
         // out. Its token's own screen can still send it: there
         // state.selectedToken picks the token, not this list.
         if (isBelowOneMillionth(t.balance)) continue;
-        if (isSpoofedSymbol(t.symbol, t.address)) continue;
+        if (isSpoofedSymbol(t.symbol, t.address, currentNetwork().chainId)) {
+            continue;
+        }
         if (fraudSet.has(t.address.toLowerCase())) continue;
         // An unknown holder count does not withhold a token the user holds:
         // only a count the explorer actually reported as below the threshold
@@ -198,13 +200,21 @@ function renderSendTokenSelect(addr) {
 // null rather than "0": this screen states it as unknown, as the confirmation
 // screen does, and Max fills nothing in for it. Only a stored quantity is
 // withdrawn: the "0" for a token that has no row at all is an absence of
-// holdings, which is true at every scale.
+// holdings, which is true at every scale. A token with no row whose tracked
+// record carries `balanceNotFetched` gets null instead, because no refresh has
+// read its balance.
 function tokenBalanceAndDecimals(addr, token) {
     const tb = (addr.tokenBalances || []).find(
         (t) => t.address.toLowerCase() === token.toLowerCase(),
     );
     const tokenDecimals = resolveTokenDecimals(token, tokenSourcesByChainId());
-    if (!tb) return { tokenBalance: "0", tokenDecimals };
+    if (!tb) {
+        const tracked = state.trackedTokens.find(
+            (t) => t.address.toLowerCase() === token.toLowerCase(),
+        );
+        const notRead = tracked && tracked.balanceNotFetched;
+        return { tokenBalance: notRead ? null : "0", tokenDecimals };
+    }
     if (tokenDecimals === null) return { tokenBalance: null, tokenDecimals };
     return { tokenBalance: tb.balance ?? null, tokenDecimals };
 }
@@ -230,6 +240,7 @@ function updateSendBalance() {
             token,
             addr.tokenBalances,
             state.trackedTokens,
+            currentNetwork().chainId,
         );
         // A null balance is a holding whose scale is unknown. Saying a figure
         // for it would be a claim about the amount, so it reads as the
@@ -385,6 +396,7 @@ function init(_ctx) {
                 token,
                 addr.tokenBalances,
                 state.trackedTokens,
+                currentNetwork().chainId,
             );
             ({ tokenDecimals } = tokenBalanceAndDecimals(addr, token));
         }

src/popup/views/settings.js

@@ -50,6 +50,11 @@ let versionClickTimer = null;
 // not the one in `state`.
 let shownNetwork = null;
 
+// Each endpoint "Save" counts its taps here, under the field that it stores.
+// Once the user taps the same "Save" again, the earlier tap shows no flash
+// message. The earlier tap stores its URL only if its write had already begun.
+const saveTaps = { rpcUrl: 0, blockscoutUrl: 0 };
+
 // One row per site origin, however many addresses it appears under, each with
 // an [x] that hands it to onRemove.
 function renderSiteList(containerId, origins, onRemove) {
@@ -347,10 +352,16 @@ function showNewSettings() {
 // shows `url`, nothing is saved. The flash message then says that the URL was
 // changed during the check. The save compares the input and sets `url` in
 // `state` in one step. So a redraw after the comparison shows `url`.
-async function saveEndpoint(field, input, url, networkId) {
+//
+// `tap` is the number of the "Save" tap that checked `url`. If the user taps
+// the same "Save" again before this save holds the lock, nothing is stored. If
+// the user taps the same "Save" again before the write ends, no flash message
+// is shown.
+async function saveEndpoint(field, input, url, networkId, tap) {
     let refused = false;
     let inputChanged = false;
     await saveState((stored) => {
+        if (saveTaps[field] !== tap) return false;
         refused =
             state.networkId !== networkId || stored.networkId !== networkId;
         inputChanged = $(input).value.trim() !== url;
@@ -358,6 +369,7 @@ async function saveEndpoint(field, input, url, networkId) {
         state[field] = url;
         stored[field] = url;
     });
+    if (saveTaps[field] !== tap) return;
     if (refused) {
         showFlash("The URL was not saved because the network changed.");
     } else if (inputChanged) {
@@ -375,6 +387,8 @@ function init(_ctx) {
     showPhrase.init();
 
     $("btn-save-rpc").addEventListener("click", async () => {
+        saveTaps.rpcUrl++;
+        const tap = saveTaps.rpcUrl;
         const url = $("settings-rpc").value.trim();
         if (!url) {
             showFlash("Please enter an RPC URL.");
@@ -395,6 +409,8 @@ function init(_ctx) {
                 }),
             });
             const json = await resp.json();
+            // The user has tapped this "Save" again since the check began.
+            if (tap !== saveTaps.rpcUrl) return;
             if (json.error) {
                 log.errorf("RPC validation error:", json.error);
                 showFlash("Endpoint returned an error.");
@@ -408,6 +424,7 @@ function init(_ctx) {
             // Cancelled by the popup closing, not failed: see pageClosed in
             // src/popup/index.js.
             if (ctx.pageClosed.aborted) return;
+            if (tap !== saveTaps.rpcUrl) return;
             // Not the error's message: fetch puts the whole URL, password and
             // key included, in the message of the error it throws for a URL
             // with a user name and password or one it cannot parse.
@@ -415,10 +432,12 @@ function init(_ctx) {
             showFlash("Could not reach endpoint.");
             return;
         }
-        await saveEndpoint("rpcUrl", "settings-rpc", url, net.id);
+        await saveEndpoint("rpcUrl", "settings-rpc", url, net.id, tap);
     });
 
     $("btn-save-blockscout").addEventListener("click", async () => {
+        saveTaps.blockscoutUrl++;
+        const tap = saveTaps.blockscoutUrl;
         const url = $("settings-blockscout").value.trim();
         if (!url) {
             showFlash("Please enter a Blockscout API URL.");
@@ -428,18 +447,26 @@ function init(_ctx) {
         showFlash("Testing endpoint...");
         try {
             const resp = await debugFetch(url + "/stats");
+            if (tap !== saveTaps.blockscoutUrl) return;
             if (!resp.ok) {
                 showFlash("Endpoint returned HTTP " + resp.status + ".");
                 return;
             }
         } catch {
             if (ctx.pageClosed.aborted) return;
+            if (tap !== saveTaps.blockscoutUrl) return;
             // Not the error's message, as for the RPC check above.
             log.errorf("Blockscout validation failed:", urlOrigin(url));
             showFlash("Could not reach endpoint.");
             return;
         }
-        await saveEndpoint("blockscoutUrl", "settings-blockscout", url, net.id);
+        await saveEndpoint(
+            "blockscoutUrl",
+            "settings-blockscout",
+            url,
+            net.id,
+            tap,
+        );
     });
 
     // Each change is made inside the save, holding the lock. So

src/popup/views/settingsAddToken.js

@@ -1,8 +1,16 @@
-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");
 const { isScamAddress } = require("../../shared/scamlist");
+const { isSpoofedSymbol } = require("../../shared/symbolSpoof");
 const { log } = require("../../shared/log");
 
 let ctx;
@@ -43,7 +51,7 @@ 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 +118,7 @@ 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();
@@ -155,8 +163,18 @@ function init(_ctx) {
                 );
                 return;
             }
+            // The balance list never shows a token that the spoof rule
+            // refuses, so such a token is not tracked. The rule never refuses
+            // a bundled token, so the "Top tokens:" buttons and the top 100
+            // dropdown need no such check.
+            if (isSpoofedSymbol(info.symbol, addr, chainId)) {
+                showFlash("Not added: this token fakes a known symbol.");
+                infoEl.textContent = "";
+                infoEl.style.visibility = "hidden";
+                return;
+            }
             log.infof("Adding token", info.symbol, addr);
-            state.trackedTokens.push({
+            trackToken({
                 address: addr,
                 symbol: info.symbol,
                 decimals: info.decimals,

src/shared/approvalAmount.js

@@ -29,7 +29,7 @@
 // string, and a token the user added by hand carries whatever lookupTokenInfo()
 // got back, so the accepted types are enumerated rather than coerced.
 const { toDecimals } = require("./transferAmount");
-const { TOKEN_BY_ADDRESS } = require("./tokenList");
+const { bundledToken } = require("./tokenList");
 const { isSpoofedSymbol } = require("./symbolSpoof");
 
 // Every decimals the explorer reported for this contract, across all the
@@ -53,12 +53,14 @@ function explorerDecimals(lower, wallets) {
 }
 
 // The decimals to render a token amount with, or null when nothing knows.
-// `sources` is { trackedTokens, wallets }, both shaped as they are on `state`.
+// `sources` is { chainId, trackedTokens, wallets }. `chainId` is the chain id
+// of the token's network. The bundled list is read only when that network is
+// Ethereum Mainnet. `trackedTokens` and `wallets` are shaped as on `state`.
 function resolveTokenDecimals(tokenAddress, sources) {
     const lower = (tokenAddress || "").toLowerCase();
     if (!lower) return null;
 
-    const bundled = TOKEN_BY_ADDRESS.get(lower);
+    const bundled = bundledToken(lower, sources && sources.chainId);
     if (bundled) {
         const d = toDecimals(bundled.decimals);
         if (d !== null) return d;
@@ -100,18 +102,19 @@ function explorerSymbol(lower, wallets) {
 // explorer reported: the same sources and the same precedence
 // resolveTokenDecimals() uses, so a token's name and its scale are drawn from
 // the same place and the two can no longer disagree about which sources they
-// trust. `sources` is { trackedTokens, wallets }, shaped as on `state`.
+// trust. `sources` is as for resolveTokenDecimals().
 //
 // A tracked or explorer-reported symbol is attacker-influenced text, so it is
-// held to the spoof rule (symbolSpoof.js): a candidate that wears a bundled or
-// native ticker from a contract not entitled to it is refused and the next
-// source tried, so resolving a symbol never becomes a new way to claim a known
-// ticker. The bundled list is the wallet's own data and is trusted as it is.
+// held to the spoof rule (symbolSpoof.js): a candidate that the rule calls a
+// spoof is refused and the next source tried, so resolving a symbol never
+// becomes a new way to claim a known ticker. The bundled list is the wallet's
+// own data and is trusted as it is.
 function resolveTokenSymbol(tokenAddress, sources) {
     const lower = (tokenAddress || "").toLowerCase();
     if (!lower) return null;
 
-    const bundled = TOKEN_BY_ADDRESS.get(lower);
+    const chainId = sources && sources.chainId;
+    const bundled = bundledToken(lower, chainId);
     if (bundled && bundled.symbol) return bundled.symbol;
 
     const tracked = ((sources && sources.trackedTokens) || []).find(
@@ -123,7 +126,7 @@ function resolveTokenSymbol(tokenAddress, sources) {
     if (reported) candidates.push(reported);
 
     for (const symbol of candidates) {
-        if (!isSpoofedSymbol(symbol, tokenAddress)) return symbol;
+        if (!isSpoofedSymbol(symbol, tokenAddress, chainId)) return symbol;
     }
     return null;
 }

src/shared/balances.js

@@ -17,7 +17,7 @@ const { ERC20_ABI } = require("./constants");
 const { NETWORKS } = require("./networks");
 const { log, debugFetch, urlOrigin } = require("./log");
 const { deriveAddressFromXpub } = require("./wallet");
-const { TOKEN_BY_ADDRESS } = require("./tokenList");
+const { bundledToken } = require("./tokenList");
 const { LOW_HOLDER_THRESHOLD, parseHoldersCount } = require("./holders");
 const { isSpoofedSymbol } = require("./symbolSpoof");
 const { toDecimals } = require("./transferAmount");
@@ -106,6 +106,9 @@ function rawUnits(value) {
 // balance is read through the RPC endpoint instead, and its row here gives that
 // entry its holder count and `decimals` (fetchTrackedTokenBalances()).
 //
+// `chainId` is the chain id of the network `blockscoutUrl` serves. The known
+// token list is used only when that network is Ethereum Mainnet.
+//
 // `decimals` and `balance` are each null when the answer is unknown, the same
 // way `holders` already is. Absence is never filled in here: this is the
 // upstream of every screen that displays a token amount, so a value invented
@@ -117,6 +120,7 @@ async function fetchTokenBalances(
     address,
     blockscoutUrl,
     trackedTokens,
+    chainId,
     signal,
 ) {
     if (!(await storedSettingIsOn("useBlockscout"))) return [];
@@ -175,7 +179,10 @@ async function fetchTokenBalances(
             // either way: copying another source into it would make
             // explorerDecimals()'s disagreement check compare something other
             // than explorer values.
-            const known = resolveTokenDecimals(tokenAddr, { trackedTokens });
+            const known = resolveTokenDecimals(tokenAddr, {
+                chainId,
+                trackedTokens,
+            });
             const scale = known !== null ? known : decimals;
             // null is a holding of an amount that cannot be stated, which is
             // not the same as a holding of zero, and must never render as one.
@@ -191,7 +198,7 @@ async function fetchTokenBalances(
             // through to the views, where the two low-holder filters treat
             // an unknown count as "do not judge" rather than as zero.
             const holders = parseHoldersCount(item.token.holders_count);
-            const isKnown = TOKEN_BY_ADDRESS.has(tokenAddr);
+            const isKnown = bundledToken(tokenAddr, chainId) !== null;
             const isTracked = trackedSet.has(tokenAddr);
             const hasEnoughHolders = holders >= LOW_HOLDER_THRESHOLD;
 
@@ -202,7 +209,9 @@ async function fetchTokenBalances(
             // Every row here is an ERC-20 the explorer reported, so it has a
             // contract address; the native ETH balance is fetched over RPC in
             // refreshBalances and never passes through this loop.
-            if (isSpoofedSymbol(item.token.symbol, tokenAddr)) continue;
+            if (isSpoofedSymbol(item.token.symbol, tokenAddr, chainId)) {
+                continue;
+            }
 
             balances.push({
                 address: item.token.address_hash,
@@ -247,19 +256,24 @@ async function fetchTokenBalances(
 // it has none. The failure is logged. A balance of zero gets no entry, as a
 // zero Blockscout reports gets none: the balance lists take a tracked token's
 // zero from the tracked list. A token whose symbol the spoof rule refuses gets
-// no entry either, as in fetchTokenBalances().
+// no entry either, as in fetchTokenBalances(), and its balance is not read.
 //
-// `signal` is as for fetchTokenBalances().
+// Resolves with `rows`, the entries, and `unread`, the tracked tokens whose
+// balance was not read, as lowercased contract addresses. A token is unread
+// when the spoof rule refuses it or its balanceOf fails.
+//
+// `chainId` and `signal` are as for fetchTokenBalances().
 async function fetchTrackedTokenBalances(
     provider,
     address,
     trackedTokens,
     previous,
     explorerRequest,
+    chainId,
     signal,
 ) {
     const listed = trackedTokens.filter(
-        (token) => !isSpoofedSymbol(token.symbol, token.address),
+        (token) => !isSpoofedSymbol(token.symbol, token.address, chainId),
     );
     // Each token's balanceOf answer, or null where it failed.
     const balances = await Promise.all(
@@ -288,12 +302,16 @@ async function fetchTrackedTokenBalances(
     const reported = explorerRows ?? previous;
 
     const rows = [];
+    const unread = trackedTokens
+        .filter((token) => !listed.includes(token))
+        .map((token) => token.address.toLowerCase());
     listed.forEach((token, i) => {
         const lower = token.address.toLowerCase();
         const entryIn = (list) =>
             list.find((row) => String(row.address).toLowerCase() === lower);
         const raw = balances[i];
         if (raw === null) {
+            unread.push(lower);
             const kept = entryIn(previous) || entryIn(explorerRows || []);
             if (kept) rows.push(kept);
             return;
@@ -301,7 +319,7 @@ async function fetchTrackedTokenBalances(
         if (raw === 0n) return;
         const entry = entryIn(reported);
         const decimals = entry ? entry.decimals : null;
-        const known = resolveTokenDecimals(lower, { trackedTokens });
+        const known = resolveTokenDecimals(lower, { chainId, trackedTokens });
         const scale = known !== null ? known : decimals;
         rows.push({
             address: token.address,
@@ -314,12 +332,15 @@ async function fetchTrackedTokenBalances(
             holders: entry ? entry.holders : null,
         });
     });
-    return rows;
+    return { rows, unread };
 }
 
 // Fetch ETH balances, ENS names, and ERC-20 token balances for all addresses.
 // `trackedTokens` are the tokens tracked on the active network. `signal` is as
 // for fetchTokenBalances().
+//
+// Resolves with the lowercased contract addresses of the tracked tokens whose
+// balance it read at every address.
 async function refreshBalances(
     wallets,
     rpcUrl,
@@ -330,8 +351,11 @@ async function refreshBalances(
 ) {
     log.debugf("refreshBalances start, rpc:", urlOrigin(rpcUrl));
     const provider = getProvider(rpcUrl, networkId);
+    const { chainId } = requireNetworkId(networkId);
     const tracked = trackedTokens || [];
     const trackedSet = new Set(tracked.map((t) => t.address.toLowerCase()));
+    // The tracked tokens whose balance was not read at some address.
+    const unread = new Set();
     const updates = [];
 
     for (const wallet of wallets) {
@@ -393,6 +417,7 @@ async function refreshBalances(
                 addr.address,
                 blockscoutUrl,
                 tracked,
+                chainId,
                 signal,
             );
             updates.push(
@@ -403,15 +428,18 @@ async function refreshBalances(
                         tracked,
                         previous,
                         explorerRequest,
+                        chainId,
                         signal,
                     ),
                     explorerRequest,
-                ]).then(([trackedRows, explorerRows]) => {
+                ]).then(([trackedResult, explorerRows]) => {
+                    for (const lower of trackedResult.unread) unread.add(lower);
                     const untrackedRows = (explorerRows ?? previous).filter(
                         (row) =>
                             !trackedSet.has(String(row.address).toLowerCase()),
                     );
-                    addr.tokenBalances = trackedRows.concat(untrackedRows);
+                    addr.tokenBalances =
+                        trackedResult.rows.concat(untrackedRows);
                     log.debugf(
                         "Token balances",
                         addr.address,
@@ -425,6 +453,7 @@ async function refreshBalances(
 
     await Promise.all(updates);
     log.debugf("refreshBalances done");
+    return [...trackedSet].filter((lower) => !unread.has(lower));
 }
 
 // Drops the balance of each token not in `trackedTokens` from every address.

src/shared/chainSwitch.js

@@ -61,20 +61,40 @@ function clearPopupCaches() {
 // (https://git.eeqj.de/sneak/AutistMask/issues/653,
 // https://git.eeqj.de/sneak/AutistMask/issues/692).
 //
+// When the stored record is on another network, a switch saved elsewhere has
+// not reached this page yet. This page first takes that switch with
+// takeStoredNetwork() (state.js), as followStoredSettings() does. The switch to
+// `newNetworkId` is then made from the stored record's network. So every
+// network's list of tracked tokens in the stored record is kept
+// (https://git.eeqj.de/sneak/AutistMask/issues/701). When the stored record is
+// already on `newNetworkId`, the switch made from there only resets the
+// balances and caches.
+//
+// When the stored record is on this page's network, this page first takes the
+// stored `networkTrackedTokens` (takeStoredNetworkTrackedTokens() in state.js),
+// because another page's save may have changed a list this page holds.
+//
 // Before the switch, `state` takes the tracked tokens that another page stored
 // since this page's last save (takeStoredTrackedTokens() in state.js). The
 // switch then puts them away under the previous network, the network they were
-// added on. When the stored record is on another network, a switch saved
-// elsewhere has not reached this page yet. The stored record's tokens are then
-// that network's, and none are taken.
+// added on.
 async function onChainSwitch(newNetworkId) {
-    const { state, saveState, takeStoredTrackedTokens } = require("./state");
+    const {
+        state,
+        saveState,
+        takeStoredNetwork,
+        takeStoredTrackedTokens,
+        takeStoredNetworkTrackedTokens,
+    } = require("./state");
     let net = null;
     await saveState((stored) => {
         if (state.networkId === newNetworkId) return false;
-        if (stored.networkId === state.networkId) {
-            takeStoredTrackedTokens(stored);
+        if (stored.networkId !== state.networkId) {
+            takeStoredNetwork(stored);
+        } else {
+            takeStoredNetworkTrackedTokens(stored);
         }
+        takeStoredTrackedTokens(stored);
         net = applyChainSwitchFields(state, newNetworkId);
         stored.lastBalanceRefresh = 0;
         stored.fraudContracts = [];

src/shared/state.js

@@ -127,10 +127,12 @@ function currentNetwork() {
 
 // `baseline` holds the persisted fields as this page held them when its last
 // loadState() finished, or when its last successful saveState() began.
-// takeStoredNetwork() and takeStoredTrackedTokens() also write into it what
-// this page has taken from the stored record since then. saveState() diffs the
-// live state against `baseline` to find only the fields THIS page changed
-// since.
+// takeStoredNetwork(), takeStoredTrackedTokens() and
+// takeStoredNetworkTrackedTokens() also write into it what this page has taken
+// from the stored record since then. `baseline` also lacks any
+// `balanceNotFetched` field that a balance refresh has deleted since
+// (clearBalanceNotFetched()). saveState() diffs the live state against
+// `baseline` 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
@@ -402,6 +404,51 @@ function mergeNetworkEndpoints(base, ours, theirs) {
     return mergeMapByKey(base, ours, theirs, mergeEndpointEntry);
 }
 
+// Merges one network's tracked tokens by contract address:
+//
+// - A token another page added or removed since this page's last save stays
+//   added or removed.
+// - A token that this page and `theirs` both hold keeps this page's record.
+// - The result holds one record per contract address.
+//
+// mergeListByIdentity() keeps records that share an identity, on purpose, for
+// wallets. A contract address names one token, so this keeps one record for it.
+// Without that, a token that `ours` and `theirs` each hold twice comes back four
+// times, and each later merge multiplies it again.
+//
+// `theirs` takes this page's records first. mergeListByIdentity() would
+// otherwise log an error for two different records of one token.
+function mergeTrackedTokens(base, ours, theirs) {
+    const contract = (token) => token.address.toLowerCase();
+    const oursByContract = new Map(
+        ours.map((token) => [contract(token), token]),
+    );
+    const merged = mergeListByIdentity(
+        base,
+        ours,
+        theirs.map((token) => oursByContract.get(contract(token)) || token),
+        contract,
+        (baseToken, ourToken) => ourToken,
+    );
+    const byContract = new Map(merged.map((token) => [contract(token), token]));
+    return [...byContract.values()];
+}
+
+// Returns a copy of `stored.networkTrackedTokens` for when this page has not yet
+// taken the switch in `stored`. `page` is this page's state. A token that this
+// page tracked or removed since its last save is tracked or removed in the list
+// of `page.networkId`, by contract address.
+function networkTrackedTokensWithChange(stored, page) {
+    return {
+        ...stored.networkTrackedTokens,
+        [page.networkId]: mergeTrackedTokens(
+            baseline.trackedTokens,
+            page.trackedTokens,
+            stored.networkTrackedTokens[page.networkId] || [],
+        ),
+    };
+}
+
 // Read-modify-write, merged per field, rather than one full-blob write.
 //
 // Every extension page (the toolbar popup, a dApp approval window) holds its
@@ -442,18 +489,27 @@ function mergeNetworkEndpoints(base, ours, theirs) {
 // comment at mergeEndpointEntry() for why the collision this closes is
 // milder than the other two.
 //
+// `trackedTokens` is merged by contract address (mergeTrackedTokens()) when this
+// page has changed it, so a token another page added or removed since this
+// page's last save stays added or removed. A token both lists hold keeps this
+// page's record. Two saves differ:
+//
+// - When the stored record is on another network than this page's, a save keeps
+//   the stored `trackedTokens`. It merges this page's change into the list in
+//   `networkTrackedTokens` for this page's network, by contract address.
+// - A save that switches networks writes this page's list whole. A switch in
+//   Settings first merges that list by contract address
+//   (takeStoredTrackedTokens()).
+//
 // Every other persisted field stays a whole-field diff:
 // `fraudContracts`/`viewStack` are arrays of scalars with no per-element
-// identity to merge by; a save diffs `trackedTokens` whole, and a switch in
-// Settings first merges that list by contract address
-// (takeStoredTrackedTokens()); `networkTrackedTokens` is diffed whole like
-// `trackedTokens` and `networkId`, the two fields a network switch moves
-// together with it; `tokenHolderCache` is a map shaped like the ones above,
-// but nothing in src/ ever writes an entry into it — it is only ever reset
-// wholesale to `{}` (applyChainSwitchFields()) — so there is no in-place
-// mutation for a whole-field diff to collide with; `viewData` is this page's
-// own UI scratch space, not data another page has any reason to share
-// membership of.
+// identity to merge by; `networkTrackedTokens` is diffed whole like `networkId`,
+// which a network switch moves together with it; `tokenHolderCache` is a map
+// shaped like the ones above, but nothing in src/ ever writes an entry into it —
+// it is only ever reset wholesale to `{}` (applyChainSwitchFields()) — so there
+// is no in-place mutation for a whole-field diff to collide with; `viewData` is
+// this page's own UI scratch space, not data another page has any reason to
+// share membership of.
 //
 // This does not make two pages that both change the SAME leaf concurrently
 // safe: last write wins on that one leaf, same as before. What it removes
@@ -527,6 +583,34 @@ async function saveStateOnce(beforeWrite) {
             merged[key] = current[key];
         }
     }
+    // When the merged record names a network other than this page's, this page
+    // has not yet taken a switch saved elsewhere. This page's `trackedTokens`
+    // is then the list of this page's network. The stored record keeps the
+    // list of this page's network in `networkTrackedTokens`. So a token that
+    // this page added or removed since its last save is added to or removed
+    // from that stored list. The merged record keeps the stored `trackedTokens`
+    // (https://git.eeqj.de/sneak/AutistMask/issues/701).
+    if (merged.networkId !== current.networkId) {
+        merged.trackedTokens = fresh.trackedTokens;
+        merged.networkTrackedTokens = networkTrackedTokensWithChange(
+            fresh,
+            current,
+        );
+    } else if (
+        baseline !== null &&
+        baseline.networkId === current.networkId &&
+        !deepEqual(current.trackedTokens, baseline.trackedTokens)
+    ) {
+        // This page's network is the one it last saved on, and the stored
+        // record is on it too, so all three lists are of one network. This
+        // page's change goes into the stored list, and another page's add or
+        // removal stays (https://git.eeqj.de/sneak/AutistMask/issues/717).
+        merged.trackedTokens = mergeTrackedTokens(
+            baseline.trackedTokens,
+            current.trackedTokens,
+            fresh.trackedTokens,
+        );
+    }
     merged.hasWallet = Boolean(merged.wallets && merged.wallets.length > 0);
     // Stamped on every write, never merged or diffed: the record that goes to
     // storage is in THIS build's shape whatever shape it was read in, which is
@@ -607,15 +691,27 @@ function saveState(beforeWrite) {
     return turn;
 }
 
-// Give this page the network switch held by `stored`, a record a save of this
-// page has just read (followStoredSettings() 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
+// Give this page the network switch held by `stored`, in `state` and in
+// `baseline` alike, as loadState() does with a whole record. `stored` is the
+// record that a save of this page has just read. followStoredSettings() in
+// src/popup/index.js and onChainSwitch() in src/shared/chainSwitch.js call this
+// from `beforeWrite`. 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.
+//
+// A token that this page tracked or removed since its last save was tracked or
+// removed on this page's network before the switch. `state` keeps that change
+// in the list in `networkTrackedTokens` for that network, merged with the
+// stored list by contract address. `baseline` takes the stored list, so the
+// save stores the change (https://git.eeqj.de/sneak/AutistMask/issues/706).
 function takeStoredNetwork(stored) {
+    const networkTrackedTokens = networkTrackedTokensWithChange(
+        stored,
+        rawState,
+    );
     copyChainSwitchFields(rawState, stored);
     copyChainSwitchFields(baseline, structuredClone(stored));
+    rawState.networkTrackedTokens = networkTrackedTokens;
 }
 
 // Give this page the tracked tokens of `stored`, a record on this page's
@@ -630,16 +726,48 @@ function takeStoredNetwork(stored) {
 // `baseline` takes the stored list, so the save stores the list in `state`
 // whenever the two differ.
 function takeStoredTrackedTokens(stored) {
-    rawState.trackedTokens = mergeListByIdentity(
+    rawState.trackedTokens = mergeTrackedTokens(
         baseline.trackedTokens,
         rawState.trackedTokens,
         stored.trackedTokens,
-        (token) => token.address.toLowerCase(),
-        (base, ours) => ours,
     );
     baseline.trackedTokens = structuredClone(stored.trackedTokens);
 }
 
+// Give `state` and `baseline` each their own copy of the stored
+// `networkTrackedTokens`. `stored` is a record on this page's network that a
+// save of this page has just read. onChainSwitch() in
+// src/shared/chainSwitch.js calls this from `beforeWrite`.
+function takeStoredNetworkTrackedTokens(stored) {
+    rawState.networkTrackedTokens = structuredClone(
+        stored.networkTrackedTokens,
+    );
+    baseline.networkTrackedTokens = structuredClone(
+        stored.networkTrackedTokens,
+    );
+}
+
+// Deletes `balanceNotFetched` from each tracked token whose lowercased
+// contract address is in `addresses`. The field goes from `stored`, from
+// `state` and from `baseline` alike. `stored` is the record a save of this
+// page has just read (doRefreshAndRender() in src/popup/index.js calls this
+// from `beforeWrite`). So the deletion is not a change this page made to its
+// tracked tokens. Unless this page has changed its tracked tokens itself, the
+// save then writes the stored list with only the field gone.
+function clearBalanceNotFetched(stored, addresses) {
+    for (const list of [
+        stored.trackedTokens,
+        rawState.trackedTokens,
+        baseline.trackedTokens,
+    ]) {
+        for (const token of list) {
+            if (addresses.includes(token.address.toLowerCase())) {
+                delete token.balanceNotFetched;
+            }
+        }
+    }
+}
+
 // 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
@@ -687,6 +815,8 @@ module.exports = {
     onSaveFailure,
     takeStoredNetwork,
     takeStoredTrackedTokens,
+    takeStoredNetworkTrackedTokens,
+    clearBalanceNotFetched,
     loadState,
     currentAddress,
     currentNetwork,

src/shared/storedSettings.js

@@ -1,5 +1,5 @@
-// Reads "Use Blockscout" or "Check recipients on Etherscan" from the stored
-// profile.
+// Reads "Use Blockscout", "Check recipients on Etherscan" or the active network
+// from the stored profile.
 //
 // Before each request that sends the user's data to Blockscout or Etherscan, the
 // wallet reads that service's setting from storage. The wallet reads the setting
@@ -7,6 +7,11 @@
 // made, and an answer that lands after the setting went off is dropped. A page's
 // own copy of the setting is not used, because another page may have just
 // changed it.
+//
+// Before asking Blockscout for the transaction history, a screen remembers
+// which network is active. If another network is active on the page or in
+// storage when the answer lands, the screen drops the answer. A switch saved
+// elsewhere reaches storage first and the page later.
 
 const { storageGet } = require("./browserApi");
 const { normalizePersisted } = require("./persistedState");
@@ -24,4 +29,15 @@ async function storedSettingIsOn(name) {
     }
 }
 
-module.exports = { storedSettingIsOn };
+// Whether `networkId` is the active network in the stored profile. A failed
+// read counts as no.
+async function storedNetworkIs(networkId) {
+    try {
+        const { autistmask } = await storageGet("autistmask");
+        return normalizePersisted(autistmask).networkId === networkId;
+    } catch {
+        return false;
+    }
+}
+
+module.exports = { storedSettingIsOn, storedNetworkIs };

src/shared/symbolSpoof.js

@@ -19,7 +19,8 @@
 // them hid the other one's holders' money (issue #276).  Membership, not
 // equality, is therefore the question — but it is the same question, asked of
 // a table that can now state the truth.  Every address in a set is one the
-// wallet ships as a real token; a contract outside the set is still a spoof.
+// wallet ships as a real token on Ethereum Mainnet.  On mainnet, a contract
+// outside the set is still a spoof.
 //
 // The symbol is attacker-controlled — it is whatever the ERC-20 contract
 // returns — so the lookup is done on a normalized form (issue #260): the
@@ -27,6 +28,7 @@
 // since that is what the user acts on.
 
 const { KNOWN_SYMBOLS } = require("./tokenList");
+const { NETWORKS } = require("./networks");
 
 // Ethereum addresses are case-insensitive: EIP-55 mixed case is a checksum
 // over the address, not part of its identity.
@@ -93,18 +95,24 @@ function normalizeSymbol(symbol) {
 }
 
 // True when a token bearing `symbol` from contract `contractAddress` is
-// impersonating a known symbol.
+// impersonating a known symbol. `chainId` is the chain id of the token's
+// network.
+//
+// The native asset's labels are known symbols on every network. The bundled
+// list's symbols are known symbols only on Ethereum Mainnet, because the list
+// holds mainnet contracts.
 //
 // An empty contract address is the native asset, which is never a spoof:
 // this is what keeps the user's real ETH out of the rule, and it holds for
 // any symbol that becomes null-mapped later, not just for ETH.
-function isSpoofedSymbol(symbol, contractAddress) {
+function isSpoofedSymbol(symbol, contractAddress, chainId) {
     const contract = normalizeAddress(contractAddress);
     if (!contract) return false;
     const sym = normalizeSymbol(symbol);
     if (!KNOWN_SYMBOLS.has(sym)) return false;
     const legit = KNOWN_SYMBOLS.get(sym);
     if (legit === null) return true;
+    if (chainId !== NETWORKS.mainnet.chainId) return false;
     return !legit.has(contract);
 }
 

src/shared/tokenList.js

@@ -3953,6 +3953,15 @@ for (const t of TOKENS) {
     TOKEN_BY_ADDRESS.set(t.address.toLowerCase(), t);
 }
 
+// The bundled list's entry for the contract at `address` on the network with
+// chain id `chainId`, or null. The list holds Ethereum Mainnet contracts only.
+// A contract at the same address on another network is another token, so any
+// other chain id gets null.
+function bundledToken(address, chainId) {
+    if (chainId !== NETWORKS.mainnet.chainId) return null;
+    return TOKEN_BY_ADDRESS.get((address || "").toLowerCase()) || null;
+}
+
 // Build a map of symbol (uppercased) -> the set of contract addresses
 // (lowercased) that legitimately bear it.  Used for spoofed-symbol detection.
 // "ETH" maps to null: the native asset has no contract, so no contract may
@@ -3969,7 +3978,8 @@ for (const t of TOKENS) {
 // hides from the balance list, the history and the send selector at its own
 // address, so the user cannot spend it (issue #276).  Naming every address
 // that bears the symbol is the only shape that says what is true; it does not
-// loosen the rule, because a contract outside the set is still a spoof.
+// loosen the rule.  On Ethereum Mainnet, a contract outside the set is still a
+// spoof.
 const KNOWN_SYMBOLS = new Map();
 KNOWN_SYMBOLS.set("ETH", null);
 for (const network of Object.values(NETWORKS)) {
@@ -3988,14 +3998,15 @@ for (const t of TOKENS) {
     }
 }
 
-// Resolve a token symbol from multiple sources, never returning "?".
-function resolveSymbol(tokenAddress, tokenBalances, trackedTokens) {
+// Resolve a token symbol from multiple sources, never returning "?". The token
+// is a contract on the network with chain id `chainId`.
+function resolveSymbol(tokenAddress, tokenBalances, trackedTokens, chainId) {
     const lower = (tokenAddress || "").toLowerCase();
     const tb = (tokenBalances || []).find(
         (t) => t.address.toLowerCase() === lower,
     );
     if (tb && tb.symbol) return tb.symbol;
-    const known = TOKEN_BY_ADDRESS.get(lower);
+    const known = bundledToken(lower, chainId);
     if (known && known.symbol) return known.symbol;
     const tracked = (trackedTokens || []).find(
         (t) => t.address.toLowerCase() === lower,
@@ -4012,5 +4023,6 @@ module.exports = {
     USD_PRICE_FEEDS,
     PRICE_FEED_BY_ADDRESS,
     getTopTokens,
+    bundledToken,
     resolveSymbol,
 };

src/shared/transactions.js

@@ -8,7 +8,7 @@
 
 const { formatEther, formatUnits } = require("ethers");
 const { log, debugFetch } = require("./log");
-const { TOKEN_BY_ADDRESS } = require("./tokenList");
+const { bundledToken } = require("./tokenList");
 const { parseHoldersCount, isLowHolderCount } = require("./holders");
 const { isSpoofedSymbol } = require("./symbolSpoof");
 const { nativeCurrencyByChainId } = require("./networks");
@@ -47,7 +47,7 @@ function parseTx(tx, addrLower, chainId) {
     let direction = normalizeAddress(from) === addrLower ? "sent" : "received";
     let directionLabel = direction === "sent" ? "Sent" : "Received";
     if (toIsContract && method && method !== "transfer") {
-        const token = TOKEN_BY_ADDRESS.get(normalizeAddress(to));
+        const token = bundledToken(to, chainId);
         if (token) {
             symbol = token.symbol;
         }
@@ -317,7 +317,10 @@ function filterTransactions(txs, filters = {}) {
         const contract = normalizeAddress(tx.contractAddress);
 
         // Filter spoofed known symbols and record the fraud contract
-        if (hideSpoofed && isSpoofedSymbol(tx.symbol, tx.contractAddress)) {
+        if (
+            hideSpoofed &&
+            isSpoofedSymbol(tx.symbol, tx.contractAddress, tx.chainId)
+        ) {
             if (contract && !fraudSet.has(contract)) {
                 fraudSet.add(contract);
                 newFraud.push(contract);

src/shared/uniswap.js

@@ -452,8 +452,8 @@ const ADDRESS_THIS = "0x0000000000000000000000000000000000000002";
 // `decimals` is null when nothing knows this token's scale. It is not
 // defaulted to 18: the swap lines land on the same approval screen as the
 // ERC-20 line, and a scale guessed there is what showed a 1,000 USDT swap as
-// 0.000000000001. `sources` is { trackedTokens, wallets }, shaped as they are
-// on `state`; resolveTokenDecimals() reads the bundled list, then those.
+// 0.000000000001. `sources` is as for resolveTokenDecimals(), which reads the
+// bundled list on Ethereum Mainnet, then the tracked tokens and the wallets.
 //
 // A null `address` means UNDETERMINED — the calldata named no currency for
 // that side — and is refused rather than named. It is not native ETH: Uniswap
@@ -988,6 +988,9 @@ function totalAmount(amounts) {
 // pays it of Token In as the step's amount in place of the rules' Amount, or
 // no amount when this decoder cannot tell what that is.
 //
+// `spent` lists the currency that each swap action spends, for each swap
+// action that this decoder could read.
+//
 // `takes` is every TAKE, TAKE_ALL and TAKE_PORTION, as the currency it takes
 // and its recipient as written, MSG_SENDER for a TAKE_ALL. TAKE_PORTION takes
 // a share of the currency, so it does not name the output side as TAKE does.
@@ -1163,6 +1166,8 @@ function decodeV4Swap(input) {
             }
         }
 
+        const spent = swaps.map((s) => s.tokenIn);
+
         // Rule 3.
         if (swapUndecoded) {
             return {
@@ -1170,6 +1175,7 @@ function decodeV4Swap(input) {
                 tokenOut: takeToken,
                 amountIn: null,
                 amountOutMin: null,
+                spent,
                 takes,
                 settledFromRouter,
                 paidByUser,
@@ -1180,7 +1186,6 @@ function decodeV4Swap(input) {
             };
         }
 
-        const spent = swaps.map((s) => s.tokenIn);
         const bought = swaps.map((s) => s.tokenOut);
 
         // Rules 1 and 2 for Token In.
@@ -1216,6 +1221,7 @@ function decodeV4Swap(input) {
             tokenOut,
             amountIn,
             amountOutMin,
+            spent,
             takes,
             settledFromRouter,
             paidByUser,
@@ -1240,6 +1246,9 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
     const release = routerRelease(toAddress, chainId);
     if (release === null) return null;
     const { commandTypeMask, commands, allowRevert } = release;
+    // The swap's tokens are contracts on the network with `chainId`, so they
+    // are named and scaled for that network.
+    const tokenSources = { ...sources, chainId };
     try {
         const parsed = ROUTER_IFACE.parseTransaction({ data });
         if (!parsed) return null;
@@ -1258,6 +1267,10 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         // ERC-20 token from the router takes none of that token from the
         // sender.
         let inputPaidByUser = false;
+        // The recipient of a WRAP_ETH that set the input side, as written,
+        // when it is not the router; otherwise null. That WRAP_ETH pays its
+        // WETH there, not to a swap step (see the Moved to lines).
+        let wrapEthRecipient = null;
         // The last PERMIT2_PERMIT this decoder read before a step set the
         // input side, or null (see permitStands after the loop).
         let permit = null;
@@ -1307,8 +1320,9 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         const commandNames = [];
 
         // THE INVARIANT: an amount and the token it is counted in always come
-        // from the same hop, or from hops that all spend that token. A figure
-        // is never rendered against a token that did not supply it.
+        // from the same hop, or from hops that all spend that token or all buy
+        // it. A figure is never rendered against a token that did not supply
+        // it.
         //
         // Both sides are therefore set as a PAIR — never field by field, and
         // never on truthiness. An address is never falsy once set but an
@@ -1357,10 +1371,12 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         // "Up to" and the amount.
         const userPaid = [];
         // A swap step the user pays for (`payerIsUser` true) takes `amount`
-        // of `token` from the sender. A V2 exact-in of ALREADY_PAID takes
-        // nothing.
-        const addUserPaid = (token, amount) => {
-            if (amount !== ALREADY_PAID) userPaid.push({ token, amount });
+        // of `token` from the sender, or at most that when `atMost` is set. A
+        // V2 exact-in of ALREADY_PAID takes nothing.
+        const addUserPaid = (token, amount, atMost = false) => {
+            if (amount !== ALREADY_PAID) {
+                userPaid.push({ token, amount, atMost });
+            }
         };
         // A step may take from the sender what this decoder did not read: a
         // V4 step whose input or one of whose SETTLEs or SETTLE_ALLs it
@@ -1423,6 +1439,10 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
             const r = recipient.toLowerCase();
             return r === ADDRESS_THIS || r === toAddress.toLowerCase();
         };
+        const isSender = (recipient) => {
+            const r = recipient.toLowerCase();
+            return r === MSG_SENDER || r === sender;
+        };
         // A swap step or V4 SETTLE pays `amount` of `token` from the router's
         // own balance. CONTRACT_BALANCE pays all of it. Any other quantity
         // counts against the amount a WRAP_ETH stated, and the steps pay all
@@ -1455,17 +1475,73 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         // A step pays `recipient`. `output` is the token a swap step or a V4
         // TAKE or TAKE_PORTION pays; other steps pass none.
         const addPayee = (recipient, output) => {
-            const r = recipient.toLowerCase();
             if (isRouter(recipient)) {
                 if (present(output)) {
                     heldByRouter.set(output.toLowerCase(), null);
                 }
-            } else if (r === MSG_SENDER || r === sender) {
+            } else if (isSender(recipient)) {
                 paidToSender = true;
             } else {
                 addPaidElsewhere(recipient);
             }
         };
+        // Each swap step that paid the sender some of the token it bought,
+        // as { step, token, amount, onlyToSender }:
+        // - `step` is the step's index;
+        // - `token` is that token;
+        // - `amount` is the step's stated minimum;
+        // - `onlyToSender` is whether the step paid all of that token to the
+        //   sender.
+        // A later step that spends that token takes the step off this list
+        // (see dropFromSum()).
+        let swapsPayingSender = [];
+        // The step being read spends `token`, so it may spend what an earlier
+        // swap step paid the sender. Each step on swapsPayingSender that
+        // bought `token` leaves the list. A step spends a token as follows:
+        // - a V2 or V3 swap step spends its input token;
+        // - a V4 step spends each token that one of its swap actions spends,
+        //   and each token that one of its SETTLEs or SETTLE_ALLs pays;
+        // - a PERMIT2_TRANSFER_FROM spends the token it moves.
+        const dropFromSum = (token) => {
+            swapsPayingSender = swapsPayingSender.filter(
+                (s) => !sameAddress(s.token, token),
+            );
+        };
+        // The minimum the output side shows for the swap step at `step`. The
+        // step buys `token` with the stated minimum `amount`, and pays
+        // `token` to `recipients`. The minimum is the step's own, unless this
+        // step and an earlier one on swapsPayingSender both pay `token` to
+        // the sender, as a route split across steps does. The minimum is then
+        // the total of all such steps' minimums. There is none when this
+        // decoder reads no minimum from one of them, or when one of them pays
+        // some of `token` elsewhere. There is also none when this decoder did
+        // not read one of them, or a step between them, in full (see
+        // stepsUnread).
+        const swapMinimum = (step, token, amount, recipients) => {
+            const toSender = recipients.filter(
+                (r) => present(r) && isSender(r),
+            );
+            if (toSender.length === 0) return amount;
+            swapsPayingSender.push({
+                step,
+                token,
+                amount,
+                onlyToSender: toSender.length === recipients.length,
+            });
+            const split = swapsPayingSender.filter((s) =>
+                sameAddress(s.token, token),
+            );
+            if (split.length < 2) return amount;
+            if (
+                split.some(
+                    (s) => !s.onlyToSender || typeof s.amount !== "bigint",
+                ) ||
+                stepsUnread.some((unread) => unread >= split[0].step)
+            ) {
+                return null;
+            }
+            return split.reduce((sum, s) => sum + s.amount, 0n);
+        };
         // A step that pays `token` to `recipient` is a hop, not a payout,
         // when the very next step is a V2 exact-in whose input is already
         // paid, whose path starts at `token`, and whose pair (see v2PairFor())
@@ -1607,6 +1683,7 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                                     : null,
                         });
                     }
+                    if (p) dropFromSum(p.token);
                 } else if (command === "BALANCE_CHECK_ERC20") {
                     const b = decodeBalanceCheck(inputs[i]);
                     if (!b) {
@@ -1649,10 +1726,18 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                         } else if (s.payerIsUser) {
                             addUserPaid(s.tokenIn, s.amountIn);
                         }
+                        dropFromSum(s.tokenIn);
                         // Always update output: in multi-step swaps (V3 → V4),
-                        // the last swap step determines the final output token
-                        // and minimum received amount.
-                        setOutput(i, s.tokenOut, s.amountOutMin, [s.recipient]);
+                        // the last swap step determines the final output
+                        // token. swapMinimum() gives the minimum.
+                        setOutput(
+                            i,
+                            s.tokenOut,
+                            swapMinimum(i, s.tokenOut, s.amountOutMin, [
+                                s.recipient,
+                            ]),
+                            [s.recipient],
+                        );
                         if (!s.payerIsUser) {
                             spendFromRouter(s.tokenIn, s.amountIn);
                         }
@@ -1673,7 +1758,15 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                         } else if (s.payerIsUser) {
                             addUserPaid(s.tokenIn, s.amountIn);
                         }
-                        setOutput(i, s.tokenOut, s.amountOutMin, [s.recipient]);
+                        dropFromSum(s.tokenIn);
+                        setOutput(
+                            i,
+                            s.tokenOut,
+                            swapMinimum(i, s.tokenOut, s.amountOutMin, [
+                                s.recipient,
+                            ]),
+                            [s.recipient],
+                        );
                         if (!s.payerIsUser) {
                             spendFromRouter(s.tokenIn, s.amountIn);
                         }
@@ -1705,7 +1798,15 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                         } else if (s.payerIsUser) {
                             addUserPaid(s.tokenIn, s.amountInMax);
                         }
-                        setOutput(i, s.tokenOut, s.amountOut, [s.recipient]);
+                        dropFromSum(s.tokenIn);
+                        setOutput(
+                            i,
+                            s.tokenOut,
+                            swapMinimum(i, s.tokenOut, s.amountOut, [
+                                s.recipient,
+                            ]),
+                            [s.recipient],
+                        );
                         if (!isHop(i, s.tokenOut, s.recipient)) {
                             addPayee(s.recipient, s.tokenOut);
                         }
@@ -1803,6 +1904,9 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                                 w.amount,
                             );
                             inputPaidByUser = true;
+                            if (!isRouter(w.recipient)) {
+                                wrapEthRecipient = w.recipient;
+                            }
                         }
                         addPayee(w.recipient);
                         // CONTRACT_BALANCE wraps all the router's ETH.
@@ -1877,6 +1981,11 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                                 addPayee(t.recipient, t.currency);
                             }
                         }
+                        for (const token of v4.spent) dropFromSum(token);
+                        for (const s of v4.paidByUser) dropFromSum(s.currency);
+                        for (const s of v4.settledFromRouter) {
+                            dropFromSum(s.currency);
+                        }
                     }
                     if (!v4 || v4.recipientUnread) {
                         payeeUnread = true;
@@ -1925,7 +2034,12 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                             setInput(v4.tokenIn, amountIn);
                         }
                         outputToken = v4.tokenOut;
-                        minOutput = v4.amountOutMin;
+                        minOutput = swapMinimum(
+                            i,
+                            v4.tokenOut,
+                            v4.amountOutMin,
+                            takeRecipients,
+                        );
                         outputEstablished = true;
                         outputUnwrapped = false;
                         unwrapIntoRouterStep = null;
@@ -1953,9 +2067,18 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                     // router still runs it.
                     const setInputHere = inputEstablished && !inputSetBefore;
                     if (setInputHere) inputPaidByUser = paidIn !== undefined;
+                    // ETH an earlier step left in the router may pay part of
+                    // the ETH that the user pays this step. The sender then
+                    // pays at most that amount.
                     for (const p of paidByUser) {
                         if (setInputHere && p === paidIn) continue;
-                        addUserPaid(p.currency, p.amount);
+                        addUserPaid(
+                            p.currency,
+                            p.amount,
+                            routerHeldEth &&
+                                p.currency ===
+                                    "0x0000000000000000000000000000000000000000",
+                        );
                     }
                     // A SETTLE of ETH from the router that `paidByUser` leaves
                     // out is a take of its own, even on the step that sets
@@ -2119,15 +2242,17 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
             permit.beforeEveryTake &&
             !stepsUnread.some((step) => step > permit.step);
         // What the steps take that the Amount line does not give, as
-        // { token, amount }. A null token is a step this decoder did not read
-        // (see spentUnread()), or a token it does not know.
+        // { token, amount, atMost, recipient }. A null token is a step this
+        // decoder did not read (see spentUnread()), or a token it does not
+        // know. `atMost` is as in `userPaid`. Only the take of a WRAP_ETH that
+        // pays elsewhere has a recipient (see wrapEthRecipient).
         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 the step that set the input side
-        // counts in `total` whoever pays that step. That amount is among them
-        // only when the user pays the step (see inputPaidByUser).
+        // The takes from the sender that `total` adds up, each a quantity, in
+        // the shape of `spentFromSender`. When there is no Amount line, each
+        // gets lines of its own (see below). The amount of the step that set
+        // the input side counts in `total` whoever pays that step. That amount
+        // is among them only when the user pays the step (see inputPaidByUser).
         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
@@ -2141,7 +2266,11 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         if (!permitStands || sameAddress(inputToken, permit.token)) {
             total = inputAmount;
             if (typeof inputAmount === "bigint" && inputPaidByUser) {
-                inTotal.push({ token: inputToken, amount: inputAmount });
+                inTotal.push({
+                    token: inputToken,
+                    amount: inputAmount,
+                    recipient: wrapEthRecipient,
+                });
             }
             if (hasFirstTake && !present(inputAmount)) {
                 firstTakeUnstated = { token: inputToken, amount: null };
@@ -2149,7 +2278,11 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         } else if (hasFirstTake) {
             // The step that set the input side spent a token other than the
             // permit's, or one not known, so its amount gets lines of its own.
-            spentFromSender.push({ token: inputToken, amount: inputAmount });
+            spentFromSender.push({
+                token: inputToken,
+                amount: inputAmount,
+                recipient: wrapEthRecipient,
+            });
         }
         if (permitStands) inputToken = permit.token;
         for (const t of userPaid) {
@@ -2208,11 +2341,11 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         // Any other output keeps its own token and figure: a swap that pays
         // its WETH to the user and then unwraps receives WETH, and one that
         // buys USDC and then unwraps the WETH it did not spend receives USDC.
-        const inInfo = tokenInfo(inputToken, sources);
+        const inInfo = tokenInfo(inputToken, tokenSources);
         const outInfo =
             outputUnwrapped || (hasUnwrapWeth && !outputEstablished)
                 ? { symbol: "ETH", decimals: 18, address: null }
-                : tokenInfo(outputToken, sources);
+                : tokenInfo(outputToken, tokenSources);
 
         const inSymbol = inInfo.symbol;
         const outSymbol = outInfo.symbol;
@@ -2332,30 +2465,48 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         // What steps take from the sender beyond the Amount line, in the shape
         // of the lines below for a PERMIT2_TRANSFER_FROM. An amount this
         // decoder does not know is said so, and a step it did not read gets
-        // that one line alone.
+        // that one line alone. A take with no recipient goes to the swap step
+        // that spends it. A take with a recipient goes to that recipient;
+        // `MSG_SENDER` means the sender.
         for (const s of spentFromSender) {
             details.push({
                 label: "Moved from the sender",
                 value: present(s.amount)
-                    ? spentText(s.amount, tokenInfo(s.token, sources), s.atMost)
-                          .display
+                    ? spentText(
+                          s.amount,
+                          tokenInfo(s.token, tokenSources),
+                          s.atMost,
+                      ).display
                     : UNDECODED_CURRENCY,
             });
             if (present(s.token)) {
                 details.push(
-                    tokenMovedLine("Token moved", tokenInfo(s.token, sources)),
+                    tokenMovedLine(
+                        "Token moved",
+                        tokenInfo(s.token, tokenSources),
+                    ),
                 );
-                details.push({
-                    label: "Moved to",
-                    value: "The swap step that spends it",
-                });
+                if (!present(s.recipient)) {
+                    details.push({
+                        label: "Moved to",
+                        value: "The swap step that spends it",
+                    });
+                } else if (s.recipient.toLowerCase() === MSG_SENDER) {
+                    details.push({ label: "Moved to", value: "The sender" });
+                } else {
+                    details.push({
+                        label: "Moved to",
+                        value: s.recipient,
+                        address: s.recipient,
+                    });
+                }
             }
         }
 
         // What each PERMIT2_TRANSFER_FROM moves: its amount, its token and
         // where it goes, an address on a line of its own.
         for (const m of movedFromSender) {
-            const info = permit2TokenInfo(m.token, sources);
+            const info = permit2TokenInfo(m.token, tokenSources);
             details.push({
                 label: "Moved from the sender",
                 value: amountText(m.amount, info).display,
@@ -2390,7 +2541,7 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                 });
                 continue;
             }
-            const info = permit2TokenInfo(p.token, sources);
+            const info = permit2TokenInfo(p.token, tokenSources);
             details.push({
                 label: "Permit2 allowance",
                 value:
@@ -2456,7 +2607,7 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
             paidTo.push({ label: "Paid to", value: PAID_TO_BRIDGE });
         }
         for (const m of movedIntoRouter) {
-            const info = permit2TokenInfo(m.token, sources);
+            const info = permit2TokenInfo(m.token, tokenSources);
             paidTo.push({
                 label: "Paid to",
                 value:
@@ -2481,7 +2632,7 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
             paidTo.push(
                 tokenMovedLine(
                     "Token moved into the router",
-                    tokenInfo(getAddress(token), sources),
+                    tokenInfo(getAddress(token), tokenSources),
                 ),
             );
         }

tests/addTokenLateAnswer.test.js

@@ -16,6 +16,7 @@ const TOKEN = {
     symbol: "TST",
     decimals: 18,
     name: "Test Token",
+    balanceNotFetched: true,
 };
 
 // A second contract address, typed after AddToken was opened again.

tests/addedTokenBalance.test.js

@@ -0,0 +1,458 @@
+// After "Add" on AddToken, AddressDetail lists the new token. Its line reads
+// `quantity unknown`, not 0.0000, until a balance refresh has read the token's
+// balance at every address, even if the popup closes and opens again
+// meanwhile. A token added on SettingsAddToken reads the same 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).
+//
+// The tracked token's record carries `balanceNotFetched` until a refresh has
+// read the token's balance. Removing the token removes that record. A network
+// switch keeps each network's records apart. A refresh takes the field off the
+// stored record's tokens and keeps another page's changes to the stored list.
+//
+// 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";
+
+// A holding of a million NEW_TOKEN, as refreshBalances() stores it.
+const MILLION = {
+    address: NEW_TOKEN,
+    name: "New Token",
+    symbol: "NEW",
+    decimals: 18,
+    balance: "1000000.0",
+    holders: 3,
+};
+
+// NEW_TOKEN as "Add" on AddToken tracks it, once a refresh has read its
+// balance.
+const NEW_TRACKED = {
+    address: NEW_TOKEN,
+    symbol: "NEW",
+    name: "New Token",
+    decimals: 18,
+};
+
+// A token that another popup page tracks.
+const OTHER_TOKEN = {
+    address: "0xCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC",
+    symbol: "OTH",
+    name: "Other Token",
+    decimals: 18,
+};
+
+afterEach(() => {
+    cleanupPopup();
+});
+
+// The popup reopened onto AddressDetail for the one address.
+function bootOnAddress(extra) {
+    return bootPopup(
+        unversionedValidProfile({
+            currentView: "address",
+            selectedWallet: 0,
+            selectedAddress: 0,
+            ...extra,
+        }),
+    );
+}
+
+// Holds the next balance refresh open. The returned function lets it finish
+// with the address's ETH balance at 2 and `tokenBalances` as its token
+// entries, having read the balance of every token tracked when it started.
+// Given null, it finishes having read no token's balance, as when every
+// balanceOf fails, and leaves the token entries as they were.
+function holdNextRefresh(page) {
+    const { refreshBalances } = require("../src/shared/balances");
+    let release;
+    refreshBalances.mockImplementationOnce(
+        async (wallets, rpcUrl, explorerUrl, trackedTokens) => {
+            const read = trackedTokens.map((t) => t.address.toLowerCase());
+            const tokenBalances = await new Promise((resolve) => {
+                release = resolve;
+            });
+            wallets[0].addresses[0].balance = "2.0";
+            if (tokenBalances === null) return [];
+            wallets[0].addresses[0].tokenBalances = tokenBalances;
+            return read;
+        },
+    );
+    return async (tokenBalances) => {
+        release(tokenBalances);
+        await page.settle();
+    };
+}
+
+// Runs the ten-second refresh to the end, finishing it as holdNextRefresh()
+// does with `tokenBalances`.
+async function refreshOnce(page, tokenBalances) {
+    const finish = holdNextRefresh(page);
+    const ticking = page.tick();
+    await page.settle();
+    await finish(tokenBalances);
+    await ticking;
+}
+
+// "+ 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");
+}
+
+// Settings' "+ Add token", NEW_TOKEN typed in, and "Add", with the contract
+// lookup answering at once. It ends on SettingsAddToken.
+async function addOnSettingsAddToken(page) {
+    const { lookupTokenInfo } = require("../src/shared/balances");
+    lookupTokenInfo.mockResolvedValueOnce({
+        symbol: "NEW",
+        decimals: 18,
+        name: "New Token",
+    });
+    await page.click("btn-settings-add-token");
+    page.node("settings-addtoken-address").value = NEW_TOKEN;
+    await page.click("btn-settings-addtoken-manual");
+}
+
+// The "[x]" button Settings draws beside the first tracked token. The page
+// stub does not turn the markup Settings draws into elements. So the list
+// hands Settings a stand-in for that button each time it is drawn, and
+// `press()` presses the last one drawn. Call it before Settings opens.
+function firstRemoveButton(page) {
+    const button = { press: null };
+    page.node("settings-tracked-tokens").querySelectorAll = () => [
+        {
+            dataset: { idx: "0" },
+            addEventListener: (name, fn) => {
+                button.press = fn;
+            },
+        },
+    ];
+    return button;
+}
+
+// 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();
+}
+
+// Another popup page saves `trackedTokens` as the tracked token list. This
+// page is not told of the write.
+function anotherPageTracks(page, trackedTokens) {
+    page.storage.write("autistmask", {
+        ...page.storage.read("autistmask"),
+        trackedTokens,
+    });
+}
+
+// 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 reading its balance", 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 reads the token's balance, which is zero.
+    await refreshOnce(page, []);
+
+    expect(newTokenRow(page)).toContain("0.0000");
+});
+
+test("closed and opened again before any refresh has read its balance, 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 reads no token's balance: the boot's stub
+    // of refreshBalances() reads 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");
+
+    await refreshOnce(page, [MILLION]);
+
+    expect(newTokenRow(page)).toContain("1000000.0000");
+});
+
+test("a refresh that could not read the new token's balance leaves its 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("Send for the new token reads its balance as unknown before any refresh has read it, and Max says so", async () => {
+    const page = await bootOnAddress();
+    const finish = holdNextRefresh(page);
+    await addNewToken(page);
+    await openToken(page, NEW_TOKEN.toLowerCase());
+
+    await page.click("btn-address-token-send");
+
+    expect(page.visibleViews()).toEqual(["send"]);
+    expect(page.text("send-balance")).toBe("Current balance: unknown (NEW)");
+
+    await page.click("btn-send-max");
+
+    expect(page.text("flash-msg")).toBe("This token's balance is unknown.");
+    await finish([MILLION]);
+});
+
+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);
+
+    await page.click("btn-settings");
+    await addOnSettingsAddToken(page);
+    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");
+
+    await refreshOnce(page, null);
+
+    expect(page.node("address-token-balance").innerHTML).toContain("2.0000");
+});
+
+test("a token removed before any refresh has read its balance leaves nothing stored, and adding it again tracks it once", async () => {
+    const page = await bootPopup(unversionedValidProfile());
+    const removeButton = firstRemoveButton(page);
+    const stored = () => page.storage.read("autistmask");
+
+    await page.click("btn-settings");
+    await addOnSettingsAddToken(page);
+    // Settings opened again from Home draws its list with the token in it.
+    await page.click("btn-settings-addtoken-back");
+    await page.click("btn-settings-back");
+    await page.click("btn-settings");
+    await removeButton.press();
+    await page.settle();
+
+    expect(stored().trackedTokens).toEqual([]);
+    // Nothing in the stored record names the token any more.
+    expect(JSON.stringify(stored()).toLowerCase()).not.toContain(
+        NEW_TOKEN.toLowerCase(),
+    );
+
+    await addOnSettingsAddToken(page);
+    // A second add of the same token is refused.
+    page.node("settings-addtoken-address").value = NEW_TOKEN;
+    await page.click("btn-settings-addtoken-manual");
+
+    const added = { address: NEW_TOKEN, symbol: "NEW", decimals: 18 };
+    expect(stored().trackedTokens).toEqual([
+        { ...added, name: "New Token", balanceNotFetched: true },
+    ]);
+
+    await refreshOnce(page, []);
+
+    expect(stored().trackedTokens).toEqual([{ ...added, name: "New Token" }]);
+});
+
+test("a refresh on another network leaves the new token reading quantity unknown on its own", async () => {
+    // Sepolia tracks a token at the same contract address, also just added.
+    const sepoliaToken = {
+        address: NEW_TOKEN,
+        symbol: "SEP",
+        name: "Sepolia Token",
+        decimals: 18,
+    };
+    const page = await bootOnAddress({
+        networkTrackedTokens: {
+            sepolia: [{ ...sepoliaToken, balanceNotFetched: true }],
+        },
+    });
+    const finishMainnet = holdNextRefresh(page);
+    await addNewToken(page);
+
+    await page.click("btn-settings");
+    await chooseNetwork(page, "sepolia");
+    // The refresh Add started returns after the switch and writes nothing.
+    await finishMainnet([MILLION]);
+    // Sepolia's refresh reads the balance of its own token.
+    await refreshOnce(page, []);
+
+    const stored = page.storage.read("autistmask");
+    expect(stored.trackedTokens).toEqual([sepoliaToken]);
+    expect(stored.networkTrackedTokens.mainnet[0].balanceNotFetched).toBe(true);
+
+    await chooseNetwork(page, "mainnet");
+    await page.click("btn-settings-back");
+
+    expect(page.visibleViews()).toEqual(["address"]);
+    expect(newTokenRow(page)).toContain("quantity unknown");
+
+    await refreshOnce(page, [MILLION]);
+
+    expect(newTokenRow(page)).toContain("1000000.0000");
+});
+
+test("a refresh keeps a token that another page added after this page loaded", async () => {
+    const page = await bootOnAddress();
+    const finish = holdNextRefresh(page);
+    await addNewToken(page);
+    const otherAdded = { ...OTHER_TOKEN, balanceNotFetched: true };
+    anotherPageTracks(page, [
+        { ...NEW_TRACKED, balanceNotFetched: true },
+        otherAdded,
+    ]);
+
+    await finish([MILLION]);
+
+    expect(page.storage.read("autistmask").trackedTokens).toEqual([
+        NEW_TRACKED,
+        otherAdded,
+    ]);
+    expect(newTokenRow(page)).toContain("1000000.0000");
+});
+
+test("a refresh does not bring back a token that another page removed after this page loaded", async () => {
+    const page = await bootOnAddress({ trackedTokens: [OTHER_TOKEN] });
+    const finish = holdNextRefresh(page);
+    await addNewToken(page);
+    anotherPageTracks(page, [{ ...NEW_TRACKED, balanceNotFetched: true }]);
+
+    await finish([MILLION]);
+
+    expect(page.storage.read("autistmask").trackedTokens).toEqual([
+        NEW_TRACKED,
+    ]);
+});

tests/approvalAmount.test.js

@@ -90,9 +90,11 @@ beforeEach(() => {
 });
 
 describe("resolveTokenDecimals", () => {
+    // The bundled list is read only for a token on Ethereum Mainnet.
     test("prefers the bundled list", () => {
         state.trackedTokens = [{ address: USDC, symbol: "USDC", decimals: 2 }];
-        expect(resolveTokenDecimals(USDC, state)).toBe(6);
+        const sources = { chainId: "0x1", trackedTokens: state.trackedTokens };
+        expect(resolveTokenDecimals(USDC, sources)).toBe(6);
     });
 
     test("reads a token the user tracks", () => {
@@ -124,7 +126,8 @@ describe("resolveTokenDecimals", () => {
     // answers 0 is used rather than fallen past like the unusable entry above.
     test("uses a bundled scale of zero", () => {
         state.trackedTokens = [{ address: SLP, symbol: "SLP", decimals: 18 }];
-        expect(resolveTokenDecimals(SLP, state)).toBe(0);
+        const sources = { chainId: "0x1", trackedTokens: state.trackedTokens };
+        expect(resolveTokenDecimals(SLP, sources)).toBe(0);
     });
 
     test("uses a tracked scale of zero", () => {

tests/approvalBundledListSepolia.test.js

@@ -0,0 +1,169 @@
+// The approval screen for a site's Sepolia transfer of the contract at USDC's
+// mainnet address, while Sepolia is active.
+//
+// The bundled token list holds Ethereum Mainnet contracts. The contract at the
+// same address on Sepolia is another token, but the screen named it USDC and
+// scaled its amount at USDC's decimals
+// (https://git.eeqj.de/sneak/AutistMask/issues/632). The bundled list now names
+// a token only on Ethereum Mainnet. The same screen for a mainnet transfer of
+// USDC, while Sepolia is active, still names USDC.
+//
+// Driven through the real approval screen, against the minimal DOM stub
+// tests/approvalTokenNetwork.test.js uses.
+
+globalThis.chrome = {
+    storage: { local: { get: async () => ({}), set: async () => {} } },
+};
+
+const { Interface } = require("ethers");
+const { state } = require("../src/shared/state");
+const { NETWORKS } = require("../src/shared/networks");
+const approval = require("../src/popup/views/approval");
+
+const FROM = "0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266";
+const RECIPIENT = "0x711e691962E5c054b78071C789A0C8CE657377aD";
+// USDC's address on Ethereum Mainnet, where the bundled list names it.
+const USDC = "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48";
+
+// FROM sends 1234500000 base units to RECIPIENT.
+const TRANSFER_DATA = new Interface([
+    "function transfer(address to, uint256 amount)",
+]).encodeFunctionData("transfer", [RECIPIENT, 1234500000n]);
+
+function makeElement(id) {
+    const classes = new Set();
+    const el = {
+        id,
+        textContent: "",
+        value: "",
+        innerHTML: "",
+        disabled: false,
+        style: {},
+        dataset: {},
+        listeners: {},
+        classList: {
+            add: (...names) => names.forEach((n) => classes.add(n)),
+            remove: (...names) => names.forEach((n) => classes.delete(n)),
+            contains: (n) => classes.has(n),
+            toggle: (n, force) => {
+                const on = force === undefined ? !classes.has(n) : force;
+                if (on) classes.add(n);
+                else classes.delete(n);
+                return on;
+            },
+        },
+        addEventListener: (name, fn) => {
+            el.listeners[name] = el.listeners[name] || [];
+            el.listeners[name].push(fn);
+        },
+        querySelectorAll: () => [],
+        appendChild: () => {},
+    };
+    // Views reach for .parentElement to hide whole sections.
+    Object.defineProperty(el, "parentElement", {
+        get: () => node(id + "-parent"),
+    });
+    return el;
+}
+
+function makeDocument() {
+    const els = new Map();
+    return {
+        getElementById(id) {
+            // The debug banner is created on demand by helpers.js; absent
+            // is the state a non-debug, non-testnet popup is in.
+            if (id === "debug-banner") return null;
+            if (!els.has(id)) els.set(id, makeElement(id));
+            return els.get(id);
+        },
+        createElement: () => makeElement("created"),
+        body: { prepend: () => {} },
+    };
+}
+
+function node(id) {
+    return globalThis.document.getElementById(id);
+}
+
+// One line of the decoded details: its label and what is drawn under it.
+function decodedLine(label) {
+    return node("approve-tx-decoded-details")
+        .innerHTML.split('<div class="mb-2">')
+        .find((line) =>
+            line.startsWith(`<div class="text-muted">${label}</div>`),
+        );
+}
+
+// Open the approval screen, with Sepolia active, for the site's transaction
+// sending TRANSFER_DATA to the contract at USDC's address on the network with
+// chain id `chainId`.
+async function showTransfer(chainId) {
+    globalThis.document = makeDocument();
+    globalThis.window = { location: { search: "" }, close: () => {} };
+    globalThis.chrome.runtime = {
+        connect: () => ({ postMessage: () => {} }),
+        sendMessage: (msg, reply) => {
+            if (!reply) return;
+            reply({
+                type: "tx",
+                origin: "https://dapp.example",
+                isPhishingDomain: false,
+                approvedFrom: FROM,
+                approvedTx: {
+                    type: 2,
+                    from: FROM,
+                    chainId,
+                    nonce: "0x7",
+                    gasLimit: "0x30d40",
+                    maxPriorityFeePerGas: "0x3b9aca00",
+                    maxFeePerGas: "0x77359400",
+                    to: USDC,
+                    value: "0x0",
+                    data: TRANSFER_DATA,
+                    accessList: [],
+                },
+            });
+        },
+    };
+    state.networkId = "sepolia";
+    state.trackedTokens = [];
+    state.networkTrackedTokens = {};
+    state.activeAddress = FROM;
+    state.wallets = [
+        {
+            type: "hd",
+            name: "Wallet 1",
+            xpub: "xpub-wallet-1",
+            encryptedSecret: "encrypted-secret-1",
+            nextIndex: 1,
+            addresses: [
+                { address: FROM, index: 0, balance: "0", tokenBalances: [] },
+            ],
+        },
+    ];
+    state.currentView = null;
+    approval.init({});
+    await approval.show(1);
+}
+
+test("names no token, and states the amount in base units", async () => {
+    await showTransfer(NETWORKS.sepolia.chainId);
+    expect(state.currentView).toBe("approve-tx");
+    expect(node("approve-tx-to").innerHTML).not.toContain("USDC");
+    expect(decodedLine("Token")).toContain(
+        '<div class="font-bold">Unknown token</div>',
+    );
+    expect(decodedLine("Amount")).toContain(
+        '<div class="font-bold">1234500000 base units (decimals unknown)</div>',
+    );
+});
+
+// A transaction is named for its own network, not the active one.
+test("a mainnet transfer of USDC is still named and scaled as USDC", async () => {
+    await showTransfer(NETWORKS.mainnet.chainId);
+    expect(state.currentView).toBe("approve-tx");
+    expect(decodedLine("Token")).toContain('<div class="font-bold">USDC</div>');
+    expect(decodedLine("Amount")).toContain(
+        '<div class="font-bold">1234.5000 USDC</div>',
+    );
+});

tests/balanceRefreshNetworkSwitch.test.js

@@ -45,6 +45,7 @@ async function holdRefresh(page) {
                 holders: null,
             },
         ];
+        return [];
     });
     const ticking = page.tick();
     await page.settle();

tests/blockscoutEtherscanSettings.test.js

@@ -720,6 +720,7 @@ describe("the popup", () => {
                 tokenRow(TRACKED, "TRK"),
                 tokenRow(UNTRACKED, "TST"),
             ];
+            return [];
         });
         const ticking = page.tick();
         await page.settle();
@@ -764,6 +765,7 @@ describe("the popup", () => {
                 addr.tokenBalances = after
                     ? [tokenRow(TRACKED, "TRK"), tokenRow(UNTRACKED, "TST")]
                     : [tokenRow(TRACKED, "TRK")];
+                return [];
             });
 
             anotherPageSaves(page, { useBlockscout: after });

tests/bundledListScreens.test.js

@@ -0,0 +1,81 @@
+// The token screen, the Send screen and the confirmation screen for the
+// contract at USDC's mainnet address. No address holds it and the user does
+// not track it, so only the bundled token list can name it.
+//
+// The bundled token list holds Ethereum Mainnet contracts, so these screens
+// name the token from it on Ethereum Mainnet only
+// (https://git.eeqj.de/sneak/AutistMask/issues/632). Driven through the real
+// popup over a stored profile.
+
+const {
+    bootPopup,
+    cleanupPopup,
+    unversionedValidProfile,
+} = require("./support/popupBoot");
+
+const USDC = "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48";
+const RECIPIENT = "0x711e691962E5c054b78071C789A0C8CE657377aD";
+
+afterEach(() => {
+    cleanupPopup();
+});
+
+// The popup reopened onto AddressToken for USDC's address, on `networkId`.
+function bootOnToken(networkId) {
+    return bootPopup(
+        unversionedValidProfile({
+            networkId,
+            currentView: "address-token",
+            viewStack: ["main", "address"],
+            selectedWallet: 0,
+            selectedAddress: 0,
+            selectedToken: USDC,
+        }),
+    );
+}
+
+// AddressToken's Send, then Review for 1 token to RECIPIENT.
+async function reviewSend(boot) {
+    await boot.click("btn-address-token-send");
+    expect(boot.visibleViews()).toEqual(["send"]);
+    boot.node("send-to").value = RECIPIENT;
+    boot.node("send-amount").value = "1";
+    await boot.click("btn-send-review");
+    expect(boot.visibleViews()).toEqual(["confirm-tx"]);
+}
+
+describe("on Ethereum Mainnet, the bundled list names the token", () => {
+    test("on the token screen", async () => {
+        const boot = await bootOnToken("mainnet");
+        expect(boot.visibleViews()).toEqual(["address-token"]);
+        expect(boot.text("address-token-title")).toContain("USDC");
+        const info = boot.node("address-token-contract-info").innerHTML;
+        expect(info).toContain(
+            '<span class="text-muted">Decimals:</span> 6</div>',
+        );
+    });
+
+    test("on the Send screen and the confirmation screen", async () => {
+        const boot = await bootOnToken("mainnet");
+        await reviewSend(boot);
+        expect(boot.text("send-balance")).toContain("USDC");
+        expect(boot.text("confirm-amount")).toContain("USDC");
+    });
+});
+
+describe("with Sepolia active, the bundled list does not name the token", () => {
+    test("on the token screen", async () => {
+        const boot = await bootOnToken("sepolia");
+        expect(boot.visibleViews()).toEqual(["address-token"]);
+        expect(boot.text("address-token-title")).not.toContain("USDC");
+        const info = boot.node("address-token-contract-info").innerHTML;
+        expect(info).not.toContain("Decimals:");
+    });
+
+    test("on the Send screen and the confirmation screen", async () => {
+        const boot = await bootOnToken("sepolia");
+        await reviewSend(boot);
+        expect(boot.text("send-balance")).not.toContain("USDC");
+        expect(boot.text("confirm-amount")).not.toContain("USDC");
+    });
+});

tests/e2e/run.js

@@ -969,7 +969,8 @@ 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 },

tests/fabricatedDecimals.test.js

@@ -111,13 +111,15 @@ function respondWith(items) {
 }
 
 // Fetch and place the result exactly where refreshBalances() places it, so the
-// approval screens read what a real refresh would have left on state.
+// approval screens read what a real refresh on Ethereum Mainnet would have
+// left on state.
 async function fetchOnto(items, trackedTokens = []) {
     respondWith(items);
     const balances = await fetchTokenBalances(
         HOLDER,
         BLOCKSCOUT,
         trackedTokens,
+        "0x1",
     );
     state.trackedTokens = trackedTokens;
     state.wallets = [

tests/firstWalletRefresh.test.js

@@ -48,6 +48,7 @@ async function boot(stored) {
         for (const wallet of wallets) {
             for (const addr of wallet.addresses) addr.balance = chainBalance;
         }
+        return [];
     });
     return { page, refreshBalances };
 }

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/historyAfterNetworkSwitch.test.js

@@ -0,0 +1,500 @@
+// Home, AddressDetail and AddressToken drop a transaction history answer that
+// lands after a network switch. A dropped answer draws no rows and saves no
+// fraud contracts (https://git.eeqj.de/sneak/AutistMask/issues/657).
+//
+// Most tests hold the history request open, switch the network or what the
+// screen shows, and then let the answer land. The views run against a minimal
+// DOM stub, as in tests/transactionListCancelled.test.js, and over
+// tests/support/storageStub.js.
+
+const { makeStorageStub } = require("./support/storageStub");
+const { STATE_SCHEMA_VERSION } = require("../src/shared/stateSchema");
+
+jest.mock("../src/shared/transactions", () => ({
+    ...jest.requireActual("../src/shared/transactions"),
+    fetchRecentTransactions: jest.fn(async () => []),
+}));
+jest.mock("../src/shared/ens", () => ({
+    resolveEnsNames: jest.fn(async () => new Map()),
+}));
+
+const { fetchRecentTransactions } = require("../src/shared/transactions");
+const { resolveEnsNames } = require("../src/shared/ens");
+const { state, loadState } = require("../src/shared/state");
+const { onChainSwitch } = require("../src/shared/chainSwitch");
+const { applyChainSwitchFields } = require("../src/shared/chainSwitchFields");
+const { storedNetworkIs } = require("../src/shared/storedSettings");
+const home = require("../src/popup/views/home");
+const addressDetail = require("../src/popup/views/addressDetail");
+const addressToken = require("../src/popup/views/addressToken");
+
+const ADDRESS = "0x1111111111111111111111111111111111111111";
+const OTHER_ADDRESS = "0x2222222222222222222222222222222222222222";
+const RECIPIENT = "0x66133E8ea0f5D1d612D2502a968757D1048c214a";
+// A contract that sends a token claiming USDT's symbol. Spotting the spoof
+// adds this contract to the fraud contracts.
+const SPOOF_CONTRACT = "0x3333333333333333333333333333333333333333";
+const TOKEN = "0x6B175474E89094C44Da98b954EedeAC495271d0F";
+
+// A profile on Ethereum Mainnet with two addresses, "Use Blockscout" on and no
+// fraud contracts.
+function profile() {
+    return {
+        schemaVersion: STATE_SCHEMA_VERSION,
+        hasWallet: true,
+        wallets: [
+            {
+                type: "hd",
+                name: "Main",
+                xpub: "xpub-main",
+                encryptedSecret: "encrypted-secret",
+                nextIndex: 2,
+                addresses: [
+                    { address: ADDRESS, balance: "1.0", tokenBalances: [] },
+                    {
+                        address: OTHER_ADDRESS,
+                        balance: "0.0",
+                        tokenBalances: [],
+                    },
+                ],
+            },
+        ],
+        activeAddress: ADDRESS,
+        networkId: "mainnet",
+        rpcUrl: "https://ethereum-rpc.publicnode.com",
+        blockscoutUrl: "https://eth.blockscout.com/api/v2",
+        useBlockscout: true,
+        fraudContracts: [],
+    };
+}
+
+// What Blockscout answers for ADDRESS on Ethereum Mainnet:
+//
+// - a transfer of ETH from ADDRESS;
+// - a transfer of the fake USDT from SPOOF_CONTRACT.
+function history() {
+    return [
+        {
+            hash: "0x85215772ed26ea8b39c2b3b18779030487efbe0b5fd7e882592b2f62b837be84",
+            blockNumber: 2,
+            from: ADDRESS,
+            to: RECIPIENT,
+            value: "1.0000",
+            exactValue: "1.0",
+            rawAmount: "1000000000000000000",
+            rawUnit: "wei",
+            symbol: "ETH",
+            timestamp: 1790000000,
+            isError: false,
+            directionLabel: "Sent",
+            direction: "sent",
+            contractAddress: null,
+            chainId: "0x1",
+        },
+        {
+            hash: "0x0d6a6e0a0d1b7d4c3b2a19087f6e5d4c3b2a19087f6e5d4c3b2a19087f6e5d4c",
+            blockNumber: 1,
+            from: SPOOF_CONTRACT,
+            to: ADDRESS,
+            value: "100.0000",
+            exactValue: "100.0",
+            rawAmount: "100000000",
+            rawUnit: "base units",
+            symbol: "USDT",
+            timestamp: 1790000000,
+            isError: false,
+            directionLabel: "Received",
+            direction: "received",
+            contractAddress: SPOOF_CONTRACT,
+            chainId: "0x1",
+        },
+    ];
+}
+
+// The next history request waits until the returned function is called, and
+// then answers with `answer`.
+function holdHistory(answer = history()) {
+    let land;
+    fetchRecentTransactions.mockImplementationOnce(
+        () =>
+            new Promise((resolve) => {
+                land = () => resolve(answer);
+            }),
+    );
+    return () => land();
+}
+
+// The next history request waits until the returned function is called, and
+// then fails.
+function holdFailure() {
+    let fail;
+    fetchRecentTransactions.mockImplementationOnce(
+        () =>
+            new Promise((resolve, reject) => {
+                fail = () => reject(new Error("Blockscout is down"));
+            }),
+    );
+    return () => fail();
+}
+
+// Another write holds the lock until the returned function is called. Every
+// save waits until then.
+function holdLock() {
+    let release;
+    const held = navigator.locks.request(
+        "autistmask",
+        () =>
+            new Promise((resolve) => {
+                release = resolve;
+            }),
+    );
+    return async () => {
+        release();
+        await held;
+    };
+}
+
+function makeElement(id) {
+    const el = {
+        id,
+        textContent: "",
+        value: "",
+        innerHTML: "",
+        style: {},
+        dataset: {},
+        classList: {
+            add: () => {},
+            remove: () => {},
+            contains: () => false,
+            toggle: () => false,
+        },
+        addEventListener: () => {},
+        querySelectorAll: () => [],
+        appendChild: () => {},
+    };
+    // Views reach for .parentElement to hide whole sections.
+    Object.defineProperty(el, "parentElement", {
+        get: () => node(id + "-parent"),
+    });
+    return el;
+}
+
+function makeDocument() {
+    const els = new Map();
+    return {
+        getElementById(id) {
+            // The debug banner is created on demand by helpers.js; absent
+            // is the state a non-debug, non-testnet popup is in.
+            if (id === "debug-banner") return null;
+            if (!els.has(id)) els.set(id, makeElement(id));
+            return els.get(id);
+        },
+        createElement: () => makeElement("created"),
+        addEventListener: () => {},
+        body: { prepend: () => {} },
+    };
+}
+
+function node(id) {
+    return globalThis.document.getElementById(id);
+}
+
+// Lets every promise that is not held open settle.
+function settle() {
+    return new Promise((resolve) => setTimeout(resolve, 0));
+}
+
+let storage;
+
+beforeEach(async () => {
+    storage = makeStorageStub({ autistmask: profile() });
+    globalThis.chrome = {
+        storage: { local: storage.local, onChanged: storage.onChanged },
+    };
+    globalThis.document = makeDocument();
+    globalThis.window = { location: { search: "" } };
+    await loadState();
+    state.viewStack = [];
+    state.selectedWallet = 0;
+    state.selectedAddress = 0;
+    state.selectedToken = "ETH";
+    const ctx = { pageClosed: new AbortController().signal };
+    addressDetail.init(ctx);
+    addressToken.init(ctx);
+});
+
+afterEach(() => {
+    delete globalThis.chrome;
+    delete globalThis.document;
+    delete globalThis.window;
+});
+
+const HOME = {
+    name: "Home",
+    listId: "home-tx-list",
+    open: () => home.render({ pageClosed: new AbortController().signal }),
+};
+const ADDRESS_DETAIL = {
+    name: "AddressDetail",
+    listId: "tx-list",
+    open: () => addressDetail.show(),
+};
+const ADDRESS_TOKEN = {
+    name: "AddressToken",
+    listId: "address-token-tx-list",
+    open: () => addressToken.show(),
+};
+
+// Three ways a test switches the network:
+//
+// - made in Settings: the page and storage have both switched;
+// - saved elsewhere: storage has switched and the page has not;
+// - not yet stored: the page has switched and storage has not.
+const SWITCHES = [
+    {
+        how: "made in Settings",
+        to: (networkId) => onChainSwitch(networkId),
+    },
+    {
+        // Another page or the background stored the switch, and this page has
+        // not followed it yet.
+        how: "saved elsewhere",
+        to: async (networkId) => {
+            const record = storage.read("autistmask");
+            applyChainSwitchFields(record, networkId);
+            storage.write("autistmask", record);
+        },
+    },
+    {
+        // The switch's own save has changed the page and has not yet written
+        // storage.
+        how: "not yet stored",
+        to: async (networkId) => {
+            applyChainSwitchFields(state, networkId);
+        },
+    },
+];
+
+// The list still shows `before`, and neither the page nor storage holds a
+// fraud contract.
+function expectNothingAdded(screen, before) {
+    expect(node(screen.listId).innerHTML).toBe(before);
+    expect(state.fraudContracts).toEqual([]);
+    expect(storage.read("autistmask").fraudContracts).toEqual([]);
+}
+
+describe.each([HOME, ADDRESS_DETAIL, ADDRESS_TOKEN])("$name", (screen) => {
+    test("an answer that lands on the same network is drawn and saved", async () => {
+        const land = holdHistory();
+        screen.open();
+        land();
+        await settle();
+
+        expect(node(screen.listId).innerHTML).toContain("tx-row");
+        expect(state.fraudContracts).toEqual([SPOOF_CONTRACT]);
+        expect(storage.read("autistmask").fraudContracts).toEqual([
+            SPOOF_CONTRACT,
+        ]);
+    });
+
+    test.each(SWITCHES)(
+        "an answer that lands after a switch $how adds nothing",
+        async ({ to }) => {
+            const land = holdHistory();
+            screen.open();
+            await settle();
+            const before = node(screen.listId).innerHTML;
+            await to("sepolia");
+            land();
+            await settle();
+
+            expectNothingAdded(screen, before);
+        },
+    );
+
+    // The answer is the transfer of ETH alone, which adds no fraud contract.
+    // Nothing is saved, so only the check before the save can drop the answer.
+    test.each(SWITCHES)(
+        "an answer without a fraud contract that lands after a switch $how adds nothing",
+        async ({ to }) => {
+            const land = holdHistory(history().slice(0, 1));
+            screen.open();
+            await settle();
+            const before = node(screen.listId).innerHTML;
+            await to("sepolia");
+            land();
+            await settle();
+
+            expectNothingAdded(screen, before);
+        },
+    );
+
+    test.each(SWITCHES)(
+        "a request that fails after a switch $how shows no message",
+        async ({ to }) => {
+            const fail = holdFailure();
+            screen.open();
+            await settle();
+            const before = node(screen.listId).innerHTML;
+            await to("sepolia");
+            fail();
+            await settle();
+
+            expect(node(screen.listId).innerHTML).toBe(before);
+        },
+    );
+
+    // The user picks Sepolia in Settings while another write holds the lock.
+    // The answer lands, and its save waits behind the switch.
+    test("an answer whose save waits behind a switch made in Settings adds nothing", async () => {
+        const land = holdHistory();
+        screen.open();
+        const before = node(screen.listId).innerHTML;
+        const releaseLock = holdLock();
+        const switching = onChainSwitch("sepolia");
+        land();
+        await settle();
+        await releaseLock();
+        await switching;
+        await settle();
+
+        expectNothingAdded(screen, before);
+    });
+
+    // The answer lands and its save waits for the lock. Another page or the
+    // background then stores a switch.
+    test("an answer whose save waits while a switch is saved elsewhere adds nothing", async () => {
+        const land = holdHistory();
+        screen.open();
+        const before = node(screen.listId).innerHTML;
+        const releaseLock = holdLock();
+        land();
+        await settle();
+        const record = storage.read("autistmask");
+        applyChainSwitchFields(record, "sepolia");
+        storage.write("autistmask", record);
+        await releaseLock();
+        await settle();
+
+        expectNothingAdded(screen, before);
+    });
+
+    // The answer lands and its save waits for the lock. The page then switches,
+    // and storage has not.
+    test("an answer whose save waits while the page switches adds nothing", async () => {
+        const land = holdHistory();
+        screen.open();
+        const before = node(screen.listId).innerHTML;
+        const releaseLock = holdLock();
+        land();
+        await settle();
+        applyChainSwitchFields(state, "sepolia");
+        await releaseLock();
+        await settle();
+
+        expectNothingAdded(screen, before);
+    });
+
+    test("a request that fails after a switch leaves the new network's rows", async () => {
+        const fail = holdFailure();
+        screen.open();
+        await onChainSwitch("sepolia");
+        fetchRecentTransactions.mockImplementationOnce(async () => history());
+        screen.open();
+        await settle();
+        const drawn = node(screen.listId).innerHTML;
+        fail();
+        await settle();
+
+        expect(drawn).toContain("tx-row");
+        expect(node(screen.listId).innerHTML).toBe(drawn);
+    });
+});
+
+describe.each([ADDRESS_DETAIL, ADDRESS_TOKEN])("$name", (screen) => {
+    test("an answer that lands once the screen shows another address adds nothing", async () => {
+        const land = holdHistory();
+        screen.open();
+        state.selectedAddress = 1;
+        screen.open();
+        await settle();
+        const before = node(screen.listId).innerHTML;
+        land();
+        await settle();
+
+        expectNothingAdded(screen, before);
+    });
+
+    test("a request that fails once the screen shows another address shows no message", async () => {
+        const fail = holdFailure();
+        screen.open();
+        state.selectedAddress = 1;
+        screen.open();
+        await settle();
+        const before = node(screen.listId).innerHTML;
+        fail();
+        await settle();
+
+        expect(node(screen.listId).innerHTML).toBe(before);
+    });
+
+    // The answer is the transfer of ETH alone, which adds no fraud contract.
+    // Nothing is saved, so only the check after the name lookup can drop the
+    // answer.
+    test("an answer whose name lookup lands after a switch adds nothing", async () => {
+        let landNames;
+        resolveEnsNames.mockImplementationOnce(
+            () =>
+                new Promise((resolve) => {
+                    landNames = () => resolve(new Map());
+                }),
+        );
+        fetchRecentTransactions.mockImplementationOnce(async () =>
+            history().slice(0, 1),
+        );
+        screen.open();
+        await settle();
+        const before = node(screen.listId).innerHTML;
+        await onChainSwitch("sepolia");
+        landNames();
+        await settle();
+
+        expectNothingAdded(screen, before);
+    });
+});
+
+test("AddressToken: an answer that lands once the screen shows another token adds nothing", async () => {
+    const land = holdHistory();
+    addressToken.show();
+    state.selectedToken = TOKEN;
+    addressToken.show();
+    await settle();
+    const before = node(ADDRESS_TOKEN.listId).innerHTML;
+    land();
+    await settle();
+
+    expectNothingAdded(ADDRESS_TOKEN, before);
+});
+
+test("AddressToken: a request that fails once the screen shows another token shows no message", async () => {
+    const fail = holdFailure();
+    addressToken.show();
+    state.selectedToken = TOKEN;
+    addressToken.show();
+    await settle();
+    const before = node(ADDRESS_TOKEN.listId).innerHTML;
+    fail();
+    await settle();
+
+    expect(node(ADDRESS_TOKEN.listId).innerHTML).toBe(before);
+});
+
+test("storedNetworkIs(): a failed read counts as no", async () => {
+    globalThis.chrome.storage.local = {
+        get: async () => {
+            throw new Error("storage is down");
+        },
+    };
+
+    await expect(storedNetworkIs("mainnet")).resolves.toBe(false);
+});

tests/holders.test.js

@@ -192,7 +192,13 @@ describe("the balance-list spam gate", () => {
                 },
             }),
         ]);
-        const balances = await fetchTokenBalances(HOLDER, BLOCKSCOUT, []);
+        // On Ethereum Mainnet, the only network the known-token list covers.
+        const balances = await fetchTokenBalances(
+            HOLDER,
+            BLOCKSCOUT,
+            [],
+            "0x1",
+        );
         expect(balances).toHaveLength(1);
         expect(balances[0].holders).toBeNull();
     });

tests/resolveTokenSymbol.test.js

@@ -67,13 +67,15 @@ beforeEach(() => {
 });
 
 describe("resolveTokenSymbol", () => {
+    // The bundled list is read only for a token on Ethereum Mainnet.
     test("reads the bundled list", () => {
-        expect(resolveTokenSymbol(USDC, state)).toBe("USDC");
+        expect(resolveTokenSymbol(USDC, { chainId: "0x1" })).toBe("USDC");
     });
 
     test("prefers the bundled list over a tracked entry", () => {
         state.trackedTokens = [{ address: USDC, symbol: "NOTUSDC" }];
-        expect(resolveTokenSymbol(USDC, state)).toBe("USDC");
+        const sources = { chainId: "0x1", trackedTokens: state.trackedTokens };
+        expect(resolveTokenSymbol(USDC, sources)).toBe("USDC");
     });
 
     test("reads a token the user tracks", () => {
@@ -104,7 +106,19 @@ describe("resolveTokenSymbol", () => {
     test("rejects a tracked entry claiming a bundled ticker it is not", () => {
         // NOVEL_TOKEN is not the real USDC contract, so it may not wear USDC.
         state.trackedTokens = [{ address: NOVEL_TOKEN, symbol: "USDC" }];
-        expect(resolveTokenSymbol(NOVEL_TOKEN, state)).toBeNull();
+        const sources = { chainId: "0x1", trackedTokens: state.trackedTokens };
+        expect(resolveTokenSymbol(NOVEL_TOKEN, sources)).toBeNull();
+    });
+
+    // The bundled list holds mainnet contracts, so on Sepolia any contract may
+    // carry one of its symbols.
+    test("on Sepolia, reads a tracked entry carrying a bundled ticker", () => {
+        state.trackedTokens = [{ address: NOVEL_TOKEN, symbol: "USDC" }];
+        const sources = {
+            chainId: "0xaa36a7",
+            trackedTokens: state.trackedTokens,
+        };
+        expect(resolveTokenSymbol(NOVEL_TOKEN, sources)).toBe("USDC");
     });
 
     test("rejects an explorer entry claiming the native ETH ticker", () => {

tests/settingsEndpointSave.test.js

@@ -167,3 +167,272 @@ test.each([
         );
     },
 );
+
+// This answer passes both endpoint checks on Ethereum Mainnet.
+const PASSING_ANSWER = {
+    ok: true,
+    json: async () => ({ result: NETWORKS.mainnet.chainId }),
+};
+
+// Both endpoint checks read this answer as an error. The RPC check reads the
+// answer's `error`. The Blockscout check reads the answer's `ok`.
+const ERROR_ANSWER = {
+    ok: false,
+    status: 500,
+    json: async () => ({ error: { code: -32603, message: "Internal error" } }),
+};
+
+// The user types a URL in Settings and taps "Save". Before the endpoint answers,
+// the user types a second URL and taps "Save" again. The second check passes
+// first. The second URL is stored, and the flash message reads "Saved.". The
+// first check then ends in one of three ways:
+//
+// - It passes.
+// - It fails, because fetch cannot reach the endpoint.
+// - It gets an answer that holds an error.
+//
+// None of the three changes the stored URL or the flash message
+// (https://git.eeqj.de/sneak/AutistMask/issues/698).
+test.each([
+    {
+        button: "btn-save-rpc",
+        input: "settings-rpc",
+        field: "rpcUrl",
+        first: "passes",
+    },
+    {
+        button: "btn-save-rpc",
+        input: "settings-rpc",
+        field: "rpcUrl",
+        first: "fails",
+    },
+    {
+        button: "btn-save-rpc",
+        input: "settings-rpc",
+        field: "rpcUrl",
+        first: "answers with an error",
+    },
+    {
+        button: "btn-save-blockscout",
+        input: "settings-blockscout",
+        field: "blockscoutUrl",
+        first: "passes",
+    },
+    {
+        button: "btn-save-blockscout",
+        input: "settings-blockscout",
+        field: "blockscoutUrl",
+        first: "fails",
+    },
+    {
+        button: "btn-save-blockscout",
+        input: "settings-blockscout",
+        field: "blockscoutUrl",
+        first: "answers with an error",
+    },
+])(
+    "$button keeps the second tap's result when the first check $first last",
+    async ({ button, input, field, first }) => {
+        const page = await bootPopup(unversionedValidProfile());
+        await page.click("btn-settings");
+        const checks = [];
+        globalThis.fetch.mockImplementation(
+            () =>
+                new Promise((resolve, reject) => {
+                    checks.push({ resolve, reject });
+                }),
+        );
+        const secondUrl = "https://second.example.invalid";
+
+        page.node(input).value = "https://first.example.invalid";
+        const firstTap = page.node(button).listeners.click.map((fn) => fn());
+        await page.settle();
+        page.node(input).value = secondUrl;
+        const secondTap = page.node(button).listeners.click.map((fn) => fn());
+        await page.settle();
+        checks[1].resolve(PASSING_ANSWER);
+        await Promise.all(secondTap);
+        await page.settle();
+        expect(page.text("flash-msg")).toBe("Saved.");
+        if (first === "passes") {
+            checks[0].resolve(PASSING_ANSWER);
+        } else if (first === "answers with an error") {
+            checks[0].resolve(ERROR_ANSWER);
+        } else {
+            // fetch rejects when it cannot reach the endpoint.
+            checks[0].reject(new TypeError("Failed to fetch"));
+        }
+        await Promise.all(firstTap);
+        await page.settle();
+
+        expect(checks).toHaveLength(2);
+        expect(page.storage.read("autistmask")[field]).toBe(secondUrl);
+        expect(page.text("flash-msg")).toBe("Saved.");
+    },
+);
+
+// The user types a URL in Settings and taps "Save". Before the endpoint answers,
+// the user empties the input and taps "Save" again. The flash message asks for
+// a URL. The first check then passes. The flash message still asks for a URL,
+// and the stored URL is unchanged.
+test.each([
+    {
+        button: "btn-save-rpc",
+        input: "settings-rpc",
+        field: "rpcUrl",
+        message: "Please enter an RPC URL.",
+    },
+    {
+        button: "btn-save-blockscout",
+        input: "settings-blockscout",
+        field: "blockscoutUrl",
+        message: "Please enter a Blockscout API URL.",
+    },
+])(
+    "$button keeps the empty-input message when the first check passes last",
+    async ({ button, input, field, message }) => {
+        const page = await bootPopup(unversionedValidProfile());
+        await page.click("btn-settings");
+        const storedUrl = page.value(input);
+        let answer;
+        globalThis.fetch.mockReturnValue(
+            new Promise((resolve) => {
+                answer = resolve;
+            }),
+        );
+
+        page.node(input).value = "https://typed.example.invalid";
+        const firstTap = page.node(button).listeners.click.map((fn) => fn());
+        await page.settle();
+        page.node(input).value = "";
+        await page.click(button);
+        expect(page.text("flash-msg")).toBe(message);
+        answer(PASSING_ANSWER);
+        await Promise.all(firstTap);
+        await page.settle();
+
+        expect(page.storage.read("autistmask")[field]).toBe(storedUrl);
+        expect(page.text("flash-msg")).toBe(message);
+    },
+);
+
+// The user types a URL in Settings and taps "Save". Another write holds the
+// lock. So the save waits for the lock once the check passes. The user then
+// taps "Save" again on the same URL. When the lock is free, the first save
+// stores nothing and shows no flash message. The second check then passes, and
+// the second save stores the URL.
+test.each([
+    { button: "btn-save-rpc", input: "settings-rpc", field: "rpcUrl" },
+    {
+        button: "btn-save-blockscout",
+        input: "settings-blockscout",
+        field: "blockscoutUrl",
+    },
+])(
+    "$button stores nothing for an earlier tap still waiting for the lock",
+    async ({ button, input, field }) => {
+        const page = await bootPopup(unversionedValidProfile());
+        await page.click("btn-settings");
+        const storedUrl = page.value(input);
+        const checks = [];
+        globalThis.fetch.mockImplementation(
+            () =>
+                new Promise((resolve) => {
+                    checks.push(resolve);
+                }),
+        );
+        const typedUrl = "https://typed.example.invalid";
+
+        page.node(input).value = typedUrl;
+        const firstTap = page.node(button).listeners.click.map((fn) => fn());
+        await page.settle();
+        let releaseLock;
+        const lockHeld = navigator.locks.request(
+            "autistmask",
+            () =>
+                new Promise((resolve) => {
+                    releaseLock = resolve;
+                }),
+        );
+        checks[0](PASSING_ANSWER);
+        await page.settle();
+        const secondTap = page.node(button).listeners.click.map((fn) => fn());
+        await page.settle();
+        releaseLock();
+        await lockHeld;
+        await Promise.all(firstTap);
+        await page.settle();
+
+        expect(page.storage.read("autistmask")[field]).toBe(storedUrl);
+        expect(page.text("flash-msg")).toBe("Testing endpoint...");
+
+        checks[1](PASSING_ANSWER);
+        await Promise.all(secondTap);
+        await page.settle();
+
+        expect(checks).toHaveLength(2);
+        expect(page.storage.read("autistmask")[field]).toBe(typedUrl);
+        expect(page.text("flash-msg")).toBe("Saved.");
+    },
+);
+
+// The user taps "Save", and the check passes. The save then begins its storage
+// write, and this test keeps the write waiting. The user taps "Save" again, and
+// the second check cannot reach the endpoint. When the write ends, the flash
+// message still reads "Could not reach endpoint.". The write stores the URL
+// anyway, because the write began before the second tap.
+test.each([
+    { button: "btn-save-rpc", input: "settings-rpc", field: "rpcUrl" },
+    {
+        button: "btn-save-blockscout",
+        input: "settings-blockscout",
+        field: "blockscoutUrl",
+    },
+])(
+    "$button keeps the second tap's message when tapped again during the write",
+    async ({ button, input, field }) => {
+        const page = await bootPopup(unversionedValidProfile());
+        await page.click("btn-settings");
+        const checks = [];
+        globalThis.fetch.mockImplementation(
+            () =>
+                new Promise((resolve, reject) => {
+                    checks.push({ resolve, reject });
+                }),
+        );
+        const typedUrl = "https://typed.example.invalid";
+
+        page.node(input).value = typedUrl;
+        const firstTap = page.node(button).listeners.click.map((fn) => fn());
+        await page.settle();
+        const { set } = page.storage.local;
+        const write = set.getMockImplementation();
+        let writeBegan = false;
+        let releaseWrite;
+        const writeHeld = new Promise((resolve) => {
+            releaseWrite = resolve;
+        });
+        set.mockImplementationOnce(async (items) => {
+            writeBegan = true;
+            await writeHeld;
+            await write(items);
+        });
+        checks[0].resolve(PASSING_ANSWER);
+        await page.settle();
+        expect(writeBegan).toBe(true);
+        const secondTap = page.node(button).listeners.click.map((fn) => fn());
+        await page.settle();
+        // fetch rejects when it cannot reach the endpoint.
+        checks[1].reject(new TypeError("Failed to fetch"));
+        await Promise.all(secondTap);
+        await page.settle();
+        expect(page.text("flash-msg")).toBe("Could not reach endpoint.");
+        releaseWrite();
+        await Promise.all(firstTap);
+        await page.settle();
+
+        expect(checks).toHaveLength(2);
+        expect(page.storage.read("autistmask")[field]).toBe(typedUrl);
+        expect(page.text("flash-msg")).toBe("Could not reach endpoint.");
+    },
+);

tests/spoofedTrackedToken.test.js

@@ -0,0 +1,134 @@
+// A token that the spoof rule refuses never shows in the balance list, even
+// tracked at zero balance with "Show tracked tokens with zero balance" on, and
+// the two add-token screens refuse to track one
+// (https://git.eeqj.de/sneak/AutistMask/issues/705). Driven through the real
+// popup over a stored profile.
+
+const {
+    bootPopup,
+    cleanupPopup,
+    unversionedValidProfile,
+    TOKEN_ADDRESS,
+} = require("./support/popupBoot");
+
+// Claims the symbol of the bundled USDT from another contract.
+const FAKE_USDT = {
+    address: TOKEN_ADDRESS,
+    symbol: "USDT",
+    decimals: 6,
+    name: "Tether USD",
+};
+// A Sepolia contract that reports USDT. The bundled list holds Ethereum Mainnet
+// contracts, so the spoof rule does not check this symbol on Sepolia
+// (https://git.eeqj.de/sneak/AutistMask/issues/632).
+const SEPOLIA_USDT = {
+    address: TOKEN_ADDRESS,
+    symbol: "USDT",
+    decimals: 6,
+    name: "Test USDT",
+};
+// A symbol the bundled list does not have, so the spoof rule passes it.
+const TEST_TOKEN = {
+    address: "0xBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB",
+    symbol: "TST",
+    decimals: 18,
+    name: "Test Token",
+};
+const REFUSED_FLASH = "Not added: this token fakes a known symbol.";
+
+afterEach(() => {
+    cleanupPopup();
+});
+
+test("on Ethereum Mainnet, a fake token tracked at zero balance is not listed while zero balances are shown", async () => {
+    const boot = await bootPopup(
+        unversionedValidProfile({
+            networkId: "mainnet",
+            currentView: "address",
+            selectedWallet: 0,
+            selectedAddress: 0,
+            trackedTokens: [FAKE_USDT, TEST_TOKEN],
+            showZeroBalanceTokens: true,
+        }),
+    );
+    const rows = boot.node("address-balances").innerHTML;
+    expect(rows).toContain(`data-token="${TEST_TOKEN.address.toLowerCase()}"`);
+    expect(rows).not.toContain(
+        `data-token="${FAKE_USDT.address.toLowerCase()}"`,
+    );
+});
+
+// Each screen is opened from AddressDetail by the buttons named, in order.
+describe.each([
+    [
+        "AddToken",
+        ["btn-add-token"],
+        "add-token",
+        "add-token-address",
+        "btn-add-token-confirm",
+    ],
+    [
+        "SettingsAddToken",
+        ["btn-settings", "btn-settings-add-token"],
+        "settings-addtoken",
+        "settings-addtoken-address",
+        "btn-settings-addtoken-manual",
+    ],
+])("%s", (_, opening, view, field, button) => {
+    test("on Ethereum Mainnet, refuses a fake token by contract address", async () => {
+        const boot = await bootPopup(
+            unversionedValidProfile({
+                networkId: "mainnet",
+                currentView: "address",
+                selectedWallet: 0,
+                selectedAddress: 0,
+            }),
+        );
+        for (const id of opening) await boot.click(id);
+        expect(boot.visibleViews()).toEqual([view]);
+        const { lookupTokenInfo } = require("../src/shared/balances");
+        lookupTokenInfo.mockResolvedValueOnce({
+            symbol: FAKE_USDT.symbol,
+            decimals: FAKE_USDT.decimals,
+            name: FAKE_USDT.name,
+        });
+        boot.node(field).value = FAKE_USDT.address;
+
+        await boot.click(button);
+        expect(boot.text("flash-msg")).toBe(REFUSED_FLASH);
+        expect(boot.visibleViews()).toEqual([view]);
+        expect(boot.storage.read("autistmask").trackedTokens).toEqual([]);
+    });
+
+    test("on Sepolia, adds a contract that reports USDT and lists it", async () => {
+        const boot = await bootPopup(
+            unversionedValidProfile({
+                networkId: "sepolia",
+                currentView: "address",
+                selectedWallet: 0,
+                selectedAddress: 0,
+                showZeroBalanceTokens: true,
+            }),
+        );
+        for (const id of opening) await boot.click(id);
+        expect(boot.visibleViews()).toEqual([view]);
+        const { lookupTokenInfo } = require("../src/shared/balances");
+        lookupTokenInfo.mockResolvedValueOnce({
+            symbol: SEPOLIA_USDT.symbol,
+            decimals: SEPOLIA_USDT.decimals,
+            name: SEPOLIA_USDT.name,
+        });
+        boot.node(field).value = SEPOLIA_USDT.address;
+
+        await boot.click(button);
+        expect(boot.text("flash-msg")).not.toBe(REFUSED_FLASH);
+        expect(boot.storage.read("autistmask").trackedTokens).toEqual([
+            expect.objectContaining(SEPOLIA_USDT),
+        ]);
+        // SettingsAddToken stays up after adding, so this draws AddressDetail.
+        require("../src/popup/views/addressDetail").show();
+        expect(boot.node("address-balances").innerHTML).toContain(
+            `data-token="${SEPOLIA_USDT.address.toLowerCase()}"`,
+        );
+    });
+});

tests/support/popupBoot.js

@@ -279,10 +279,11 @@ async function bootPopup(stored, options) {
         getAddressValue: () => ({ usd: null, partial: false }),
     }));
     // scanForAddresses() answers in the real one's shape, a scan that found
-    // no used address: AddWallet reads `addresses` from it.
+    // no used address: AddWallet reads `addresses` from it. refreshBalances()
+    // answers as a refresh that read no tracked token's balance.
     jest.doMock("../../src/shared/balances", () => ({
         fetchTokenBalances: jest.fn(async () => []),
-        refreshBalances: jest.fn(async () => {}),
+        refreshBalances: jest.fn(async () => []),
         dropUntrackedTokens: jest.requireActual("../../src/shared/balances")
             .dropUntrackedTokens,
         lookupTokenInfo: jest.fn(async () => null),

tests/symbolSpoof.test.js

@@ -72,6 +72,11 @@ const {
 const { renderSendTokenSelect } = require("../src/popup/views/send");
 const { state } = require("../src/shared/state");
 const { debugFetch } = require("../src/shared/log");
+const { NETWORKS } = require("../src/shared/networks");
+
+// The bundled list's symbols are known symbols only on Ethereum Mainnet.
+const MAINNET = NETWORKS.mainnet.chainId;
+const SEPOLIA = NETWORKS.sepolia.chainId;
 
 // The fake "Ethereum" token with symbol "ETH" from the attack documented in
 // README.md, given a holder count high enough to clear every other filter so
@@ -116,14 +121,29 @@ describe("the shared rule", () => {
     });
 
     test("a known symbol from its own contract is not a spoof", () => {
-        expect(isSpoofedSymbol("USDC", USDC_CONTRACT)).toBe(false);
-        expect(isSpoofedSymbol("usdc", USDC_CONTRACT.toUpperCase())).toBe(
-            false,
-        );
+        expect(isSpoofedSymbol("USDC", USDC_CONTRACT, MAINNET)).toBe(false);
+        expect(
+            isSpoofedSymbol("usdc", USDC_CONTRACT.toUpperCase(), MAINNET),
+        ).toBe(false);
     });
 
     test("a known symbol from another contract is a spoof", () => {
-        expect(isSpoofedSymbol("USDC", FAKE_ETH_CONTRACT)).toBe(true);
+        expect(isSpoofedSymbol("USDC", FAKE_ETH_CONTRACT, MAINNET)).toBe(true);
+    });
+
+    // https://git.eeqj.de/sneak/AutistMask/issues/632: the bundled list holds
+    // mainnet contracts, so on Sepolia any contract may carry one of its
+    // symbols.
+    test("on Sepolia, a bundled symbol from any contract is not a spoof", () => {
+        expect(isSpoofedSymbol("USDC", FAKE_ETH_CONTRACT, SEPOLIA)).toBe(false);
+        expect(isSpoofedSymbol("USDC", USDC_CONTRACT, SEPOLIA)).toBe(false);
+    });
+
+    test("on Sepolia, the native asset's labels are still reserved", () => {
+        expect(isSpoofedSymbol("ETH", FAKE_ETH_CONTRACT, SEPOLIA)).toBe(true);
+        expect(isSpoofedSymbol("SepoliaETH", FAKE_ETH_CONTRACT, SEPOLIA)).toBe(
+            true,
+        );
     });
 
     test("a symbol that is not in the table is not judged here", () => {
@@ -164,7 +184,9 @@ describe("the shared rule: symbols that render as a known symbol", () => {
     test("ASCII padding does not buy a pass", () => {
         expect(isSpoofedSymbol(" ETH ", FAKE_ETH_CONTRACT)).toBe(true);
         expect(isSpoofedSymbol("\tETH\n", FAKE_ETH_CONTRACT)).toBe(true);
-        expect(isSpoofedSymbol("  usdc  ", FAKE_ETH_CONTRACT)).toBe(true);
+        expect(isSpoofedSymbol("  usdc  ", FAKE_ETH_CONTRACT, MAINNET)).toBe(
+            true,
+        );
     });
 
     test("non-breaking and other Unicode spaces do not either", () => {
@@ -243,7 +265,9 @@ describe("the shared rule: symbols that render as a known symbol", () => {
 
     test("compatibility forms fold onto the symbol they imitate", () => {
         expect(isSpoofedSymbol(FULLWIDTH_ETH, FAKE_ETH_CONTRACT)).toBe(true);
-        expect(isSpoofedSymbol(FULLWIDTH_USDC, FAKE_ETH_CONTRACT)).toBe(true);
+        expect(
+            isSpoofedSymbol(FULLWIDTH_USDC, FAKE_ETH_CONTRACT, MAINNET),
+        ).toBe(true);
     });
 
     // The two knowingly open classes, asserted here so that the boundary is
@@ -271,8 +295,10 @@ describe("the shared rule: symbols that render as a known symbol", () => {
     });
 
     test("a genuine contract still bears its own padded symbol", () => {
-        expect(isSpoofedSymbol(" USDC ", USDC_CONTRACT)).toBe(false);
-        expect(isSpoofedSymbol(ZWSP + "WETH", WETH_CONTRACT)).toBe(false);
+        expect(isSpoofedSymbol(" USDC ", USDC_CONTRACT, MAINNET)).toBe(false);
+        expect(isSpoofedSymbol(ZWSP + "WETH", WETH_CONTRACT, MAINNET)).toBe(
+            false,
+        );
     });
 
     // Normalization must not invent a match.  Interior ASCII whitespace is
@@ -296,7 +322,7 @@ describe("the shared rule: symbols that render as a known symbol", () => {
             expect(symbol).toMatch(/^[!-~]+$/);
             if (addresses === null) continue;
             for (const address of addresses) {
-                expect(isSpoofedSymbol(symbol, address)).toBe(false);
+                expect(isSpoofedSymbol(symbol, address, MAINNET)).toBe(false);
             }
         }
     });
@@ -317,7 +343,7 @@ describe("the shared rule: symbols that render as a known symbol", () => {
 describe("the shipped token list", () => {
     test("no bundled token is filtered at its own address", () => {
         const filtered = TOKENS.filter((t) =>
-            isSpoofedSymbol(t.symbol, t.address),
+            isSpoofedSymbol(t.symbol, t.address, MAINNET),
         ).map((t) => t.symbol + " @ " + t.address);
         expect(filtered).toEqual([]);
     });
@@ -360,7 +386,9 @@ describe("the shipped token list", () => {
         expect(shared.length).toBeGreaterThan(0);
         for (const [, list] of shared) {
             for (const t of list) {
-                expect(isSpoofedSymbol(t.symbol, t.address)).toBe(false);
+                expect(isSpoofedSymbol(t.symbol, t.address, MAINNET)).toBe(
+                    false,
+                );
             }
         }
     });
@@ -404,7 +432,7 @@ describe("the shipped token list", () => {
                 [...addresses].sort(),
             );
             for (const address of addresses) {
-                expect(isSpoofedSymbol(symbol, address)).toBe(false);
+                expect(isSpoofedSymbol(symbol, address, MAINNET)).toBe(false);
             }
         }
     });
@@ -421,7 +449,9 @@ describe("the shipped token list", () => {
         }
         for (const [symbol, list] of bySymbol) {
             if (list.length < 2) continue;
-            expect(isSpoofedSymbol(symbol, FAKE_ETH_CONTRACT)).toBe(true);
+            expect(isSpoofedSymbol(symbol, FAKE_ETH_CONTRACT, MAINNET)).toBe(
+                true,
+            );
         }
     });
 });
@@ -506,10 +536,40 @@ describe("surface 2: the Send token selector", () => {
     }
 
     beforeEach(() => {
+        state.networkId = "mainnet";
         state.fraudContracts = [];
         state.hideLowHolderTokens = true;
     });
 
+    afterAll(() => {
+        state.networkId = "mainnet";
+    });
+
+    // A token reporting USDC's symbol from another contract.
+    function otherUsdc() {
+        return {
+            address: FAKE_ETH_CONTRACT,
+            symbol: "USDC",
+            decimals: 6,
+            balance: "12.5",
+            holders: 900000,
+        };
+    }
+
+    test("a bundled symbol from another contract is not selectable", () => {
+        render([otherUsdc()]);
+        expect(select.children).toEqual([]);
+    });
+
+    // https://git.eeqj.de/sneak/AutistMask/issues/632: the bundled list holds
+    // mainnet contracts, so on Sepolia any contract may carry its symbols.
+    test("with Sepolia active, a bundled symbol from another contract is selectable", () => {
+        state.networkId = "sepolia";
+        render([otherUsdc()]);
+        expect(select.children).toHaveLength(1);
+        expect(select.children[0].value).toBe(FAKE_ETH_CONTRACT);
+    });
+
     test("a fake ETH token is not selectable", () => {
         render([
             {
@@ -627,7 +687,12 @@ describe("surface 3: the balance list", () => {
                 decimals: "6",
             }),
         ]);
-        const balances = await fetchTokenBalances(HOLDER, BLOCKSCOUT, []);
+        const balances = await fetchTokenBalances(
+            HOLDER,
+            BLOCKSCOUT,
+            [],
+            MAINNET,
+        );
         expect(balances).toHaveLength(1);
         expect(balances[0].symbol).toBe(" USDC ");
     });
@@ -641,11 +706,40 @@ describe("surface 3: the balance list", () => {
                 decimals: "6",
             }),
         ]);
-        const balances = await fetchTokenBalances(HOLDER, BLOCKSCOUT, []);
+        const balances = await fetchTokenBalances(
+            HOLDER,
+            BLOCKSCOUT,
+            [],
+            MAINNET,
+        );
         expect(balances).toHaveLength(1);
         expect(balances[0].symbol).toBe("USDC");
     });
 
+    // https://git.eeqj.de/sneak/AutistMask/issues/632: the bundled list holds
+    // mainnet contracts, so on Sepolia any contract may carry its symbols.
+    test("a bundled symbol from another contract is listed on Sepolia only", async () => {
+        respondWith([fakeEthItem({ symbol: "USDC", decimals: "6" })]);
+        expect(
+            await fetchTokenBalances(HOLDER, BLOCKSCOUT, [], MAINNET),
+        ).toEqual([]);
+        const sepolia = await fetchTokenBalances(
+            HOLDER,
+            BLOCKSCOUT,
+            [],
+            SEPOLIA,
+        );
+        expect(sepolia).toHaveLength(1);
+        expect(sepolia[0].symbol).toBe("USDC");
+    });
+
+    test("a fake ETH token is filtered on Sepolia too", async () => {
+        respondWith([fakeEthItem()]);
+        expect(
+            await fetchTokenBalances(HOLDER, BLOCKSCOUT, [], SEPOLIA),
+        ).toEqual([]);
+    });
+
     // The trap in this change: the user's real ETH balance is not an ERC-20
     // and is fetched over RPC in refreshBalances, so it never passes through
     // this loop at all.  An explorer row that is not an ERC-20 is dropped

tests/trackedTokenBalances.test.js

@@ -133,13 +133,13 @@ function trackedRow(balance, decimals = null, holders = null) {
     };
 }
 
-async function refresh(addresses, trackedTokens) {
+async function refresh(addresses, trackedTokens, networkId = "mainnet") {
     await refreshBalances(
         [{ addresses }],
         RPC_URL,
         EXPLORER_URL,
         trackedTokens,
-        "mainnet",
+        networkId,
         new AbortController().signal,
     );
     return addresses;
@@ -307,3 +307,104 @@ test("a tracked token wearing a known symbol from another contract is not listed
     );
     expect(first.tokenBalances).toEqual([]);
 });
+
+test("the refresh resolves with each tracked token whose balance it read at every address", async () => {
+    const flaky = "0x9999999999999999999999999999999999999999";
+    holdings[TOKEN] = { [FIRST]: 2000000n, [SECOND]: 0n };
+    // balanceOf answers at FIRST and fails at SECOND.
+    holdings[flaky] = { [FIRST]: 2000000n };
+    const read = await refreshBalances(
+        [
+            {
+                addresses: [
+                    { address: FIRST, tokenBalances: [] },
+                    { address: SECOND, tokenBalances: [] },
+                ],
+            },
+        ],
+        RPC_URL,
+        EXPLORER_URL,
+        [
+            TRACKED,
+            { address: flaky, symbol: "FLK", name: "Flaky", decimals: 6 },
+            // A known symbol from another contract: its balance is not read.
+            { address: OTHER, symbol: "USDC", name: "Fake", decimals: 6 },
+        ],
+        "mainnet",
+        new AbortController().signal,
+    );
+    expect(read).toEqual([TOKEN]);
+});
+
+// https://git.eeqj.de/sneak/AutistMask/issues/632: the bundled list holds
+// Ethereum Mainnet contracts. A token outside the tracked tokens with an
+// unknown holder count is listed only when the bundled list names it.
+test("an untracked bundled token with an unknown holder count is listed on Ethereum Mainnet only", async () => {
+    explorerRows = [explorerRow(USDC, "USDC", 5000000, null)];
+    const [mainnet] = await refresh(
+        [{ address: FIRST, tokenBalances: [] }],
+        [],
+    );
+    expect(mainnet.tokenBalances).toEqual([
+        {
+            address: USDC,
+            name: "USDC",
+            symbol: "USDC",
+            decimals: 6,
+            balance: "5.0",
+            holders: null,
+        },
+    ]);
+    const [sepolia] = await refresh(
+        [{ address: FIRST, tokenBalances: [] }],
+        [],
+        "sepolia",
+    );
+    expect(sepolia.tokenBalances).toEqual([]);
+});
+
+test("a tracked token at a bundled token's address takes the bundled scale on Ethereum Mainnet only", async () => {
+    holdings[USDC] = { [FIRST]: 5000000n };
+    // The tracked entry records no decimals, and Blockscout fails.
+    const tracked = [
+        { address: USDC, symbol: "USDC", name: "USD Coin", decimals: null },
+    ];
+    const row = (balance) => ({
+        address: USDC,
+        name: "USD Coin",
+        symbol: "USDC",
+        decimals: null,
+        balance: balance,
+        holders: null,
+    });
+    const [mainnet] = await refresh(
+        [{ address: FIRST, tokenBalances: [] }],
+        tracked,
+    );
+    expect(mainnet.tokenBalances).toEqual([row("5.0")]);
+    const [sepolia] = await refresh(
+        [{ address: FIRST, tokenBalances: [] }],
+        tracked,
+        "sepolia",
+    );
+    expect(sepolia.tokenBalances).toEqual([row(null)]);
+});
+
+test("with Sepolia active, a tracked token wearing a bundled symbol from another contract is listed", async () => {
+    holdings[OTHER] = { [FIRST]: 5000000n };
+    const [first] = await refresh(
+        [{ address: FIRST, tokenBalances: [] }],
+        [{ address: OTHER, symbol: "USDC", name: "Other", decimals: 6 }],
+        "sepolia",
+    );
+    expect(first.tokenBalances).toEqual([
+        {
+            address: OTHER,
+            name: "Other",
+            symbol: "USDC",
+            decimals: null,
+            balance: "5.0",
+            holders: null,
+        },
+    ]);
+});

tests/trackedTokensPerNetwork.test.js

@@ -117,6 +117,17 @@ async function chooseNetwork(boot, networkId) {
     await boot.settle();
 }
 
+// Adds NEW_TOKEN_ADDRESS by contract address on SettingsAddToken, as the user
+// does. Returns the record the add tracks.
+async function addNewToken(boot) {
+    const { lookupTokenInfo } = require("../src/shared/balances");
+    const info = { symbol: "NEW", decimals: 18, name: "New Token" };
+    lookupTokenInfo.mockResolvedValueOnce(info);
+    boot.node("settings-addtoken-address").value = NEW_TOKEN_ADDRESS;
+    await boot.click("btn-settings-addtoken-manual");
+    return { address: NEW_TOKEN_ADDRESS, ...info, balanceNotFetched: true };
+}
+
 // The Settings gear, a switch to Sepolia, and Back.
 async function gearSwitchBack(boot) {
     await boot.click("btn-settings");
@@ -162,7 +173,9 @@ test("a token added by contract address on Sepolia is tracked on Sepolia only",
         "sepolia",
         expect.anything(),
     );
-    expect(stored().trackedTokens).toEqual([SEPOLIA_TOKEN]);
+    // No refresh has read the new token's balance yet.
+    const added = { ...SEPOLIA_TOKEN, balanceNotFetched: true };
+    expect(stored().trackedTokens).toEqual([added]);
 
     await boot.click("btn-settings");
     await chooseNetwork(boot, "mainnet");
@@ -174,7 +187,7 @@ test("a token added by contract address on Sepolia is tracked on Sepolia only",
 
     await chooseNetwork(boot, "sepolia");
     expect(stored().networkId).toBe("sepolia");
-    expect(stored().trackedTokens).toEqual([SEPOLIA_TOKEN]);
+    expect(stored().trackedTokens).toEqual([added]);
     const onSepolia = boot.node("settings-tracked-tokens").innerHTML;
     expect(onSepolia).toContain("TST");
     expect(onSepolia).not.toContain("DAI");
@@ -267,6 +280,192 @@ test("a token tracked on Sepolia when another page switched there is not tracked
     expect(stored.networkTrackedTokens.mainnet).toEqual([]);
 });
 
+// Another popup page saves a switch to Sepolia, where TST is tracked. Before
+// taking that switch, this page adds a token on Ethereum Mainnet. The add's
+// save adds the token to Ethereum Mainnet's list and leaves Sepolia's list as
+// it was.
+test("a token added before this page takes another page's switch is tracked on Ethereum Mainnet", async () => {
+    const boot = await bootOnAddToken("mainnet", {
+        trackedTokens: [MAINNET_TOKEN],
+        networkTrackedTokens: { sepolia: [SEPOLIA_TOKEN] },
+    });
+    expect(boot.pageErrors).toEqual([]);
+    boot.storage.write("autistmask", {
+        ...boot.storage.read("autistmask"),
+        networkId: "sepolia",
+        trackedTokens: [SEPOLIA_TOKEN],
+        networkTrackedTokens: {
+            mainnet: [MAINNET_TOKEN],
+            sepolia: [SEPOLIA_TOKEN],
+        },
+    });
+    const { lookupTokenInfo } = require("../src/shared/balances");
+    lookupTokenInfo.mockResolvedValueOnce({
+        symbol: "NEW",
+        decimals: 18,
+        name: "New Token",
+    });
+
+    boot.node("settings-addtoken-address").value = NEW_TOKEN_ADDRESS;
+    await boot.click("btn-settings-addtoken-manual");
+
+    const stored = boot.storage.read("autistmask");
+    expect(stored.networkId).toBe("sepolia");
+    expect(stored.trackedTokens).toEqual([SEPOLIA_TOKEN]);
+    expect(stored.networkTrackedTokens.mainnet).toEqual([
+        MAINNET_TOKEN,
+        {
+            address: NEW_TOKEN_ADDRESS,
+            symbol: "NEW",
+            decimals: 18,
+            name: "New Token",
+            balanceNotFetched: true,
+        },
+    ]);
+});
+
+// Another popup page tracks DAI on Ethereum Mainnet and then saves a switch to
+// Sepolia. This page does not track DAI. Before taking that switch, this page
+// adds a token on Ethereum Mainnet. The add's save puts both DAI and the new
+// token on Ethereum Mainnet's list.
+test("a token added before this page takes another page's switch joins that page's tokens on Ethereum Mainnet", async () => {
+    const boot = await bootOnAddToken("mainnet");
+    expect(boot.pageErrors).toEqual([]);
+    boot.storage.write("autistmask", {
+        ...boot.storage.read("autistmask"),
+        networkId: "sepolia",
+        trackedTokens: [],
+        networkTrackedTokens: { mainnet: [MAINNET_TOKEN] },
+    });
+    const { lookupTokenInfo } = require("../src/shared/balances");
+    lookupTokenInfo.mockResolvedValueOnce({
+        symbol: "NEW",
+        decimals: 18,
+        name: "New Token",
+    });
+
+    boot.node("settings-addtoken-address").value = NEW_TOKEN_ADDRESS;
+    await boot.click("btn-settings-addtoken-manual");
+
+    const stored = boot.storage.read("autistmask");
+    expect(stored.networkId).toBe("sepolia");
+    expect(stored.trackedTokens).toEqual([]);
+    expect(stored.networkTrackedTokens.mainnet).toEqual([
+        MAINNET_TOKEN,
+        {
+            address: NEW_TOKEN_ADDRESS,
+            symbol: "NEW",
+            decimals: 18,
+            name: "New Token",
+            balanceNotFetched: true,
+        },
+    ]);
+});
+
+// Another popup page saves a switch to Sepolia, where TST is tracked. Before
+// taking that switch, this page removes DAI on Ethereum Mainnet, as the `[x]`
+// on a tracked token in Settings does. The removal's save drops DAI from
+// Ethereum Mainnet's list and leaves Sepolia's list as it was.
+test("a token removed before this page takes another page's switch is gone from Ethereum Mainnet", async () => {
+    const boot = await bootPopup(
+        unversionedValidProfile({
+            trackedTokens: [MAINNET_TOKEN],
+            networkTrackedTokens: { sepolia: [SEPOLIA_TOKEN] },
+        }),
+    );
+    expect(boot.pageErrors).toEqual([]);
+    boot.storage.write("autistmask", {
+        ...boot.storage.read("autistmask"),
+        networkId: "sepolia",
+        trackedTokens: [SEPOLIA_TOKEN],
+        networkTrackedTokens: {
+            mainnet: [MAINNET_TOKEN],
+            sepolia: [SEPOLIA_TOKEN],
+        },
+    });
+
+    const { state, saveState } = require("../src/shared/state");
+    state.trackedTokens.splice(0, 1);
+    await saveState();
+
+    const stored = boot.storage.read("autistmask");
+    expect(stored.networkId).toBe("sepolia");
+    expect(stored.trackedTokens).toEqual([SEPOLIA_TOKEN]);
+    expect(stored.networkTrackedTokens.mainnet).toEqual([]);
+});
+
+// Another popup page tracks DAI on Ethereum Mainnet and then saves a switch to
+// Sepolia. That switch puts DAI away under Ethereum Mainnet. This page has not
+// taken the switch yet. A switch to Sepolia in this page's Settings keeps DAI
+// on Ethereum Mainnet's list.
+test("a token another page tracked before its own switch stays tracked on Ethereum Mainnet", async () => {
+    const boot = await bootPopup(unversionedValidProfile());
+    expect(boot.pageErrors).toEqual([]);
+    await boot.click("btn-settings");
+    boot.storage.write("autistmask", {
+        ...boot.storage.read("autistmask"),
+        networkId: "sepolia",
+        trackedTokens: [],
+        networkTrackedTokens: { mainnet: [MAINNET_TOKEN] },
+    });
+
+    await chooseNetwork(boot, "sepolia");
+
+    const stored = boot.storage.read("autistmask");
+    expect(stored.networkId).toBe("sepolia");
+    expect(stored.networkTrackedTokens.mainnet).toEqual([MAINNET_TOKEN]);
+});
+
+// This page switches to Sepolia. Another popup page has not taken that switch,
+// and its save adds a token to Ethereum Mainnet's list. This page switches back
+// and tracks that token.
+test("a token another page added on Ethereum Mainnet is tracked when this page switches back there", async () => {
+    const boot = await bootPopup(
+        unversionedValidProfile({ trackedTokens: [MAINNET_TOKEN] }),
+    );
+    expect(boot.pageErrors).toEqual([]);
+    await boot.click("btn-settings");
+    await chooseNetwork(boot, "sepolia");
+    const newToken = {
+        address: NEW_TOKEN_ADDRESS,
+        symbol: "NEW",
+        decimals: 18,
+        name: "New Token",
+    };
+    boot.storage.write("autistmask", {
+        ...boot.storage.read("autistmask"),
+        networkTrackedTokens: { mainnet: [MAINNET_TOKEN, newToken] },
+    });
+
+    await chooseNetwork(boot, "mainnet");
+
+    const stored = boot.storage.read("autistmask");
+    expect(stored.networkId).toBe("mainnet");
+    expect(stored.trackedTokens).toEqual([MAINNET_TOKEN, newToken]);
+});
+
+// This page tracks DAI on Ethereum Mainnet and switches to Sepolia. Another
+// popup page has not taken that switch, and its save removes DAI from Ethereum
+// Mainnet's list. This page switches back and does not track DAI again.
+test("a token another page removed on Ethereum Mainnet stays removed when this page switches back there", async () => {
+    const boot = await bootPopup(
+        unversionedValidProfile({ trackedTokens: [MAINNET_TOKEN] }),
+    );
+    expect(boot.pageErrors).toEqual([]);
+    await boot.click("btn-settings");
+    await chooseNetwork(boot, "sepolia");
+    boot.storage.write("autistmask", {
+        ...boot.storage.read("autistmask"),
+        networkTrackedTokens: { mainnet: [] },
+    });
+
+    await chooseNetwork(boot, "mainnet");
+
+    const stored = boot.storage.read("autistmask");
+    expect(stored.networkId).toBe("mainnet");
+    expect(stored.trackedTokens).toEqual([]);
+});
+
 // Another popup page records a fraud contract on Ethereum Mainnet after this
 // page's last save. The switch to Sepolia drops that fraud contract, as the
 // switch drops this page's own.
@@ -334,10 +533,276 @@ test("a token added while a switch in Settings waits for the lock stays tracked
             symbol: "NEW",
             decimals: 18,
             name: "New Token",
+            balanceNotFetched: true,
         },
     ]);
 });
 
+// The contract lookup on SettingsAddToken answers on Ethereum Mainnet while
+// this page's switch to Sepolia waits for the lock. Another popup page holds
+// the lock and stores its own switch to Sepolia, with DAI tracked on Ethereum
+// Mainnet. This page's switch keeps DAI and the new token on Ethereum Mainnet's
+// list.
+test("a token added while a switch in Settings waits for another page's switch stays tracked on Ethereum Mainnet", async () => {
+    const boot = await bootOnAddToken("mainnet");
+    expect(boot.pageErrors).toEqual([]);
+    const { lookupTokenInfo } = require("../src/shared/balances");
+    let answer;
+    lookupTokenInfo.mockImplementationOnce(
+        () =>
+            new Promise((resolve) => {
+                answer = resolve;
+            }),
+    );
+    boot.node("settings-addtoken-address").value = NEW_TOKEN_ADDRESS;
+    const adding = boot.click("btn-settings-addtoken-manual");
+    await boot.click("btn-settings");
+
+    let releaseLock;
+    const lockHeld = navigator.locks.request(
+        "autistmask",
+        () =>
+            new Promise((resolve) => {
+                releaseLock = resolve;
+            }),
+    );
+    const select = boot.node("settings-network");
+    select.value = "sepolia";
+    const switching = Promise.all(select.listeners.change.map((fn) => fn()));
+    await boot.settle();
+    boot.storage.write("autistmask", {
+        ...boot.storage.read("autistmask"),
+        networkId: "sepolia",
+        trackedTokens: [],
+        networkTrackedTokens: { mainnet: [MAINNET_TOKEN] },
+    });
+
+    answer({ symbol: "NEW", decimals: 18, name: "New Token" });
+    await boot.settle();
+    releaseLock();
+    await lockHeld;
+    await switching;
+    await adding;
+
+    const stored = boot.storage.read("autistmask");
+    expect(stored.networkId).toBe("sepolia");
+    expect(stored.trackedTokens).toEqual([]);
+    expect(stored.networkTrackedTokens.mainnet).toEqual([
+        MAINNET_TOKEN,
+        {
+            address: NEW_TOKEN_ADDRESS,
+            symbol: "NEW",
+            decimals: 18,
+            name: "New Token",
+            balanceNotFetched: true,
+        },
+    ]);
+});
+
+// Another popup page holds the lock and stores its switch to Sepolia, with DAI
+// tracked on Ethereum Mainnet. This page waits for the lock to take that
+// switch. Meanwhile, the contract lookup on SettingsAddToken answers on
+// Ethereum Mainnet. When this page takes that switch, DAI and the new token
+// stay on Ethereum Mainnet's list.
+test("a token added while this page waits to take another page's switch stays tracked on Ethereum Mainnet", async () => {
+    const boot = await bootOnAddToken("mainnet");
+    expect(boot.pageErrors).toEqual([]);
+    let releaseLock;
+    const lockHeld = navigator.locks.request(
+        "autistmask",
+        () =>
+            new Promise((resolve) => {
+                releaseLock = resolve;
+            }),
+    );
+    await boot.storage.local.set({
+        autistmask: {
+            ...boot.storage.read("autistmask"),
+            networkId: "sepolia",
+            trackedTokens: [],
+            networkTrackedTokens: { mainnet: [MAINNET_TOKEN] },
+        },
+    });
+    await boot.settle();
+    const { lookupTokenInfo } = require("../src/shared/balances");
+    lookupTokenInfo.mockResolvedValueOnce({
+        symbol: "NEW",
+        decimals: 18,
+        name: "New Token",
+    });
+
+    boot.node("settings-addtoken-address").value = NEW_TOKEN_ADDRESS;
+    const adding = boot.click("btn-settings-addtoken-manual");
+    await boot.settle();
+    releaseLock();
+    await lockHeld;
+    await adding;
+    await boot.settle();
+
+    const stored = boot.storage.read("autistmask");
+    expect(stored.networkId).toBe("sepolia");
+    expect(stored.trackedTokens).toEqual([]);
+    expect(stored.networkTrackedTokens.mainnet).toEqual([
+        MAINNET_TOKEN,
+        {
+            address: NEW_TOKEN_ADDRESS,
+            symbol: "NEW",
+            decimals: 18,
+            name: "New Token",
+            balanceNotFetched: true,
+        },
+    ]);
+});
+
+// This page tracks DAI on Ethereum Mainnet. Another popup page holds the lock
+// and stores its switch to Sepolia, with DAI on Ethereum Mainnet's list. This
+// page waits for the lock to take that switch. Meanwhile, the user removes DAI,
+// as the `[x]` on a tracked token in Settings does. When this page takes that
+// switch, DAI is gone from Ethereum Mainnet's list.
+test("a token removed while this page waits to take another page's switch is gone from Ethereum Mainnet", async () => {
+    const boot = await bootPopup(
+        unversionedValidProfile({ trackedTokens: [MAINNET_TOKEN] }),
+    );
+    expect(boot.pageErrors).toEqual([]);
+    let releaseLock;
+    const lockHeld = navigator.locks.request(
+        "autistmask",
+        () =>
+            new Promise((resolve) => {
+                releaseLock = resolve;
+            }),
+    );
+    await boot.storage.local.set({
+        autistmask: {
+            ...boot.storage.read("autistmask"),
+            networkId: "sepolia",
+            trackedTokens: [],
+            networkTrackedTokens: { mainnet: [MAINNET_TOKEN] },
+        },
+    });
+    await boot.settle();
+
+    const { state, saveState } = require("../src/shared/state");
+    state.trackedTokens.splice(0, 1);
+    const removing = saveState();
+    releaseLock();
+    await lockHeld;
+    await removing;
+    await boot.settle();
+
+    const stored = boot.storage.read("autistmask");
+    expect(stored.networkId).toBe("sepolia");
+    expect(stored.trackedTokens).toEqual([]);
+    expect(stored.networkTrackedTokens.mainnet).toEqual([]);
+});
+
+// Another popup page tracks DAI after this page's last save. This page then
+// adds a token. Its save keeps DAI.
+test("a token another page added stays when this page adds a token", async () => {
+    const boot = await bootOnAddToken("mainnet");
+    expect(boot.pageErrors).toEqual([]);
+    boot.storage.write("autistmask", {
+        ...boot.storage.read("autistmask"),
+        trackedTokens: [MAINNET_TOKEN],
+    });
+
+    const added = await addNewToken(boot);
+
+    expect(boot.storage.read("autistmask").trackedTokens).toEqual([
+        MAINNET_TOKEN,
+        added,
+    ]);
+});
+
+// Another popup page tracks a new token after this page's last save. This page
+// then removes DAI, as the `[x]` on a tracked token in Settings does. Its save
+// keeps the new token.
+test("a token another page added stays when this page removes a token", async () => {
+    const boot = await bootPopup(
+        unversionedValidProfile({ trackedTokens: [MAINNET_TOKEN] }),
+    );
+    expect(boot.pageErrors).toEqual([]);
+    const otherPageToken = {
+        address: NEW_TOKEN_ADDRESS,
+        symbol: "NEW",
+        decimals: 18,
+        name: "New Token",
+    };
+    boot.storage.write("autistmask", {
+        ...boot.storage.read("autistmask"),
+        trackedTokens: [MAINNET_TOKEN, otherPageToken],
+    });
+
+    const { state, saveState } = require("../src/shared/state");
+    state.trackedTokens.splice(0, 1);
+    await saveState();
+
+    expect(boot.storage.read("autistmask").trackedTokens).toEqual([
+        otherPageToken,
+    ]);
+});
+
+// Another popup page stops tracking DAI after this page's last save. This page
+// still holds DAI and adds a token. Its save does not store DAI again.
+test("a token another page removed stays removed when this page adds a token", async () => {
+    const boot = await bootOnAddToken("mainnet", {
+        trackedTokens: [MAINNET_TOKEN],
+    });
+    expect(boot.pageErrors).toEqual([]);
+    boot.storage.write("autistmask", {
+        ...boot.storage.read("autistmask"),
+        trackedTokens: [],
+    });
+
+    const added = await addNewToken(boot);
+
+    expect(boot.storage.read("autistmask").trackedTokens).toEqual([added]);
+});
+
+// Another popup page tracks DAI and the new token after this page's last save,
+// and its refresh has read the new token's balance. This page adds the new token
+// too, so the two pages hold different records for it. The save stores one
+// record for the new token, this page's, and keeps DAI.
+test("a token both pages added is stored once, with this page's record", async () => {
+    const boot = await bootOnAddToken("mainnet");
+    expect(boot.pageErrors).toEqual([]);
+    boot.storage.write("autistmask", {
+        ...boot.storage.read("autistmask"),
+        trackedTokens: [
+            MAINNET_TOKEN,
+            {
+                address: NEW_TOKEN_ADDRESS,
+                symbol: "NEW",
+                decimals: 18,
+                name: "New Token",
+            },
+        ],
+    });
+
+    const added = await addNewToken(boot);
+
+    expect(boot.storage.read("autistmask").trackedTokens).toEqual([
+        MAINNET_TOKEN,
+        added,
+    ]);
+});
+
+// This page and the stored list each hold DAI twice. This page then adds a
+// token. Its save stores DAI once.
+test("a token held twice is stored once when this page adds a token", async () => {
+    const boot = await bootOnAddToken("mainnet", {
+        trackedTokens: [MAINNET_TOKEN, MAINNET_TOKEN],
+    });
+    expect(boot.pageErrors).toEqual([]);
+
+    const added = await addNewToken(boot);
+
+    expect(boot.storage.read("autistmask").trackedTokens).toEqual([
+        MAINNET_TOKEN,
+        added,
+    ]);
+});
+
 describe("Back after a switch from the Settings gear", () => {
     test("SettingsAddToken no longer offers the common tokens", async () => {
         const boot = await bootOnAddToken("mainnet");

tests/transactions.test.js

@@ -144,6 +144,7 @@ function tokenTx(overrides = {}) {
         isError: false,
         contractAddress: USDC_CONTRACT,
         holders: 3500000,
+        chainId: "0x1",
         ...overrides,
     };
 }
@@ -259,6 +260,32 @@ describe("known-symbol spoof verification", () => {
         expect(result.newFraudContracts).toEqual([NOVEL_SPAM_CONTRACT]);
     });
 
+    // https://git.eeqj.de/sneak/AutistMask/issues/632: the bundled list holds
+    // mainnet contracts, so its symbols are not known symbols on Sepolia.
+    test("on Sepolia, a bundled symbol from another contract is kept", () => {
+        const sepoliaToken = tokenTx({
+            symbol: "USDC",
+            contractAddress: NOVEL_SPAM_CONTRACT,
+            holders: 5000000,
+            chainId: "0xaa36a7",
+        });
+        const result = filterTransactions([sepoliaToken], filters());
+        expect(result.transactions).toEqual([sepoliaToken]);
+        expect(result.newFraudContracts).toEqual([]);
+    });
+
+    test('on Sepolia, "ETH" as an ERC-20 is still spoofed', () => {
+        const fakeEth = tokenTx({
+            symbol: "ETH",
+            contractAddress: NOVEL_SPAM_CONTRACT,
+            holders: 5000000,
+            chainId: "0xaa36a7",
+        });
+        expect(filterTransactions([fakeEth], filters()).transactions).toEqual(
+            [],
+        );
+    });
+
     test("the genuine contract for that symbol is not spoofed", () => {
         const genuine = tokenTx();
         const result = filterTransactions([genuine], filters());
@@ -1495,6 +1522,41 @@ describe("fetchRecentTransactions merge and dedup", () => {
         expect(mainnet[0].chainId).toBe("0x1");
     });
 
+    // https://git.eeqj.de/sneak/AutistMask/issues/632: the bundled token list
+    // names a contract only on Ethereum Mainnet. On Sepolia, a call to the
+    // contract at USDC's mainnet address is labelled with the network's native
+    // currency. A call to any contract the wallet does not name gets that label.
+    test("a contract call on Sepolia is not named by the bundled list", async () => {
+        respondWith(
+            [
+                {
+                    hash: "0x" + "b".repeat(64),
+                    block_number: 21000095,
+                    timestamp: TS,
+                    from: { hash: VICTIM },
+                    to: { hash: USDC_CONTRACT, is_contract: true },
+                    value: "0",
+                    method: "approve",
+                    status: "ok",
+                },
+            ],
+            [],
+        );
+        const sepolia = await fetchRecentTransactions(
+            VICTIM,
+            BLOCKSCOUT,
+            "0xaa36a7",
+        );
+        expect(sepolia[0].directionLabel).toBe("Approve");
+        expect(sepolia[0].symbol).toBe("SepoliaETH");
+        const mainnet = await fetchRecentTransactions(
+            VICTIM,
+            BLOCKSCOUT,
+            "0x1",
+        );
+        expect(mainnet[0].symbol).toBe("USDC");
+    });
+
     test("the fake token transfer survives fetching and is then filtered", async () => {
         respondWith(
             [],

tests/uniswap.test.js

@@ -1428,8 +1428,8 @@ describe("uniswap decoder", () => {
         ];
 
         // execute() of these command bytes and inputs, decoded as sent by
-        // the user.
-        function decodeSteps(commands, inputs) {
+        // the user to `router`.
+        function decodeSteps(commands, inputs, router = ROUTER_ADDR) {
             const data = buildExecute(
                 solidityPacked(
                     commands.map(() => "uint8"),
@@ -1438,7 +1438,7 @@ describe("uniswap decoder", () => {
                 inputs,
                 9999999999n,
             );
-            return uniswap.decode(data, ROUTER_ADDR, "0x1", {}, USER_ADDR);
+            return uniswap.decode(data, router, "0x1", {}, USER_ADDR);
         }
 
         // The first step: a V3 exact-in of 600 USDT for USDC, paid by the
@@ -2424,6 +2424,335 @@ describe("uniswap decoder", () => {
             expect(linesBetweenTokens(result)).toEqual(lines);
         });
 
+        // https://git.eeqj.de/sneak/AutistMask/issues/665 — a WRAP_ETH that
+        // sets the input side and pays its WETH to anyone but the router
+        // names that recipient on its Moved to line. On next each row read
+        // The swap step that spends it.
+        const ONE_ETH = 1000000000000000000n;
+        const MSG_SENDER = "0x0000000000000000000000000000000000000001";
+        // The lines of a WRAP_ETH of 1 ETH whose Moved to line reads `to`.
+        const wrapLines = (to) => [
+            ["Moved from the sender", "1.0000 ETH"],
+            ["Token moved", "ETH"],
+            ["Moved to", to],
+        ];
+        test.each([
+            {
+                kind: "a WRAP_ETH of 1 ETH to another address, then an EXECUTE_SUB_PLAN",
+                commands: [0x0b, 0x21],
+                inputs: [encodeWrapEth(OTHER_ADDR, ONE_ETH), SUB_PLAN],
+                lines: [
+                    ...wrapLines(OTHER_ADDR),
+                    ["Moved from the sender", UNDECODED],
+                ],
+            },
+            {
+                kind: "a WRAP_ETH of 1 ETH to address(1), then an EXECUTE_SUB_PLAN",
+                commands: [0x0b, 0x21],
+                inputs: [encodeWrapEth(MSG_SENDER, ONE_ETH), SUB_PLAN],
+                lines: [
+                    ...wrapLines("The sender"),
+                    ["Moved from the sender", UNDECODED],
+                ],
+            },
+            {
+                kind: "a PERMIT2_PERMIT of 5,000 USDT to the router, a WRAP_ETH of 1 ETH to another address, then a V3 exact-in of 600 USDT",
+                commands: [0x0a, 0x0b, 0x00],
+                inputs: [
+                    encodePermit2(USDT_ADDR, 5000000000n, ROUTER_ADDR),
+                    encodeWrapEth(OTHER_ADDR, ONE_ETH),
+                    V3_600,
+                ],
+                lines: [["Amount", "5000.0000 USDT"], ...wrapLines(OTHER_ADDR)],
+            },
+        ])("$kind", ({ commands, inputs, lines }) => {
+            const result = decodeSteps(commands, inputs);
+            expect(linesBetweenTokens(result)).toEqual(lines);
+        });
+
+        // https://git.eeqj.de/sneak/AutistMask/issues/665 — V4Router pays a
+        // SETTLE of ETH from the router's own ETH, whichever payer it names.
+        // After an earlier step that may leave ETH in the router, the ETH that
+        // the user pays a V4 step reads as a maximum, on lines of its own.
+        // Every row reads at least the ETH that can leave the wallet. The two
+        // rows marked "reads as on next" read the same on next. On next every
+        // other row added that ETH to the Amount line, or read it as an exact
+        // amount.
+        //
+        // ADDRESS_THIS is the router on every release.
+        const ADDRESS_THIS = "0x0000000000000000000000000000000000000002";
+        const WRAP_INTO_ROUTER = encodeWrapEth(ADDRESS_THIS, ONE_ETH);
+        // UNWRAP_WETH has the layout of WRAP_ETH.
+        const UNWRAP_INTO_ROUTER = encodeWrapEth(ADDRESS_THIS, 0n);
+        // A V4 step swapping `amount` of ETH for USDC, with a SETTLE of
+        // OPEN_DELTA by the user.
+        const v4EthForUsdc = (amount) =>
+            encodeV4Swap(
+                new Uint8Array([
+                    V4_SWAP_EXACT_IN_SINGLE_ID,
+                    V4_SETTLE_ID,
+                    V4_TAKE_ALL_ID,
+                ]),
+                [
+                    encodeV4ExactInSingle(ZERO_ADDR, USDC_ADDR, amount, 1n),
+                    settle(ZERO_ADDR, 0n, true),
+                    encodeV4TakeAll(USDC_ADDR, 0n),
+                ],
+            );
+        const V4_ONE_ETH = v4EthForUsdc(ONE_ETH);
+        // A TRANSFER or PAY_PORTION of `amount` of `token` to another
+        // address.
+        const payOut = (token, amount) =>
+            coder.encode(
+                ["address", "address", "uint256"],
+                [token, OTHER_ADDR, amount],
+            );
+        // An ACROSS_V4_DEPOSIT_V3 of `amount` of ETH (`useNative` set), from
+        // the sender to the sender on chain id 8453.
+        const acrossEth = (amount) =>
+            coder.encode(
+                [
+                    "tuple(address,address,address,address,uint256,uint256,uint256,address,uint32,uint32,uint32,bytes,bool)",
+                ],
+                [
+                    [
+                        USER_ADDR,
+                        USER_ADDR,
+                        WETH_ADDR,
+                        WETH_ADDR,
+                        amount,
+                        1n,
+                        8453n,
+                        ZERO_ADDR,
+                        0,
+                        0,
+                        0,
+                        "0x",
+                        true,
+                    ],
+                ],
+            );
+        // The lines of ETH the sender pays a V4 step, of `amount`.
+        const ethLines = (amount) => [
+            ["Moved from the sender", amount],
+            ["Token moved", "ETH"],
+            ["Moved to", "The swap step that spends it"],
+        ];
+        test.each([
+            {
+                kind: "a WRAP_ETH of 1 ETH into the router, then a V4 swap of 1 ETH that the user settles, reads as on next",
+                commands: [0x0b, 0x10],
+                inputs: [WRAP_INTO_ROUTER, V4_ONE_ETH],
+                lines: [["Amount", "2.0000 ETH"]],
+            },
+            {
+                kind: "a WRAP_ETH of 1 ETH into the router, an UNWRAP_WETH into the router, then a V4 swap of 1 ETH that the user settles",
+                commands: [0x0b, 0x0c, 0x10],
+                inputs: [WRAP_INTO_ROUTER, UNWRAP_INTO_ROUTER, V4_ONE_ETH],
+                lines: [
+                    ["Amount", "1.0000 ETH"],
+                    ...ethLines("Up to 1.0000 ETH"),
+                ],
+            },
+            {
+                kind: "the same with a TRANSFER of 1 ETH to another address after the UNWRAP_WETH",
+                commands: [0x0b, 0x0c, 0x05, 0x10],
+                inputs: [
+                    WRAP_INTO_ROUTER,
+                    UNWRAP_INTO_ROUTER,
+                    payOut(ZERO_ADDR, ONE_ETH),
+                    V4_ONE_ETH,
+                ],
+                lines: [
+                    ["Amount", "1.0000 ETH"],
+                    ...ethLines("Up to 1.0000 ETH"),
+                ],
+            },
+            {
+                kind: "the same with a PAY_PORTION of 5,000 bips of WETH to another address before the UNWRAP_WETH",
+                commands: [0x0b, 0x06, 0x0c, 0x10],
+                inputs: [
+                    WRAP_INTO_ROUTER,
+                    payOut(WETH_ADDR, 5000n),
+                    UNWRAP_INTO_ROUTER,
+                    V4_ONE_ETH,
+                ],
+                lines: [
+                    ["Amount", "1.0000 ETH"],
+                    ...ethLines("Up to 1.0000 ETH"),
+                ],
+            },
+            {
+                kind: "the same with a WRAP_ETH of 1 ETH to another address after the UNWRAP_WETH",
+                commands: [0x0b, 0x0c, 0x0b, 0x10],
+                inputs: [
+                    WRAP_INTO_ROUTER,
+                    UNWRAP_INTO_ROUTER,
+                    encodeWrapEth(OTHER_ADDR, ONE_ETH),
+                    V4_ONE_ETH,
+                ],
+                lines: [
+                    ["Amount", "1.0000 ETH"],
+                    ...ethLines("Up to 1.0000 ETH"),
+                ],
+            },
+            {
+                kind: "the same on UniversalRouterV2_1_2 with an ACROSS_V4_DEPOSIT_V3 of 1 ETH after the UNWRAP_WETH",
+                router: ROUTER_V2_1_2_ADDR,
+                commands: [0x0b, 0x0c, 0x40, 0x10],
+                inputs: [
+                    WRAP_INTO_ROUTER,
+                    UNWRAP_INTO_ROUTER,
+                    acrossEth(ONE_ETH),
+                    V4_ONE_ETH,
+                ],
+                lines: [
+                    ["Amount", "1.0000 ETH"],
+                    ...ethLines("Up to 1.0000 ETH"),
+                ],
+            },
+            {
+                kind: "a V3 exact-in of 600 USDT that the user pays, a WRAP_ETH of 1 ETH into the router, an UNWRAP_WETH into the router, then a V4 swap of 1 ETH that the user settles",
+                commands: [0x00, 0x0b, 0x0c, 0x10],
+                inputs: [
+                    V3_600,
+                    WRAP_INTO_ROUTER,
+                    UNWRAP_INTO_ROUTER,
+                    V4_ONE_ETH,
+                ],
+                lines: [
+                    ["Amount", "600.0000 USDT"],
+                    ...ethLines("Up to 1.0000 ETH"),
+                ],
+            },
+            {
+                kind: "a V3 exact-in of 600 USDT for WETH paid to the router, an UNWRAP_WETH into the router, then a V4 swap of 1 ETH that the user settles",
+                commands: [0x00, 0x0c, 0x10],
+                inputs: [
+                    encodeV3SwapExactIn(ADDRESS_THIS, USDT_600, 1n, [
+                        USDT_ADDR,
+                        WETH_ADDR,
+                    ]),
+                    UNWRAP_INTO_ROUTER,
+                    V4_ONE_ETH,
+                ],
+                lines: [
+                    ["Amount", "600.0000 USDT"],
+                    ...ethLines("Up to 1.0000 ETH"),
+                ],
+            },
+            {
+                kind: "a V4 swap of 600 USDT that takes ETH into the router, then a V4 swap of 5 ETH that the user settles",
+                commands: [0x10, 0x10],
+                inputs: [
+                    encodeV4Swap(
+                        new Uint8Array([
+                            V4_SWAP_EXACT_IN_SINGLE_ID,
+                            V4_SETTLE_ID,
+                            V4_TAKE_ID,
+                        ]),
+                        [
+                            encodeV4ExactInSingle(
+                                USDT_ADDR,
+                                ZERO_ADDR,
+                                USDT_600,
+                                1n,
+                            ),
+                            settle(USDT_ADDR, 0n, true),
+                            take(ZERO_ADDR, ADDRESS_THIS, 0n),
+                        ],
+                    ),
+                    v4EthForUsdc(5n * ONE_ETH),
+                ],
+                lines: [
+                    ["Amount", "600.0000 USDT"],
+                    ...ethLines("Up to 5.0000 ETH"),
+                ],
+            },
+            {
+                kind: "a WRAP_ETH of 1 ETH into the router, an UNWRAP_WETH into the router, then a V4 exact-out paid in ETH with a SETTLE_ALL of at most 3 ETH, reads as on next",
+                commands: [0x0b, 0x0c, 0x10],
+                inputs: [
+                    WRAP_INTO_ROUTER,
+                    UNWRAP_INTO_ROUTER,
+                    encodeV4Swap(
+                        new Uint8Array([
+                            V4_SWAP_EXACT_OUT_SINGLE_ID,
+                            V4_SETTLE_ALL_ID,
+                            V4_TAKE_ALL_ID,
+                        ]),
+                        [
+                            encodeV4ExactOutSingle(
+                                ZERO_ADDR,
+                                USDC_ADDR,
+                                390000000n,
+                                3n * ONE_ETH,
+                            ),
+                            encodeV4SettleAll(ZERO_ADDR, 3n * ONE_ETH),
+                            encodeV4TakeAll(USDC_ADDR, 0n),
+                        ],
+                    ),
+                ],
+                lines: [
+                    ...wrapLines("The swap step that spends it"),
+                    ...ethLines(UNDECODED),
+                ],
+            },
+            {
+                kind: "a WRAP_ETH of 1 ETH into the router, a V3 exact-out of at most 1 WETH paid from the router, an UNWRAP_WETH into the router, then a V4 swap of 1 ETH that the user settles",
+                commands: [0x0b, 0x01, 0x0c, 0x10],
+                inputs: [
+                    WRAP_INTO_ROUTER,
+                    encodeV3SwapExactOut(
+                        USER_ADDR,
+                        390000000n,
+                        ONE_ETH,
+                        [USDC_ADDR, WETH_ADDR],
+                        false,
+                    ),
+                    UNWRAP_INTO_ROUTER,
+                    V4_ONE_ETH,
+                ],
+                lines: [
+                    ["Amount", "Up to 1.0000 ETH"],
+                    ...ethLines("Up to 1.0000 ETH"),
+                ],
+            },
+            {
+                kind: "a WRAP_ETH of 1 ETH into the router, a V4 exact-out paid from the router's WETH, an UNWRAP_WETH into the router, then a V4 swap of 1 ETH that the user settles",
+                commands: [0x0b, 0x10, 0x0c, 0x10],
+                inputs: [
+                    WRAP_INTO_ROUTER,
+                    encodeV4Swap(
+                        new Uint8Array([
+                            V4_SWAP_EXACT_OUT_SINGLE_ID,
+                            V4_SETTLE_ID,
+                            V4_TAKE_ALL_ID,
+                        ]),
+                        [
+                            encodeV4ExactOutSingle(
+                                WETH_ADDR,
+                                USDC_ADDR,
+                                390000000n,
+                                ONE_ETH,
+                            ),
+                            settle(WETH_ADDR, 0n, false),
+                            encodeV4TakeAll(USDC_ADDR, 0n),
+                        ],
+                    ),
+                    UNWRAP_INTO_ROUTER,
+                    V4_ONE_ETH,
+                ],
+                lines: [
+                    ["Amount", "1.0000 ETH"],
+                    ...ethLines("Up to 1.0000 ETH"),
+                ],
+            },
+        ])("$kind", ({ router, commands, inputs, lines }) => {
+            const result = decodeSteps(commands, inputs, router);
+            expect(linesBetweenTokens(result)).toEqual(lines);
+        });
+
         // A V3_SWAP_EXACT_OUT the user pays for, of at most `amountInMax`
         // USDT for USDC.
         const v3ExactOut = (amountInMax) =>
@@ -2871,8 +3200,9 @@ describe("uniswap decoder", () => {
                         ...USDT_400_GROUP,
                         ...ONE_USDT_LINES(OTHER_ADDR),
                     ],
-                    // The last swap step's minimum.
-                    minimum: "390.0000 USDC",
+                    // Both swap steps pay USDC to the user, so the minimum
+                    // is the sum of their two minimums.
+                    minimum: "980.0000 USDC",
                 },
             ])(
                 "$kind shows each take's own lines and the allowances, and no Amount figure or Min. received",
@@ -3638,6 +3968,356 @@ describe("uniswap decoder", () => {
                 ]);
             });
         });
+
+        // https://git.eeqj.de/sneak/AutistMask/issues/647 — on next at
+        // f550d8c, a split whose steps each pay WETH to the user showed only
+        // the last step's minimum.
+        describe("the minimum of a split that pays WETH to the user", () => {
+            const WETH_01 = 100000000000000000n;
+            const WETH_02 = 200000000000000000n;
+            const WETH_03 = 300000000000000000n;
+            // A V3 exact-in of 600 USDT for at least 0.3 WETH, and a V2
+            // exact-in of 400 USDT for at least 0.2 WETH, each paid to the
+            // user.
+            const V3_TO_WETH = encodeV3SwapExactIn(
+                USER_ADDR,
+                USDT_600,
+                WETH_03,
+                [USDT_ADDR, WETH_ADDR],
+            );
+            const V2_TO_WETH = encodeV2SwapExactIn(
+                USER_ADDR,
+                USDT_400,
+                WETH_02,
+                [USDT_ADDR, WETH_ADDR],
+            );
+            // A V4 step that swaps 400 USDT for at least 0.2 WETH, with these
+            // TAKEs of the WETH.
+            const v4ToWeth = (...takes) =>
+                encodeV4Swap(
+                    new Uint8Array([
+                        V4_SWAP_EXACT_IN_SINGLE_ID,
+                        V4_SETTLE_ID,
+                        ...takes.map(() => V4_TAKE_ID),
+                    ]),
+                    [
+                        encodeV4ExactInSingle(
+                            USDT_ADDR,
+                            WETH_ADDR,
+                            USDT_400,
+                            WETH_02,
+                        ),
+                        encodeV4Settle(USDT_ADDR), // paid by the user
+                        ...takes,
+                    ],
+                );
+            // The swap's minimum line as [label, value], or undefined.
+            const minimum = (result) =>
+                result.details
+                    .filter(
+                        (d) =>
+                            d.label === "Min. received" ||
+                            d.label === "Min. paid out",
+                    )
+                    .map((d) => [d.label, d.value])[0];
+
+            test("a V3 and a V2 exact-in show the total of their minimums", () => {
+                const result = decodeSteps(
+                    [0x00, 0x08],
+                    [V3_TO_WETH, V2_TO_WETH],
+                );
+                expect(minimum(result)).toEqual([
+                    "Min. received",
+                    "0.5000 WETH",
+                ]);
+            });
+
+            test("a V3 exact-in and a V4 step show the total of their minimums", () => {
+                const result = decodeSteps(
+                    [0x00, 0x10],
+                    [V3_TO_WETH, v4ToWeth(encodeV4Take(WETH_ADDR))],
+                );
+                expect(minimum(result)).toEqual([
+                    "Min. received",
+                    "0.5000 WETH",
+                ]);
+            });
+
+            // The second route buys DAI for the router, then swaps all of it
+            // from the router for at least 0.2 WETH.
+            test("a route that hops through DAI counts its last hop's minimum", () => {
+                const result = decodeSteps(
+                    [0x00, 0x08, 0x00],
+                    [
+                        V3_TO_WETH,
+                        encodeV2SwapExactIn(ROUTER_ADDR, USDT_400, DAI_400, [
+                            USDT_ADDR,
+                            DAI_ADDR,
+                        ]),
+                        coder.encode(
+                            ["address", "uint256", "uint256", "bytes", "bool"],
+                            [
+                                USER_ADDR,
+                                2n ** 255n, // CONTRACT_BALANCE
+                                WETH_02,
+                                encodeV3Path([DAI_ADDR, WETH_ADDR]),
+                                false, // paid from the router
+                            ],
+                        ),
+                    ],
+                );
+                expect(minimum(result)).toEqual([
+                    "Min. received",
+                    "0.5000 WETH",
+                ]);
+            });
+
+            // The middle step swaps 0.3 of the user's WETH for USDC, so the
+            // sum of minimums starts again after it.
+            test.each([
+                {
+                    kind: "a V3 exact-in",
+                    command: 0x00,
+                    input: encodeV3SwapExactIn(USER_ADDR, WETH_03, 1n, [
+                        WETH_ADDR,
+                        USDC_ADDR,
+                    ]),
+                },
+                {
+                    kind: "a V2 exact-in",
+                    command: 0x08,
+                    input: encodeV2SwapExactIn(USER_ADDR, WETH_03, 1n, [
+                        WETH_ADDR,
+                        USDC_ADDR,
+                    ]),
+                },
+                {
+                    kind: "a V2 exact-out",
+                    command: 0x09,
+                    input: encodeV2SwapExactOut(USER_ADDR, 1n, WETH_03, [
+                        WETH_ADDR,
+                        USDC_ADDR,
+                    ]),
+                },
+                {
+                    kind: "a V3 exact-out",
+                    command: 0x01,
+                    input: encodeV3SwapExactOut(USER_ADDR, 1n, WETH_03, [
+                        USDC_ADDR,
+                        WETH_ADDR,
+                    ]),
+                },
+            ])(
+                "$kind that spends WETH between them leaves the last step's minimum",
+                ({ command, input }) => {
+                    const result = decodeSteps(
+                        [0x00, command, 0x08],
+                        [V3_TO_WETH, input, V2_TO_WETH],
+                    );
+                    expect(minimum(result)).toEqual([
+                        "Min. received",
+                        "0.2000 WETH",
+                    ]);
+                },
+            );
+
+            // The middle step swaps 0.3 WETH and 400 DAI for USDC, both paid
+            // by the user. It spends WETH whichever SETTLE comes last.
+            test.each([
+                { order: "WETH first", settled: [WETH_ADDR, DAI_ADDR] },
+                { order: "DAI first", settled: [DAI_ADDR, WETH_ADDR] },
+            ])(
+                "a V4 step that spends WETH and DAI between them leaves the last step's minimum, with the SETTLE of $order",
+                ({ settled }) => {
+                    const wethAndDaiForUsdc = encodeV4Swap(
+                        new Uint8Array([
+                            V4_SWAP_EXACT_IN_SINGLE_ID,
+                            V4_SWAP_EXACT_IN_SINGLE_ID,
+                            V4_SETTLE_ID,
+                            V4_SETTLE_ID,
+                            V4_TAKE_ALL_ID,
+                        ]),
+                        [
+                            encodeV4ExactInSingle(
+                                WETH_ADDR,
+                                USDC_ADDR,
+                                WETH_03,
+                                1n,
+                            ),
+                            encodeV4ExactInSingle(
+                                DAI_ADDR,
+                                USDC_ADDR,
+                                DAI_400,
+                                1n,
+                            ),
+                            ...settled.map((token) => encodeV4Settle(token)),
+                            encodeV4TakeAll(USDC_ADDR, 0n),
+                        ],
+                    );
+                    const result = decodeSteps(
+                        [0x00, 0x10, 0x08],
+                        [V3_TO_WETH, wethAndDaiForUsdc, V2_TO_WETH],
+                    );
+                    expect(minimum(result)).toEqual([
+                        "Min. received",
+                        "0.2000 WETH",
+                    ]);
+                },
+            );
+
+            // The middle step's swap actions buy WETH with the user's USDT,
+            // then swap all of that WETH for USDC.
+            test("a V4 step that swaps through WETH between them leaves the last step's minimum", () => {
+                const usdtToUsdcThroughWeth = encodeV4Swap(
+                    new Uint8Array([
+                        V4_SWAP_EXACT_IN_SINGLE_ID,
+                        V4_SWAP_EXACT_IN_SINGLE_ID,
+                        V4_SETTLE_ID,
+                        V4_TAKE_ALL_ID,
+                    ]),
+                    [
+                        encodeV4ExactInSingle(
+                            USDT_ADDR,
+                            WETH_ADDR,
+                            USDT_400,
+                            WETH_01,
+                        ),
+                        encodeV4ExactInSingle(WETH_ADDR, USDC_ADDR, 0n, 1n),
+                        encodeV4Settle(USDT_ADDR), // paid by the user
+                        encodeV4TakeAll(USDC_ADDR, 0n),
+                    ],
+                );
+                const result = decodeSteps(
+                    [0x00, 0x10, 0x08],
+                    [V3_TO_WETH, usdtToUsdcThroughWeth, V2_TO_WETH],
+                );
+                expect(minimum(result)).toEqual([
+                    "Min. received",
+                    "0.2000 WETH",
+                ]);
+            });
+
+            // The middle step has no swap action. Its SETTLE or SETTLE_ALL
+            // pays 0.3 WETH, and its TAKE pays that WETH to another address.
+            test.each([
+                {
+                    payment: "a SETTLE of WETH paid by the user",
+                    actions: [V4_SETTLE_ID, V4_TAKE_ID],
+                    params: [
+                        settle(WETH_ADDR, WETH_03, true),
+                        take(WETH_ADDR, OTHER_ADDR, 0n),
+                    ],
+                },
+                {
+                    payment: "a SETTLE of WETH paid from the router",
+                    actions: [V4_SETTLE_ID, V4_TAKE_ID],
+                    params: [
+                        settle(WETH_ADDR, WETH_03, false),
+                        take(WETH_ADDR, OTHER_ADDR, 0n),
+                    ],
+                },
+                {
+                    payment: "a SETTLE_ALL of WETH",
+                    actions: [V4_TAKE_ID, V4_SETTLE_ALL_ID],
+                    params: [
+                        take(WETH_ADDR, OTHER_ADDR, WETH_03),
+                        encodeV4SettleAll(WETH_ADDR, WETH_03),
+                    ],
+                },
+            ])(
+                "a V4 step with $payment between them leaves the last step's minimum",
+                ({ actions, params }) => {
+                    const wethToOther = encodeV4Swap(
+                        new Uint8Array(actions),
+                        params,
+                    );
+                    const result = decodeSteps(
+                        [0x00, 0x10, 0x08],
+                        [V3_TO_WETH, wethToOther, V2_TO_WETH],
+                    );
+                    expect(minimum(result)).toEqual([
+                        "Min. paid out",
+                        "0.2000 WETH",
+                    ]);
+                },
+            );
+
+            test("a PERMIT2_TRANSFER_FROM of WETH between them leaves the last step's minimum", () => {
+                const result = decodeSteps(
+                    [0x00, 0x02, 0x08],
+                    [
+                        V3_TO_WETH,
+                        permit2TransferFrom(WETH_ADDR, OTHER_ADDR, WETH_03),
+                        V2_TO_WETH,
+                    ],
+                );
+                expect(minimum(result)).toEqual([
+                    "Min. paid out",
+                    "0.2000 WETH",
+                ]);
+            });
+
+            // The decoder reads no minimum from a V4 exact-out action.
+            test("a step that states no minimum leaves no figure", () => {
+                const exactOut = encodeV4Swap(
+                    new Uint8Array([
+                        V4_SWAP_EXACT_OUT_SINGLE_ID,
+                        V4_SETTLE_ALL_ID,
+                        V4_TAKE_ALL_ID,
+                    ]),
+                    [
+                        encodeV4ExactOutSingle(
+                            USDT_ADDR,
+                            WETH_ADDR,
+                            WETH_02,
+                            USDT_400,
+                        ),
+                        encodeV4SettleAll(USDT_ADDR, USDT_400),
+                        encodeV4TakeAll(WETH_ADDR, 0n),
+                    ],
+                );
+                const result = decodeSteps(
+                    [0x10, 0x00],
+                    [exactOut, V3_TO_WETH],
+                );
+                expect(minimum(result)).toBeUndefined();
+                expect(detail(result, "Paid to")).toBeUndefined();
+            });
+
+            test("a step that pays some of its WETH to the router leaves no figure", () => {
+                const result = decodeSteps(
+                    [0x00, 0x10],
+                    [
+                        V3_TO_WETH,
+                        v4ToWeth(
+                            take(WETH_ADDR, USER_ADDR, WETH_01),
+                            take(WETH_ADDR, ROUTER_ADDR, 0n),
+                        ),
+                    ],
+                );
+                expect(minimum(result)).toBeUndefined();
+            });
+
+            // The router still runs a swap step whose recipient cannot be
+            // read, and that step may spend the WETH the first step paid.
+            test("a step between them that cannot be read leaves no figure", () => {
+                const result = decodeSteps(
+                    [0x00, 0x00, 0x08],
+                    [
+                        V3_TO_WETH,
+                        dirtyWord(
+                            encodeV3SwapExactIn(USER_ADDR, WETH_03, 1n, [
+                                WETH_ADDR,
+                                USDC_ADDR,
+                            ]),
+                            0,
+                        ),
+                        V2_TO_WETH,
+                    ],
+                );
+                expect(minimum(result)).toBeUndefined();
+            });
+        });
     });
 
     // https://git.eeqj.de/sneak/AutistMask/issues/359 — the output half, in

tests/unknownScaleSend.test.js

@@ -167,7 +167,8 @@ function row(token = {}, value = FIVE_WETH) {
 }
 
 // Fetch the explorer's rows through the real fetcher and put them exactly where
-// refreshBalances() puts them. The node reports the holding the explorer does.
+// refreshBalances() puts them on Ethereum Mainnet. The node reports the holding
+// the explorer does.
 async function fetchOnto(items) {
     mockProvider.tokenUnits = BigInt(items[0].value);
     debugFetch.mockImplementation(async () => ({
@@ -176,7 +177,7 @@ async function fetchOnto(items) {
         statusText: "OK",
         json: async () => items,
     }));
-    const balances = await fetchTokenBalances(HOLDER, BLOCKSCOUT, []);
+    const balances = await fetchTokenBalances(HOLDER, BLOCKSCOUT, [], "0x1");
     state.wallets = [
         {
             name: "Wallet 1",