fix: a Permit2 transfer of the zero address never reads as ETH (closes #685)

Permit2 moves no ETH, but the swap decoder read the zero address in a
PERMIT2_TRANSFER_FROM as ETH, with an ETH figure. Such a move now names
the zero address as its token and gives its amount in base units. The
token is named on `Token moved` and `Token moved into the router`, and
the amount is on `Moved from the sender` and `Paid to`.

The zero-address check the permit lines already made is now one function,
permit2TokenInfo(), which the move lines share. tokenMovedLine() takes
the token's info instead of its address.

A V4 step of ETH that states no amount still gets its own lines beside
such a move. A test covers that case.

Model: opus-5-5

README.md

@@ -1277,18 +1277,22 @@ see Transaction Decoding), do not always read as a number. They can read:
   step pays nothing itself and swaps whatever an earlier step sent to the pair,
   so the calldata states no quantity. A V3 exact-in `amountIn` of zero has no
   such meaning and is shown as a zero.
-- `None (no minimum guaranteed)`: the swap's `Min. received` line, when it shows
-  a V2, V3 or V4 swap's minimum of zero. The router passes a
-  `BALANCE_CHECK_ERC20` step whenever the balance is at least `minBalance`, so a
-  zero `minBalance` guarantees nothing. A check with a zero `minBalance` sets
-  neither `Token Out` nor `Min. received`. A nonzero `minBalance` sets both
-  lines, as a swap step does. Only a check of the transaction's sender's own
-  balance sets either line; a check of any other address sets neither (see
-  Transaction Decoding). A `BALANCE_CHECK_ERC20` step that the router lets fail
-  without reverting the transaction (see Transaction Decoding) guarantees
-  nothing either, whatever its `minBalance`, and is read as one whose
-  `minBalance` is zero. A minimum stated by a V4 swap step the router lets fail
-  is likewise read as zero.
+- `None (no minimum guaranteed)`: the swap's `Min. received` line, when the
+  minimum it shows is zero, whether a V2, V3 or V4 swap's minimum or a
+  `BALANCE_CHECK_ERC20` step's `minBalance`. Before
+  [#359](https://git.eeqj.de/sneak/AutistMask/issues/359), a zero `minBalance`
+  read `0.0000` when the token's scale was known. The router passes a balance
+  check whenever the balance is at least `minBalance`, so a zero `minBalance`
+  guarantees nothing: it sets `Token Out` and `Min. received` only when the
+  output side holds no minimum, not even a zero one, at the point the check is
+  reached, and otherwise leaves the current token and figure in place. A nonzero
+  `minBalance` sets both lines, as a swap step does. Only a check of the
+  transaction's sender's own balance sets either line; a check of any other
+  address sets neither (see Transaction Decoding). A `BALANCE_CHECK_ERC20` step
+  that the router lets fail without reverting the transaction (see Transaction
+  Decoding) guarantees nothing either, whatever its `minBalance`, and is read as
+  one whose `minBalance` is zero. A minimum stated by a V4 swap step the router
+  lets fail is likewise read as zero.
 
 The swap's `Token In` and `Token Out` lines name a currency, not an amount; each
 reads `Unknown (not named in the calldata)` when the decoder found no token for
@@ -2279,11 +2283,6 @@ view would leave a wallet one click from deletion.
           no user data and is made whether or not "Use Blockscout" is ticked.
     - If the network changes before either "Save" stores its URL, the URL is not
       saved and a flash message says so
-    - Either "Save" stores its URL only if the input still shows that URL when
-      the endpoint answers. Otherwise a flash message says that the URL was not
-      saved
-    - If the user taps the same "Save" again before the endpoint answers, the
-      earlier tap stores nothing and shows no flash message
     - Etherscan:
         - "Check recipients on Etherscan" checkbox, unticked until the user
           ticks it
@@ -3398,8 +3397,7 @@ Currently supported:
   `Balance Check (of another address)`. A check whose input does not decode,
   such as one whose owner word has a nonzero top byte (the router reads the
   owner from the word's last 20 bytes), likewise sets neither, and it is listed
-  as `Balance Check (could not be decoded)`. A check with a zero `minBalance`
-  sets neither `Token Out` nor the minimum. When a swap step, `TAKE` or
+  as `Balance Check (could not be decoded)`. When a swap step, `TAKE` or
   `TAKE_PORTION` pays the router any token, the swap's output or another, a
   `WRAP_ETH` pays it WETH, or an `UNWRAP_WETH` into the router turns WETH a step
   paid it into ETH, that token stays in the router unless a later step pays out

src/popup/views/settings.js

@@ -50,11 +50,6 @@ let versionClickTimer = null;
 // not the one in `state`.
 let shownNetwork = null;
 
-// Each endpoint "Save" counts its taps here, under the field that it stores. A
-// tap stores its URL and shows a flash message only while it is the latest tap
-// of its "Save".
-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) {
@@ -339,43 +334,16 @@ function showNewSettings() {
 // src/popup/index.js) between setting the URL and writing it. If the active
 // network is no longer `networkId`, on this page or in the stored record,
 // nothing is saved. The flash message then says that the network changed.
-//
-// The save writes only the fields that differ from what this page last saved.
-// Another page may have stored a different URL since then. So `url` is set in
-// the stored record too. "Saved." then means that the stored record holds
-// `url`.
-//
-// `input` is the id of the input that the user typed `url` in. When another
-// page changes the network, "Use Blockscout" or "Check recipients on
-// Etherscan", this page draws Settings again. A redraw during the endpoint
-// check puts the URL from `state` back in the input. So if the input no longer
-// 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`.
-//
-// `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) {
+async function saveEndpoint(field, url, networkId) {
     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;
-        if (refused || inputChanged) return false;
+        if (refused) return false;
         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) {
-        showFlash(
-            "The URL was not saved because it was changed during the check.",
-        );
     } else {
         showFlash("Saved.");
     }
@@ -387,8 +355,6 @@ 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.");
@@ -409,8 +375,6 @@ 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.");
@@ -424,7 +388,6 @@ 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.
@@ -432,12 +395,10 @@ function init(_ctx) {
             showFlash("Could not reach endpoint.");
             return;
         }
-        await saveEndpoint("rpcUrl", "settings-rpc", url, net.id, tap);
+        await saveEndpoint("rpcUrl", url, net.id);
     });
 
     $("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.");
@@ -447,26 +408,18 @@ 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,
-            tap,
-        );
+        await saveEndpoint("blockscoutUrl", url, net.id);
     });
 
     // Each change is made inside the save, holding the lock. So

src/popup/views/transactionDetail.js

@@ -311,21 +311,10 @@ function populateOnChainDetails(txData, chainId) {
     }
 }
 
-// Whether TransactionDetail still holds the transaction with `txHash` on
-// `chainId`. Opening another transaction replaces the one TransactionDetail
-// holds. A visit to Settings does not.
-function holdsTransaction(txHash, chainId) {
-    const tx = state.viewData.tx;
-    return tx?.hash === txHash && tx?.chainId === chainId;
-}
-
 // Reads the block, network details and calldata from Blockscout, and decodes
 // the calldata. While the stored "Use Blockscout" is off, Blockscout is not
 // asked. An answer that lands after the setting went off is dropped
 // (src/shared/storedSettings.js). Either way none of them is shown.
-//
-// Blockscout can answer after the user has opened another transaction. That
-// answer is dropped.
 async function loadFullTxDetails(txHash, chainId) {
     if (!(await storedSettingIsOn("useBlockscout"))) return;
     const section = $("tx-detail-calldata-section");
@@ -344,7 +333,6 @@ async function loadFullTxDetails(txHash, chainId) {
         if (!resp.ok) return;
         const txData = await resp.json();
         if (!(await storedSettingIsOn("useBlockscout"))) return;
-        if (!holdsTransaction(txHash, chainId)) return;
 
         // Populate on-chain detail fields (block, nonce, gas, fee)
         populateOnChainDetails(txData, chainId);

src/shared/chainSwitch.js

@@ -47,30 +47,12 @@ function clearPopupCaches() {
 // lock, so it is never switched while a follow of a switch saved elsewhere
 // waits for the lock (followStoredSettings() in src/popup/index.js): that
 // follow runs first, and this switch is made after it.
-//
-// The save writes only the fields that differ from what this page last saved.
-// When this page last saved a balance of "0", clearing that balance is no
-// change. So the switch also resets these fields in the stored record:
-//
-// - every address's balance and token balances;
-// - the time of the last balance refresh.
-//
-// A balance that the background or another page stored since this page's last
-// save is then not kept under the new network
-// (https://git.eeqj.de/sneak/AutistMask/issues/653).
 async function onChainSwitch(newNetworkId) {
     const { state, saveState } = require("./state");
     let net = null;
-    await saveState((stored) => {
+    await saveState(() => {
         if (state.networkId === newNetworkId) return false;
         net = applyChainSwitchFields(state, newNetworkId);
-        stored.lastBalanceRefresh = 0;
-        for (const wallet of stored.wallets) {
-            for (const addr of wallet.addresses) {
-                addr.balance = "0";
-                addr.tokenBalances = [];
-            }
-        }
         clearPopupCaches();
     });
     return net;

src/shared/state.js

@@ -591,10 +591,8 @@ function reportSaveFailure(err) {
 //
 // `beforeWrite`, when given, is called inside the lock with the stored record
 // as just read, before this page's state is compared against it. It may change
-// `state`, and this save writes that change. It may also change the stored
-// record. A field that this page did not change is then written as
-// `beforeWrite` left it. When it returns false, nothing is written; any other
-// return lets the save go ahead.
+// `state`, and this save writes that change. When it returns false, nothing is
+// written; any other return lets the save go ahead.
 function saveState(beforeWrite) {
     const turn = withLock("autistmask", () => saveStateOnce(beforeWrite));
     // Every failed save is reported, whether or not the caller awaited this

src/shared/uniswap.js

@@ -1629,13 +1629,13 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                     } else {
                         // The router passes this check whenever the owner
                         // holds at least minBalance, so a zero one guarantees
-                        // nothing. A check the router lets fail guarantees
-                        // nothing either, so it is read as a zero one. A zero
-                        // check sets neither Token Out nor the minimum. Any
+                        // nothing and does not replace a minimum an earlier
+                        // step stated. A check the router lets fail guarantees
+                        // nothing either, so it is read as a zero one. Any
                         // other minBalance sets the output side as a swap
-                        // does. The check pays nobody.
+                        // does. It pays nobody.
                         const minBalance = allowedToFail ? 0n : b.minBalance;
-                        if (minBalance !== 0n) {
+                        if (!(minBalance === 0n && present(minOutput))) {
                             setOutput(i, b.token, minBalance, []);
                         }
                         keepsRouterWeth = true;

tests/balanceRefreshNetworkSwitch.test.js

@@ -6,10 +6,6 @@
 // approved a site's request, which changes only the stored record. Driven
 // through the real popup over a stored profile on Ethereum Mainnet. The same
 // refresh in the background is in tests/backgroundStateIsolation.test.js.
-//
-// The last test covers a balance refresh by the background that is saved while
-// a switch in Settings waits for the lock
-// (https://git.eeqj.de/sneak/AutistMask/issues/653).
 
 const {
     bootPopup,
@@ -163,50 +159,3 @@ test("a refresh that returns after the background switched the network writes no
 
     expectNothingStored(page);
 });
-
-// The background's refresh saves Ethereum Mainnet's balances while the switch
-// in Settings waits for the lock. This page last saved a balance of "0" and no
-// token balances, the values that the switch sets.
-test("a background refresh saved while a switch in Settings waits for the lock leaves none of its balances stored", async () => {
-    const profile = unversionedValidProfile();
-    profile.wallets[0].addresses[0].balance = "0";
-    const page = await bootPopup(profile);
-    expect(page.pageErrors).toEqual([]);
-    const background = require("../src/background/state");
-    await page.click("btn-settings");
-
-    // The background takes the lock first and holds it until the test calls
-    // `letGo()`. It then saves balances as backgroundRefresh() in
-    // src/background/index.js does.
-    let letGo;
-    const refreshSave = background.updateState(async (fresh) => {
-        await new Promise((resolve) => {
-            letGo = resolve;
-        });
-        fresh.wallets[0].addresses[0].balance = "7.0";
-        fresh.wallets[0].addresses[0].tokenBalances = [
-            {
-                address: TOKEN_ADDRESS,
-                name: "Test Token",
-                symbol: "TST",
-                decimals: 18,
-                balance: "5.0",
-                holders: null,
-            },
-        ];
-        fresh.lastBalanceRefresh = Date.now();
-    });
-    await page.settle();
-
-    const select = page.node("settings-network");
-    select.value = "sepolia";
-    const switching = Promise.all(select.listeners.change.map((fn) => fn()));
-    await page.settle();
-
-    letGo();
-    await refreshSave;
-    await switching;
-    await page.settle();
-
-    expectNothingStored(page);
-});

tests/settingsEndpointSave.test.js

@@ -1,393 +0,0 @@
-// Another page stores a different RPC or Blockscout URL for the same network.
-// Then the user taps "Save" in Settings on this page, on the URL that this page
-// loaded. The URL on screen is stored, and the flash message reads "Saved."
-// (https://git.eeqj.de/sneak/AutistMask/issues/688). Driven through the real
-// popup over a stored profile on Ethereum Mainnet.
-
-const {
-    bootPopup,
-    cleanupPopup,
-    unversionedValidProfile,
-} = require("./support/popupBoot");
-const { NETWORKS } = require("../src/shared/networks");
-
-afterEach(() => {
-    cleanupPopup();
-});
-
-test.each([
-    { button: "btn-save-rpc", input: "settings-rpc", field: "rpcUrl" },
-    {
-        button: "btn-save-blockscout",
-        input: "settings-blockscout",
-        field: "blockscoutUrl",
-    },
-])(
-    "$button stores the URL on screen after another page stored a different one",
-    async ({ button, input, field }) => {
-        const page = await bootPopup(unversionedValidProfile());
-        await page.click("btn-settings");
-        const url = page.value(input);
-        // This write sends this page no storage change event.
-        page.storage.write("autistmask", {
-            ...page.storage.read("autistmask"),
-            [field]: "https://other-page.example.invalid",
-        });
-        // This answer passes both endpoint checks on Ethereum Mainnet. The RPC
-        // check reads Ethereum Mainnet's chain id from it. The Blockscout check
-        // reads `ok`.
-        globalThis.fetch.mockResolvedValue({
-            ok: true,
-            json: async () => ({ result: NETWORKS.mainnet.chainId }),
-        });
-
-        await page.click(button);
-
-        expect(page.storage.read("autistmask")[field]).toBe(url);
-        expect(page.text("flash-msg")).toBe("Saved.");
-    },
-);
-
-// The user types a URL in Settings and taps "Save". While the check waits for
-// the endpoint's answer, another page turns "Use Blockscout" on. This page
-// follows that change and draws Settings again, with the stored URL in the
-// input. The check then passes. The typed URL is not stored. The flash message
-// says that the URL was changed during the check
-// (https://git.eeqj.de/sneak/AutistMask/issues/695).
-test.each([
-    { button: "btn-save-rpc", input: "settings-rpc", field: "rpcUrl" },
-    {
-        button: "btn-save-blockscout",
-        input: "settings-blockscout",
-        field: "blockscoutUrl",
-    },
-])(
-    "$button stores nothing when Settings is drawn again during the check",
-    async ({ button, input, field }) => {
-        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 saving = page.node(button).listeners.click.map((fn) => fn());
-        await page.settle();
-        // The browser announces this write to this page.
-        await page.storage.local.set({
-            autistmask: {
-                ...page.storage.read("autistmask"),
-                useBlockscout: true,
-            },
-        });
-        await page.settle();
-        expect(page.node("settings-use-blockscout").checked).toBe(true);
-        // This answer passes both endpoint checks on Ethereum Mainnet.
-        answer({
-            ok: true,
-            json: async () => ({ result: NETWORKS.mainnet.chainId }),
-        });
-        await Promise.all(saving);
-        await page.settle();
-
-        expect(page.storage.read("autistmask")[field]).toBe(storedUrl);
-        expect(page.value(input)).toBe(storedUrl);
-        expect(page.text("flash-msg")).toBe(
-            "The URL was not saved because it was changed during the check.",
-        );
-    },
-);
-
-// As above, but another write holds the lock. So this page's follow of the
-// change to "Use Blockscout" waits for the lock. The endpoint answers while the
-// input still shows the typed URL. The save then asks for the lock, after the
-// follow did. So the follow draws Settings again before the save compares the
-// input.
-test.each([
-    { button: "btn-save-rpc", input: "settings-rpc", field: "rpcUrl" },
-    {
-        button: "btn-save-blockscout",
-        input: "settings-blockscout",
-        field: "blockscoutUrl",
-    },
-])(
-    "$button stores nothing when Settings is drawn again while the save waits for the lock",
-    async ({ button, input, field }) => {
-        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;
-            }),
-        );
-        const typedUrl = "https://typed.example.invalid";
-
-        page.node(input).value = typedUrl;
-        const saving = page.node(button).listeners.click.map((fn) => fn());
-        await page.settle();
-        let releaseLock;
-        const lockHeld = navigator.locks.request(
-            "autistmask",
-            () =>
-                new Promise((resolve) => {
-                    releaseLock = resolve;
-                }),
-        );
-        // The browser announces this write to this page.
-        await page.storage.local.set({
-            autistmask: {
-                ...page.storage.read("autistmask"),
-                useBlockscout: true,
-            },
-        });
-        await page.settle();
-        // This answer passes both endpoint checks on Ethereum Mainnet.
-        answer({
-            ok: true,
-            json: async () => ({ result: NETWORKS.mainnet.chainId }),
-        });
-        await page.settle();
-        expect(page.value(input)).toBe(typedUrl);
-        releaseLock();
-        await lockHeld;
-        await Promise.all(saving);
-        await page.settle();
-
-        expect(page.node("settings-use-blockscout").checked).toBe(true);
-        expect(page.storage.read("autistmask")[field]).toBe(storedUrl);
-        expect(page.value(input)).toBe(storedUrl);
-        expect(page.text("flash-msg")).toBe(
-            "The URL was not saved because it was changed during the check.",
-        );
-    },
-);
-
-// 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". 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/trackedTokensPerNetwork.test.js

@@ -177,78 +177,6 @@ test("a token added by contract address on Sepolia is tracked on Sepolia only",
     expect(onSepolia).not.toContain("DAI");
 });
 
-// Another popup page tracks DAI on Ethereum Mainnet after this page's last
-// save. The switch's save writes only the token lists that this page changed.
-// So DAI stays in `trackedTokens`, the active network's list.
-test("a token another page tracked before a switch in Settings stays in trackedTokens", async () => {
-    const boot = await bootPopup(unversionedValidProfile());
-    expect(boot.pageErrors).toEqual([]);
-    boot.storage.write("autistmask", {
-        ...boot.storage.read("autistmask"),
-        trackedTokens: [MAINNET_TOKEN],
-    });
-
-    await boot.click("btn-settings");
-    await chooseNetwork(boot, "sepolia");
-
-    const stored = boot.storage.read("autistmask");
-    expect(stored.networkId).toBe("sepolia");
-    expect(stored.trackedTokens).toEqual([MAINNET_TOKEN]);
-    expect(stored.networkTrackedTokens.mainnet).toEqual([]);
-});
-
-// The contract lookup on SettingsAddToken answers on Ethereum Mainnet while the
-// switch to Sepolia waits for the lock. The page adds the token to Ethereum
-// Mainnet's list. The switch then keeps that list for Ethereum Mainnet.
-test("a token added while a switch in Settings waits for the lock 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");
-
-    // Another write holds the lock, so the switch's save waits for it.
-    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();
-
-    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([
-        {
-            address: NEW_TOKEN_ADDRESS,
-            symbol: "NEW",
-            decimals: 18,
-            name: "New Token",
-        },
-    ]);
-});
-
 describe("Back after a switch from the Settings gear", () => {
     test("SettingsAddToken no longer offers the common tokens", async () => {
         const boot = await bootOnAddToken("mainnet");

tests/transactionDetailLateAnswer.test.js

@@ -1,202 +0,0 @@
-// TransactionDetail shows only details that Blockscout gave for the
-// transaction on screen (https://git.eeqj.de/sneak/AutistMask/issues/675).
-//
-// The screen asks Blockscout for its transaction and does not wait for the
-// answer. So the user can press Back and open another transaction before
-// Blockscout answers for the first. The first answer must then fill nothing on
-// the second transaction's screen. An answer that lands while Settings is up
-// must still fill TransactionDetail.
-//
-// Driven through the real popup over a stored profile
-// (tests/support/popupBoot.js). Each transaction is opened as a history screen
-// opens it: the current screen is pushed, then transactionDetail.show() draws
-// the transaction.
-
-"use strict";
-
-const {
-    bootPopup,
-    cleanupPopup,
-    unversionedValidProfile,
-    ADDRESS,
-} = require("./support/popupBoot");
-
-const MAINNET_BLOCKSCOUT = "https://eth.blockscout.com/api/v2";
-const SEPOLIA_BLOCKSCOUT = "https://eth-sepolia.blockscout.com/api/v2";
-const RECIPIENT = "0x2222222222222222222222222222222222222222";
-
-// A history entry for a send of 1 `symbol` from ADDRESS to RECIPIENT, on the
-// network with `chainId`.
-function historyEntry(hash, chainId, symbol) {
-    return {
-        hash,
-        from: ADDRESS,
-        to: RECIPIENT,
-        value: "1.0000",
-        exactValue: "1.0",
-        symbol,
-        timestamp: 1790000000,
-        isError: false,
-        direction: "sent",
-        directionLabel: "Sent",
-        contractAddress: null,
-        chainId,
-    };
-}
-
-const FIRST = historyEntry("0x" + "aa".repeat(32), "0x1", "ETH");
-const SECOND = historyEntry("0x" + "bb".repeat(32), "0x1", "ETH");
-// A transaction on Sepolia with the same hash as FIRST.
-const FIRST_ON_SEPOLIA = historyEntry(FIRST.hash, "0xaa36a7", "SepoliaETH");
-
-// The URL that asks Blockscout for `entry`, on the network it was sent on.
-function requestUrl(entry) {
-    const blockscout =
-        entry.chainId === "0x1" ? MAINNET_BLOCKSCOUT : SEPOLIA_BLOCKSCOUT;
-    return blockscout + "/transactions/" + entry.hash;
-}
-
-// What Blockscout reports for each transaction, by the URL that asks for it.
-const ANSWERS = {
-    [requestUrl(FIRST)]: {
-        block_number: 21000001,
-        nonce: 4441,
-        fee: { value: "21000000000000" },
-        raw_input: "0x11111111",
-        method: "firstMethod",
-    },
-    [requestUrl(SECOND)]: {
-        block_number: 21000002,
-        nonce: 4442,
-        fee: { value: "42000000000000" },
-        raw_input: "0x22222222",
-        method: "secondMethod",
-    },
-    [requestUrl(FIRST_ON_SEPOLIA)]: {
-        block_number: 21000003,
-        nonce: 4443,
-        fee: { value: "63000000000000" },
-        raw_input: "0x33333333",
-        method: "sepoliaMethod",
-    },
-};
-
-// The text each answer puts on screen: its block, nonce, fee, method name and
-// raw data. No text from one answer appears in another.
-const FIRST_SHOWN = [
-    "21000001",
-    "4441",
-    "0.000021 ETH",
-    "firstMethod",
-    "0x11111111",
-];
-const SECOND_SHOWN = [
-    "21000002",
-    "4442",
-    "0.000042 ETH",
-    "secondMethod",
-    "0x22222222",
-];
-const FIRST_ON_SEPOLIA_SHOWN = [
-    "21000003",
-    "4443",
-    "0.000063 SepoliaETH",
-    "sepoliaMethod",
-    "0x33333333",
-];
-
-// Everything drawn in the fields that Blockscout's answer fills.
-function drawnDetails(page) {
-    return [
-        "tx-detail-block",
-        "tx-detail-nonce",
-        "tx-detail-fee",
-        "tx-detail-calldata-action",
-        "tx-detail-rawdata",
-    ]
-        .map((id) => page.node(id).innerHTML + page.node(id).textContent)
-        .join("\n");
-}
-
-// Opens `entry` on TransactionDetail, as a history screen does.
-function open(entry) {
-    require("../src/popup/views/helpers").pushCurrentView();
-    require("../src/popup/views/transactionDetail").show(entry);
-}
-
-// The URLs of every request to Blockscout so far, in order.
-function requestedUrls() {
-    return globalThis.fetch.mock.calls.map(([url]) => url);
-}
-
-// Boots the popup on Home with "Use Blockscout" on. Blockscout answers every
-// request at once from ANSWERS, except the request for `held`. Returns the
-// page and answer(), which lets the answer for `held` land.
-async function bootWithHeldRequest(held) {
-    const page = await bootPopup(
-        unversionedValidProfile({ useBlockscout: true }),
-    );
-    let answer;
-    const heldAnswer = new Promise((resolve) => {
-        answer = resolve;
-    });
-    globalThis.fetch = jest.fn(async (url) => {
-        if (url === requestUrl(held)) await heldAnswer;
-        return { ok: true, status: 200, json: async () => ANSWERS[url] };
-    });
-    return { page, answer: () => answer() };
-}
-
-// The user opens `first`, whose request to Blockscout is held. Then the user
-// presses Back and opens `second`. Then the answer for `first` lands. Returns
-// the page.
-async function firstAnswerLandsOnSecond(first, second) {
-    const { page, answer } = await bootWithHeldRequest(first);
-    open(first);
-    await page.settle();
-    await page.click("btn-tx-back");
-    expect(page.visibleViews()).toEqual(["main"]);
-    open(second);
-    await page.settle();
-    expect(requestedUrls()).toEqual([requestUrl(first), requestUrl(second)]);
-    answer();
-    await page.settle();
-    expect(page.visibleViews()).toEqual(["transaction"]);
-    return page;
-}
-
-afterEach(() => {
-    cleanupPopup();
-});
-
-test("an answer for the first transaction that lands on the second one's screen fills nothing", async () => {
-    const page = await firstAnswerLandsOnSecond(FIRST, SECOND);
-
-    const drawn = drawnDetails(page);
-    for (const text of SECOND_SHOWN) expect(drawn).toContain(text);
-    for (const text of FIRST_SHOWN) expect(drawn).not.toContain(text);
-});
-
-test("an answer for a hash on mainnet that lands on the same hash's screen on Sepolia fills nothing", async () => {
-    const page = await firstAnswerLandsOnSecond(FIRST, FIRST_ON_SEPOLIA);
-
-    const drawn = drawnDetails(page);
-    for (const text of FIRST_ON_SEPOLIA_SHOWN) expect(drawn).toContain(text);
-    for (const text of FIRST_SHOWN) expect(drawn).not.toContain(text);
-});
-
-test("an answer that lands while Settings is up still fills TransactionDetail", async () => {
-    const { page, answer } = await bootWithHeldRequest(FIRST);
-    open(FIRST);
-    await page.settle();
-    await page.click("btn-settings");
-    expect(page.visibleViews()).toEqual(["settings"]);
-    answer();
-    await page.settle();
-    await page.click("btn-settings");
-
-    expect(page.visibleViews()).toEqual(["transaction"]);
-    expect(requestedUrls()).toEqual([requestUrl(FIRST)]);
-    const drawn = drawnDetails(page);
-    for (const text of FIRST_SHOWN) expect(drawn).toContain(text);
-});

tests/uniswap.test.js

@@ -4380,9 +4380,10 @@ describe("uniswap decoder", () => {
         expect(detail(result, "Min. received").value).toBe("2.0000 USDC");
     });
 
-    // A zero balance check sets neither Token Out nor the minimum. The route
-    // pays only the WRAP_ETH's WETH, to the router, where it stays.
-    test("a zero balance check after a WRAP_ETH into the router names no output token and no minimum", () => {
+    // With no minimum stated before it, a zero balance check is what sets the
+    // output side, and it guarantees nothing. No step pays anyone, so the
+    // minimum is not said to be received.
+    test("a zero balance check with no earlier minimum states no minimum", () => {
         const data = buildExecute(
             solidityPacked(["uint8", "uint8"], [0x0b, 0x0e]),
             [
@@ -4395,16 +4396,9 @@ describe("uniswap decoder", () => {
         const result = uniswap.decode(data, ROUTER_ADDR, "0x1", {}, USER_ADDR);
         expect(result).not.toBeNull();
 
-        expect(detail(result, "Token Out").value).toBe(
-            "Unknown (not named in the calldata)",
-        );
-        expect(detail(result, "Min. paid out")).toBeUndefined();
-        expect(detail(result, "Min. received")).toBeUndefined();
-        expect(detail(result, "Paid to").value).toBe(
-            "The router, where it stays (no later step pays it out)",
-        );
-        expect(detail(result, "Token moved into the router").address).toBe(
-            WETH_ADDR,
+        expect(detail(result, "Token Out").value).toContain("USDT");
+        expect(detail(result, "Min. paid out").value).toBe(
+            "None (no minimum guaranteed)",
         );
     });
 

tests/uniswapRecipient.test.js

@@ -688,62 +688,6 @@ describe("an UNWRAP_WETH makes the output ETH only when the router holds it", ()
         ]);
     });
 
-    // The same route, then a balance check of the sender's USDC with a zero
-    // minimum. The check guarantees nothing, so Token Out stays ETH
-    // (https://git.eeqj.de/sneak/AutistMask/issues/649).
-    test("the same route, then a zero balance check of USDC, still reads as ETH with no minimum", () => {
-        const result = decode(
-            execute(
-                v4Swap(
-                    SWAP_USDT_FOR_WETH,
-                    SETTLE_USDT,
-                    take(WETH, MSG_SENDER, (ONE_WETH * 6n) / 10n),
-                    take(WETH, ADDRESS_THIS),
-                ),
-                unwrapWeth(MSG_SENDER),
-                balanceCheck(USDC, 0n),
-            ),
-        );
-        expect(result.name).toBe("Swap USDT → ETH");
-        expect(detail(result, "Token Out").value).toBe("ETH");
-        expect(labels(result)).toEqual([
-            "Protocol",
-            "Token In",
-            "Amount",
-            "Token Out",
-            "Steps",
-            "Deadline",
-        ]);
-    });
-
-    // A PERMIT2_TRANSFER_FROM moves the sender's WETH into the router. An
-    // UNWRAP_WETH pays that WETH to the user as ETH. A zero balance check of
-    // USDC sets neither Token Out nor the minimum, before the UNWRAP_WETH or
-    // after it (https://git.eeqj.de/sneak/AutistMask/issues/649).
-    test.each([
-        {
-            kind: "before the UNWRAP_WETH",
-            steps: [balanceCheck(USDC, 0n), unwrapWeth(MSG_SENDER)],
-        },
-        {
-            kind: "after the UNWRAP_WETH",
-            steps: [unwrapWeth(MSG_SENDER), balanceCheck(USDC, 0n)],
-        },
-    ])(
-        "WETH moved into the router and unwrapped, with a zero balance check of USDC $kind, reads as ETH with no minimum",
-        ({ steps }) => {
-            const result = decode(
-                execute(
-                    permit2TransferFrom(WETH, ADDRESS_THIS, ONE_WETH),
-                    ...steps,
-                ),
-            );
-            expect(detail(result, "Token Out").value).toBe("ETH");
-            expect(detail(result, "Min. received")).toBeUndefined();
-            expect(detail(result, "Min. paid out")).toBeUndefined();
-        },
-    );
-
     // A TAKE the decoder cannot read may pay part of the WETH to the user.
     test("one V4 step paying WETH to the router beside a TAKE that cannot be read, then an UNWRAP_WETH, reads as ETH with no minimum", () => {
         const result = decode(
@@ -2876,16 +2820,17 @@ describe("the allow-revert flag", () => {
         },
     );
 
-    test("a BALANCE_CHECK_ERC20 with the flag, and no minimum before it, names no output token and no minimum", () => {
+    test("a BALANCE_CHECK_ERC20 with the flag, and no minimum before it, states none", () => {
         const check = balanceCheck(WETH, ONE_WETH);
         expect(detail(decode(execute(check)), "Min. paid out").value).toBe(
             "1.0000 WETH",
         );
 
         const withFlag = decode(execute(flagged(check)));
-        expect(detail(withFlag, "Token Out").value).toBe(UNNAMED);
-        expect(detail(withFlag, "Min. paid out")).toBeUndefined();
-        expect(detail(withFlag, "Min. received")).toBeUndefined();
+        expect(detail(withFlag, "Token Out").address).toBe(WETH);
+        expect(detail(withFlag, "Min. paid out").value).toBe(
+            "None (no minimum guaranteed)",
+        );
     });
 
     // Only the routers from UniversalRouterV2 on let a PERMIT2_PERMIT fail.