fix: show balances and fees below 0.000001 as nonzero on the send screens (closes #343)

The stored ETH and token balances and the send-confirm screen's fee were each
cut to six decimal places, and a token holding cut to zero was dropped, so a
value below 0.000001 read as zero. Balances are now stored exactly, whatever
decimals a token declares, and every nonzero token holding is kept; the balance
check reads a token balance to its first 18 places. The balance lists, the
send-screen token selector, the address total and the remove-address warning
leave out a holding below 0.000001 themselves, through isBelowOneMillionth().
The send and send-confirm screens' balances, reserve and insufficient-balance
messages go through truncateAmountNeverZero(). The send-confirm and approval
screens both render the fee through formatFee(), which prices the exact fee in
USD.

Model: opus-5-5

TODO.md

@@ -62,26 +62,6 @@ but the review is broader than any of them.
   render the fee through `formatFee()` in `src/popup/views/helpers.js`, which
   prices the exact fee in USD, so the same fee reads the same on both, USD value
   included.
-
-- 2026-10-04: The flash line keeps to the one line it reserves at any message
-  length ([#252](https://git.eeqj.de/sneak/AutistMask/issues/252)). A message
-  that wrapped pushed the whole screen below it down. `#flash-msg` no longer
-  wraps: text too long for the line is cut with an ellipsis, and `showFlash()`
-  puts the whole message in the line's title. Every message is also reworded to
-  at most 50 characters so none is cut; none carries a wallet name or text from
-  a server, and the add-token screens flash a fixed line for any error other
-  than a contract that is not a token. A new test in `tests/e2e/run.js` puts a
-  message several lines long on the line and fails if the line or the screen
-  below it moves. The two approval-screen error boxes are left to
-  [#297](https://git.eeqj.de/sneak/AutistMask/issues/297).
-
-- 2026-10-04: A method the wallet does not implement is refused with EIP-1193
-  code `4200` ([#279](https://git.eeqj.de/sneak/AutistMask/issues/279)). The
-  background's `Unsupported method: <method>` error carried no code, so a site
-  probing for an optional method could not tell "not implemented" from "the call
-  failed". The message is unchanged; the background's other errors with no code
-  are untouched.
-
 - 2026-10-04: Settings lists the sites connected without "Remember", and
   removing a site there disconnects it
   ([#406](https://git.eeqj.de/sneak/AutistMask/issues/406)). Such a connection

src/background/index.js

@@ -932,9 +932,7 @@ async function handleRpc(method, params, origin) {
         }
     }
 
-    // EIP-1193 4200 lets a site tell "this wallet does not implement that"
-    // from "that call failed", and fall back.
-    return { error: { code: 4200, message: "Unsupported method: " + method } };
+    return { error: { message: "Unsupported method: " + method } };
 }
 
 // The body of eth_sendTransaction, from the connection check through to the

src/content/inpage.js

@@ -31,12 +31,11 @@
     // an error instead of accepting the refusal.
     //
     // Whatever code arrived is passed through verbatim rather than being
-    // matched against a list: the extension emits codes such as 4001, 4100,
-    // 4200 and 4902, and a code this file has never heard of is still the
-    // truth about what happened. An error reported with no code at all stays
-    // a plain Error — a ProviderRpcError whose `code` is undefined would
-    // advertise a conformance it does not have. `message` is untouched in
-    // every case.
+    // matched against a list: the extension emits 4001, 4100 and 4902 today,
+    // and a code this file has never heard of is still the truth about what
+    // happened. An error reported with no code at all stays a plain Error —
+    // a ProviderRpcError whose `code` is undefined would advertise a
+    // conformance it does not have. `message` is untouched in every case.
     function toPageError(error) {
         const message = (error && error.message) || "Request failed";
         if (error && error.code !== undefined && error.code !== null) {

src/popup/dustThreshold.js

@@ -19,9 +19,13 @@
 // that the user did not type — the same silent substitution the visible
 // rejection message exists to end.
 
-// Must render on ONE line of #flash-msg; see showFlash() in
-// src/popup/views/helpers.js for how long that is.
-const DUST_THRESHOLD_MESSAGE = "Enter a whole number of gwei, zero or greater.";
+// Must render on ONE line of #flash-msg, whose reserved height
+// (min-h-[1.25rem]) is exactly one line at text-xs. A string long enough to
+// wrap to two lines pushes the settings view down, which the No Layout Shift
+// policy forbids. Do not lengthen this without re-running the layout test in
+// tests/e2e/run.js, which measures the flash line and goes red on a shift.
+const DUST_THRESHOLD_MESSAGE =
+    "Please enter a whole number of gwei, zero or greater.";
 
 // Returns the threshold in gwei, or null if the input is not one.
 function parseDustThresholdGwei(raw) {

src/popup/index.html

@@ -33,7 +33,7 @@
             <!-- ============ FLASH MESSAGE AREA ============ -->
             <div
                 id="flash-msg"
-                class="text-xs text-muted min-h-[1.25rem] mb-1 truncate"
+                class="text-xs text-muted min-h-[1.25rem] mb-1"
             ></div>
 
             <!-- ============ WELCOME / FIRST USE ============ -->

src/popup/views/addToken.js

@@ -28,7 +28,9 @@ function init(ctx) {
     $("btn-add-token-confirm").addEventListener("click", async () => {
         const contractAddr = $("add-token-address").value.trim();
         if (!contractAddr || !contractAddr.startsWith("0x")) {
-            showFlash("Enter a valid contract address starting with 0x.");
+            showFlash(
+                "Please enter a valid contract address starting with 0x.",
+            );
             return;
         }
         const already = state.trackedTokens.find(
@@ -69,15 +71,8 @@ function init(ctx) {
             require("./addressDetail").show();
         } catch (e) {
             const detail = e.shortMessage || e.message || String(e);
-            log.errorf("Adding token failed for", contractAddr, detail);
-            // lookupTokenInfo() rejects a contract with a one-line message
-            // starting "Not a valid ERC-20 token". Any other error, such as a
-            // failed save, can be far longer, so it is only logged.
-            showFlash(
-                detail.startsWith("Not a valid ERC-20 token")
-                    ? detail
-                    : "Could not add the token.",
-            );
+            log.errorf("Token lookup failed for", contractAddr, detail);
+            showFlash(detail);
             infoEl.textContent = "";
             infoEl.style.visibility = "hidden";
         }

src/popup/views/addWallet.js

@@ -142,13 +142,15 @@ function validatePassword() {
 async function importMnemonic(ctx) {
     const mnemonic = $("wallet-mnemonic").value.trim();
     if (!mnemonic) {
-        showFlash("Enter a recovery phrase, or press the die.");
+        showFlash("Enter a recovery phrase or press the die to generate one.");
         return;
     }
     const words = mnemonic.split(/\s+/);
     if (words.length !== 12 && words.length !== 24) {
         showFlash(
-            "Recovery phrase must be 12 or 24 words, not " + words.length + ".",
+            "Recovery phrase must be 12 or 24 words. You entered " +
+                words.length +
+                ".",
         );
         return;
     }
@@ -161,12 +163,14 @@ async function importMnemonic(ctx) {
     const { xpub, firstAddress } = hdWalletFromMnemonic(mnemonic);
     const xpubDup = findWalletByXpub(xpub);
     if (xpubDup) {
-        showFlash("This recovery phrase is already added.");
+        showFlash(
+            "This recovery phrase is already added (" + xpubDup.name + ").",
+        );
         return;
     }
     const addrDup = findWalletByAddress(firstAddress);
     if (addrDup) {
-        showFlash("Address already exists in a wallet.");
+        showFlash("Address already exists in wallet (" + addrDup.name + ").");
         return;
     }
     const encrypted = await encryptWithPassword(mnemonic, pw);
@@ -225,7 +229,9 @@ async function importPrivateKey(ctx) {
     if (!pw) return;
     const duplicate = findWalletByAddress(addr);
     if (duplicate) {
-        showFlash("This address already exists in a wallet.");
+        showFlash(
+            "This address already exists in wallet (" + duplicate.name + ").",
+        );
         return;
     }
     const encrypted = await encryptWithPassword(key, pw);
@@ -252,29 +258,36 @@ async function importXprvKey(ctx) {
         return;
     }
     if (!isValidXprv(xprv)) {
-        showFlash("That extended private key is not valid.");
+        showFlash(
+            "That extended private key is not valid. Please check it and try again.",
+        );
         return;
     }
     if (!isMasterExtendedKey(xprv)) {
-        showFlash("Please paste the master key, not a child key.");
+        showFlash(
+            "That is an account-level or child key, which cannot be imported. " +
+                "Please paste the master extended private key for the wallet.",
+        );
         return;
     }
     let result;
     try {
         result = hdWalletFromXprv(xprv);
     } catch {
-        showFlash("That extended private key is not valid.");
+        showFlash(
+            "That extended private key is not valid. Please check it and try again.",
+        );
         return;
     }
     const { xpub, firstAddress } = result;
     const xpubDup = findWalletByXpub(xpub);
     if (xpubDup) {
-        showFlash("This key is already added.");
+        showFlash("This key is already added (" + xpubDup.name + ").");
         return;
     }
     const addrDup = findWalletByAddress(firstAddress);
     if (addrDup) {
-        showFlash("Address already exists in a wallet.");
+        showFlash("Address already exists in wallet (" + addrDup.name + ").");
         return;
     }
     const pw = validatePassword();

src/popup/views/helpers.js

@@ -228,19 +228,15 @@ function clearFlash() {
         flashTimer = null;
     }
     $("flash-msg").textContent = "";
-    $("flash-msg").title = "";
 }
 
-// The flash line reserves exactly one line, and a message that wrapped would
-// push the screen below it down (README, No Layout Shift). So #flash-msg never
-// wraps: text too long for the line is cut with an ellipsis, and the whole
-// message is also put in the line's title. Write messages to fit, at most 50
-// characters, so none is cut.
 function showFlash(msg, duration = 2000) {
     clearFlash();
     $("flash-msg").textContent = msg;
-    $("flash-msg").title = msg;
-    flashTimer = setTimeout(clearFlash, duration);
+    flashTimer = setTimeout(() => {
+        $("flash-msg").textContent = "";
+        flashTimer = null;
+    }, duration);
 }
 
 // A stored token balance as a number, or null when there is no number in it.

src/popup/views/send.js

@@ -67,13 +67,13 @@ function validateToAddress(value) {
             if (checksummed !== v) {
                 return {
                     valid: false,
-                    error: "Address checksum is invalid. Check the address.",
+                    error: "Address checksum is invalid. Please double-check the address.",
                 };
             }
         } catch {
             return {
                 valid: false,
-                error: "Address checksum is invalid. Check the address.",
+                error: "Address checksum is invalid. Please double-check the address.",
             };
         }
     }
@@ -224,7 +224,7 @@ function init(_ctx) {
                 const provider = getProvider(state.rpcUrl, state.networkId);
                 const resolved = await provider.resolveName(to);
                 if (!resolved) {
-                    showFlash("That ENS name has no address.");
+                    showFlash("Could not resolve " + to);
                     return;
                 }
                 resolvedTo = resolved;

src/popup/views/settings.js

@@ -264,12 +264,18 @@ function init(ctx) {
             const json = await resp.json();
             if (json.error) {
                 log.errorf("RPC validation error:", json.error);
-                showFlash("Endpoint returned an error.");
+                showFlash("Endpoint returned error: " + json.error.message);
                 return;
             }
             const net = currentNetwork();
             if (json.result !== net.chainId) {
-                showFlash("Wrong network: expected " + net.name + ".");
+                showFlash(
+                    "Wrong network (expected " +
+                        net.name +
+                        ", got chain " +
+                        json.result +
+                        ").",
+                );
                 return;
             }
         } catch (e) {

src/popup/views/settingsAddToken.js

@@ -115,7 +115,9 @@ function init(_ctx) {
     $("btn-settings-addtoken-manual").addEventListener("click", async () => {
         const addr = $("settings-addtoken-address").value.trim();
         if (!addr || !addr.startsWith("0x")) {
-            showFlash("Enter a valid contract address starting with 0x.");
+            showFlash(
+                "Please enter a valid contract address starting with 0x.",
+            );
             return;
         }
         if (isTracked(addr)) {
@@ -153,15 +155,8 @@ function init(_ctx) {
             ctx.doRefreshAndRender();
         } catch (e) {
             const detail = e.shortMessage || e.message || String(e);
-            log.errorf("Adding token failed for", addr, detail);
-            // lookupTokenInfo() rejects a contract with a one-line message
-            // starting "Not a valid ERC-20 token". Any other error, such as a
-            // failed save, can be far longer, so it is only logged.
-            showFlash(
-                detail.startsWith("Not a valid ERC-20 token")
-                    ? detail
-                    : "Could not add the token.",
-            );
+            log.errorf("Token lookup failed for", addr, detail);
+            showFlash(detail);
             infoEl.textContent = "";
             infoEl.style.visibility = "hidden";
         }

src/shared/walletDefects.js

@@ -41,10 +41,12 @@ const DEFECTS = {
                 "changed or removed, and this wallet stays until you delete " +
                 "it yourself.",
         ],
-        // One line, for the flash on a blocked Send and the inline error on
-        // the approval screens. It must fit on the flash line; see showFlash()
-        // in src/popup/views/helpers.js.
-        shortMessage: "This wallet cannot sign. See the wallet list.",
+        // One sentence for the places that have room for one: the flash on a
+        // blocked Send, the inline error on the approval screens.
+        shortMessage:
+            "This wallet cannot sign, because it was imported from an " +
+            "extended private key that is not a master key. The wallet list " +
+            "explains what happened.",
     },
 };
 

tests/dustThreshold.test.js

@@ -99,13 +99,12 @@ describe("the flash line the message is shown in", () => {
     // length, including one that wrapped to two lines and pushed the
     // settings view down 12px.
     //
-    // The line cuts a message too long for it with an ellipsis (see
-    // showFlash() in src/popup/views/helpers.js). The assertions that
-    // measure that, in a real browser at the documented 360x600 popup, are
-    // "a rejected dust threshold shifts no layout (#233)" and "an over-long
-    // flash message keeps to one line (#252)" in tests/e2e/run.js, run by
-    // make test-e2e. They are not in make check because REPO_POLICIES.md
-    // caps make test at 20 seconds and a browser suite does not fit.
+    // The assertion that actually measures — empty line vs. the message,
+    // real Chromium, documented 360x600 popup — is
+    // "a rejected dust threshold shifts no layout (#233)" in
+    // tests/e2e/run.js, run by make test-e2e. It is not in make check
+    // because REPO_POLICIES.md caps make test at 20 seconds and a browser
+    // suite does not fit; run it before changing the wording.
     test("reserves its height in the markup", () => {
         const flashLine = POPUP_HTML.match(
             /<div\s+id="flash-msg"\s+class="([^"]*)"/,

tests/e2e/run.js

@@ -1320,13 +1320,17 @@ async function waitForFilledFlashLine(page) {
 }
 
 // README, No Layout Shift: the rejection message goes into #flash-msg,
-// whose min-h-[1.25rem] reserves exactly ONE line at text-xs, and which
-// cuts a message too long for that line with an ellipsis rather than wrap
-// it. This shows the real message and measures that nothing moves; the
-// test after it does the same with a message several lines long. Both
-// measure rather than inspect markup: the unit suite runs on the node
-// environment with no layout engine, where every height is zero (see the
-// note in tests/dustThreshold.test.js).
+// whose min-h-[1.25rem] reserves exactly ONE line at text-xs. Reserving
+// the space is not enough on its own — a message too long for one line
+// wraps and pushes everything below it down anyway, which is what the
+// first version of this change shipped: 75 characters, 32px, the settings
+// view and the threshold field 12px lower than with an empty line.
+//
+// So this measures rather than inspects markup. It is the only assertion
+// in the repo that can see the wording grow: the unit suite runs on the
+// node environment with no layout engine, where every height is zero (see
+// the note in tests/dustThreshold.test.js). Lengthen
+// DUST_THRESHOLD_MESSAGE past one line and this test goes red.
 test("a rejected dust threshold shifts no layout (#233)", async (env) => {
     const page = await openPopup(env.ctx, env.popupUrl);
     try {
@@ -1373,11 +1377,11 @@ test("a rejected dust threshold shifts no layout (#233)", async (env) => {
         );
         assert(
             after.flashHeight === before.flashHeight,
-            "the message does not keep to the reserved line: " +
+            "the message does not fit the reserved line: " +
                 before.flashHeight +
                 "px empty vs " +
                 after.flashHeight +
-                "px with the message",
+                "px with the message. Shorten DUST_THRESHOLD_MESSAGE",
         );
         assert(
             after.settingsTop === before.settingsTop,
@@ -1396,59 +1400,6 @@ test("a rejected dust threshold shifts no layout (#233)", async (env) => {
     }
 });
 
-// ------------------------------------------------ the flash line (#252)
-
-// #flash-msg never wraps: a message too long for its one line is cut with an
-// ellipsis (see showFlash() in src/popup/views/helpers.js). This puts a
-// message several lines long into it and measures that the line and the
-// screen below it stay where they were.
-test("an over-long flash message keeps to one line (#252)", async (env) => {
-    const page = await openPopup(env.ctx, env.popupUrl);
-    try {
-        await page.setViewportSize(POPUP_VIEWPORT);
-        await openSettings(page);
-
-        const before = await page.evaluate(measureFlashLine);
-        const overflows = await page.evaluate(() => {
-            const line = document.getElementById("flash-msg");
-            line.textContent =
-                "This message is far too long for one line. ".repeat(5);
-            return line.scrollWidth > line.clientWidth;
-        });
-        const after = await page.evaluate(measureFlashLine);
-
-        assert(
-            after.flashHeight === before.flashHeight,
-            "the flash line is " +
-                before.flashHeight +
-                "px before and " +
-                after.flashHeight +
-                "px with an over-long message, so it wraps",
-        );
-        assert(
-            after.settingsTop === before.settingsTop,
-            "the settings view moved " +
-                (after.settingsTop - before.settingsTop) +
-                "px when the message appeared",
-        );
-        assert(
-            after.fieldTop === before.fieldTop,
-            "the dust threshold field moved " +
-                (after.fieldTop - before.fieldTop) +
-                "px when the message appeared",
-        );
-        // Checked last: a line that wraps does not run past its right edge,
-        // so this only shows the message really was cut once nothing moved.
-        assert(
-            overflows,
-            "the message fits on the line, so it proves nothing: " +
-                JSON.stringify(after.text),
-        );
-    } finally {
-        await page.close();
-    }
-});
-
 // --------------------------------------------- confirmation screen (#238)
 //
 // The screen that decides what gets signed. The arithmetic underneath it

tests/flashLine.test.js

@@ -1,130 +0,0 @@
-// The flash line (#252). #flash-msg reserves one line and cuts a message too
-// long for it with an ellipsis; that is measured in a real browser by
-// tests/e2e/run.js. Here: showFlash() keeps the whole message readable in the
-// line's title, and the two add-token screens flash a fixed line, not the text
-// of whatever error adding the token threw.
-
-const ADDRESS = "0x1111111111111111111111111111111111111111";
-
-let elements;
-
-function fakeElement() {
-    return {
-        value: "",
-        textContent: "",
-        title: "",
-        style: {},
-        listeners: {},
-        addEventListener(event, handler) {
-            this.listeners[event] = handler;
-        },
-    };
-}
-
-// Stands in for document.getElementById(): one fake element per id.
-function element(id) {
-    return (elements[id] ||= fakeElement());
-}
-
-beforeEach(() => {
-    jest.resetModules();
-    elements = {};
-    globalThis.document = { getElementById: element };
-    // state.js reads chrome.storage.local at load.
-    globalThis.chrome = {
-        storage: { local: { get: async () => ({}), set: async () => {} } },
-    };
-});
-
-afterEach(() => {
-    jest.dontMock("../src/popup/views/helpers");
-    jest.dontMock("../src/shared/state");
-    jest.dontMock("../src/shared/balances");
-    jest.restoreAllMocks();
-    jest.useRealTimers();
-    delete globalThis.document;
-    delete globalThis.chrome;
-});
-
-test("showFlash() puts the whole message in the title, and clears both", () => {
-    jest.useFakeTimers();
-    const { showFlash } = require("../src/popup/views/helpers");
-
-    showFlash("Saved.");
-    expect(element("flash-msg").textContent).toBe("Saved.");
-    expect(element("flash-msg").title).toBe("Saved.");
-
-    jest.advanceTimersByTime(2000);
-    expect(element("flash-msg").textContent).toBe("");
-    expect(element("flash-msg").title).toBe("");
-});
-
-describe.each([
-    ["addToken", "add-token-address", "btn-add-token-confirm"],
-    [
-        "settingsAddToken",
-        "settings-addtoken-address",
-        "btn-settings-addtoken-manual",
-    ],
-])("adding a token on %s", (view, field, button) => {
-    let flashes;
-    let errors;
-
-    // Clicks the screen's add button with lookupTokenInfo() and saveState()
-    // replaced by the given functions.
-    async function add(lookupTokenInfo, saveState) {
-        flashes = [];
-        errors = jest.spyOn(console, "error").mockImplementation(() => {});
-        jest.spyOn(console, "log").mockImplementation(() => {});
-        jest.doMock("../src/shared/balances", () => ({ lookupTokenInfo }));
-        jest.doMock("../src/shared/state", () => ({
-            state: { trackedTokens: [] },
-            saveState,
-        }));
-        jest.doMock("../src/popup/views/helpers", () => ({
-            $: element,
-            showView: () => {},
-            showFlash: (msg) => flashes.push(msg),
-            escapeHtml: (s) => s,
-            goBack: () => {},
-        }));
-
-        require("../src/popup/views/" + view).init({
-            doRefreshAndRender: () => {},
-        });
-        element(field).value = ADDRESS;
-        await element(button).listeners.click();
-    }
-
-    test("a failed save flashes a fixed line and logs the error", async () => {
-        const detail = "A sentence about the stored record. ".repeat(4);
-
-        await add(
-            async () => ({ symbol: "TKN", decimals: 18, name: "Token" }),
-            async () => {
-                throw new Error(detail);
-            },
-        );
-
-        expect(flashes).toEqual(["Could not add the token."]);
-        expect(errors).toHaveBeenCalledWith(
-            "[AutistMask]",
-            "Adding token failed for",
-            ADDRESS,
-            detail,
-        );
-    });
-
-    test("a contract that is not a token flashes the lookup message", async () => {
-        const detail = "Not a valid ERC-20 token (symbol() failed).";
-
-        await add(
-            async () => {
-                throw new Error(detail);
-            },
-            async () => {},
-        );
-
-        expect(flashes).toEqual([detail]);
-    });
-});

tests/inpageErrors.test.js

@@ -49,12 +49,11 @@ class StubCustomEvent extends StubEvent {
     }
 }
 
-// Examples of codes the background emits on the RPC path, read out of
-// src/background/index.js. The provider must not know any list of codes — it
-// passes through whatever arrived — but the cases below are real ones.
+// Every code the background emits on the RPC path today, read out of
+// src/background/index.js. The provider must not know this list — it passes
+// through whatever arrived — but the cases below are the real ones.
 const REJECTED = 4001; // user rejected the request
 const UNAUTHORIZED = 4100; // site not connected / wrong address
-const UNSUPPORTED_METHOD = 4200; // a method the wallet does not implement
 const UNRECOGNIZED_CHAIN = 4902; // switch/add to an unsupported chain
 
 // A stub window with the four things inpage.js touches: message listeners,
@@ -116,41 +115,6 @@ async function rejectionFrom(start, response) {
     return outcome.error;
 }
 
-// The reply the real background worker (src/background/index.js) sends for
-// `method`, loaded against just enough of the extension API to receive one
-// RPC message. Same shape as tests/coldWorkerChainId.test.js.
-function backgroundReply(method) {
-    jest.resetModules();
-    jest.doMock("../src/shared/alarms", () => ({
-        BALANCE_REFRESH_ALARM: "balance",
-        BALANCE_REFRESH_PERIOD_MINUTES: 1,
-        ensureRecurringAlarms: async () => {},
-        registerAlarmHandlers: () => {},
-    }));
-
-    let messageListener = null;
-    global.chrome = {
-        runtime: {
-            onMessage: {
-                addListener: (fn) => {
-                    messageListener = fn;
-                },
-            },
-            onConnect: { addListener: () => {} },
-        },
-    };
-
-    require("../src/background/index");
-
-    return new Promise((resolve) => {
-        messageListener(
-            { type: "AUTISTMASK_RPC", method, params: [] },
-            { origin: "https://dapp.example" },
-            resolve,
-        );
-    });
-}
-
 describe("an EIP-1193 code reaches the page", () => {
     test("a user rejection arrives as code 4001", async () => {
         const err = await rejectionFrom(
@@ -200,9 +164,8 @@ describe("an EIP-1193 code reaches the page", () => {
         expect(err.message).toBe(message);
     });
 
-    // The provider is not allowed to know the codes above: any other code,
-    // including one added to the background later, must reach the page
-    // without inpage.js being edited.
+    // The provider is not allowed to know the list above: a code added to the
+    // background later must reach the page without this file being edited.
     test("a code the provider has never heard of is passed through", async () => {
         const err = await rejectionFrom(
             (p) => p.request({ method: "eth_accounts" }),
@@ -240,26 +203,6 @@ describe("an EIP-1193 code reaches the page", () => {
     });
 });
 
-// The reply here is the background's own, not one written in this file: it
-// used to carry no code for a method the wallet does not implement
-// (https://git.eeqj.de/sneak/AutistMask/issues/279), so a site probing for an
-// optional method could not tell "not implemented" from "the call failed".
-describe("a method the wallet does not implement", () => {
-    afterEach(() => {
-        delete global.chrome;
-    });
-
-    test("reaches the page as code 4200", async () => {
-        const method = "wallet_noSuchMethod";
-        const err = await rejectionFrom(
-            (p) => p.request({ method }),
-            await backgroundReply(method),
-        );
-        expect(err.code).toBe(UNSUPPORTED_METHOD);
-        expect(err.message).toBe("Unsupported method: " + method);
-    });
-});
-
 describe("the message is untouched", () => {
     test("a coded error keeps the message byte for byte", async () => {
         const message =