fix: use the gas limit a site sends as gas (closes #207)

Sites send the gas limit under its JSON-RPC name, `gas`. ethers only
reads `gasLimit`, so the field was dropped and the node's estimate was
shown and signed instead. The page's request now takes `gas` as the gas
limit, and the existing ceiling, display and comparison with the signed
transaction cover it as they already did `gasLimit`. A request that
gives both with different values is refused.

Model: opus-5-5

README.md

@@ -422,11 +422,12 @@ captured at `eth_sendRawTransaction` rather than against anything the extension
 reported, rejecting each prompt is required to return a rejection to the page
 rather than hang or resolve, a network switch request is required to leave the
 stored network unchanged and send no `chainChanged` until it is approved, a
-prompt raised while another approval window has focus is required to open a
-window of its own, and the password is required to be absent from every message
-the approval window sends to the background — with the message that would carry
-it required to be present, so that check cannot pass by observing nothing. That
-last one is the standing floor under
+network switch in Settings is required to send the page `chainChanged` with the
+new chain id, a prompt raised while another approval window has focus is
+required to open a window of its own, and the password is required to be absent
+from every message the approval window sends to the background — with the
+message that would carry it required to be present, so that check cannot pass by
+observing nothing. That last one is the standing floor under
 [#157](https://git.eeqj.de/sneak/AutistMask/issues/157).
 
 The limits of that coverage and of the rest of the Chrome suite, none of them
@@ -1789,7 +1790,8 @@ view would leave a wallet one click from deletion.
       network changes only here, or when the user approves a site's request on
       **NetworkApproval**; either way, switching restores the RPC and Blockscout
       endpoints last used on that network, or that network's defaults if it has
-      none
+      none, and sends `chainChanged` with the new chain id to every open tab.
+      Choosing the network already active changes nothing and sends nothing
     - Ethereum RPC: endpoint URL input + "Save" button (validated against
       `eth_chainId` before being saved)
     - Blockscout API: endpoint URL input + "Save" button (validated against
@@ -2069,7 +2071,9 @@ view would leave a wallet one click from deletion.
   artifact can be compared with it field for field. A nonce the site supplies is
   ignored: the nonce is always the account's next nonce from the node, so a site
   cannot replace one of the user's pending transactions or leave this one stuck
-  behind a gap. A request that cannot be populated — unreachable node, reverting
+  behind a gap. A gas limit the site supplies, as `gas` or `gasLimit`, is used
+  in place of the node's estimate; a request giving both with different values
+  is refused. A request that cannot be populated — unreachable node, reverting
   gas estimate — opens no window and is failed back to the site. Only one
   transaction approval exists at a time: populating fixes the nonce, so a second
   `eth_sendTransaction` arriving while one is unanswered is refused with

TODO.md

@@ -2,10 +2,9 @@
 
 - `git pull` `next` and cut a branch from it — one branch per issue, named
   `issue-<N>-<slug>`. Never branch from `main`.
-- Do the work as one commit whose title ends with ` (closes #N)`, with the
-  `TODO.md` update in that same commit.
-- Move Next Step to the top of Completed Steps; move the top item of Future
-  Steps into Next Step.
+- Do the work as one commit whose title ends with ` (closes #N)`.
+- Add no entry to Completed Steps. What landed is recorded on the tracker and in
+  `git log`, where each commit title names the issue it closes.
 - Run `make fmt`, then `make check`. A feature branch may be red; `next` and
   `main` may not.
 - Rebase onto current `next` immediately before pushing — other branches land on
@@ -44,6 +43,25 @@ then continue tagging as milestones land.
 
 # Completed Steps
 
+- 2026-10-08: The browser suites no longer read a screen before the page has
+  shown it ([#502](https://git.eeqj.de/sneak/AutistMask/issues/502)). Their wait
+  for a screen used to pass as soon as the element laid out, which every view
+  does until the page's stylesheet has applied, so an approval test could read
+  the prompt's fields before the page's script had filled them. `visible()` in
+  `tests/e2e/harness.js` and `waitVisible()` in `tests/e2e/firefox/driver.js`
+  now also wait for the page to finish loading and for neither the element nor
+  anything around it to carry the `hidden` class that `showView()` puts on every
+  view but the current one. No caller changed.
+
+- 2026-10-08: Switching the network in Settings now tells open pages
+  ([#500](https://git.eeqj.de/sneak/AutistMask/issues/500)). Once the switch is
+  saved, Settings asks the background to send `chainChanged` with the new chain
+  id to every open tab, through the same function an approved site request uses.
+  Choosing the network already active changes nothing and sends nothing. Only
+  the extension's own pages can ask for this. `tests/chainSwitchGate.test.js`
+  drives the real Settings view against the background, and the Chrome suite
+  checks that the test page hears both switches.
+
 - 2026-10-07: A site can no longer switch the wallet's network by itself
   ([#408](https://git.eeqj.de/sneak/AutistMask/issues/408)). A connected site's
   `wallet_switchEthereumChain` request for the other supported network opens a

src/background/index.js

@@ -1471,6 +1471,7 @@ runtime.onMessage.addListener((msg, sender, sendResponse) => {
         "AUTISTMASK_ADDRESSES_REMOVED",
         "AUTISTMASK_GET_CONNECTED_SITES",
         "AUTISTMASK_REMOVE_SITE",
+        "AUTISTMASK_NETWORK_CHANGED",
     ];
     if (POPUP_ONLY_TYPES.includes(msg.type) && !isExtensionSender(sender)) {
         sendResponse({ error: "Unauthorized sender" });
@@ -1854,6 +1855,13 @@ runtime.onMessage.addListener((msg, sender, sendResponse) => {
         broadcastSiteRemoved(msg.origin);
         return false;
     }
+
+    // Settings switched the network and has saved it. Open tabs are told the
+    // new chain id the same way as after a site's approved switch request.
+    if (msg.type === "AUTISTMASK_NETWORK_CHANGED") {
+        broadcastChainChanged(msg.chainId);
+        return false;
+    }
 });
 
 module.exports = { PROXY_METHODS };

src/popup/views/settings.js

@@ -316,7 +316,11 @@ function init(ctx) {
     const networkSelect = $("settings-network");
     networkSelect.addEventListener("change", async () => {
         const newId = networkSelect.value;
+        if (newId === state.networkId) return;
         const net = await onChainSwitch(newId);
+        // Open pages are told by the background, as after a site's approved
+        // switch request.
+        notify({ type: "AUTISTMASK_NETWORK_CHANGED", chainId: net.chainId });
         $("settings-rpc").value = state.rpcUrl;
         $("settings-blockscout").value = state.blockscoutUrl;
         showFlash("Switched to " + net.name + ".");

src/shared/approvalTx.js

@@ -31,6 +31,7 @@ const {
     VoidSigner,
     accessListify,
     getAddress,
+    getBigInt,
     getBytes,
     hexlify,
     toQuantity,
@@ -47,10 +48,11 @@ const {
 // minutes long, which is not a wait anyone will sit through.
 const POPULATE_TIMEOUT_MS = 20000;
 
-// The request fields taken from the page. Anything else is dropped rather than
-// passed to ethers: the object is page-controlled, and a future ethers that
-// learns to carry a new transaction field must not start picking one up out of
-// it without this module knowing.
+// The request fields taken from the page, plus `gas`, which requestFrom()
+// takes as the gas limit. Anything else is dropped rather than passed to
+// ethers: the object is page-controlled, and a future ethers that learns to
+// carry a new transaction field must not start picking one up out of it
+// without this module knowing.
 //
 // The nonce is not taken from the page; it is always the account's next nonce
 // from the network. A page that chose it could replace one of the user's
@@ -84,6 +86,16 @@ function present(v) {
     return v !== null && v !== undefined && v !== "";
 }
 
+// Whether two quantities from the page are the same number. One that is not a
+// number matches nothing.
+function sameQuantity(a, b) {
+    try {
+        return getBigInt(a) === getBigInt(b);
+    } catch {
+        return false;
+    }
+}
+
 // These strings reach the user through the requesting page, so they are full
 // sentences even when the tail of one came from ethers or from the node.
 function sentence(text) {
@@ -111,6 +123,20 @@ function requestFrom(txParams, from) {
     for (const key of REQUEST_FIELDS) {
         if (present(txParams[key])) request[key] = txParams[key];
     }
+    // JSON-RPC calls the gas limit `gas`, and that is the name sites send.
+    // ethers only reads `gasLimit`: left as `gas` it would be dropped and an
+    // estimate signed in its place.
+    if (present(txParams.gas)) {
+        if (
+            present(request.gasLimit) &&
+            !sameQuantity(request.gasLimit, txParams.gas)
+        ) {
+            throw fail(
+                "The site asked for two different gas limits for this transaction.",
+            );
+        }
+        request.gasLimit = txParams.gas;
+    }
     if (
         present(request.type) &&
         !ALLOWED_TX_TYPES.includes(Number(request.type))

tests/approvalTx.test.js

@@ -9,7 +9,7 @@
 // requesting page or the RPC node can say turns it into an approval that
 // should never have been raised.
 
-const { Network, Wallet } = require("ethers");
+const { Network, Transaction, Wallet, toQuantity } = require("ethers");
 const {
     prepareApprovalTx,
     serializeApprovedTx,
@@ -138,6 +138,43 @@ describe("prepareApprovalTx", () => {
         expect(approved.maxFeePerGas).toBe("0x12a05f200");
     });
 
+    // `gas` is the JSON-RPC name for the gas limit and the one sites send.
+    // The node would estimate 21000; the site's 200000 is what is shown and
+    // what is signed.
+    test("uses the gas limit a site sends as gas", async () => {
+        const approved = await prepareApprovalTx(
+            providerWith(),
+            signer.address,
+            { ...TX_PARAMS, gas: "0x30d40" },
+        );
+        expect(approved.gasLimit).toBe("0x30d40");
+        const signed = Transaction.from(
+            await signer.signTransaction({ ...approved }),
+        );
+        expect(signed.gasLimit).toBe(200000n);
+    });
+
+    test("accepts gas and gasLimit that name the same number", async () => {
+        const approved = await prepareApprovalTx(
+            providerWith(),
+            signer.address,
+            { ...TX_PARAMS, gas: "0x30d40", gasLimit: 200000 },
+        );
+        expect(approved.gasLimit).toBe("0x30d40");
+    });
+
+    test("refuses gas and gasLimit that disagree", async () => {
+        await expect(
+            prepareApprovalTx(providerWith(), signer.address, {
+                ...TX_PARAMS,
+                gas: "0x30d40",
+                gasLimit: "0x5208",
+            }),
+        ).rejects.toThrow(
+            "The site asked for two different gas limits for this transaction.",
+        );
+    });
+
     test("carries an access list the request asked for", async () => {
         const approved = await prepareApprovalTx(
             providerWith(),
@@ -212,6 +249,15 @@ describe("prepareApprovalTx", () => {
         ).rejects.toThrow(/gas limit no network this wallet supports/);
     });
 
+    test("refuses a gas limit the site sent above the ceiling", async () => {
+        await expect(
+            prepareApprovalTx(providerWith(), signer.address, {
+                ...TX_PARAMS,
+                gas: toQuantity(MAX_GAS_LIMIT + 1n),
+            }),
+        ).rejects.toThrow(/gas limit no network this wallet supports/);
+    });
+
     // The combined bound at population: a gas limit and a fee that are each
     // under their own ceiling but multiply to thousands of ETH is refused
     // before the approval window opens, so the user is never shown a

tests/chainSwitchGate.test.js

@@ -16,7 +16,9 @@
 //
 // The endpoint half of #308 lives in tests/networkEndpoints.test.js, which
 // covers the popup's chain switch; this file covers the background's, which
-// goes through storage rather than the shared state singleton.
+// goes through storage rather than the shared state singleton. The last block
+// covers what the background tells open tabs when the user switches the
+// network in Settings.
 
 const { networkById } = require("../src/shared/networks");
 const { makeStorageStub } = require("./support/storageStub");
@@ -225,6 +227,14 @@ function loadBackground() {
         answerPrompt,
         closePrompt,
         opened,
+        // A message to the background from `sender`, and its answer.
+        send: (msg, sender) => {
+            let reply = null;
+            messageListener(msg, sender, (r) => {
+                reply = r;
+            });
+            return reply;
+        },
         walletState: () => storage.read("autistmask"),
         chainChangedEvents: () =>
             toTabs.filter((m) => m.eventName === "chainChanged"),
@@ -390,3 +400,109 @@ describe("only the user switches the network", () => {
         expect(bg.walletState().rpcUrl).toBe(CUSTOM_RPC);
     });
 });
+
+// Switching the network in Settings tells open pages, as an approved site
+// request does (https://git.eeqj.de/sneak/AutistMask/issues/500). These drive
+// the real Settings view over the background's storage, with what it sends
+// delivered to the background from the extension's own page.
+describe("switching the network in Settings tells every open tab", () => {
+    const POPUP = { url: EXT_URL + "src/popup/index.html" };
+
+    // A stand-in for one DOM node: enough of an element for init() to set
+    // properties on it and hang listeners off it.
+    function fakeElement() {
+        return {
+            value: "",
+            checked: false,
+            textContent: "",
+            style: {},
+            dataset: {},
+            classList: { add() {}, remove() {} },
+            listeners: {},
+            addEventListener(event, handler) {
+                this.listeners[event] = handler;
+            },
+            querySelectorAll: () => [],
+        };
+    }
+
+    // Settings, opened the way the popup opens it. Returns its network
+    // selector.
+    async function openSettings(bg) {
+        const elements = {};
+        const element = (id) => (elements[id] ||= fakeElement());
+        jest.doMock("../src/popup/views/helpers", () => ({
+            $: element,
+            showView: () => {},
+            updateDebugBanner: () => {},
+            showFlash: () => {},
+            escapeHtml: (s) => s,
+            flashCopyFeedback: () => {},
+            goBack: () => {},
+            pushCurrentView: () => {},
+            onViewLeave: () => {},
+            VIEWS: [],
+        }));
+        global.chrome.runtime.sendMessage = (msg) => {
+            bg.send(msg, POPUP);
+        };
+        await require("../src/shared/state").loadState();
+        require("../src/popup/views/settings").init({
+            pageClosed: new AbortController().signal,
+        });
+        const select = element("settings-network");
+        select.value = "mainnet";
+        return select;
+    }
+
+    // The user picks `networkId` in the selector.
+    async function choose(select, networkId) {
+        select.value = networkId;
+        await select.listeners.change();
+        await settle();
+    }
+
+    afterEach(() => {
+        jest.dontMock("../src/popup/views/helpers");
+    });
+
+    test("switching to the other network sends chainChanged once, with its chain id", async () => {
+        const bg = loadBackground();
+        const select = await openSettings(bg);
+
+        await choose(select, "sepolia");
+
+        expect(bg.walletState().networkId).toBe("sepolia");
+        expect(bg.chainChangedEvents()).toEqual([
+            {
+                type: "AUTISTMASK_EVENT",
+                eventName: "chainChanged",
+                data: SEPOLIA.chainId,
+            },
+        ]);
+    });
+
+    test("choosing the network already active changes nothing and sends nothing", async () => {
+        const bg = loadBackground();
+        const select = await openSettings(bg);
+        const before = bg.walletState();
+
+        await choose(select, "mainnet");
+
+        expect(bg.walletState()).toEqual(before);
+        expect(bg.chainChangedEvents()).toEqual([]);
+    });
+
+    test("a page cannot make the background send chainChanged", async () => {
+        const bg = loadBackground();
+
+        const reply = bg.send(
+            { type: "AUTISTMASK_NETWORK_CHANGED", chainId: SEPOLIA.chainId },
+            { url: CONNECTED_ORIGIN + "/" },
+        );
+        await settle();
+
+        expect(reply).toEqual({ error: "Unauthorized sender" });
+        expect(bg.chainChangedEvents()).toEqual([]);
+    });
+});

tests/e2e/firefox/driver.js

@@ -279,12 +279,18 @@ class Driver {
 
     // Shown means shown: in the popup a view is switched by toggling a
     // "hidden" class, and an element that is present but collapsed is not
-    // the thing a test means by visible.
+    // the thing a test means by visible. Until the page's stylesheet has
+    // applied that class hides nothing and every view lays out, so the page
+    // must also have finished loading, which it does only after its
+    // stylesheet, and neither the element nor anything enclosing it may
+    // carry the class (https://git.eeqj.de/sneak/AutistMask/issues/502).
     async waitVisible(selector, timeout = DEFAULT_WAIT_MS) {
         return this.waitFor(
             "selector " + selector + " to be visible",
             `const el = document.querySelector(arguments[0]);
-             if (!el) return false;
+             if (document.readyState !== "complete" || !el) return false;
+             if (el.closest(".hidden")) return false;
+             if (getComputedStyle(el).visibility !== "visible") return false;
              const r = el.getBoundingClientRect();
              return r.width > 0 && r.height > 0;`,
             [selector],

tests/e2e/harness.js

@@ -333,8 +333,33 @@ async function launch(routeOpts) {
 
 const PASSWORD = "e2e-harness-password";
 
+// Waits until the page shows `selector`, not only until it lays out. Until the
+// page's stylesheet has applied, the `hidden` class that showView() keeps on
+// every view but the current one hides nothing and every view lays out, so a
+// test could read a screen before the page's script had filled it
+// (https://git.eeqj.de/sneak/AutistMask/issues/502). So the page must also
+// have finished loading, which it does only after its stylesheet, and neither
+// the element nor anything enclosing it may carry `hidden`. Polled on a timer:
+// animation frames are not guaranteed to a window that is not in front.
 async function visible(page, selector, timeout = 15000) {
-    await page.waitForSelector(selector, { state: "visible", timeout });
+    await page
+        .waitForFunction(
+            (sel) => {
+                const el = document.querySelector(sel);
+                if (document.readyState !== "complete" || !el) return false;
+                if (el.closest(".hidden")) return false;
+                if (getComputedStyle(el).visibility !== "visible") return false;
+                const r = el.getBoundingClientRect();
+                return r.width > 0 && r.height > 0;
+            },
+            selector,
+            { polling: 50, timeout },
+        )
+        .catch((e) => {
+            throw new Error(
+                "the page did not show " + selector + ": " + e.message,
+            );
+        });
 }
 
 // An empty WebAssembly module: magic number and version header, no

tests/e2e/run.js

@@ -4538,6 +4538,42 @@ test("a site's network switch changes nothing until the user approves it (#408)"
     );
 });
 
+// Switching the network in Settings tells the page too, as an approved site
+// request does (https://git.eeqj.de/sneak/AutistMask/issues/500). The wallet
+// goes back to mainnet the same way at the end.
+test("a network switch in Settings tells the page (#500)", async (env) => {
+    const { mainnet, sepolia } = NETWORKS;
+    const before = await storedNetwork(env.page);
+    assert(
+        before.networkId === "mainnet",
+        "this test starts on mainnet, not on " + before.networkId,
+    );
+    const eventsBefore = (await chainChangedEvents(env.dapp)).length;
+    await openSettings(env.page);
+
+    await env.page.selectOption("#settings-network", "sepolia");
+    let events = await chainChangedEvents(env.dapp, eventsBefore + 1);
+    assert(
+        events.length === eventsBefore + 1 &&
+            events[events.length - 1].data === sepolia.chainId,
+        "the page was not told of the switch to Sepolia: " +
+            JSON.stringify(events),
+    );
+
+    await env.page.selectOption("#settings-network", "mainnet");
+    events = await chainChangedEvents(env.dapp, eventsBefore + 2);
+    assert(
+        events.length === eventsBefore + 2 &&
+            events[events.length - 1].data === mainnet.chainId,
+        "the page was not told of the switch back to mainnet: " +
+            JSON.stringify(events),
+    );
+    assert(
+        isDeepStrictEqual(await storedNetwork(env.page), before),
+        "switching back did not restore the mainnet network and endpoints",
+    );
+});
+
 // The closing pass over both boundaries at once. Every message the section
 // put on either channel is re-read here and required to be free of the
 // password — and required to be there at all, method by method, so the