test: containerized Chrome end-to-end harness that drives the real popup (closes #181)

Runs the real popup in a pinned containerized Chrome and fails on any uncaught
page error or console.error. Also fixes the two defects it caught: the missing
showView import in addToken.js and the missing addressDotHtml import in
transactionDetail.js.

closes #150
closes #151

tests/e2e/network.js

@@ -0,0 +1,334 @@
+// Browser-level network interception for the end-to-end suite.
+//
+// Every http(s) request the extension makes — from the popup page AND
+// from the MV3 background service worker — is fulfilled from these
+// fixtures, so the suite is deterministic and runs entirely offline. The
+// probe that motivated this harness (see issue #181) observed live calls
+// to Blockscout returning 401 inside the container, which would make any
+// assertion about rendered transaction data worthless.
+//
+// Service-worker coverage is not free: ctx.route() only sees worker
+// traffic when PW_EXPERIMENTAL_SERVICE_WORKER_NETWORK_EVENTS=1 is set in
+// the environment, which script/test-e2e does. Without it the phishing
+// blocklist fetch that src/background/index.js issues at worker startup
+// silently reaches raw.githubusercontent.com on the open internet, and
+// src/shared/phishingDomains.js swallows the failure so nothing surfaces
+// it. That is not left to trust: waitForServiceWorkerTraffic() below
+// backs the launch-time canary in harness.js, which fails the entire
+// suite if worker requests stop being visible here.
+//
+// Anything not explicitly stubbed here is aborted AND reported to the
+// error collector, so a newly added outbound call shows up as a test
+// failure rather than as intermittent flakiness.
+
+"use strict";
+
+// Fictional ERC-20 used to seed the transaction-detail test. The symbol
+// must not collide with any entry in src/shared/tokenList.js, or
+// isSpoofedSymbol() in src/shared/transactions.js drops the transfer as a
+// symbol-spoofing attempt; holders_count must be >= 1000 or the default
+// hideLowHolderTokens filter drops it. Either would make the test pass
+// vacuously by never rendering a row at all.
+const STUB_TOKEN = {
+    address: "0xe2e0000000000000000000000000000000000e2e",
+    symbol: "E2E",
+    name: "End To End Test Token",
+    decimals: "6",
+    holders: "12345",
+};
+
+const STUB_COUNTERPARTY = "0xc0ffee0000000000000000000000000000c0ffee";
+
+const STUB_TX_HASH =
+    "0xe2e0000000000000000000000000000000000000000000000000000000000e2e";
+
+const STUB_BLOCK_NUMBER = 21000000;
+
+// Fixed instant so timeAgo() output is stable across runs.
+const STUB_TX_TIMESTAMP = "2026-01-02T03:04:05.000000Z";
+
+// A 32-byte zero word. Returned for every eth_call, which is what makes
+// ethers' ENS reverse lookup resolve to "no resolver set" and return null
+// instead of throwing. A throw would be logged by src/shared/ens.js via
+// log.errorf(), i.e. console.error, which fails the run on its own.
+const ZERO_WORD = "0x" + "0".repeat(64);
+
+const RPC_RESULTS = {
+    eth_chainId: "0x1",
+    net_version: "1",
+    eth_blockNumber: "0x1406f40",
+    eth_getBalance: "0x0",
+    eth_call: ZERO_WORD,
+    eth_gasPrice: "0x3b9aca00",
+    eth_estimateGas: "0x5208",
+    eth_getTransactionCount: "0x0",
+    eth_maxPriorityFeePerGas: "0x3b9aca00",
+};
+
+function tokenObject() {
+    return {
+        address_hash: STUB_TOKEN.address,
+        address: STUB_TOKEN.address,
+        symbol: STUB_TOKEN.symbol,
+        name: STUB_TOKEN.name,
+        decimals: STUB_TOKEN.decimals,
+        holders_count: STUB_TOKEN.holders,
+        type: "ERC-20",
+    };
+}
+
+// One received ERC-20 transfer of 1.5 E2E to the address under test.
+function tokenTransferItems(address) {
+    return [
+        {
+            transaction_hash: STUB_TX_HASH,
+            block_number: STUB_BLOCK_NUMBER,
+            timestamp: STUB_TX_TIMESTAMP,
+            from: { hash: STUB_COUNTERPARTY },
+            to: { hash: address },
+            total: { decimals: STUB_TOKEN.decimals, value: "1500000" },
+            token: tokenObject(),
+        },
+    ];
+}
+
+// Full details for STUB_TX_HASH. raw_input is "0x" so the calldata
+// decoder short-circuits; the on-chain detail fields still populate.
+function transactionDetails() {
+    return {
+        hash: STUB_TX_HASH,
+        block_number: STUB_BLOCK_NUMBER,
+        nonce: 7,
+        gas_used: "51000",
+        gas_price: "1000000000",
+        fee: { value: "51000000000000" },
+        raw_input: "0x",
+        status: "ok",
+    };
+}
+
+function jsonResponse(route, body) {
+    return route.fulfill({
+        status: 200,
+        contentType: "application/json",
+        body: JSON.stringify(body),
+    });
+}
+
+// Extract the address from a Blockscout /addresses/<addr>/... path.
+function blockscoutAddress(pathname) {
+    const m = pathname.match(/\/addresses\/(0x[0-9a-fA-F]{40})\//);
+    return m ? m[1] : null;
+}
+
+function handleRpc(route, postData, report) {
+    let payload;
+    try {
+        payload = JSON.parse(postData || "null");
+    } catch {
+        report("unstubbed RPC: unparseable body " + String(postData));
+        return route.abort();
+    }
+    // ethers batches by default, so the body may be an array.
+    const batch = Array.isArray(payload) ? payload : [payload];
+
+    // Anything that is not a JSON-RPC object, or a batch of them, is not
+    // RPC at all and must be reported like any other unrecognised
+    // outbound traffic rather than dereferenced. request.postData()
+    // returns null both for a bodyless POST and for a body Playwright
+    // cannot decode as UTF-8 (sendBeacon with a Blob, or any binary
+    // payload), so this is not an empty-string special case: it rejects
+    // every non-object payload, exactly as the catch above rejects every
+    // unparseable one.
+    if (
+        payload === null ||
+        typeof payload !== "object" ||
+        !batch.every((req) => req !== null && typeof req === "object")
+    ) {
+        report("unstubbed request: POST " + route.request().url());
+        return route.abort();
+    }
+    const replies = batch.map((req) => {
+        const result = RPC_RESULTS[req.method];
+        if (result === undefined) {
+            report("unstubbed RPC method: " + req.method);
+            return {
+                jsonrpc: "2.0",
+                id: req.id,
+                error: { code: -32601, message: "unstubbed in e2e harness" },
+            };
+        }
+        return { jsonrpc: "2.0", id: req.id, result };
+    });
+    return jsonResponse(route, Array.isArray(payload) ? replies : replies[0]);
+}
+
+const TRACE_TRUE = ["1", "true", "yes", "on"];
+const TRACE_FALSE = ["", "0", "false", "no", "off"];
+
+// Whether E2E_TRACE_NETWORK asks for the request trace.
+//
+// A set-but-unrecognised value is a hard error rather than a quiet
+// "off": E2E_TRACE_NETWORK=true asking for a trace and getting silence
+// is the operator being lied to about what the harness is doing, which
+// is the whole failure mode this suite exists to eliminate. Refusing to
+// guess costs one line and one obvious error message.
+function traceEnabled(raw) {
+    if (raw === undefined || raw === null) return false;
+    const v = String(raw).trim().toLowerCase();
+    if (TRACE_TRUE.includes(v)) return true;
+    if (TRACE_FALSE.includes(v)) return false;
+    throw new Error(
+        "E2E_TRACE_NETWORK is set to " +
+            JSON.stringify(String(raw)) +
+            ", which is not a recognised on/off value. Use one of " +
+            TRACE_TRUE.join(", ") +
+            " to enable the request trace, or one of " +
+            TRACE_FALSE.slice(1).join(", ") +
+            " to disable it. Refusing to guess: a diagnostic that silently " +
+            "does nothing is worse than one that is not there",
+    );
+}
+
+/**
+ * Route every http(s) request through local fixtures.
+ *
+ * @param {import("playwright-core").BrowserContext} ctx
+ * @param {object} opts
+ * @param {(text: string) => void} opts.report  called for unstubbed traffic
+ * @param {boolean} [opts.seedTokenTransfer]  serve the stubbed ERC-20
+ *   transfer. Read at request time, so a test can flip it on the same
+ *   options object without re-registering the route.
+ * @returns {Promise<{waitForServiceWorkerTraffic: (ms: number) =>
+ *   Promise<string|null>}>}
+ */
+async function installNetworkStubs(ctx, opts) {
+    const report = opts.report;
+
+    // First request seen that originated in a service worker, and the
+    // resolver waiting for it. This is what proves worker interception is
+    // actually in force; see waitForServiceWorkerTraffic below.
+    let firstWorkerRequest = null;
+    let announceWorkerRequest = null;
+
+    // E2E_TRACE_NETWORK=1 prints every request that reaches this handler,
+    // tagged [sw] when it originated in the background service worker.
+    // It exists so the isolation claim above can be re-checked by anyone
+    // in one command, without editing files: the phishing blocklist fetch
+    // showing up with an [sw] tag is the proof that the worker really is
+    // intercepted and that the raw.githubusercontent.com stub below is
+    // live code rather than decoration.
+    const trace = traceEnabled(process.env.E2E_TRACE_NETWORK);
+
+    // Regex rather than a glob so chrome-extension:// resource loads are
+    // never touched — routing those would break the popup itself.
+    await ctx.route(/^https?:\/\//, async (route) => {
+        const req = route.request();
+        const url = new URL(req.url());
+        const p = url.pathname;
+        const fromWorker = !!req.serviceWorker();
+
+        if (fromWorker && !firstWorkerRequest) {
+            firstWorkerRequest = req.method() + " " + req.url();
+            if (announceWorkerRequest)
+                announceWorkerRequest(firstWorkerRequest);
+        }
+
+        if (trace) {
+            const origin = fromWorker ? "[sw] " : "[page] ";
+            console.log("# routed " + origin + req.method() + " " + req.url());
+        }
+
+        // JSON-RPC endpoint (any host): a POST with a JSON-RPC body.
+        if (req.method() === "POST") {
+            return handleRpc(route, req.postData(), report);
+        }
+
+        // Blockscout v2
+        if (p.includes("/api/v2/")) {
+            if (/\/addresses\/0x[0-9a-fA-F]{40}\/transactions$/.test(p)) {
+                return jsonResponse(route, { items: [] });
+            }
+            if (/\/addresses\/0x[0-9a-fA-F]{40}\/token-transfers$/.test(p)) {
+                const addr = blockscoutAddress(p);
+                return jsonResponse(route, {
+                    items:
+                        opts.seedTokenTransfer && addr
+                            ? tokenTransferItems(addr)
+                            : [],
+                });
+            }
+            if (/\/addresses\/0x[0-9a-fA-F]{40}\/token-balances$/.test(p)) {
+                return jsonResponse(route, []);
+            }
+            if (p.endsWith("/transactions/" + STUB_TX_HASH)) {
+                return jsonResponse(route, transactionDetails());
+            }
+        }
+
+        // CoinDesk price tick
+        if (url.hostname.endsWith("coindesk.com")) {
+            return jsonResponse(route, { Data: {} });
+        }
+
+        // MetaMask phishing blocklist
+        if (
+            url.hostname === "raw.githubusercontent.com" ||
+            p.endsWith("/eth-phishing-detect/main/src/config.json")
+        ) {
+            return jsonResponse(route, {
+                version: 2,
+                tolerance: 2,
+                fuzzylist: [],
+                whitelist: [],
+                blacklist: [],
+            });
+        }
+
+        // Best-effort Etherscan address labels: served as an empty page.
+        if (url.hostname.endsWith("etherscan.io")) {
+            return route.fulfill({
+                status: 200,
+                contentType: "text/html",
+                body: "<html><body></body></html>",
+            });
+        }
+
+        report("unstubbed request: " + req.method() + " " + req.url());
+        return route.abort();
+    });
+
+    return {
+        /**
+         * Resolve with the first service-worker-originated request this
+         * handler saw, or null if none arrives within `ms`.
+         *
+         * The background worker fetches the phishing blocklist at
+         * startup, unconditionally, within about a second of the context
+         * coming up — so under working interception this resolves almost
+         * immediately. Nothing arriving means worker traffic is bypassing
+         * the handler entirely and going to the real internet, which the
+         * caller turns into a hard failure of the whole suite.
+         */
+        waitForServiceWorkerTraffic(ms) {
+            if (firstWorkerRequest) return Promise.resolve(firstWorkerRequest);
+            return new Promise((resolve) => {
+                const timer = setTimeout(() => {
+                    announceWorkerRequest = null;
+                    resolve(null);
+                }, ms);
+                announceWorkerRequest = (req) => {
+                    clearTimeout(timer);
+                    announceWorkerRequest = null;
+                    resolve(req);
+                };
+            });
+        },
+    };
+}
+
+module.exports = {
+    installNetworkStubs,
+    STUB_TOKEN,
+    STUB_TX_HASH,
+};