fix(ci): await complete browser fixture restoration

Wait for the restored document's matching CDP load event before closing the observer. Drain storage verifier providers and surface cleanup failures so the next scenario receives a settled page.

scripts/lib/browser-scenario-storage-e2e.mjs

@@ -10,6 +10,7 @@ import {
   runScenarioCli,
   scenarioProfiles,
 } from "./browser-scenario-verifier.mjs";
+import { closeVerifierResources } from "./verifier-cleanup.mjs";
 
 const scenarioFor = (browser, origin) =>
   browserScenarioSchema.parse({
@@ -299,6 +300,7 @@ const verifyConnectedStorage = async (endpoint, targetId, origin) => {
     target.webSocketDebuggerUrl,
     "capture_browser_scenario",
   );
+  let failure;
   try {
     await assertStorageKeyPartition(observer, origin);
     const result = await runScenarioCli(scenario);
@@ -313,11 +315,14 @@ const verifyConnectedStorage = async (endpoint, targetId, origin) => {
     assert.equal(capture.browser.cleanup, "disconnected-external");
     await verifyCallerDebuggerPause(observer, origin, scenario);
     await verifyCancelledStorage(observer, endpoint, targetId, scenario);
+  } catch (cause) {
+    failure = cause;
+    throw cause;
   } finally {
-    await raceWithTimeout(restoreTarget(observer, target.url), 1_000).catch(
-      () => undefined,
+    await closeVerifierResources(
+      [() => restoreTarget(observer, target.url), () => observer.close()],
+      failure,
     );
-    await raceWithTimeout(observer.close(), 1_000).catch(() => undefined);
   }
 };
 
@@ -503,7 +508,8 @@ const verifyCallerDebuggerPause = async (caller, origin, scenario) => {
     ],
   });
   let settled = false;
-  const pending = createBrowserScenarioProvider(process.env)
+  const provider = createBrowserScenarioProvider(process.env);
+  const pending = provider
     .captureScenario(debuggerScenario, { signal: controller.signal })
     .finally(() => {
       settled = true;
@@ -586,9 +592,10 @@ const verifyCallerDebuggerPause = async (caller, origin, scenario) => {
     });
   } finally {
     unsubscribe();
-    await raceWithTimeout(caller.send("Debugger.disable"), 1_000).catch(
-      () => undefined,
-    );
+    await closeVerifierResources([
+      () => caller.send("Debugger.disable"),
+      () => provider.close(),
+    ]);
   }
 };
 
@@ -615,38 +622,43 @@ const verifyCancelledStorage = async (
     expression: "performance.timeOrigin",
     returnByValue: true,
   });
-  const pending = createBrowserScenarioProvider(process.env).captureScenario(
-    cancelledScenario,
-    { signal: controller.signal },
-  );
-  await waitForNewDocument(
-    observer,
-    "/storage-main",
-    priorDocument.result.value,
-  );
-  const state = await observer.send("Runtime.evaluate", {
-    expression:
-      "JSON.parse(document.querySelector('#main-report').textContent)",
-    returnByValue: true,
+  const provider = createBrowserScenarioProvider(process.env);
+  const pending = provider.captureScenario(cancelledScenario, {
+    signal: controller.signal,
   });
-  assert.deepEqual(state.result.value, {
-    local: "main-initial",
-    session: "main-session-initial",
-    removed: "main-remove-seed",
-    empty: "main-empty-seed",
-  });
-  controller.abort(new Error("cancel storage seed scenario"));
-  const result = await pending;
-  assert.ok(
-    !result.ok ||
-      result.value.steps.some(({ status }) => status === "cancelled"),
-    "Cancellation unexpectedly completed every scenario step",
-  );
-  const targets = await (await fetch(`${endpoint}/json/list`)).json();
-  assert.ok(
-    targets.some(({ id }) => id === targetId),
-    "Cancelled connect-mode storage cleanup closed the external target",
-  );
+  try {
+    await waitForNewDocument(
+      observer,
+      "/storage-main",
+      priorDocument.result.value,
+    );
+    const state = await observer.send("Runtime.evaluate", {
+      expression:
+        "JSON.parse(document.querySelector('#main-report').textContent)",
+      returnByValue: true,
+    });
+    assert.deepEqual(state.result.value, {
+      local: "main-initial",
+      session: "main-session-initial",
+      removed: "main-remove-seed",
+      empty: "main-empty-seed",
+    });
+    controller.abort(new Error("cancel storage seed scenario"));
+    const result = await pending;
+    assert.ok(
+      !result.ok ||
+        result.value.steps.some(({ status }) => status === "cancelled"),
+      "Cancellation unexpectedly completed every scenario step",
+    );
+    const targets = await (await fetch(`${endpoint}/json/list`)).json();
+    assert.ok(
+      targets.some(({ id }) => id === targetId),
+      "Cancelled connect-mode storage cleanup closed the external target",
+    );
+  } finally {
+    controller.abort();
+    await provider.close();
+  }
 };
 
 const waitForNewDocument = async (connection, path, priorTimeOrigin) => {
@@ -669,15 +681,38 @@ const waitForNewDocument = async (connection, path, priorTimeOrigin) => {
 };
 
 const restoreTarget = async (connection, url) => {
-  await connection.send("Page.navigate", { url });
-  const deadline = Date.now() + 10_000;
-  while (Date.now() < deadline) {
-    const result = await connection.send("Runtime.evaluate", {
-      expression: "location.href",
-      returnByValue: true,
-    });
-    if (result.result.value === url) return;
-    await new Promise((resolve) => setTimeout(resolve, 25));
+  const loaded = new Set();
+  let loaderId;
+  let resolveLoaded;
+  const load = new Promise((resolve) => {
+    resolveLoaded = resolve;
+  });
+  const unsubscribe = connection.onEvent((event) => {
+    if (
+      event.method !== "Page.lifecycleEvent" ||
+      event.params?.name !== "load" ||
+      typeof event.params.loaderId !== "string"
+    )
+      return;
+    loaded.add(event.params.loaderId);
+    if (event.params.loaderId === loaderId) resolveLoaded();
+  });
+  try {
+    await connection.send("Page.setLifecycleEventsEnabled", { enabled: true });
+    const navigation = await connection.send("Page.navigate", { url });
+    assert.equal(navigation.errorText, undefined);
+    assert.equal(typeof navigation.loaderId, "string");
+    loaderId = navigation.loaderId;
+    // A URL changes at commit, before old child frames have been retired.
+    // Do not hand the shared page to the next verifier until this load ends.
+    if (!loaded.has(loaderId))
+      await raceWithTimeout(load, 10_000, () => {
+        throw new Error(
+          "External browser did not finish restoring its document",
+        );
+      });
+  } finally {
+    unsubscribe();
+    await connection.send("Page.setLifecycleEventsEnabled", { enabled: false });
   }
-  throw new Error("External browser did not return to its original URL");
 };