Bug 1696137 - Fix timeouts in browser_reopen_all_windows.js, r=annyG

We currently wait for the "sessionstore-single-window-restored" notification and
*then* start listening for individual "SSTabRestored" events. This doesn't work
because we may fire those events before we get the chance to create the listener.

Listening for "browser-window-before-show" works consistently, but we need
references to the windows *before* they start restoring, so we have
to manually run the "Restore All Windows" code, instead of clicking the Library
button.

Originally part of the patch stack for bug 1703556.

Differential Revision: https://phabricator.services.mozilla.com/D112887

browser/components/sessionstore/test/browser_reopen_all_windows.js

@@ -19,9 +19,39 @@ var URLS_WIN2 = [
 ];
 var EXPECTED_URLS_WIN2 = ["about:blank", ...URLS_WIN2];
 
-add_task(async () => {
-  requestLongerTimeout(4);
+requestLongerTimeout(4);
 
+function allTabsRestored(win, expectedUrls) {
+  return new Promise(resolve => {
+    let tabsRestored = 0;
+    function handler(event) {
+      let spec = event.target.linkedBrowser.currentURI.spec;
+      if (expectedUrls.includes(spec)) {
+        tabsRestored++;
+      }
+      info(`Got SSTabRestored for ${spec}, tabsRestored=${tabsRestored}`);
+      if (tabsRestored === expectedUrls.length) {
+        win.gBrowser.tabContainer.removeEventListener(
+          "SSTabRestored",
+          handler,
+          true
+        );
+        resolve();
+      }
+    }
+    win.gBrowser.tabContainer.addEventListener("SSTabRestored", handler, true);
+  });
+}
+
+async function windowAndTabsRestored(win, expectedUrls) {
+  await TestUtils.topicObserved(
+    "browser-window-before-show",
+    subject => subject === win
+  );
+  return allTabsRestored(win, expectedUrls);
+}
+
+add_task(async () => {
   await SpecialPowers.pushPrefEnv({
     set: [
       // Set the pref to true so we know exactly how many tabs should be restoring at
@@ -60,106 +90,30 @@ add_task(async () => {
     "The closed windows was added to Recently Closed Windows"
   );
 
-  // Library -> History -> Recently Closed Windows -> Reopen all Windows
-
-  // Show the Library view.
-  info("About to open the PanelUI menu");
-  let appMenu = document.getElementById("PanelUI-menu-button");
-  let appMenuPopup = document.getElementById("appMenu-popup");
-  let PopupShownPromise = BrowserTestUtils.waitForEvent(
-    appMenuPopup,
-    "popupshown"
-  );
-  appMenu.click();
-  await PopupShownPromise;
-
-  let promise;
-  if (!gProton) {
-    info("About to click on the Library option");
-
-    document.getElementById("appMenu-library-button").click();
-    let libraryView = document.getElementById("appMenu-libraryView");
-    promise = BrowserTestUtils.waitForEvent(libraryView, "ViewShown");
-    await promise;
+  // We previously used to manually navigate the Library menu to click the
+  // "Reopen all Windows" button, but that reopens all windows at once without
+  // returning a reference to each window. Since we need to attach listeners to
+  // these windows *before* they start restoring tabs, we now manually call
+  // undoCloseWindow() here, which has the same effect, but also gives us the
+  // window references.
+  info("Reopening windows");
+  let restoredWindows = [];
+  while (SessionStore.getClosedWindowCount() > 0) {
+    restoredWindows.unshift(undoCloseWindow());
   }
+  is(restoredWindows.length, 2, "Reopened correct number of windows");
 
-  // Navigate to the History subview.
-  info("About to click on the History option");
-  let historyId = gProton
-    ? "appMenu-history-button"
-    : "appMenu-library-history-button";
-  document.getElementById(historyId).click();
-  let historyView = document.getElementById("PanelUI-history");
-  promise = BrowserTestUtils.waitForEvent(historyView, "ViewShown");
-  await promise;
-
-  // Click on "Recently Closed Windows"
-  info("About to click on 'Recently Closed Windows'");
-  document.getElementById("appMenuRecentlyClosedWindows").click();
-  let recentlyClosedWindowsView = document.getElementById(
-    "appMenu-library-recentlyClosedWindows"
+  let win1Restored = windowAndTabsRestored(
+    restoredWindows[0],
+    EXPECTED_URLS_WIN1
   );
-  promise = BrowserTestUtils.waitForEvent(
-    recentlyClosedWindowsView,
-    "ViewShown"
-  );
-  await promise;
-
-  // Click on "Restore All Windows"
-  var restoreAll = document.getElementsByClassName(
-    "restoreallitem subviewbutton subviewbutton-iconic panel-subview-footer-button"
-  );
-
-  // Wait for all windows to be restored
-  var observedWin1 = TestUtils.topicObserved(
-    "sessionstore-single-window-restored",
-    subject => {
-      return subject.gBrowser.tabs.length == EXPECTED_URLS_WIN1.length;
-    }
-  );
-  var observedWin2 = TestUtils.topicObserved(
-    "sessionstore-single-window-restored",
-    subject => {
-      return subject.gBrowser.tabs.length == EXPECTED_URLS_WIN2.length;
-    }
-  );
-  var allPromises = Promise.all([observedWin1, observedWin2]);
-  restoreAll[0].click();
-  var restoredWindows = (await allPromises).map(([subject, data]) => subject);
-  let allTabsRestored = PromiseUtils.defer();
-  var tabsRestored = 0;
-  function SSTabRestoredHandler() {
-    tabsRestored++;
-    info(`Received a SSTabRestored event`);
-    if (tabsRestored == EXPECTED_URLS_WIN1.length + EXPECTED_URLS_WIN2.length) {
-      info(`All tabs have been restored`);
-      restoredWindows[0].gBrowser.tabContainer.removeEventListener(
-        "SSTabRestored",
-        SSTabRestoredHandler,
-        true
-      );
-      restoredWindows[1].gBrowser.tabContainer.removeEventListener(
-        "SSTabRestored",
-        SSTabRestoredHandler,
-        true
-      );
-      allTabsRestored.resolve();
-    }
-  }
-  info("About to add an event listener for SSTabRestored");
-  restoredWindows[0].gBrowser.tabContainer.addEventListener(
-    "SSTabRestored",
-    SSTabRestoredHandler,
-    true
-  );
-  restoredWindows[1].gBrowser.tabContainer.addEventListener(
-    "SSTabRestored",
-    SSTabRestoredHandler,
-    true
+  let win2Restored = windowAndTabsRestored(
+    restoredWindows[1],
+    EXPECTED_URLS_WIN2
   );
 
   info("About to wait for tabs to be restored");
-  await allTabsRestored.promise;
+  await Promise.all([win1Restored, win2Restored]);
 
   is(
     restoredWindows[0].gBrowser.tabs.length,

browser/components/sessionstore/test/empty.html

@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-
+<meta charset="UTF-8">
 <html>
   <body>
   </body>