From 3eb44baf8394dbc5b56efdd28b72555751d3d3e1 Mon Sep 17 00:00:00 2001
From: Brad Werth <bwerth@mozilla.com>
Date: Tue, 30 Jan 2024 18:07:40 +0000
Subject: [PATCH] Bug 1865372 Part 2: Update test timings.
 r=fxview-reviewers,sfoster

This changes browser_opentabs_recency.js to check for window occlusion
before calling window.restore, and if waiting for the
occlusionstatechange event, waiting an extra event loop to ensure that
all the listeners have fired. This is necessary to ensure that the
browsing context has become active, which is the next check in the
helper function.

Differential Revision: https://phabricator.services.mozilla.com/D199647
---
 .../tests/browser/browser_opentabs_recency.js      | 42 +++++++++++++++-------
 1 file changed, 29 insertions(+), 13 deletions(-)

diff --git a/browser/components/firefoxview/tests/browser/browser_opentabs_recency.js b/browser/components/firefoxview/tests/browser/browser_opentabs_recency.js
index 63574ae23664..e5beb4700a33 100644
--- a/browser/components/firefoxview/tests/browser/browser_opentabs_recency.js
+++ b/browser/components/firefoxview/tests/browser/browser_opentabs_recency.js
@@ -46,33 +46,49 @@ async function restoreWindow(win) {
     win,
     "sizemodechange"
   );
+
+  // Check if we also need to wait for occlusion to be updated.
+  let promiseOcclusion;
+  let willWaitForOcclusion = win.isFullyOccluded;
+  if (willWaitForOcclusion) {
+    // Not only do we need to wait for the occlusionstatechange event,
+    // we also have to wait *one more event loop* to ensure that the
+    // other listeners to the occlusionstatechange events have fired.
+    // Otherwise, our browsing context might not have become active
+    // at the point where we receive the occlusionstatechange event.
+    promiseOcclusion = BrowserTestUtils.waitForEvent(
+      win,
+      "occlusionstatechange"
+    ).then(() => new Promise(resolve => SimpleTest.executeSoon(resolve)));
+  } else {
+    promiseOcclusion = Promise.resolve();
+  }
+
   info("Calling window.restore");
   win.restore();
   // From browser/base/content/test/general/browser_minimize.js:
   // On Ubuntu `window.restore` doesn't seem to work, use a timer to make the
   // test fail faster and more cleanly than with a test timeout.
-  info("Waiting for sizemodechange event");
+  info(
+    `Waiting for sizemodechange ${
+      willWaitForOcclusion ? "and occlusionstatechange " : ""
+    }event`
+  );
   let timer;
   await Promise.race([
-    promiseSizeModeChange,
+    Promise.all([promiseSizeModeChange, promiseOcclusion]),
     new Promise((resolve, reject) => {
       // eslint-disable-next-line mozilla/no-arbitrary-setTimeout
       timer = setTimeout(() => {
-        reject("timed out waiting for sizemodechange event");
+        reject(
+          `timed out waiting for sizemodechange sizemodechange ${
+            willWaitForOcclusion ? "and occlusionstatechange " : ""
+          }event`
+        );
       }, 5000);
     }),
   ]);
   clearTimeout(timer);
-  info(
-    "Waiting occlusionstatechange if win.isFullyOccluded: " +
-      win.isFullyOccluded
-  );
-  // From browser/base/content/test/general/browser_minimize.js:
-  // The sizemodechange event can sometimes be fired before the
-  // occlusionstatechange event, especially in chaos mode.
-  if (win.isFullyOccluded) {
-    await BrowserTestUtils.waitForEvent(win, "occlusionstatechange");
-  }
   ok(
     win.gBrowser.selectedTab.linkedBrowser.docShellIsActive,
     "Docshell should be active again"
-- 
2.11.4.GIT