1 files changed, 55 insertions, 0 deletions
diff --git a/browser/components/customizableui/test/browser_1087303_button_fullscreen.js b/browser/components/customizableui/test/browser_1087303_button_fullscreen.js
new file mode 100644
index 0000000000..f67e81b892
--- /dev/null
+++ b/browser/components/customizableui/test/browser_1087303_button_fullscreen.js
@@ -0,0 +1,55 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+/* eslint-disable mozilla/no-arbitrary-setTimeout */
+
+"use strict";
+
+add_task(async function () {
+  info("Check fullscreen button existence and functionality");
+
+  CustomizableUI.addWidgetToArea(
+    "fullscreen-button",
+    CustomizableUI.AREA_FIXED_OVERFLOW_PANEL
+  );
+  registerCleanupFunction(() => CustomizableUI.reset());
+
+  await waitForOverflowButtonShown();
+
+  await document.getElementById("nav-bar").overflowable.show();
+
+  let fullscreenButton = document.getElementById("fullscreen-button");
+  ok(fullscreenButton, "Fullscreen button appears in Panel Menu");
+
+  let fullscreenPromise = promiseFullscreenChange();
+  fullscreenButton.click();
+  await fullscreenPromise;
+
+  ok(window.fullScreen, "Fullscreen mode was opened");
+
+  // exit full screen mode
+  fullscreenPromise = promiseFullscreenChange();
+  window.fullScreen = !window.fullScreen;
+  await fullscreenPromise;
+
+  ok(!window.fullScreen, "Successfully exited fullscreen");
+});
+
+function promiseFullscreenChange() {
+  return new Promise((resolve, reject) => {
+    info("Wait for fullscreen change");
+
+    let timeoutId = setTimeout(() => {
+      window.removeEventListener("fullscreen", onFullscreenChange, true);
+      reject("Fullscreen change did not happen within " + 20000 + "ms");
+    }, 20000);
+
+    function onFullscreenChange(event) {
+      clearTimeout(timeoutId);
+      window.removeEventListener("fullscreen", onFullscreenChange, true);
+      info("Fullscreen event received");
+      resolve();
+    }
+    window.addEventListener("fullscreen", onFullscreenChange, true);
+  });
+}