1 files changed, 127 insertions, 0 deletions
diff --git a/toolkit/content/tests/browser/browser_media_wakelock_webaudio.js b/toolkit/content/tests/browser/browser_media_wakelock_webaudio.js
new file mode 100644
index 0000000000..7c40b5fe1a
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+++ b/toolkit/content/tests/browser/browser_media_wakelock_webaudio.js
@@ -0,0 +1,127 @@
+/**
+ * Test if wakelock can be required correctly when we play web audio. The
+ * wakelock should only be required when web audio is audible.
+ */
+
+const AUDIO_WAKELOCK_NAME = "audio-playing";
+const VIDEO_WAKELOCK_NAME = "video-playing";
+
+add_task(async function testCheckAudioWakelockWhenChangeTabVisibility() {
+  await checkWakelockWhenChangeTabVisibility({
+    description: "playing audible web audio",
+    needLock: true,
+  });
+  await checkWakelockWhenChangeTabVisibility({
+    description: "suspended web audio",
+    additionalParams: {
+      suspend: true,
+    },
+    needLock: false,
+  });
+});
+
+add_task(
+  async function testBrieflyAudibleAudioContextReleasesAudioWakeLockWhenInaudible() {
+    const tab = await BrowserTestUtils.openNewForegroundTab(
+      window.gBrowser,
+      "about:blank"
+    );
+
+    info(`make a short noise on web audio`);
+    await Promise.all([
+      // As the sound would only happen for a really short period, calling
+      // checking wakelock first helps to ensure that we won't miss that moment.
+      waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+        needLock: true,
+        isForegroundLock: true,
+      }),
+      createWebAudioDocument(tab, { stopTimeOffset: 0.1 }),
+    ]);
+    await ensureNeverAcquireVideoWakelock();
+
+    info(`audio wakelock should be released after web audio becomes silent`);
+    await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, false, {
+      needLock: false,
+    });
+    await ensureNeverAcquireVideoWakelock();
+
+    await BrowserTestUtils.removeTab(tab);
+  }
+);
+
+/**
+ * Following are helper functions.
+ */
+async function checkWakelockWhenChangeTabVisibility({
+  description,
+  additionalParams,
+  needLock,
+  elementIdForEnteringPIPMode,
+}) {
+  const originalTab = gBrowser.selectedTab;
+  info(`start a new tab for '${description}'`);
+  const mediaTab = await BrowserTestUtils.openNewForegroundTab(
+    window.gBrowser,
+    "about:blank"
+  );
+  await createWebAudioDocument(mediaTab, additionalParams);
+  await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+    needLock,
+    isForegroundLock: true,
+  });
+  await ensureNeverAcquireVideoWakelock();
+
+  info(`switch media tab to background`);
+  await BrowserTestUtils.switchTab(window.gBrowser, originalTab);
+  await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+    needLock,
+    isForegroundLock: false,
+  });
+  await ensureNeverAcquireVideoWakelock();
+
+  info(`switch media tab to foreground again`);
+  await BrowserTestUtils.switchTab(window.gBrowser, mediaTab);
+  await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+    needLock,
+    isForegroundLock: true,
+  });
+  await ensureNeverAcquireVideoWakelock();
+
+  info(`remove media tab`);
+  BrowserTestUtils.removeTab(mediaTab);
+}
+
+function createWebAudioDocument(tab, { stopTimeOffset, suspend } = {}) {
+  return SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [suspend, stopTimeOffset],
+    async (suspend, stopTimeOffset) => {
+      // Create an oscillatorNode to produce sound.
+      content.ac = new content.AudioContext();
+      const ac = content.ac;
+      const dest = ac.destination;
+      const source = new content.OscillatorNode(ac);
+      source.start(ac.currentTime);
+      source.connect(dest);
+
+      if (stopTimeOffset) {
+        source.stop(ac.currentTime + 0.1);
+      }
+
+      if (suspend) {
+        await content.ac.suspend();
+      } else {
+        while (ac.state != "running") {
+          info(`wait until AudioContext starts running`);
+          await new Promise(r => (ac.onstatechange = r));
+        }
+        info("AudioContext is running");
+      }
+    }
+  );
+}
+
+function ensureNeverAcquireVideoWakelock() {
+  // Web audio won't play any video, we never need video wakelock.
+  return waitForExpectedWakeLockState(VIDEO_WAKELOCK_NAME, { needLock: false });
+}