1 files changed, 73 insertions, 0 deletions
diff --git a/dom/base/test/browser_timeout_throttling_with_audio_playback.js b/dom/base/test/browser_timeout_throttling_with_audio_playback.js
new file mode 100644
index 0000000000..078b3c01a5
--- /dev/null
+++ b/dom/base/test/browser_timeout_throttling_with_audio_playback.js
@@ -0,0 +1,73 @@
+// The tab closing code leaves an uncaught rejection. This test has been
+// whitelisted until the issue is fixed.
+if (!gMultiProcessBrowser) {
+  const { PromiseTestUtils } = ChromeUtils.importESModule(
+    "resource://testing-common/PromiseTestUtils.sys.mjs"
+  );
+  PromiseTestUtils.expectUncaughtRejection(/is no longer, usable/);
+}
+
+const kBaseURI = "http://mochi.test:8888/browser/dom/base/test/empty.html";
+var testURLs = [
+  "http://mochi.test:8888/browser/dom/base/test/file_audioLoop.html",
+  "http://mochi.test:8888/browser/dom/base/test/file_audioLoopInIframe.html",
+  "http://mochi.test:8888/browser/dom/base/test/file_webaudio_startstop.html",
+];
+
+// We want to ensure that while audio is being played back, a background tab is
+// treated the same as a foreground tab as far as timeout throttling is concerned.
+// So we use a 100,000 second minimum timeout value for background tabs.  This
+// means that in case the test fails, it will time out in practice, but just for
+// sanity the test condition ensures that the observed timeout delay falls in
+// this range.
+const kMinTimeoutBackground = 100 * 1000 * 1000;
+
+const kDelay = 10;
+
+async function runTest(url) {
+  let currentTab = gBrowser.selectedTab;
+  let newTab = await BrowserTestUtils.openNewForegroundTab(gBrowser, kBaseURI);
+  let newBrowser = gBrowser.getBrowserForTab(newTab);
+
+  // Wait for the UI to indicate that audio is being played back.
+  let promise = BrowserTestUtils.waitForAttribute("soundplaying", newTab);
+  BrowserTestUtils.startLoadingURIString(newBrowser, url);
+  await promise;
+
+  // Put the tab in the background.
+  await BrowserTestUtils.switchTab(gBrowser, currentTab);
+
+  let timeout = await SpecialPowers.spawn(
+    newBrowser,
+    [kDelay],
+    function (delay) {
+      return new Promise(resolve => {
+        let before = new Date();
+        content.window.setTimeout(function () {
+          let after = new Date();
+          resolve(after - before);
+        }, delay);
+      });
+    }
+  );
+  Assert.lessOrEqual(
+    timeout,
+    kMinTimeoutBackground,
+    `Got the correct timeout (${timeout})`
+  );
+
+  // All done.
+  BrowserTestUtils.removeTab(newTab);
+}
+
+add_setup(async function () {
+  await SpecialPowers.pushPrefEnv({
+    set: [["dom.min_background_timeout_value", kMinTimeoutBackground]],
+  });
+});
+
+add_task(async function test() {
+  for (var url of testURLs) {
+    await runTest(url);
+  }
+});