1 files changed, 130 insertions, 0 deletions
diff --git a/dom/media/mediacontrol/tests/browser/browser_media_control_supported_keys.js b/dom/media/mediacontrol/tests/browser/browser_media_control_supported_keys.js
new file mode 100644
index 0000000000..2312e90c88
--- /dev/null
+++ b/dom/media/mediacontrol/tests/browser/browser_media_control_supported_keys.js
@@ -0,0 +1,130 @@
+const PAGE_NON_AUTOPLAY =
+  "https://example.com/browser/dom/media/mediacontrol/tests/browser/file_non_autoplay.html";
+
+const testVideoId = "video";
+const sDefaultSupportedKeys = ["focus", "play", "pause", "playpause", "stop"];
+
+add_task(async function setupTestingPref() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["media.mediacontrol.testingevents.enabled", true],
+      ["dom.media.mediasession.enabled", true],
+    ],
+  });
+});
+
+/**
+ * Supported media keys are used for indicating what UI button should be shown
+ * on the virtual control interface. All supported media keys are listed in
+ * `MediaKey` in `MediaController.webidl`. Some media keys are defined as
+ * default media keys which are always supported. Otherwise, other media keys
+ * have to have corresponding action handler on the active media session in
+ * order to be added to the supported keys.
+ */
+add_task(async function testDefaultSupportedKeys() {
+  info(`open media page`);
+  const tab = await createLoadedTabWrapper(PAGE_NON_AUTOPLAY);
+
+  info(`start media`);
+  await playMedia(tab, testVideoId);
+
+  info(`should use default supported keys`);
+  await supportedKeysShouldEqualTo(tab, sDefaultSupportedKeys);
+
+  info(`remove tab`);
+  await tab.close();
+});
+
+add_task(async function testNoActionHandlerBeingSet() {
+  info(`open media page`);
+  const tab = await createLoadedTabWrapper(PAGE_NON_AUTOPLAY);
+
+  info(`start media`);
+  await playMedia(tab, testVideoId);
+
+  info(`create media session but not set any action handler`);
+  await setMediaSessionSupportedAction(tab, []);
+
+  info(
+    `should use default supported keys even if ` +
+      `media session doesn't have any action handler`
+  );
+  await supportedKeysShouldEqualTo(tab, sDefaultSupportedKeys);
+
+  info(`remove tab`);
+  await tab.close();
+});
+
+add_task(async function testSettingActionsWhichAreAlreadyDefaultKeys() {
+  info(`open media page`);
+  const tab = await createLoadedTabWrapper(PAGE_NON_AUTOPLAY);
+
+  info(`start media`);
+  await playMedia(tab, testVideoId);
+
+  info(`create media session but not set any action handler`);
+  await setMediaSessionSupportedAction(tab, ["play", "pause", "stop"]);
+
+  info(
+    `those actions has already been included in default supported keys, so ` +
+      `the result should still be default supported keys`
+  );
+  await supportedKeysShouldEqualTo(tab, sDefaultSupportedKeys);
+
+  info(`remove tab`);
+  await tab.close();
+});
+
+add_task(async function testSettingActionsWhichAreNotDefaultKeys() {
+  info(`open media page`);
+  const tab = await createLoadedTabWrapper(PAGE_NON_AUTOPLAY);
+
+  info(`start media`);
+  await playMedia(tab, testVideoId);
+
+  info(`create media session but not set any action handler`);
+  let nonDefaultActions = [
+    "seekbackward",
+    "seekforward",
+    "previoustrack",
+    "nexttrack",
+  ];
+  await setMediaSessionSupportedAction(tab, nonDefaultActions);
+
+  info(
+    `supported keys should include those actions which are not default supported keys`
+  );
+  let expectedKeys = sDefaultSupportedKeys.concat(nonDefaultActions);
+  await supportedKeysShouldEqualTo(tab, expectedKeys);
+
+  info(`remove tab`);
+  await tab.close();
+});
+
+/**
+ * The following are helper functions.
+ */
+async function supportedKeysShouldEqualTo(tab, expectedKeys) {
+  const controller = tab.linkedBrowser.browsingContext.mediaController;
+  const supportedKeys = controller.supportedKeys;
+  while (JSON.stringify(expectedKeys) != JSON.stringify(supportedKeys)) {
+    await new Promise(r => (controller.onsupportedkeyschange = r));
+  }
+  for (let idx = 0; idx < expectedKeys.length; idx++) {
+    is(
+      supportedKeys[idx],
+      expectedKeys[idx],
+      `'${supportedKeys[idx]}' should equal to '${expectedKeys[idx]}'`
+    );
+  }
+}
+
+function setMediaSessionSupportedAction(tab, actions) {
+  return SpecialPowers.spawn(tab.linkedBrowser, [actions], actionArr => {
+    for (let action of actionArr) {
+      content.navigator.mediaSession.setActionHandler(action, () => {
+        info(`set '${action}' action handler`);
+      });
+    }
+  });
+}