1 files changed, 83 insertions, 0 deletions
diff --git a/browser/components/preferences/tests/browser_media_control.js b/browser/components/preferences/tests/browser_media_control.js
new file mode 100644
index 0000000000..6512fb9e74
--- /dev/null
+++ b/browser/components/preferences/tests/browser_media_control.js
@@ -0,0 +1,83 @@
+/**
+ * Media control check box should change the media control pref, vice versa.
+ */
+const MEDIA_CONTROL_PREF = "media.hardwaremediakeys.enabled";
+
+add_task(async function testMediaControlCheckBox() {
+  const prefs = await openPreferencesViaOpenPreferencesAPI("paneGeneral", {
+    leaveOpen: true,
+  });
+  is(prefs.selectedPane, "paneGeneral", "General pane was selected");
+
+  const checkBox = gBrowser.contentDocument.getElementById(
+    "mediaControlToggleEnabled"
+  );
+  ok(checkBox, "check box exists");
+
+  // The pref is true by default.
+  await modifyPrefAndWaitUntilCheckBoxChanges(false);
+  await modifyPrefAndWaitUntilCheckBoxChanges(true);
+  await toggleCheckBoxAndWaitUntilPrefValueChanges(false);
+  await toggleCheckBoxAndWaitUntilPrefValueChanges(true);
+  BrowserTestUtils.removeTab(gBrowser.selectedTab);
+});
+
+async function modifyPrefAndWaitUntilCheckBoxChanges(isEnabled) {
+  info((isEnabled ? "enable" : "disable") + " the pref");
+  const checkBox = gBrowser.contentDocument.getElementById(
+    "mediaControlToggleEnabled"
+  );
+  await SpecialPowers.pushPrefEnv({
+    set: [[MEDIA_CONTROL_PREF, isEnabled]],
+  });
+  await TestUtils.waitForCondition(
+    _ => checkBox.checked == isEnabled,
+    "Waiting for the checkbox gets checked"
+  );
+  is(checkBox.checked, isEnabled, `check box status is correct`);
+  checkAndClearTelemetryProbe(isEnabled);
+}
+
+async function toggleCheckBoxAndWaitUntilPrefValueChanges(isChecked) {
+  info((isChecked ? "check" : "uncheck") + " the check box");
+  const checkBox = gBrowser.contentDocument.getElementById(
+    "mediaControlToggleEnabled"
+  );
+  checkBox.click();
+  is(
+    Services.prefs.getBoolPref(MEDIA_CONTROL_PREF),
+    isChecked,
+    "the pref's value is correct"
+  );
+  checkAndClearTelemetryProbe(isChecked, true /* check UI */);
+}
+
+/**
+ * These telemetry related variable and method should be removed after the
+ * telemetry probe `MEDIA_CONTROL_SETTING_CHANGE` gets expired.
+ */
+const HISTOGRAM_ID = "MEDIA_CONTROL_SETTING_CHANGE";
+const HISTOGRAM_KEYS = {
+  EnableFromUI: 0,
+  EnableTotal: 1,
+  DisableFromUI: 2,
+  DisableTotal: 3,
+};
+
+function checkAndClearTelemetryProbe(isEnable, checkUI = false) {
+  const histogram = Services.telemetry.getHistogramById(HISTOGRAM_ID);
+  let keyTotal = isEnable ? "EnableTotal" : "DisableTotal";
+  let keyUI = null;
+  if (checkUI) {
+    keyUI = isEnable ? "EnableFromUI" : "DisableFromUI";
+  }
+  for (let [key, val] of Object.entries(histogram.snapshot().values)) {
+    if (key == HISTOGRAM_KEYS[keyTotal]) {
+      ok(val, "Increase the amount for the probe 'changeing total setting'");
+    }
+    if (keyUI && key == HISTOGRAM_KEYS[keyUI]) {
+      ok(val, "Increase the amount for the probe 'changeing setting from UI'");
+    }
+  }
+  histogram.clear();
+}