1 files changed, 34 insertions, 0 deletions
diff --git a/testing/web-platform/tests/battery-status/resources/battery-status-helpers.js b/testing/web-platform/tests/battery-status/resources/battery-status-helpers.js
new file mode 100644
index 0000000000..02acfe6c29
--- /dev/null
+++ b/testing/web-platform/tests/battery-status/resources/battery-status-helpers.js
@@ -0,0 +1,34 @@
+'use strict';
+
+// These tests rely on the User Agent providing an implementation of
+// platform battery status backends.
+//
+// In Chromium-based browsers this implementation is provided by a polyfill
+// in order to reduce the amount of test-only code shipped to users. To enable
+// these tests the browser must be run with these options:
+//
+//   --enable-blink-features=MojoJS,MojoJSTest
+
+let mockBatteryMonitor = undefined;
+
+function battery_status_test(func, name, properties) {
+  promise_test(async t => {
+    if (mockBatteryMonitor === undefined) {
+      if (isChromiumBased) {
+        const mocks =
+            await import('/resources/chromium/mock-battery-monitor.js');
+        mockBatteryMonitor = mocks.mockBatteryMonitor;
+      }
+    }
+    assert_implements(
+        mockBatteryMonitor, 'missing mockBatteryMonitor after initialization');
+
+    mockBatteryMonitor.start();
+
+    t.add_cleanup(() => {
+      mockBatteryMonitor.reset();
+      return mockBatteryMonitor.stop();
+    });
+    return func(t, mockBatteryMonitor);
+  }, name, properties);
+}