Update web-platform-tests to revision 60220357131c65146444da1f54624d5b54d0975d

tests/wpt/web-platform-tests/background-fetch/resources/utils.js

@@ -1,26 +1,52 @@
 'use strict';
 
+let nextBackgroundFetchId = 0;
+
+// Waits for a single message received from a registered Service Worker.
+async function getMessageFromServiceWorker() {
+  return new Promise(resolve => {
+    function listener(event) {
+      navigator.serviceWorker.removeEventListener('message', listener);
+      resolve(event.data);
+    }
+
+    navigator.serviceWorker.addEventListener('message', listener);
+  });
+}
+
+// Registers the instrumentation Service Worker located at "resources/sw.js"
+// with a scope unique to the test page that's running, and waits for it to be
+// activated. The Service Worker will be unregistered automatically.
+//
 // Depends on /service-workers/service-worker/resources/test-helpers.sub.js
 async function registerAndActivateServiceWorker(test) {
   const script = 'resources/sw.js';
   const scope = 'resources/scope' + location.pathname;
+
   let serviceWorkerRegistration =
       await service_worker_unregister_and_register(test, script, scope);
-  add_completion_callback(() => {
-    serviceWorkerRegistration.unregister();
-  });
+
+  add_completion_callback(() => serviceWorkerRegistration.unregister());
+
   await wait_for_state(test, serviceWorkerRegistration.installing, 'activated');
   return serviceWorkerRegistration;
 }
 
+// Creates a Promise test for |func| given the |description|. The |func| will be
+// executed with the `backgroundFetch` object of an activated Service Worker
+// Registration.
 function backgroundFetchTest(func, description) {
   promise_test(async t => {
     const serviceWorkerRegistration = await registerAndActivateServiceWorker(t);
+    serviceWorkerRegistration.active.postMessage(null /* unused */);
+
+    assert_equals(await getMessageFromServiceWorker(), 'ready');
+
     return func(t, serviceWorkerRegistration.backgroundFetch);
   }, description);
 }
 
-let _nextBackgroundFetchTag = 0;
-function uniqueTag() {
-  return 'tag' + _nextBackgroundFetchTag++;
-}
+// Returns a Background Fetch ID that's unique for the current page.
+function uniqueId() {
+  return 'id' + nextBackgroundFetchId++;
+}