Implement the Request/Response bits of Background Fetch

third_party/WebKit/LayoutTests/http/tests/background_fetch/resources/background-fetch-fail-event-worker.js

+'use strict';
+
+importScripts('/resources/testharness.js');
+
+test(function() {
+  assert_own_property(self, 'BackgroundFetchFailEvent');
+
+  // The `tag` and `failedFetches` are required options in the
+  // BackgroundFetchFailEventInit. The latter must be a sequence of
+  // BackgroundFetchSettledRequest instances.
+  assert_throws(null, () => new BackgroundFetchFailEvent('BackgroundFetchFailEvent'));
+  assert_throws(null, () => new BackgroundFetchFailEvent('BackgroundFetchFailEvent', {}));
+  assert_throws(null, () => new BackgroundFetchFailEvent('BackgroundFetchFailEvent', { tag: 'foo' }));
+  assert_throws(null, () => new BackgroundFetchFailEvent('BackgroundFetchFailEvent', { tag: 'foo', failedFetches: 'bar' }));
+
+  const failedFetches = [
+    new BackgroundFetchSettledRequest(new Request('non-existing-image.png'), new Response()),
+    new BackgroundFetchSettledRequest(new Request('non-existing-image-2.png'), new Response())
+  ];
+
+  const event = new BackgroundFetchFailEvent('BackgroundFetchFailEvent', {
+    tag: 'my-tag',
+    failedFetches
+  });
+
+  assert_equals(event.type, 'BackgroundFetchFailEvent');
+  assert_equals(event.cancelable, false);
+  assert_equals(event.bubbles, false);
+  assert_equals(event.tag, 'my-tag');
+
+  assert_true(Array.isArray(event.failedFetches));
+  assert_array_equals(event.failedFetches, failedFetches);
+
+  assert_inherits(event, 'waitUntil');
+
+}, 'Verifies that the BackgroundFetchFailEvent can be constructed.');