diff --git a/packages/service-worker/worker/test/prefetch_spec.ts b/packages/service-worker/worker/test/prefetch_spec.ts
index 4f3dc11be9..24cee1d23c 100644
--- a/packages/service-worker/worker/test/prefetch_spec.ts
+++ b/packages/service-worker/worker/test/prefetch_spec.ts
@@ -10,9 +10,10 @@ import {PrefetchAssetGroup} from '../src/assets';
 import {CacheDatabase} from '../src/db-cache';
 import {IdleScheduler} from '../src/idle';
 import {MockCache} from '../testing/cache';
+import {MockExtendableEvent} from '../testing/events';
 import {MockRequest} from '../testing/fetch';
 import {MockFileSystemBuilder, MockServerStateBuilder, tmpHashTable, tmpManifestSingleAssetGroup} from '../testing/mock';
-import {MockExtendableEvent, SwTestHarnessBuilder} from '../testing/scope';
+import {SwTestHarnessBuilder} from '../testing/scope';
 import {envIsSupported} from '../testing/utils';
 
 (function() {
diff --git a/packages/service-worker/worker/testing/events.ts b/packages/service-worker/worker/testing/events.ts
new file mode 100644
index 0000000000..f42c1698a0
--- /dev/null
+++ b/packages/service-worker/worker/testing/events.ts
@@ -0,0 +1,118 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+export class MockEvent implements Event {
+  readonly AT_TARGET = -1;
+  readonly BUBBLING_PHASE = -1;
+  readonly CAPTURING_PHASE = -1;
+  readonly NONE = -1;
+
+  readonly bubbles = false;
+  cancelBubble = false;
+  readonly cancelable = false;
+  readonly composed = false;
+  readonly currentTarget = null;
+  readonly defaultPrevented = false;
+  readonly eventPhase = -1;
+  readonly isTrusted = false;
+  returnValue = false;
+  readonly srcElement = null;
+  readonly target = null;
+  readonly timeStamp = Date.now();
+
+  constructor(readonly type: string) {}
+
+  composedPath(): EventTarget[] {
+    this.notImplemented();
+  }
+  initEvent(type: string, bubbles?: boolean, cancelable?: boolean): void {
+    this.notImplemented();
+  }
+  preventDefault(): void {
+    this.notImplemented();
+  }
+  stopImmediatePropagation(): void {
+    this.notImplemented();
+  }
+  stopPropagation(): void {
+    this.notImplemented();
+  }
+
+  private notImplemented(): never {
+    throw new Error('Method not implemented in `MockEvent`.');
+  }
+}
+
+export class MockExtendableEvent extends MockEvent implements ExtendableEvent {
+  private queue: Promise<void>[] = [];
+
+  get ready(): Promise<void> {
+    return (async () => {
+      while (this.queue.length > 0) {
+        await this.queue.shift();
+      }
+    })();
+  }
+
+  waitUntil(promise: Promise<void>): void {
+    this.queue.push(promise);
+  }
+}
+
+export class MockActivateEvent extends MockExtendableEvent {
+  constructor() {
+    super('activate');
+  }
+}
+
+export class MockFetchEvent extends MockExtendableEvent {
+  response: Promise<Response|undefined> = Promise.resolve(undefined);
+
+  constructor(
+      readonly request: Request, readonly clientId: string, readonly resultingClientId: string) {
+    super('fetch');
+  }
+
+  respondWith(promise: Promise<Response>): Promise<Response> {
+    this.response = promise;
+    return promise;
+  }
+}
+
+export class MockInstallEvent extends MockExtendableEvent {
+  constructor() {
+    super('install');
+  }
+}
+
+export class MockMessageEvent extends MockExtendableEvent {
+  constructor(readonly data: Object, readonly source: MockClient|null) {
+    super('message');
+  }
+}
+
+export class MockNotificationEvent extends MockExtendableEvent {
+  readonly notification = {
+    ...this._notification,
+    close: () => undefined,
+  };
+
+  constructor(private _notification: any, readonly action?: string) {
+    super('notification');
+  }
+}
+
+export class MockPushEvent extends MockExtendableEvent {
+  data = {
+    json: () => this._data,
+  };
+
+  constructor(private _data: object) {
+    super('push');
+  }
+}
diff --git a/packages/service-worker/worker/testing/scope.ts b/packages/service-worker/worker/testing/scope.ts
index 8c8b9602d3..2619a8de94 100644
--- a/packages/service-worker/worker/testing/scope.ts
+++ b/packages/service-worker/worker/testing/scope.ts
@@ -13,6 +13,7 @@ import {AssetGroupConfig, Manifest} from '../src/manifest';
 import {sha1} from '../src/sha1';
 
 import {MockCacheStorage} from './cache';
+import {MockActivateEvent, MockFetchEvent, MockInstallEvent, MockMessageEvent, MockNotificationEvent, MockPushEvent} from './events';
 import {MockHeaders, MockRequest, MockResponse} from './fetch';
 import {MockServerState, MockServerStateBuilder} from './mock';
 import {normalizeUrl, parseUrl} from './utils';
@@ -356,109 +357,3 @@ export class ConfigBuilder {
     };
   }
 }
-
-class MockEvent implements Event {
-  readonly AT_TARGET = -1;
-  readonly BUBBLING_PHASE = -1;
-  readonly CAPTURING_PHASE = -1;
-  readonly NONE = -1;
-
-  readonly bubbles = false;
-  cancelBubble = false;
-  readonly cancelable = false;
-  readonly composed = false;
-  readonly currentTarget = null;
-  readonly defaultPrevented = false;
-  readonly eventPhase = -1;
-  readonly isTrusted = false;
-  returnValue = false;
-  readonly srcElement = null;
-  readonly target = null;
-  readonly timeStamp = Date.now();
-
-  constructor(readonly type: string) {}
-
-  composedPath(): EventTarget[] {
-    this.notImplemented();
-  }
-  initEvent(type: string, bubbles?: boolean, cancelable?: boolean): void {
-    this.notImplemented();
-  }
-  preventDefault(): void {
-    this.notImplemented();
-  }
-  stopImmediatePropagation(): void {
-    this.notImplemented();
-  }
-  stopPropagation(): void {
-    this.notImplemented();
-  }
-
-  private notImplemented(): never {
-    throw new Error('Method not implemented in `MockEvent`.');
-  }
-}
-
-export class MockExtendableEvent extends MockEvent implements ExtendableEvent {
-  private queue: Promise<void>[] = [];
-
-  waitUntil(promise: Promise<void>): void {
-    this.queue.push(promise);
-  }
-
-  get ready(): Promise<void> {
-    return (async () => {
-      while (this.queue.length > 0) {
-        await this.queue.shift();
-      }
-    })();
-  }
-}
-
-class MockFetchEvent extends MockExtendableEvent {
-  response: Promise<Response|undefined> = Promise.resolve(undefined);
-
-  constructor(
-      readonly request: Request, readonly clientId: string, readonly resultingClientId: string) {
-    super('fetch');
-  }
-
-  respondWith(promise: Promise<Response>): Promise<Response> {
-    this.response = promise;
-    return promise;
-  }
-}
-
-class MockMessageEvent extends MockExtendableEvent {
-  constructor(readonly data: Object, readonly source: MockClient|null) {
-    super('message');
-  }
-}
-
-class MockPushEvent extends MockExtendableEvent {
-  constructor(private _data: Object) {
-    super('push');
-  }
-  data = {
-    json: () => this._data,
-  };
-}
-
-class MockNotificationEvent extends MockExtendableEvent {
-  constructor(private _notification: any, readonly action?: string) {
-    super('notification');
-  }
-  readonly notification = {...this._notification, close: () => undefined};
-}
-
-class MockInstallEvent extends MockExtendableEvent {
-  constructor() {
-    super('install');
-  }
-}
-
-class MockActivateEvent extends MockExtendableEvent {
-  constructor() {
-    super('activate');
-  }
-}