what's new: data-source test (#4876)

Add test for notification center `_data_source/`

tensorboard/webapp/notification_center/BUILD

@@ -33,6 +33,7 @@ tf_ng_web_test_suite(
     name = "notification_center_test",
     testonly = True,
     deps = [
+        "//tensorboard/webapp/notification_center/_data_source:_data_source_test",
         "//tensorboard/webapp/notification_center/_redux:_redux_test",
         "//tensorboard/webapp/notification_center/_views:_views_test",
     ],

tensorboard/webapp/notification_center/_data_source/BUILD

@@ -43,3 +43,21 @@ tf_ts_library(
         "@npm//rxjs",
     ],
 )
+
+tf_ts_library(
+    name = "_data_source_test",
+    testonly = True,
+    srcs = [
+        "notification_center_data_source_test.ts",
+    ],
+    deps = [
+        ":_data_source",
+        ":testing",
+        ":types",
+        "//tensorboard/webapp/angular:expect_angular_core_testing",
+        "//tensorboard/webapp/webapp_data_source:http_client",
+        "//tensorboard/webapp/webapp_data_source:http_client_testing",
+        "@npm//@types/jasmine",
+        "@npm//rxjs",
+    ],
+)

tensorboard/webapp/notification_center/_data_source/notification_center_data_source_test.ts

@@ -0,0 +1,88 @@
+/* Copyright 2021 The TensorFlow Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+==============================================================================*/
+import {TestBed} from '@angular/core/testing';
+
+import {HttpErrorResponse} from '../../webapp_data_source/tb_http_client';
+import {
+  HttpTestingController,
+  TBHttpClientTestingModule,
+} from '../../webapp_data_source/tb_http_client_testing';
+import {NotificationCenterDataSource} from './backend_types';
+import {TBNotificationCenterDataSource} from './notification_center_data_source';
+import {buildNotificationResponse} from './testing';
+import {throwError} from 'rxjs';
+
+describe('TBNotificationCenterDataSource test', () => {
+  let httpMock: HttpTestingController;
+  let dataSource: NotificationCenterDataSource;
+
+  beforeEach(async () => {
+    await TestBed.configureTestingModule({
+      imports: [TBHttpClientTestingModule],
+      providers: [
+        {
+          provide: NotificationCenterDataSource,
+          useClass: TBNotificationCenterDataSource,
+        },
+      ],
+    }).compileComponents();
+
+    httpMock = TestBed.inject(HttpTestingController);
+    dataSource = TestBed.inject(NotificationCenterDataSource);
+  });
+
+  afterEach(() => {
+    httpMock.verify();
+  });
+
+  it('fetches empty notifications', () => {
+    const resultSpy = jasmine.createSpy();
+    dataSource.fetchNotifications().subscribe(resultSpy);
+    const req = httpMock.expectOne('data/notifications');
+    req.flush({notifications: [{}]});
+
+    expect(resultSpy).toHaveBeenCalledWith({notifications: [{}]});
+  });
+
+  it('fetches non-empty notifications', () => {
+    const resultSpy = jasmine.createSpy();
+    dataSource.fetchNotifications().subscribe(resultSpy);
+    const req = httpMock.expectOne('data/notifications');
+    req.flush(buildNotificationResponse());
+
+    expect(resultSpy).toHaveBeenCalledWith(buildNotificationResponse());
+  });
+
+  it('throws error when notification fetch failed', () => {
+    const error = new ErrorEvent('Request failed');
+    const errorResponse = {
+      url: 'data/notifications',
+      status: 123,
+      statusText: 'something went wrong',
+    };
+    const resultSpy = jasmine.createSpy();
+    const errorSpy = jasmine.createSpy();
+
+    dataSource.fetchNotifications().subscribe(resultSpy, errorSpy);
+    httpMock.expectOne('data/notifications').error(error, errorResponse);
+
+    const httpErrorResponse = new HttpErrorResponse({
+      error,
+      ...errorResponse,
+    });
+    expect(resultSpy).not.toHaveBeenCalled();
+    expect(errorSpy).toHaveBeenCalledWith(httpErrorResponse);
+  });
+});