Wrapped logic to perform HTTP requests with fetch into an HttpClient class

test/common/services/ImageDownloader.test.ts

@@ -1,22 +1,25 @@
+import { Mock } from 'ts-mockery';
 import { ImageDownloader } from '../../../src/common/services/ImageDownloader';
+import { HttpClient } from '../../../src/common/services/HttpClient';
 import { windowMock } from '../../__mocks__/Window.mock';
 
 describe('ImageDownloader', () => {
-  const fetch = jest.fn();
+  const fetchBlob = jest.fn();
+  const httpClient = Mock.of<HttpClient>({ fetchBlob });
   let imageDownloader: ImageDownloader;
 
   beforeEach(() => {
     jest.clearAllMocks();
     (global as any).URL = { createObjectURL: () => '' };
 
-    imageDownloader = new ImageDownloader(fetch, windowMock);
+    imageDownloader = new ImageDownloader(httpClient, windowMock);
   });
 
   it('calls URL with response type blob', async () => {
-    fetch.mockResolvedValue({ blob: () => new Blob() });
+    fetchBlob.mockResolvedValue(new Blob());
 
     await imageDownloader.saveImage('/foo/bar.png', 'my-image.png');
 
-    expect(fetch).toHaveBeenCalledWith('/foo/bar.png');
+    expect(fetchBlob).toHaveBeenCalledWith('/foo/bar.png');
   });
 });