1 files changed, 110 insertions, 0 deletions

diff --git a/spec/frontend/blame/streaming/index_spec.js b/spec/frontend/blame/streaming/index_spec.js
new file mode 100644
index 00000000000..e048ce3f70e
--- /dev/null
+++ b/spec/frontend/blame/streaming/index_spec.js
@@ -0,0 +1,110 @@
+import waitForPromises from 'helpers/wait_for_promises';
+import { renderBlamePageStreams } from '~/blame/streaming';
+import { setHTMLFixture } from 'helpers/fixtures';
+import { renderHtmlStreams } from '~/streaming/render_html_streams';
+import { rateLimitStreamRequests } from '~/streaming/rate_limit_stream_requests';
+import { handleStreamedAnchorLink } from '~/streaming/handle_streamed_anchor_link';
+import { toPolyfillReadable } from '~/streaming/polyfills';
+import { createAlert } from '~/alert';
+
+jest.mock('~/streaming/render_html_streams');
+jest.mock('~/streaming/rate_limit_stream_requests');
+jest.mock('~/streaming/handle_streamed_anchor_link');
+jest.mock('~/streaming/polyfills');
+jest.mock('~/sentry');
+jest.mock('~/alert');
+
+global.fetch = jest.fn();
+
+describe('renderBlamePageStreams', () => {
+  let stopAnchor;
+  const PAGES_URL = 'https://example.com/';
+  const findStreamContainer = () => document.querySelector('#blame-stream-container');
+  const findStreamLoadingIndicator = () => document.querySelector('#blame-stream-loading');
+
+  const setupHtml = (totalExtraPages = 0) => {
+    setHTMLFixture(`
+      <div id="blob-content-holder"
+        data-total-extra-pages="${totalExtraPages}"
+        data-pages-url="${PAGES_URL}"
+      ></div>
+      <div id="blame-stream-container"></div>
+      <div id="blame-stream-loading"></div>
+    `);
+  };
+
+  handleStreamedAnchorLink.mockImplementation(() => stopAnchor);
+  rateLimitStreamRequests.mockImplementation(({ factory, total }) => {
+    return Array.from({ length: total }, (_, i) => {
+      return Promise.resolve(factory(i));
+    });
+  });
+  toPolyfillReadable.mockImplementation((obj) => obj);
+
+  beforeEach(() => {
+    stopAnchor = jest.fn();
+    fetch.mockClear();
+  });
+
+  it('does nothing for an empty page', async () => {
+    await renderBlamePageStreams();
+
+    expect(handleStreamedAnchorLink).not.toHaveBeenCalled();
+    expect(renderHtmlStreams).not.toHaveBeenCalled();
+  });
+
+  it('renders a single stream', async () => {
+    let res;
+    const stream = new Promise((resolve) => {
+      res = resolve;
+    });
+    renderHtmlStreams.mockImplementationOnce(() => stream);
+    setupHtml();
+
+    renderBlamePageStreams(stream);
+
+    expect(handleStreamedAnchorLink).toHaveBeenCalledTimes(1);
+    expect(stopAnchor).toHaveBeenCalledTimes(0);
+    expect(renderHtmlStreams).toHaveBeenCalledWith([stream], findStreamContainer());
+    expect(findStreamLoadingIndicator()).not.toBe(null);
+
+    res();
+    await waitForPromises();
+
+    expect(stopAnchor).toHaveBeenCalledTimes(1);
+    expect(findStreamLoadingIndicator()).toBe(null);
+  });
+
+  it('renders rest of the streams', async () => {
+    const stream = Promise.resolve();
+    const stream2 = Promise.resolve({ body: null });
+    fetch.mockImplementationOnce(() => stream2);
+    setupHtml(1);
+
+    await renderBlamePageStreams(stream);
+
+    expect(fetch.mock.calls[0][0].toString()).toBe(`${PAGES_URL}?page=3`);
+    expect(renderHtmlStreams).toHaveBeenCalledWith([stream, stream2], findStreamContainer());
+  });
+
+  it('shows an error message when failed', async () => {
+    const stream = Promise.resolve();
+    const error = new Error();
+    renderHtmlStreams.mockImplementationOnce(() => Promise.reject(error));
+    setupHtml();
+
+    try {
+      await renderBlamePageStreams(stream);
+    } catch (err) {
+      expect(err).toBe(error);
+    }
+
+    expect(createAlert).toHaveBeenCalledWith({
+      message: 'Blame could not be loaded as a single page.',
+      primaryButton: {
+        text: 'View blame as separate pages',
+        clickHandler: expect.any(Function),
+      },
+    });
+  });
+});