Add a metadata mock

Right now, we don't test the metadata endpoint
really at all. To test it, this mock adds a sample
response that could be paired with the diff_file
mock.

spec/frontend/diffs/mock_data/diff_file.js

@@ -13,6 +13,7 @@ export default {
   blob_name: 'CHANGELOG',
   blob_icon: '<i aria-hidden="true" data-hidden="true" class="fa fa-file-text-o fa-fw"></i>',
   file_hash: '1c497fbb3a46b78edf04cc2a2fa33f67e3ffbe2a',
+  file_identifier_hash: '928f8286952bda02d674b692addcbe077084663a',
   file_path: 'CHANGELOG',
   new_file: false,
   deleted_file: false,

spec/frontend/diffs/mock_data/diff_metadata.js

+/* eslint-disable import/prefer-default-export */
+/* https://gitlab.com/gitlab-org/frontend/rfcs/-/issues/20 */
+
+export const diffMetadata = {
+  real_size: '1',
+  size: 1,
+  branch_name: 'update-changelog',
+  source_branch_exists: true,
+  target_branch_name: 'master',
+  commit: null,
+  context_commits: null,
+  merge_request_diff: {
+    version_index: null,
+    created_at: '2019-11-07T06:48:35.202Z',
+    commits_count: 1,
+    latest: true,
+    short_commit_sha: 'eb227b3e',
+    base_version_path: '/gitlab-org/gitlab-test/-/merge_requests/4/diffs?diff_id=4',
+    head_version_path: '/gitlab-org/gitlab-test/-/merge_requests/4/diffs?diff_head=true',
+    version_path: '/gitlab-org/gitlab-test/-/merge_requests/4/diffs?diff_id=4',
+    compare_path:
+      '/gitlab-org/gitlab-test/-/merge_requests/4/diffs?diff_id=4\u0026start_sha=eb227b3e214624708c474bdab7bde7afc17cefcc',
+  },
+  start_version: null,
+  latest_diff: true,
+  latest_version_path: '/gitlab-org/gitlab-test/-/merge_requests/4/diffs',
+  added_lines: 2,
+  removed_lines: 0,
+  render_overflow_warning: false,
+  email_patch_path: '/gitlab-org/gitlab-test/-/merge_requests/4.patch',
+  plain_diff_path: '/gitlab-org/gitlab-test/-/merge_requests/4.diff',
+  merge_request_diffs: [
+    {
+      version_index: null,
+      created_at: '2019-11-07T06:48:35.202Z',
+      commits_count: 1,
+      latest: true,
+      short_commit_sha: 'eb227b3e',
+      base_version_path: '/gitlab-org/gitlab-test/-/merge_requests/4/diffs?diff_id=4',
+      head_version_path: '/gitlab-org/gitlab-test/-/merge_requests/4/diffs?diff_head=true',
+      version_path: '/gitlab-org/gitlab-test/-/merge_requests/4/diffs?diff_id=4',
+      compare_path:
+        '/gitlab-org/gitlab-test/-/merge_requests/4/diffs?diff_id=4\u0026start_sha=eb227b3e214624708c474bdab7bde7afc17cefcc',
+    },
+  ],
+  diff_files: [
+    {
+      added_lines: 2,
+      removed_lines: 0,
+      new_path: 'CHANGELOG',
+      old_path: 'CHANGELOG',
+      new_file: false,
+      deleted_file: false,
+      file_identifier_hash: '928f8286952bda02d674b692addcbe077084663a',
+      file_hash: '1c497fbb3a46b78edf04cc2a2fa33f67e3ffbe2a',
+    },
+  ],
+};

spec/frontend/diffs/store/actions_spec.js

@@ -53,6 +53,7 @@ import * as utils from '~/diffs/store/utils';
 import * as commonUtils from '~/lib/utils/common_utils';
 import { mergeUrlParams } from '~/lib/utils/url_utility';
 import { useLocalStorageSpy } from 'helpers/local_storage_helper';
+import { diffMetadata } from '../mock_data/diff_metadata';
 import createFlash from '~/flash';
 
 jest.mock('~/flash', () => jest.fn());
@@ -259,13 +260,19 @@ describe('DiffsStoreActions', () => {
   });
 
   describe('fetchDiffFilesMeta', () => {
-    it('should fetch diff meta information', done => {
-      const endpointMetadata = '/fetch/diffs_meta?view=inline';
-      const mock = new MockAdapter(axios);
-      const data = { diff_files: [] };
-      const res = { data };
-      mock.onGet(endpointMetadata).reply(200, res);
+    const endpointMetadata = '/fetch/diffs_metadata.json?view=inline';
+    const noFilesData = { ...diffMetadata };
+    let mock;
+
+    beforeEach(() => {
+      mock = new MockAdapter(axios);
+
+      delete noFilesData.diff_files;
 
+      mock.onGet(endpointMetadata).reply(200, diffMetadata);
+    });
+
+    it('should fetch diff meta information', done => {
       testAction(
         fetchDiffFilesMeta,
         {},
@@ -273,8 +280,8 @@ describe('DiffsStoreActions', () => {
         [
           { type: types.SET_LOADING, payload: true },
           { type: types.SET_LOADING, payload: false },
-          { type: types.SET_MERGE_REQUEST_DIFFS, payload: [] },
-          { type: types.SET_DIFF_DATA, payload: { data } },
+          { type: types.SET_MERGE_REQUEST_DIFFS, payload: diffMetadata.merge_request_diffs },
+          { type: types.SET_DIFF_DATA, payload: noFilesData },
         ],
         [],
         () => {
@@ -390,13 +397,18 @@ describe('DiffsStoreActions', () => {
     });
 
     describe('fetchDiffFilesMeta', () => {
-      it('should fetch diff meta information', done => {
-        const endpointMetadata = '/fetch/diffs_meta';
-        const mock = new MockAdapter(axios);
-        const data = { diff_files: [] };
-        const res = { data };
-        mock.onGet(endpointMetadata).reply(200, res);
+      const endpointMetadata = '/fetch/diffs_metadata.json';
+      const noFilesData = { ...diffMetadata };
+      let mock;
 
+      beforeEach(() => {
+        mock = new MockAdapter(axios);
+
+        delete noFilesData.diff_files;
+
+        mock.onGet(endpointMetadata).reply(200, diffMetadata);
+      });
+      it('should fetch diff meta information', done => {
         testAction(
           fetchDiffFilesMeta,
           {},
@@ -404,8 +416,8 @@ describe('DiffsStoreActions', () => {
           [
             { type: types.SET_LOADING, payload: true },
             { type: types.SET_LOADING, payload: false },
-            { type: types.SET_MERGE_REQUEST_DIFFS, payload: [] },
-            { type: types.SET_DIFF_DATA, payload: { data } },
+            { type: types.SET_MERGE_REQUEST_DIFFS, payload: diffMetadata.merge_request_diffs },
+            { type: types.SET_DIFF_DATA, payload: noFilesData },
           ],
           [],
           () => {

spec/frontend/diffs/store/utils_spec.js

@@ -14,9 +14,11 @@ import {
 } from '~/diffs/constants';
 import { MERGE_REQUEST_NOTEABLE_TYPE } from '~/notes/constants';
 import diffFileMockData from '../mock_data/diff_file';
+import { diffMetadata } from '../mock_data/diff_metadata';
 import { noteableDataMock } from '../../notes/mock_data';
 
 const getDiffFileMock = () => JSON.parse(JSON.stringify(diffFileMockData));
+const getDiffMetadataMock = () => JSON.parse(JSON.stringify(diffMetadata));
 
 describe('DiffsStoreUtils', () => {
   describe('findDiffFile', () => {
@@ -430,6 +432,7 @@ describe('DiffsStoreUtils', () => {
   });
 
   describe('prepareDiffData', () => {
+    describe('for regular diff files', () => {
       let mock;
       let preparedDiff;
       let splitInlineDiff;
@@ -438,6 +441,7 @@ describe('DiffsStoreUtils', () => {
 
       beforeEach(() => {
         mock = getDiffFileMock();
+
         preparedDiff = { diff_files: [mock] };
         splitInlineDiff = {
           diff_files: [{ ...mock, parallel_diff_lines: undefined }],
@@ -539,6 +543,69 @@ describe('DiffsStoreUtils', () => {
       });
     });
 
+    describe('for diff metadata', () => {
+      let mock;
+      let preparedDiffFiles;
+
+      beforeEach(() => {
+        mock = getDiffMetadataMock();
+
+        preparedDiffFiles = utils.prepareDiffData(mock);
+      });
+
+      it('sets the renderIt and collapsed attribute on files', () => {
+        expect(preparedDiffFiles[0].renderIt).toBeTruthy();
+        expect(preparedDiffFiles[0].collapsed).toBeFalsy();
+      });
+
+      it('guarantees an empty array of lines for both diff styles', () => {
+        expect(preparedDiffFiles[0].parallel_diff_lines.length).toEqual(0);
+        expect(preparedDiffFiles[0].highlighted_diff_lines.length).toEqual(0);
+      });
+
+      it('leaves files in the existing state', () => {
+        const fileMock = getDiffFileMock();
+        const metaData = getDiffMetadataMock();
+        const priorFiles = [fileMock];
+        const updatedFilesList = utils.prepareDiffData(metaData, priorFiles);
+
+        expect(updatedFilesList.length).toEqual(2);
+        expect(updatedFilesList[0]).toEqual(fileMock);
+      });
+
+      it('adds a new file to the file that already exists in state', () => {
+        // This is actually buggy behavior:
+        // Because the metadata doesn't include a content_sha,
+        // the de-duplicator in prepareDiffData doesn't realize it
+        // should combine these two.
+
+        // This buggy behavior hasn't caused a defect YET, because
+        // `diffs_metadata.json` is only called the first time the
+        // diffs app starts up, which is:
+        // - after a fresh page load
+        // - after you switch to the changes tab *the first time*
+
+        // This test should begin FAILING and can be reversed to check
+        // for just a single file when this is implemented:
+        // https://gitlab.com/groups/gitlab-org/-/epics/2852#note_304803233
+
+        const fileMock = getDiffFileMock();
+        const metaMock = getDiffMetadataMock();
+        const priorFiles = [{ ...fileMock }];
+        const updatedFilesList = utils.prepareDiffData(metaMock, priorFiles);
+
+        expect(updatedFilesList).toEqual([
+          fileMock,
+          {
+            ...metaMock.diff_files[0],
+            highlighted_diff_lines: [],
+            parallel_diff_lines: [],
+          },
+        ]);
+      });
+    });
+  });
+
   describe('isDiscussionApplicableToLine', () => {
     const diffPosition = {
       baseSha: 'ed13df29948c41ba367caa757ab3ec4892509910',