Merge branch '55932-diff-viewer-refactor' into 'master'

Refactor MR FE components to rely on DiffViewer instead of DiffFile

Closes #55932

See merge request gitlab-org/gitlab-ce!24454

app/assets/javascripts/diffs/components/diff_content.vue

 <script>
 import { mapActions, mapGetters, mapState } from 'vuex';
 import DiffViewer from '~/vue_shared/components/diff_viewer/diff_viewer.vue';
-import EmptyFileViewer from '~/vue_shared/components/diff_viewer/viewers/empty_file.vue';
+import NotDiffableViewer from '~/vue_shared/components/diff_viewer/viewers/not_diffable.vue';
+import NoPreviewViewer from '~/vue_shared/components/diff_viewer/viewers/no_preview.vue';
 import InlineDiffView from './inline_diff_view.vue';
 import ParallelDiffView from './parallel_diff_view.vue';
 import NoteForm from '../../notes/components/note_form.vue';
@@ -9,6 +10,7 @@ import ImageDiffOverlay from './image_diff_overlay.vue';
 import DiffDiscussions from './diff_discussions.vue';
 import { IMAGE_DIFF_POSITION_TYPE } from '../constants';
 import { getDiffMode } from '../store/utils';
+import { diffViewerModes } from '~/ide/constants';
 
 export default {
   components: {
@@ -18,7 +20,8 @@ export default {
     NoteForm,
     DiffDiscussions,
     ImageDiffOverlay,
-    EmptyFileViewer,
+    NotDiffableViewer,
+    NoPreviewViewer,
   },
   props: {
     diffFile: {
@@ -42,11 +45,17 @@ export default {
     diffMode() {
       return getDiffMode(this.diffFile);
     },
+    diffViewerMode() {
+      return this.diffFile.viewer.name;
+    },
     isTextFile() {
-      return this.diffFile.viewer.name === 'text';
+      return this.diffViewerMode === diffViewerModes.text;
+    },
+    noPreview() {
+      return this.diffViewerMode === diffViewerModes.no_preview;
     },
-    errorMessage() {
-      return this.diffFile.viewer.error;
+    notDiffable() {
+      return this.diffViewerMode === diffViewerModes.not_diffable;
     },
     diffFileCommentForm() {
       return this.getCommentFormForDiffFile(this.diffFile.file_hash);
@@ -78,11 +87,10 @@ export default {
 
 <template>
   <div class="diff-content">
-    <div v-if="!errorMessage" class="diff-viewer">
+    <div class="diff-viewer">
       <template v-if="isTextFile">
-        <empty-file-viewer v-if="diffFile.empty" />
         <inline-diff-view
-          v-else-if="isInlineView"
+          v-if="isInlineView"
           :diff-file="diffFile"
           :diff-lines="diffFile.highlighted_diff_lines || []"
           :help-page-path="helpPagePath"
@@ -94,9 +102,12 @@ export default {
           :help-page-path="helpPagePath"
         />
       </template>
+      <not-diffable-viewer v-else-if="notDiffable" />
+      <no-preview-viewer v-else-if="noPreview" />
       <diff-viewer
         v-else
         :diff-mode="diffMode"
+        :diff-viewer-mode="diffViewerMode"
         :new-path="diffFile.new_path"
         :new-sha="diffFile.diff_refs.head_sha"
         :old-path="diffFile.old_path"
@@ -132,8 +143,5 @@ export default {
         </div>
       </diff-viewer>
     </div>
-    <div v-else class="diff-viewer">
-      <div class="nothing-here-block" v-html="errorMessage"></div>
-    </div>
   </div>
 </template>

app/assets/javascripts/diffs/components/diff_file.vue

@@ -7,6 +7,7 @@ import { GlLoadingIcon } from '@gitlab/ui';
 import eventHub from '../../notes/event_hub';
 import DiffFileHeader from './diff_file_header.vue';
 import DiffContent from './diff_content.vue';
+import { diffViewerErrors } from '~/ide/constants';
 
 export default {
   components: {
@@ -33,15 +34,14 @@ export default {
     return {
       isLoadingCollapsedDiff: false,
       forkMessageVisible: false,
+      isCollapsed: this.file.viewer.collapsed || false,
+      renderIt: this.file.renderIt,
     };
   },
   computed: {
     ...mapState('diffs', ['currentDiffFileId']),
     ...mapGetters(['isNotesFetched']),
     ...mapGetters('diffs', ['getDiffFileDiscussions']),
-    isCollapsed() {
-      return this.file.collapsed || false;
-    },
     viewBlobLink() {
       return sprintf(
         __('You can %{linkStart}view the blob%{linkEnd} instead.'),
@@ -52,19 +52,8 @@ export default {
         false,
       );
     },
-    showExpandMessage() {
-      return (
-        this.isCollapsed ||
-        (!this.file.highlighted_diff_lines &&
-          !this.isLoadingCollapsedDiff &&
-          !this.file.too_large &&
-          this.file.text &&
-          !this.file.renamed_file &&
-          !this.file.mode_changed)
-      );
-    },
     showLoadingIcon() {
-      return this.isLoadingCollapsedDiff || (!this.file.renderIt && !this.isCollapsed);
+      return this.isLoadingCollapsedDiff || (!this.renderIt && !this.isCollapsed);
     },
     hasDiffLines() {
       return (
@@ -73,9 +62,15 @@ export default {
         this.file.parallel_diff_lines.length > 0
       );
     },
+    isFileTooLarge() {
+      return this.file.viewer.error === diffViewerErrors.too_large;
+    },
+    errorMessage() {
+      return this.file.viewer.error_message;
+    },
   },
   watch: {
-    'file.collapsed': function fileCollapsedWatch(newVal, oldVal) {
+    isCollapsed: function fileCollapsedWatch(newVal, oldVal) {
       if (!newVal && oldVal && !this.hasDiffLines) {
         this.handleLoadCollapsedDiff();
       }
@@ -90,8 +85,8 @@ export default {
       if (!this.hasDiffLines) {
         this.handleLoadCollapsedDiff();
       } else {
-        this.file.collapsed = !this.file.collapsed;
-        this.file.renderIt = true;
+        this.isCollapsed = !this.isCollapsed;
+        this.renderIt = true;
       }
     },
     handleLoadCollapsedDiff() {
@@ -100,8 +95,8 @@ export default {
       this.loadCollapsedDiff(this.file)
         .then(() => {
           this.isLoadingCollapsedDiff = false;
-          this.file.collapsed = false;
-          this.file.renderIt = true;
+          this.isCollapsed = false;
+          this.renderIt = true;
         })
         .then(() => {
           requestIdleCallback(
@@ -164,21 +159,25 @@ export default {
         Cancel
       </button>
     </div>
-
-    <diff-content
-      v-if="!isCollapsed && file.renderIt"
-      :class="{ hidden: isCollapsed || file.too_large }"
-      :diff-file="file"
-      :help-page-path="helpPagePath"
-    />
     <gl-loading-icon v-if="showLoadingIcon" class="diff-content loading" />
-    <div v-else-if="showExpandMessage" class="nothing-here-block diff-collapsed">
-      {{ __('This diff is collapsed.') }}
-      <a class="click-to-expand js-click-to-expand" href="#" @click.prevent="handleToggle">{{
-        __('Click to expand it.')
-      }}</a>
-    </div>
-    <div v-if="file.too_large" class="nothing-here-block diff-collapsed js-too-large-diff">
+    <template v-else>
+      <div v-if="errorMessage" class="diff-viewer">
+        <div class="nothing-here-block" v-html="errorMessage"></div>
+      </div>
+      <div v-else-if="isCollapsed" class="nothing-here-block diff-collapsed">
+        {{ __('This diff is collapsed.') }}
+        <a class="click-to-expand js-click-to-expand" href="#" @click.prevent="handleToggle">{{
+          __('Click to expand it.')
+        }}</a>
+      </div>
+      <diff-content
+        v-else
+        :class="{ hidden: isCollapsed || isFileTooLarge }"
+        :diff-file="file"
+        :help-page-path="helpPagePath"
+      />
+    </template>
+    <div v-if="isFileTooLarge" class="nothing-here-block diff-collapsed js-too-large-diff">
       {{ __('This source diff could not be displayed because it is too large.') }}
       <span v-html="viewBlobLink"></span>
     </div>

app/assets/javascripts/diffs/components/diff_file_header.vue

@@ -8,6 +8,7 @@ import FileIcon from '~/vue_shared/components/file_icon.vue';
 import { GlTooltipDirective } from '@gitlab/ui';
 import { truncateSha } from '~/lib/utils/text_utility';
 import { __, s__, sprintf } from '~/locale';
+import { diffViewerModes } from '~/ide/constants';
 import EditButton from './edit_button.vue';
 import DiffStats from './diff_stats.vue';
 
@@ -118,6 +119,12 @@ export default {
     gfmCopyText() {
       return `\`${this.diffFile.file_path}\``;
     },
+    isFileRenamed() {
+      return this.diffFile.viewer.name === diffViewerModes.renamed;
+    },
+    isModeChanged() {
+      return this.diffFile.viewer.name === diffViewerModes.mode_changed;
+    },
   },
   mounted() {
     polyfillSticky(this.$refs.header);
@@ -165,7 +172,7 @@ export default {
           aria-hidden="true"
           css-classes="js-file-icon append-right-5"
         />
-        <span v-if="diffFile.renamed_file">
+        <span v-if="isFileRenamed">
           <strong
             v-gl-tooltip
             :title="diffFile.old_path"
@@ -193,7 +200,7 @@ export default {
         css-class="btn-default btn-transparent btn-clipboard"
       />
 
-      <small v-if="diffFile.mode_changed" ref="fileMode">
+      <small v-if="isModeChanged" ref="fileMode">
         {{ diffFile.a_mode }} → {{ diffFile.b_mode }}
       </small>
 

app/assets/javascripts/diffs/store/actions.js

@@ -17,6 +17,7 @@ import {
   TREE_LIST_STORAGE_KEY,
   WHITESPACE_STORAGE_KEY,
 } from '../constants';
+import { diffViewerModes } from '~/ide/constants';
 
 export const setBaseConfig = ({ commit }, options) => {
   const { endpoint, projectPath } = options;
@@ -91,7 +92,7 @@ export const renderFileForDiscussionId = ({ commit, rootState, state }, discussi
         commit(types.RENDER_FILE, file);
       }
 
-      if (file.collapsed) {
+      if (file.viewer.collapsed) {
         eventHub.$emit(`loadCollapsedDiff/${file.file_hash}`);
         scrollToElement(document.getElementById(file.file_hash));
       } else {
@@ -105,7 +106,8 @@ export const startRenderDiffsQueue = ({ state, commit }) => {
   const checkItem = () =>
     new Promise(resolve => {
       const nextFile = state.diffFiles.find(
-        file => !file.renderIt && (!file.collapsed || !file.text),
+        file =>
+          !file.renderIt && (!file.viewer.collapsed || !file.viewer.name === diffViewerModes.text),
       );
 
       if (nextFile) {

app/assets/javascripts/diffs/store/getters.js

@@ -4,7 +4,8 @@ export const isParallelView = state => state.diffViewType === PARALLEL_DIFF_VIEW
 
 export const isInlineView = state => state.diffViewType === INLINE_DIFF_VIEW_TYPE;
 
-export const hasCollapsedFile = state => state.diffFiles.some(file => file.collapsed);
+export const hasCollapsedFile = state =>
+  state.diffFiles.some(file => file.viewer && file.viewer.collapsed);
 
 export const commitId = state => (state.commit && state.commit.id ? state.commit.id : null);
 

app/assets/javascripts/diffs/store/utils.js

 import _ from 'underscore';
-import { diffModes } from '~/ide/constants';
 import { truncatePathMiddleToLength } from '~/lib/utils/text_utility';
+import { diffModes, diffViewerModes } from '~/ide/constants';
 import {
   LINE_POSITION_LEFT,
   LINE_POSITION_RIGHT,
@@ -248,7 +248,8 @@ export function prepareDiffData(diffData) {
 
     Object.assign(file, {
       renderIt: showingLines < LINES_TO_BE_RENDERED_DIRECTLY,
-      collapsed: file.text && showingLines > MAX_LINES_TO_BE_RENDERED,
+      collapsed:
+        file.viewer.name === diffViewerModes.text && showingLines > MAX_LINES_TO_BE_RENDERED,
       discussions: [],
     });
   }
@@ -404,7 +405,9 @@ export const getDiffMode = diffFile => {
   const diffModeKey = Object.keys(diffModes).find(key => diffFile[`${key}_file`]);
   return (
     diffModes[diffModeKey] ||
-    (diffFile.mode_changed && diffModes.mode_changed) ||
+    (diffFile.viewer &&
+      diffFile.viewer.name === diffViewerModes.mode_changed &&
+      diffViewerModes.mode_changed) ||
     diffModes.replaced
   );
 };

app/assets/javascripts/ide/constants.js

@@ -24,6 +24,22 @@ export const diffModes = {
   mode_changed: 'mode_changed',
 };
 
+export const diffViewerModes = Object.freeze({
+  not_diffable: 'not_diffable',
+  no_preview: 'no_preview',
+  added: 'added',
+  deleted: 'deleted',
+  renamed: 'renamed',
+  mode_changed: 'mode_changed',
+  text: 'text',
+  image: 'image',
+});
+
+export const diffViewerErrors = Object.freeze({
+  too_large: 'too_large',
+  stored_externally: 'server_side_but_stored_externally',
+});
+
 export const rightSidebarViews = {
   pipelines: { name: 'pipelines-list', keepAlive: true },
   jobsDetail: { name: 'jobs-detail', keepAlive: false },

app/assets/javascripts/notes/components/diff_with_note.vue

@@ -5,6 +5,7 @@ import DiffViewer from '~/vue_shared/components/diff_viewer/diff_viewer.vue';
 import ImageDiffOverlay from '~/diffs/components/image_diff_overlay.vue';
 import { GlSkeletonLoading } from '@gitlab/ui';
 import { getDiffMode } from '~/diffs/store/utils';
+import { diffViewerModes } from '~/ide/constants';
 
 export default {
   components: {
@@ -31,6 +32,12 @@ export default {
     diffMode() {
       return getDiffMode(this.discussion.diff_file);
     },
+    diffViewerMode() {
+      return this.discussion.diff_file.viewer.name;
+    },
+    isTextFile() {
+      return this.diffViewerMode === diffViewerModes.text;
+    },
     hasTruncatedDiffLines() {
       return (
         this.discussion.truncated_diff_lines && this.discussion.truncated_diff_lines.length !== 0
@@ -58,18 +65,14 @@ export default {
 </script>
 
 <template>
-  <div :class="{ 'text-file': discussion.diff_file.text }" class="diff-file file-holder">
+  <div :class="{ 'text-file': isTextFile }" class="diff-file file-holder">
     <diff-file-header
       :discussion-path="discussion.discussion_path"
       :diff-file="discussion.diff_file"
       :can-current-user-fork="false"
-      :expanded="!discussion.diff_file.collapsed"
+      :expanded="!discussion.diff_file.viewer.collapsed"
     />
-    <div
-      v-if="discussion.diff_file.text"
-      :class="$options.userColorSchemeClass"
-      class="diff-content code"
-    >
+    <div v-if="isTextFile" :class="$options.userColorSchemeClass" class="diff-content code">
       <table>
         <template v-if="hasTruncatedDiffLines">
           <tr
@@ -109,6 +112,7 @@ export default {
     <div v-else>
       <diff-viewer
         :diff-mode="diffMode"
+        :diff-viewer-mode="diffViewerMode"
         :new-path="discussion.diff_file.new_path"
         :new-sha="discussion.diff_file.diff_refs.head_sha"
         :old-path="discussion.diff_file.old_path"

app/assets/javascripts/vue_shared/components/diff_viewer/diff_viewer.vue

 <script>
-import { diffModes } from '~/ide/constants';
-import { viewerInformationForPath } from '../content_viewer/lib/viewer_utils';
+import { diffViewerModes, diffModes } from '~/ide/constants';
 import ImageDiffViewer from './viewers/image_diff_viewer.vue';
 import DownloadDiffViewer from './viewers/download_diff_viewer.vue';
 import RenamedFile from './viewers/renamed.vue';
@@ -12,6 +11,10 @@ export default {
       type: String,
       required: true,
     },
+    diffViewerMode: {
+      type: String,
+      required: true,
+    },
     newPath: {
       type: String,
       required: true,
@@ -46,7 +49,7 @@ export default {
   },
   computed: {
     viewer() {
-      if (this.diffMode === diffModes.renamed) {
+      if (this.diffViewerMode === diffViewerModes.renamed) {
         return RenamedFile;
       } else if (this.diffMode === diffModes.mode_changed) {
         return ModeChanged;
@@ -54,11 +57,8 @@ export default {
 
       if (!this.newPath) return null;
 
-      const previewInfo = viewerInformationForPath(this.newPath);
-      if (!previewInfo) return DownloadDiffViewer;
-
-      switch (previewInfo.id) {
-        case 'image':
+      switch (this.diffViewerMode) {
+        case diffViewerModes.image:
           return ImageDiffViewer;
         default:
           return DownloadDiffViewer;

app/assets/javascripts/vue_shared/components/diff_viewer/viewers/no_preview.vue

+<template>
+  <div class="nothing-here-block">
+    {{ __('No preview for this file type') }}
+  </div>
+</template>

app/assets/javascripts/vue_shared/components/diff_viewer/viewers/not_diffable.vue

+<template>
+  <div class="nothing-here-block">
+    {{ __('This diff was suppressed by a .gitattributes entry.') }}
+  </div>
+</template>

app/serializers/diff_file_base_entity.rb

@@ -72,17 +72,20 @@ class DiffFileBaseEntity < Grape::Entity
   expose :old_path
   expose :new_path
   expose :new_file?, as: :new_file
-  expose :collapsed?, as: :collapsed
-  expose :text?, as: :text
+  expose :renamed_file?, as: :renamed_file
+  expose :deleted_file?, as: :deleted_file
+
   expose :diff_refs
+
   expose :stored_externally?, as: :stored_externally
   expose :external_storage
-  expose :renamed_file?, as: :renamed_file
-  expose :deleted_file?, as: :deleted_file
+
   expose :mode_changed?, as: :mode_changed
   expose :a_mode
   expose :b_mode
 
+  expose :viewer, using: DiffViewerEntity
+
   private
 
   def memoized_submodule_links(diff_file)

app/serializers/diff_file_entity.rb

@@ -4,12 +4,10 @@ class DiffFileEntity < DiffFileBaseEntity
   include CommitsHelper
   include IconsHelper
 
-  expose :too_large?, as: :too_large
-  expose :empty?, as: :empty
   expose :added_lines
   expose :removed_lines
 
-  expose :load_collapsed_diff_url, if: -> (diff_file, options) { diff_file.text? && options[:merge_request] } do |diff_file|
+  expose :load_collapsed_diff_url, if: -> (diff_file, options) { diff_file.viewer.collapsed? && options[:merge_request] } do |diff_file|
     merge_request = options[:merge_request]
     project = merge_request.target_project
 
@@ -36,10 +34,6 @@ class DiffFileEntity < DiffFileBaseEntity
     project_blob_path(project, tree_join(diff_file.content_sha, diff_file.new_path))
   end
 
-  expose :viewer, using: DiffViewerEntity do |diff_file|
-    diff_file.rich_viewer || diff_file.simple_viewer
-  end
-
   expose :replaced_view_path, if: -> (_, options) { options[:merge_request] } do |diff_file|
     image_diff = diff_file.rich_viewer && diff_file.rich_viewer.partial_name == 'image'
     image_replaced = diff_file.old_content_sha && diff_file.old_content_sha != diff_file.content_sha

app/serializers/diff_viewer_entity.rb

 # frozen_string_literal: true
 
 class DiffViewerEntity < Grape::Entity
-  # Partial name refers directly to a Rails feature, let's avoid
-  # using this on the frontend.
   expose :partial_name, as: :name
-  expose :error do |diff_viewer|
-    diff_viewer.render_error_message
-  end
+  expose :render_error, as: :error
+  expose :render_error_message, as: :error_message
+  expose :collapsed?, as: :collapsed
 end

lib/gitlab/diff/file.rb

@@ -293,6 +293,10 @@ module Gitlab
         end
       end
 
+      def viewer
+        rich_viewer || simple_viewer
+      end
+
       def simple_viewer
         @simple_viewer ||= simple_viewer_class.new(self)
       end

spec/features/merge_request/user_creates_image_diff_notes_spec.rb

@@ -222,6 +222,11 @@ describe 'Merge request > User creates image diff notes', :js do
   end
 
   def create_image_diff_note
+    expand_text = 'Click to expand it.'
+    page.all('a', text: expand_text).each do |element|
+      element.click
+    end
+
     find('.js-add-image-diff-note-button', match: :first).click
     find('.diff-content .note-textarea').native.send_keys('image diff test comment')
     click_button 'Comment'

spec/fixtures/api/schemas/entities/diff_viewer.json

@@ -14,6 +14,17 @@
         "string",
         "null"
       ]
+    },
+    "error_message": {
+      "type": [
+        "string",
+        "null"
+      ]
+    },
+    "collapsed": {
+      "type": [
+        "boolean"
+      ]
     }
   },
   "additionalProperties": false

spec/javascripts/diffs/components/diff_content_spec.js

@@ -6,6 +6,7 @@ import { GREEN_BOX_IMAGE_URL, RED_BOX_IMAGE_URL } from 'spec/test_constants';
 import '~/behaviors/markdown/render_gfm';
 import diffFileMockData from '../mock_data/diff_file';
 import discussionsMockData from '../mock_data/diff_discussions';
+import { diffViewerModes } from '~/ide/constants';
 
 describe('DiffContent', () => {
   const Component = Vue.extend(DiffContentComponent);
@@ -52,26 +53,39 @@ describe('DiffContent', () => {
 
   describe('empty files', () => {
     beforeEach(() => {
-      vm.diffFile.empty = true;
       vm.diffFile.highlighted_diff_lines = [];
       vm.diffFile.parallel_diff_lines = [];
     });
 
-    it('should render a message', done => {
+    it('should render a no preview message if viewer returns no preview', done => {
+      vm.diffFile.viewer.name = diffViewerModes.no_preview;
       vm.$nextTick(() => {
         const block = vm.$el.querySelector('.diff-viewer .nothing-here-block');
 
         expect(block).not.toBe(null);
-        expect(block.textContent.trim()).toContain('Empty file');
+        expect(block.textContent.trim()).toContain('No preview for this file type');
+
+        done();
+      });
+    });
+
+    it('should render a not diffable message if viewer returns not diffable', done => {
+      vm.diffFile.viewer.name = diffViewerModes.not_diffable;
+      vm.$nextTick(() => {
+        const block = vm.$el.querySelector('.diff-viewer .nothing-here-block');
+
+        expect(block).not.toBe(null);
+        expect(block.textContent.trim()).toContain(
+          'This diff was suppressed by a .gitattributes entry',
+        );
 
         done();
       });
     });
 
     it('should not render multiple messages', done => {
-      vm.diffFile.mode_changed = true;
       vm.diffFile.b_mode = '100755';
-      vm.diffFile.viewer.name = 'mode_changed';
+      vm.diffFile.viewer.name = diffViewerModes.mode_changed;
 
       vm.$nextTick(() => {
         expect(vm.$el.querySelectorAll('.nothing-here-block').length).toBe(1);
@@ -81,6 +95,7 @@ describe('DiffContent', () => {
     });
 
     it('should not render diff table', done => {
+      vm.diffFile.viewer.name = diffViewerModes.no_preview;
       vm.$nextTick(() => {
         expect(vm.$el.querySelector('table')).toBe(null);
 
@@ -157,6 +172,7 @@ describe('DiffContent', () => {
         vm.diffFile.new_sha = 'DEF';
         vm.diffFile.old_path = 'test.abc';
         vm.diffFile.old_sha = 'ABC';
+        vm.diffFile.viewer.name = diffViewerModes.added;
 
         vm.$nextTick(() => {
           expect(el.querySelectorAll('.js-diff-inline-view').length).toEqual(0);

spec/javascripts/diffs/components/diff_file_header_spec.js

@@ -4,15 +4,15 @@ import diffsModule from '~/diffs/store/modules';
 import notesModule from '~/notes/stores/modules';
 import DiffFileHeader from '~/diffs/components/diff_file_header.vue';
 import { mountComponentWithStore } from 'spec/helpers/vue_mount_component_helper';
+import diffDiscussionsMockData from '../mock_data/diff_discussions';
+import { diffViewerModes } from '~/ide/constants';
 
 Vue.use(Vuex);
 
-const discussionFixture = 'merge_requests/diff_discussion.json';
-
 describe('diff_file_header', () => {
   let vm;
   let props;
-  const diffDiscussionMock = getJSONFixture(discussionFixture)[0];
+  const diffDiscussionMock = diffDiscussionsMockData;
   const Component = Vue.extend(DiffFileHeader);
 
   const store = new Vuex.Store({
@@ -303,13 +303,13 @@ describe('diff_file_header', () => {
       });
 
       it('displays old and new path if the file was renamed', () => {
-        props.diffFile.renamed_file = true;
+        props.diffFile.viewer.name = diffViewerModes.renamed;
 
         vm = mountComponentWithStore(Component, { props, store });
 
         expect(filePaths()).toHaveLength(2);
-        expect(filePaths()[0]).toHaveText(props.diffFile.old_path);
-        expect(filePaths()[1]).toHaveText(props.diffFile.new_path);
+        expect(filePaths()[0]).toHaveText(props.diffFile.old_path_html);
+        expect(filePaths()[1]).toHaveText(props.diffFile.new_path_html);
       });
     });
 
@@ -319,14 +319,12 @@ describe('diff_file_header', () => {
       const button = vm.$el.querySelector('.btn-clipboard');
 
       expect(button).not.toBe(null);
-      expect(button.dataset.clipboardText).toBe(
-        '{"text":"files/ruby/popen.rb","gfm":"`files/ruby/popen.rb`"}',
-      );
+      expect(button.dataset.clipboardText).toBe('{"text":"CHANGELOG.rb","gfm":"`CHANGELOG.rb`"}');
     });
 
     describe('file mode', () => {
       it('it displays old and new file mode if it changed', () => {
-        props.diffFile.mode_changed = true;
+        props.diffFile.viewer.name = diffViewerModes.mode_changed;
 
         vm = mountComponentWithStore(Component, { props, store });
 
@@ -338,7 +336,7 @@ describe('diff_file_header', () => {
       });
 
       it('does not display the file mode if it has not changed', () => {
-        props.diffFile.mode_changed = false;
+        props.diffFile.viewer.name = diffViewerModes.text;
 
         vm = mountComponentWithStore(Component, { props, store });
 

spec/javascripts/diffs/components/diff_file_spec.js

 import Vue from 'vue';
 import DiffFileComponent from '~/diffs/components/diff_file.vue';
+import { diffViewerModes, diffViewerErrors } from '~/ide/constants';
 import store from '~/mr_notes/stores';
 import { createComponentWithStore } from 'spec/helpers/vue_mount_component_helper';
 import diffFileMockData from '../mock_data/diff_file';
@@ -27,8 +28,8 @@ describe('DiffFile', () => {
       expect(el.querySelector('.file-title-name').innerText.indexOf(file_path)).toBeGreaterThan(-1);
       expect(el.querySelector('.js-syntax-highlight')).toBeDefined();
 
-      expect(vm.file.renderIt).toEqual(false);
-      vm.file.renderIt = true;
+      expect(vm.renderIt).toEqual(false);
+      vm.renderIt = true;
 
       vm.$nextTick(() => {
         expect(el.querySelectorAll('.line_content').length).toBeGreaterThan(5);
@@ -38,9 +39,9 @@ describe('DiffFile', () => {
     describe('collapsed', () => {
       it('should not have file content', done => {
         expect(vm.$el.querySelectorAll('.diff-content').length).toEqual(1);
-        expect(vm.file.collapsed).toEqual(false);
-        vm.file.collapsed = true;
-        vm.file.renderIt = true;
+        expect(vm.isCollapsed).toEqual(false);
+        vm.isCollapsed = true;
+        vm.renderIt = true;
 
         vm.$nextTick(() => {
           expect(vm.$el.querySelectorAll('.diff-content').length).toEqual(0);
@@ -50,9 +51,8 @@ describe('DiffFile', () => {
       });
 
       it('should have collapsed text and link', done => {
-        vm.file.renderIt = true;
-        vm.file.collapsed = false;
-        vm.file.highlighted_diff_lines = null;
+        vm.renderIt = true;
+        vm.isCollapsed = true;
 
         vm.$nextTick(() => {
           expect(vm.$el.innerText).toContain('This diff is collapsed');
@@ -63,8 +63,8 @@ describe('DiffFile', () => {
       });
 
       it('should have collapsed text and link even before rendered', done => {
-        vm.file.renderIt = false;
-        vm.file.collapsed = true;
+        vm.renderIt = false;
+        vm.isCollapsed = true;
 
         vm.$nextTick(() => {
           expect(vm.$el.innerText).toContain('This diff is collapsed');
@@ -75,10 +75,10 @@ describe('DiffFile', () => {
       });
 
       it('should be collapsed for renamed files', done => {
-        vm.file.renderIt = true;
-        vm.file.collapsed = false;
+        vm.renderIt = true;
+        vm.isCollapsed = false;
         vm.file.highlighted_diff_lines = null;
-        vm.file.renamed_file = true;
+        vm.file.viewer.name = diffViewerModes.renamed;
 
         vm.$nextTick(() => {
           expect(vm.$el.innerText).not.toContain('This diff is collapsed');
@@ -88,10 +88,10 @@ describe('DiffFile', () => {
       });
 
       it('should be collapsed for mode changed files', done => {
-        vm.file.renderIt = true;
-        vm.file.collapsed = false;
+        vm.renderIt = true;
+        vm.isCollapsed = false;
         vm.file.highlighted_diff_lines = null;
-        vm.file.mode_changed = true;
+        vm.file.viewer.name = diffViewerModes.mode_changed;
 
         vm.$nextTick(() => {
           expect(vm.$el.innerText).not.toContain('This diff is collapsed');
@@ -101,7 +101,7 @@ describe('DiffFile', () => {
       });
 
       it('should have loading icon while loading a collapsed diffs', done => {
-        vm.file.collapsed = true;
+        vm.isCollapsed = true;
         vm.isLoadingCollapsedDiff = true;
 
         vm.$nextTick(() => {
@@ -116,7 +116,7 @@ describe('DiffFile', () => {
   describe('too large diff', () => {
     it('should have too large warning and blob link', done => {
       const BLOB_LINK = '/file/view/path';
-      vm.file.too_large = true;
+      vm.file.viewer.error = diffViewerErrors.too_large;
       vm.file.view_path = BLOB_LINK;
 
       vm.$nextTick(() => {
@@ -140,11 +140,11 @@ describe('DiffFile', () => {
 
       vm.file.highlighted_diff_lines = undefined;
       vm.file.parallel_diff_lines = [];
-      vm.file.collapsed = true;
+      vm.isCollapsed = true;
 
       vm.$nextTick()
         .then(() => {
-          vm.file.collapsed = false;
+          vm.isCollapsed = false;
 
           return vm.$nextTick();
         })

spec/javascripts/diffs/mock_data/diff_discussions.js

@@ -266,7 +266,7 @@ 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_path: 'CHANGELOG',
+    file_path: 'CHANGELOG.rb',
     new_file: false,
     deleted_file: false,
     renamed_file: false,
@@ -286,7 +286,7 @@ export default {
     content_sha: 'c48ee0d1bf3b30453f5b32250ce03134beaa6d13',
     stored_externally: null,
     external_storage: null,
-    old_path_html: ['CHANGELOG', 'CHANGELOG'],
+    old_path_html: 'CHANGELOG_OLD',
     new_path_html: 'CHANGELOG',
     context_lines_path:
       '/gitlab-org/gitlab-test/blob/c48ee0d1bf3b30453f5b32250ce03134beaa6d13/CHANGELOG/diff',
@@ -485,6 +485,10 @@ export default {
         },
       },
     ],
+    viewer: {
+      name: 'text',
+      error: null,
+    },
   },
   diff_discussion: true,
   truncated_diff_lines: [

spec/javascripts/diffs/mock_data/diff_file.js

@@ -25,6 +25,8 @@ export default {
   text: true,
   viewer: {
     name: 'text',
+    error: null,
+    collapsed: false,
   },
   added_lines: 2,
   removed_lines: 0,

spec/javascripts/diffs/store/actions_spec.js

@@ -262,12 +262,16 @@ describe('DiffsStoreActions', () => {
           {
             id: 1,
             renderIt: false,
-            collapsed: false,
+            viewer: {
+              collapsed: false,
+            },
           },
           {
             id: 2,
             renderIt: false,
-            collapsed: false,
+            viewer: {
+              collapsed: false,
+            },
           },
         ],
       };
@@ -766,7 +770,9 @@ describe('DiffsStoreActions', () => {
       diffFiles: [
         {
           file_hash: 'HASH',
-          collapsed,
+          viewer: {
+            collapsed,
+          },
           renderIt,
         },
       ],

spec/javascripts/diffs/store/getters_spec.js

@@ -51,13 +51,13 @@ describe('Diffs Module Getters', () => {
 
   describe('hasCollapsedFile', () => {
     it('returns true when all files are collapsed', () => {
-      localState.diffFiles = [{ collapsed: true }, { collapsed: true }];
+      localState.diffFiles = [{ viewer: { collapsed: true } }, { viewer: { collapsed: true } }];
 
       expect(getters.hasCollapsedFile(localState)).toEqual(true);
     });
 
     it('returns true when at least one file is collapsed', () => {
-      localState.diffFiles = [{ collapsed: false }, { collapsed: true }];
+      localState.diffFiles = [{ viewer: { collapsed: false } }, { viewer: { collapsed: true } }];
 
       expect(getters.hasCollapsedFile(localState)).toEqual(true);
     });

spec/javascripts/diffs/store/mutations_spec.js

@@ -121,8 +121,14 @@ describe('DiffsStoreMutations', () => {
   describe('ADD_COLLAPSED_DIFFS', () => {
     it('should update the state with the given data for the given file hash', () => {
       const fileHash = 123;
-      const state = { diffFiles: [{}, { file_hash: fileHash, existing_field: 0 }] };
-      const data = { diff_files: [{ file_hash: fileHash, extra_field: 1, existing_field: 1 }] };
+      const state = {
+        diffFiles: [{}, { file_hash: fileHash, existing_field: 0 }],
+      };
+      const data = {
+        diff_files: [
+          { file_hash: fileHash, extra_field: 1, existing_field: 1, viewer: { name: 'text' } },
+        ],
+      };
 
       mutations[types.ADD_COLLAPSED_DIFFS](state, { file: state.diffFiles[1], data });
 

spec/javascripts/diffs/store/utils_spec.js

@@ -601,7 +601,7 @@ describe('DiffsStoreUtils', () => {
     it('returns mode_changed if key has no match', () => {
       expect(
         utils.getDiffMode({
-          mode_changed: true,
+          viewer: { name: 'mode_changed' },
         }),
       ).toBe('mode_changed');
     });

spec/javascripts/vue_shared/components/diff_viewer/diff_viewer_spec.js

@@ -22,6 +22,7 @@ describe('DiffViewer', () => {
 
     createComponent({
       diffMode: 'replaced',
+      diffViewerMode: 'image',
       newPath: GREEN_BOX_IMAGE_URL,
       newSha: 'ABC',
       oldPath: RED_BOX_IMAGE_URL,
@@ -45,6 +46,7 @@ describe('DiffViewer', () => {
   it('renders fallback download diff display', done => {
     createComponent({
       diffMode: 'replaced',
+      diffViewerMode: 'added',
       newPath: 'test.abc',
       newSha: 'ABC',
       oldPath: 'testold.abc',
@@ -72,6 +74,7 @@ describe('DiffViewer', () => {
   it('renders renamed component', () => {
     createComponent({
       diffMode: 'renamed',
+      diffViewerMode: 'renamed',
       newPath: 'test.abc',
       newSha: 'ABC',
       oldPath: 'testold.abc',
@@ -84,6 +87,7 @@ describe('DiffViewer', () => {
   it('renders mode changed component', () => {
     createComponent({
       diffMode: 'mode_changed',
+      diffViewerMode: 'image',
       newPath: 'test.abc',
       newSha: 'ABC',
       oldPath: 'testold.abc',

spec/serializers/diff_file_entity_spec.rb

@@ -22,7 +22,7 @@ describe DiffFileEntity do
     let(:request) { EntityRequest.new(project: project, current_user: user) }
     let(:merge_request) { create(:merge_request, source_project: project, target_project: project) }
     let(:entity) { described_class.new(diff_file, request: request, merge_request: merge_request) }
-    let(:exposed_urls) { %i(load_collapsed_diff_url edit_path view_path context_lines_path) }
+    let(:exposed_urls) { %i(edit_path view_path context_lines_path) }
 
     it_behaves_like 'diff file entity'
 
@@ -38,6 +38,12 @@ describe DiffFileEntity do
         expect(response[attribute]).to include(merge_request.target_project.to_param)
       end
     end
+
+    it 'exposes load_collapsed_diff_url if the file viewer is collapsed' do
+      allow(diff_file.viewer).to receive(:collapsed?) { true }
+
+      expect(subject).to include(:load_collapsed_diff_url)
+    end
   end
 
   context '#parallel_diff_lines' do

spec/support/shared_examples/serializers/diff_file_entity_examples.rb

@@ -6,9 +6,9 @@ shared_examples 'diff file base entity' do
                                :submodule_tree_url, :old_path_html,
                                :new_path_html, :blob, :can_modify_blob,
                                :file_hash, :file_path, :old_path, :new_path,
-                               :collapsed, :text, :diff_refs, :stored_externally,
+                               :viewer, :diff_refs, :stored_externally,
                                :external_storage, :renamed_file, :deleted_file,
-                               :mode_changed, :a_mode, :b_mode, :new_file)
+                               :a_mode, :b_mode, :new_file)
   end
 
   # Converted diff files from GitHub import does not contain blob file
@@ -30,9 +30,9 @@ shared_examples 'diff file entity' do
   it_behaves_like 'diff file base entity'
 
   it 'exposes correct attributes' do
-    expect(subject).to include(:too_large, :added_lines, :removed_lines,
+    expect(subject).to include(:added_lines, :removed_lines,
                                :context_lines_path, :highlighted_diff_lines,
-                               :parallel_diff_lines, :empty)
+                               :parallel_diff_lines)
   end
 
   it 'includes viewer' do