Merge branch 'changes_tab_vue_refactoring-ee' into 'master'

Changes tab VUE refactoring (EE port)

See merge request gitlab-org/gitlab-ee!6017

app/assets/javascripts/autosave.js

@@ -31,8 +31,10 @@ export default class Autosave {
     // https://github.com/vuejs/vue/issues/2804#issuecomment-216968137
     const event = new Event('change', { bubbles: true, cancelable: false });
     const field = this.field.get(0);
+    if (field) {
       field.dispatchEvent(event);
     }
+  }
 
   save() {
     if (!this.field.length) return;

app/assets/javascripts/diff_notes/components/resolve_btn.js

-/* eslint-disable comma-dangle, object-shorthand, func-names, quote-props, no-else-return, camelcase, max-len */
 /* global CommentsStore */
 /* global ResolveService */
 
@@ -41,54 +40,54 @@ const ResolveBtn = Vue.extend({
       required: true,
     },
   },
-  data: function () {
+  data() {
     return {
       discussions: CommentsStore.state,
-      loading: false
+      loading: false,
     };
   },
   computed: {
-    discussion: function () {
+    discussion() {
       return this.discussions[this.discussionId];
     },
-    note: function () {
+    note() {
       return this.discussion ? this.discussion.getNote(this.noteId) : {};
     },
-    buttonText: function () {
+    buttonText() {
       if (this.isResolved) {
         return `Resolved by ${this.resolvedByName}`;
       } else if (this.canResolve) {
         return 'Mark as resolved';
-      } else {
-        return 'Unable to resolve';
       }
+
+      return 'Unable to resolve';
     },
-    isResolved: function () {
+    isResolved() {
       if (this.note) {
         return this.note.resolved;
-      } else {
-        return false;
       }
+
+      return false;
     },
-    resolvedByName: function () {
+    resolvedByName() {
       return this.note.resolved_by;
     },
   },
   watch: {
-    'discussions': {
+    discussions: {
       handler: 'updateTooltip',
-      deep: true
-    }
+      deep: true,
+    },
   },
-  mounted: function () {
+  mounted() {
     $(this.$refs.button).tooltip({
-      container: 'body'
+      container: 'body',
     });
   },
-  beforeDestroy: function () {
+  beforeDestroy() {
     CommentsStore.delete(this.discussionId, this.noteId);
   },
-  created: function () {
+  created() {
     CommentsStore.create({
       discussionId: this.discussionId,
       noteId: this.noteId,
@@ -101,43 +100,41 @@ const ResolveBtn = Vue.extend({
     });
   },
   methods: {
-    updateTooltip: function () {
+    updateTooltip() {
       this.$nextTick(() => {
         $(this.$refs.button)
           .tooltip('hide')
           .tooltip('_fixTitle');
       });
     },
-    resolve: function () {
+    resolve() {
       if (!this.canResolve) return;
 
       let promise;
       this.loading = true;
 
       if (this.isResolved) {
-        promise = ResolveService
-          .unresolve(this.noteId);
+        promise = ResolveService.unresolve(this.noteId);
       } else {
-        promise = ResolveService
-          .resolve(this.noteId);
+        promise = ResolveService.resolve(this.noteId);
       }
 
       promise
         .then(resp => resp.json())
-        .then((data) => {
+        .then(data => {
           this.loading = false;
 
-          const resolved_by = data ? data.resolved_by : null;
+          const resolvedBy = data ? data.resolved_by : null;
 
-          CommentsStore.update(this.discussionId, this.noteId, !this.isResolved, resolved_by);
+          CommentsStore.update(this.discussionId, this.noteId, !this.isResolved, resolvedBy);
           this.discussion.updateHeadline(data);
           gl.mrWidget.checkStatus();
-          document.dispatchEvent(new CustomEvent('refreshVueNotes'));
-
           this.updateTooltip();
         })
-        .catch(() => new Flash('An error occurred when trying to resolve a comment. Please try again.'));
-    }
+        .catch(
+          () => new Flash('An error occurred when trying to resolve a comment. Please try again.'),
+        );
+    },
   },
 });
 

app/assets/javascripts/diff_notes/diff_notes_bundle.js

-/* eslint-disable func-names, comma-dangle, new-cap, no-new */
-/* global ResolveCount */
+/* eslint-disable func-names, new-cap */
 
 import $ from 'jquery';
 import Vue from 'vue';
@@ -15,12 +14,13 @@ import './components/resolve_count';
 import './components/resolve_discussion_btn';
 import './components/diff_note_avatars';
 import './components/new_issue_for_discussion';
-import { hasVueMRDiscussionsCookie } from '../lib/utils/common_utils';
 
 export default () => {
-  const projectPathHolder = document.querySelector('.merge-request') || document.querySelector('.commit-box');
+  const projectPathHolder =
+    document.querySelector('.merge-request') || document.querySelector('.commit-box');
   const projectPath = projectPathHolder.dataset.projectPath;
-  const COMPONENT_SELECTOR = 'resolve-btn, resolve-discussion-btn, jump-to-discussion, comment-and-resolve-btn, new-issue-for-discussion-btn';
+  const COMPONENT_SELECTOR =
+    'resolve-btn, resolve-discussion-btn, jump-to-discussion, comment-and-resolve-btn, new-issue-for-discussion-btn';
 
   window.gl = window.gl || {};
   window.gl.diffNoteApps = {};
@@ -28,9 +28,9 @@ export default () => {
   window.ResolveService = new gl.DiffNotesResolveServiceClass(projectPath);
 
   gl.diffNotesCompileComponents = () => {
-    $('diff-note-avatars').each(function () {
+    $('diff-note-avatars').each(function() {
       const tmp = Vue.extend({
-        template: $(this).get(0).outerHTML
+        template: $(this).get(0).outerHTML,
       });
       const tmpApp = new tmp().$mount();
 
@@ -41,12 +41,12 @@ export default () => {
       });
     });
 
-    const $components = $(COMPONENT_SELECTOR).filter(function () {
+    const $components = $(COMPONENT_SELECTOR).filter(function() {
       return $(this).closest('resolve-count').length !== 1;
     });
 
     if ($components) {
-      $components.each(function () {
+      $components.each(function() {
         const $this = $(this);
         const noteId = $this.attr(':note-id');
         const discussionId = $this.attr(':discussion-id');
@@ -54,7 +54,7 @@ export default () => {
         if ($this.is('comment-and-resolve-btn') && !discussionId) return;
 
         const tmp = Vue.extend({
-          template: $this.get(0).outerHTML
+          template: $this.get(0).outerHTML,
         });
         const tmpApp = new tmp().$mount();
 
@@ -69,15 +69,5 @@ export default () => {
 
   gl.diffNotesCompileComponents();
 
-  const resolveCountAppEl = document.querySelector('#resolve-count-app');
-  if (!hasVueMRDiscussionsCookie() && resolveCountAppEl) {
-    new Vue({
-      el: resolveCountAppEl,
-      components: {
-        'resolve-count': ResolveCount
-      },
-    });
-  }
-
   $(window).trigger('resize.nav');
 };

app/assets/javascripts/diff_notes/services/resolve.js

@@ -8,8 +8,12 @@ window.gl = window.gl || {};
 
 class ResolveServiceClass {
   constructor(root) {
-    this.noteResource = Vue.resource(`${root}/notes{/noteId}/resolve?html=true`);
-    this.discussionResource = Vue.resource(`${root}/merge_requests{/mergeRequestId}/discussions{/discussionId}/resolve?html=true`);
+    this.noteResource = Vue.resource(
+      `${root}/notes{/noteId}/resolve?html=true`,
+    );
+    this.discussionResource = Vue.resource(
+      `${root}/merge_requests{/mergeRequestId}/discussions{/discussionId}/resolve?html=true`,
+    );
   }
 
   resolve(noteId) {
@@ -33,7 +37,7 @@ class ResolveServiceClass {
 
     promise
       .then(resp => resp.json())
-      .then((data) => {
+      .then(data => {
         discussion.loading = false;
         const resolvedBy = data ? data.resolved_by : null;
 
@@ -45,9 +49,13 @@ class ResolveServiceClass {
 
         if (gl.mrWidget) gl.mrWidget.checkStatus();
         discussion.updateHeadline(data);
-        document.dispatchEvent(new CustomEvent('refreshVueNotes'));
       })
-      .catch(() => new Flash('An error occurred when trying to resolve a discussion. Please try again.'));
+      .catch(
+        () =>
+          new Flash(
+            'An error occurred when trying to resolve a discussion. Please try again.',
+          ),
+      );
   }
 
   resolveAll(mergeRequestId, discussionId) {
@@ -55,10 +63,13 @@ class ResolveServiceClass {
 
     discussion.loading = true;
 
-    return this.discussionResource.save({
+    return this.discussionResource.save(
+      {
         mergeRequestId,
         discussionId,
-    }, {});
+      },
+      {},
+    );
   }
 
   unResolveAll(mergeRequestId, discussionId) {
@@ -66,10 +77,13 @@ class ResolveServiceClass {
 
     discussion.loading = true;
 
-    return this.discussionResource.delete({
+    return this.discussionResource.delete(
+      {
         mergeRequestId,
         discussionId,
-    }, {});
+      },
+      {},
+    );
   }
 }
 

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

+<script>
+import { mapState, mapGetters, mapActions } from 'vuex';
+import Icon from '~/vue_shared/components/icon.vue';
+import { __ } from '~/locale';
+import createFlash from '~/flash';
+import LoadingIcon from '../../vue_shared/components/loading_icon.vue';
+import CompareVersions from './compare_versions.vue';
+import ChangedFiles from './changed_files.vue';
+import DiffFile from './diff_file.vue';
+import NoChanges from './no_changes.vue';
+import HiddenFilesWarning from './hidden_files_warning.vue';
+
+export default {
+  name: 'DiffsApp',
+  components: {
+    Icon,
+    LoadingIcon,
+    CompareVersions,
+    ChangedFiles,
+    DiffFile,
+    NoChanges,
+    HiddenFilesWarning,
+  },
+  props: {
+    endpoint: {
+      type: String,
+      required: true,
+    },
+    shouldShow: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    currentUser: {
+      type: Object,
+      required: true,
+    },
+  },
+  data() {
+    return {
+      activeFile: '',
+    };
+  },
+  computed: {
+    ...mapState({
+      isLoading: state => state.diffs.isLoading,
+      diffFiles: state => state.diffs.diffFiles,
+      diffViewType: state => state.diffs.diffViewType,
+      mergeRequestDiffs: state => state.diffs.mergeRequestDiffs,
+      mergeRequestDiff: state => state.diffs.mergeRequestDiff,
+      latestVersionPath: state => state.diffs.latestVersionPath,
+      startVersion: state => state.diffs.startVersion,
+      commit: state => state.diffs.commit,
+      targetBranchName: state => state.diffs.targetBranchName,
+      renderOverflowWarning: state => state.diffs.renderOverflowWarning,
+      numTotalFiles: state => state.diffs.realSize,
+      numVisibleFiles: state => state.diffs.size,
+      plainDiffPath: state => state.diffs.plainDiffPath,
+      emailPatchPath: state => state.diffs.emailPatchPath,
+    }),
+    ...mapGetters(['isParallelView']),
+    targetBranch() {
+      return {
+        branchName: this.targetBranchName,
+        versionIndex: -1,
+        path: '',
+      };
+    },
+    notAllCommentsDisplayed() {
+      if (this.commit) {
+        return __('Only comments from the following commit are shown below');
+      } else if (this.startVersion) {
+        return __(
+          "Not all comments are displayed because you're comparing two versions of the diff.",
+        );
+      }
+      return __(
+        "Not all comments are displayed because you're viewing an old version of the diff.",
+      );
+    },
+    showLatestVersion() {
+      if (this.commit) {
+        return __('Show latest version of the diff');
+      }
+      return __('Show latest version');
+    },
+  },
+  watch: {
+    diffViewType() {
+      this.adjustView();
+    },
+    shouldShow() {
+      this.adjustView();
+    },
+  },
+  mounted() {
+    this.setEndpoint(this.endpoint);
+    this
+      .fetchDiffFiles()
+      .catch(() => {
+        createFlash(__('Something went wrong on our end. Please try again!'));
+      });
+  },
+  created() {
+    this.adjustView();
+  },
+  methods: {
+    ...mapActions(['setEndpoint', 'fetchDiffFiles']),
+    setActive(filePath) {
+      this.activeFile = filePath;
+    },
+    unsetActive(filePath) {
+      if (this.activeFile === filePath) {
+        this.activeFile = '';
+      }
+    },
+    adjustView() {
+      if (this.shouldShow && this.isParallelView) {
+        window.mrTabs.expandViewContainer();
+      } else {
+        window.mrTabs.resetViewContainer();
+      }
+    },
+  },
+};
+</script>
+
+<template>
+  <div v-if="shouldShow">
+    <div
+      v-if="isLoading"
+      class="loading"
+    >
+      <loading-icon />
+    </div>
+    <div
+      v-else
+      id="diffs"
+      :class="{ active: shouldShow }"
+      class="diffs tab-pane"
+    >
+      <compare-versions
+        v-if="!commit && mergeRequestDiffs.length > 1"
+        :merge-request-diffs="mergeRequestDiffs"
+        :merge-request-diff="mergeRequestDiff"
+        :start-version="startVersion"
+        :target-branch="targetBranch"
+      />
+
+      <hidden-files-warning
+        v-if="renderOverflowWarning"
+        :visible="numVisibleFiles"
+        :total="numTotalFiles"
+        :plain-diff-path="plainDiffPath"
+        :email-patch-path="emailPatchPath"
+      />
+
+      <div
+        v-if="commit || startVersion || (mergeRequestDiff && !mergeRequestDiff.latest)"
+        class="mr-version-controls"
+      >
+        <div class="content-block comments-disabled-notif clearfix">
+          <i class="fa fa-info-circle"></i>
+          {{ notAllCommentsDisplayed }}
+          <div class="pull-right">
+            <a
+              :href="latestVersionPath"
+              class="btn btn-sm"
+            >
+              {{ showLatestVersion }}
+            </a>
+          </div>
+        </div>
+      </div>
+
+      <changed-files
+        :diff-files="diffFiles"
+        :active-file="activeFile"
+      />
+
+      <div
+        v-if="diffFiles.length > 0"
+        class="files"
+      >
+        <diff-file
+          v-for="file in diffFiles"
+          :key="file.newPath"
+          :file="file"
+          :current-user="currentUser"
+          @setActive="setActive(file.filePath)"
+          @unsetActive="unsetActive(file.filePath)"
+        />
+      </div>
+      <no-changes v-else />
+    </div>
+  </div>
+</template>

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

+<script>
+import { mapGetters, mapActions } from 'vuex';
+import ClipboardButton from '~/vue_shared/components/clipboard_button.vue';
+import Icon from '~/vue_shared/components/icon.vue';
+import { pluralize } from '~/lib/utils/text_utility';
+import { getParameterValues, mergeUrlParams } from '~/lib/utils/url_utility';
+import { contentTop } from '~/lib/utils/common_utils';
+import { __ } from '~/locale';
+import ChangedFilesDropdown from './changed_files_dropdown.vue';
+import changedFilesMixin from '../mixins/changed_files';
+
+export default {
+  components: {
+    Icon,
+    ChangedFilesDropdown,
+    ClipboardButton,
+  },
+  mixins: [changedFilesMixin],
+  props: {
+    activeFile: {
+      type: String,
+      required: false,
+      default: '',
+    },
+  },
+  data() {
+    return {
+      isStuck: false,
+      maxWidth: 'auto',
+      offsetTop: 0,
+    };
+  },
+  computed: {
+    ...mapGetters(['isInlineView', 'isParallelView', 'areAllFilesCollapsed']),
+    sumAddedLines() {
+      return this.sumValues('addedLines');
+    },
+    sumRemovedLines() {
+      return this.sumValues('removedLines');
+    },
+    whitespaceVisible() {
+      return !getParameterValues('w')[0];
+    },
+    toggleWhitespaceText() {
+      if (this.whitespaceVisible) {
+        return __('Hide whitespace changes');
+      }
+      return __('Show whitespace changes');
+    },
+    toggleWhitespacePath() {
+      if (this.whitespaceVisible) {
+        return mergeUrlParams({ w: 1 }, window.location.href);
+      }
+
+      return mergeUrlParams({ w: 0 }, window.location.href);
+    },
+    top() {
+      return `${this.offsetTop}px`;
+    },
+  },
+  created() {
+    document.addEventListener('scroll', this.handleScroll);
+    this.offsetTop = contentTop();
+  },
+  beforeDestroy() {
+    document.removeEventListener('scroll', this.handleScroll);
+  },
+  methods: {
+    ...mapActions(['setInlineDiffViewType', 'setParallelDiffViewType', 'expandAllFiles']),
+    pluralize,
+    handleScroll() {
+      if (!this.updating) {
+        requestAnimationFrame(this.updateIsStuck);
+        this.updating = true;
+      }
+    },
+    updateIsStuck() {
+      if (!this.$refs.wrapper) {
+        return;
+      }
+
+      const scrollPosition = window.scrollY;
+
+      this.isStuck = scrollPosition + this.offsetTop >= this.$refs.placeholder.offsetTop;
+      this.updating = false;
+    },
+    sumValues(key) {
+      return this.diffFiles.reduce((total, file) => total + file[key], 0);
+    },
+  },
+};
+</script>
+
+<template>
+  <span>
+    <div ref="placeholder"></div>
+    <div
+      ref="wrapper"
+      :style="{ top }"
+      :class="{'is-stuck': isStuck}"
+      class="content-block oneline-block diff-files-changed diff-files-changed-merge-request
+      files-changed js-diff-files-changed"
+    >
+      <div class="files-changed-inner">
+        <div
+          class="inline-parallel-buttons d-none d-md-block"
+        >
+          <a
+            v-if="areAllFilesCollapsed"
+            class="btn btn-default"
+            @click="expandAllFiles"
+          >
+            {{ __('Expand all') }}
+          </a>
+          <a
+            :href="toggleWhitespacePath"
+            class="btn btn-default"
+          >
+            {{ toggleWhitespaceText }}
+          </a>
+          <div class="btn-group">
+            <button
+              id="inline-diff-btn"
+              :class="{ active: isInlineView }"
+              type="button"
+              class="btn js-inline-diff-button"
+              data-view-type="inline"
+              @click="setInlineDiffViewType"
+            >
+              {{ __('Inline') }}
+            </button>
+            <button
+              id="parallel-diff-btn"
+              :class="{ active: isParallelView }"
+              type="button"
+              class="btn js-parallel-diff-button"
+              data-view-type="parallel"
+              @click="setParallelDiffViewType"
+            >
+              {{ __('Side-by-side') }}
+            </button>
+          </div>
+        </div>
+
+        <div class="commit-stat-summary dropdown">
+          <changed-files-dropdown
+            :diff-files="diffFiles"
+          />
+
+          <span
+            v-show="activeFile"
+            class="prepend-left-5"
+          >
+            <strong class="prepend-right-5">
+              {{ truncatedDiffPath(activeFile) }}
+            </strong>
+            <clipboard-button
+              :text="activeFile"
+              :title="s__('Copy file name to clipboard')"
+              tooltip-placement="bottom"
+              tooltip-container="body"
+              class="btn btn-default btn-transparent btn-clipboard"
+            />
+          </span>
+
+          <span
+            v-show="!isStuck"
+            id="diff-stats"
+            class="diff-stats-additions-deletions-expanded"
+          >
+            with
+            <strong class="cgreen">
+              {{ pluralize(`${sumAddedLines} addition`, sumAddedLines) }}
+            </strong>
+            and
+            <strong class="cred">
+              {{ pluralize(`${sumRemovedLines} deletion`, sumRemovedLines) }}
+            </strong>
+          </span>
+        </div>
+      </div>
+    </div>
+  </span>
+</template>

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

+<script>
+import Icon from '~/vue_shared/components/icon.vue';
+import changedFilesMixin from '../mixins/changed_files';
+
+export default {
+  components: {
+    Icon,
+  },
+  mixins: [changedFilesMixin],
+  data() {
+    return {
+      searchText: '',
+    };
+  },
+  computed: {
+    filteredDiffFiles() {
+      return this.diffFiles.filter(file =>
+        file.filePath.toLowerCase().includes(this.searchText.toLowerCase()),
+      );
+    },
+  },
+  methods: {
+    clearSearch() {
+      this.searchText = '';
+    },
+  },
+};
+</script>
+
+<template>
+  <span>
+    Showing
+    <button
+      class="diff-stats-summary-toggler"
+      data-toggle="dropdown"
+      type="button"
+      aria-expanded="false"
+    >
+      <span>
+        {{ n__('%d changed file', '%d changed files', diffFiles.length) }}
+      </span>
+      <icon
+        :size="8"
+        name="chevron-down"
+      />
+    </button>
+    <div class="dropdown-menu diff-file-changes">
+      <div class="dropdown-input">
+        <input
+          v-model="searchText"
+          type="search"
+          class="dropdown-input-field"
+          placeholder="Search files"
+          autocomplete="off"
+        />
+        <i
+          v-if="searchText.length === 0"
+          aria-hidden="true"
+          data-hidden="true"
+          class="fa fa-search dropdown-input-search">
+        </i>
+        <i
+          v-else
+          role="button"
+          class="fa fa-times dropdown-input-search"
+          @click="clearSearch"
+        ></i>
+      </div>
+      <ul>
+        <li
+          v-for="diffFile in filteredDiffFiles"
+          :key="diffFile.name"
+        >
+          <a
+            :href="`#${diffFile.fileHash}`"
+            :title="diffFile.newPath"
+            class="diff-changed-file"
+          >
+            <icon
+              :name="fileChangedIcon(diffFile)"
+              :size="16"
+              :class="fileChangedClass(diffFile)"
+              class="diff-file-changed-icon append-right-8"
+            />
+            <span class="diff-changed-file-content append-right-8">
+              <strong
+                v-if="diffFile.blob && diffFile.blob.name"
+                class="diff-changed-file-name"
+              >
+                {{ diffFile.blob.name }}
+              </strong>
+              <strong
+                v-else
+                class="diff-changed-blank-file-name"
+              >
+                {{ s__('Diffs|No file name available') }}
+              </strong>
+              <span class="diff-changed-file-path prepend-top-5">
+                {{ truncatedDiffPath(diffFile.blob.path) }}
+              </span>
+            </span>
+            <span class="diff-changed-stats">
+              <span class="cgreen">
+                +{{ diffFile.addedLines }}
+              </span>
+              <span class="cred">
+                -{{ diffFile.removedLines }}
+              </span>
+            </span>
+          </a>
+        </li>
+
+        <li
+          v-show="filteredDiffFiles.length === 0"
+          class="dropdown-menu-empty-item"
+        >
+          <a>
+            {{ __('No files found') }}
+          </a>
+        </li>
+      </ul>
+    </div>
+  </span>
+</template>

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

+<script>
+import CompareVersionsDropdown from './compare_versions_dropdown.vue';
+
+export default {
+  components: {
+    CompareVersionsDropdown,
+  },
+  props: {
+    mergeRequestDiffs: {
+      type: Array,
+      required: true,
+    },
+    mergeRequestDiff: {
+      type: Object,
+      required: true,
+    },
+    startVersion: {
+      type: Object,
+      required: false,
+      default: null,
+    },
+    targetBranch: {
+      type: Object,
+      required: false,
+      default: null,
+    },
+  },
+  computed: {
+    comparableDiffs() {
+      return this.mergeRequestDiffs.slice(1);
+    },
+  },
+};
+</script>
+
+<template>
+  <div class="mr-version-controls">
+    <div class="mr-version-menus-container content-block">
+      Changes between
+      <compare-versions-dropdown
+        :other-versions="mergeRequestDiffs"
+        :merge-request-version="mergeRequestDiff"
+        :show-commit-count="true"
+        class="mr-version-dropdown"
+      />
+      and
+      <compare-versions-dropdown
+        :other-versions="comparableDiffs"
+        :start-version="startVersion"
+        :target-branch="targetBranch"
+        class="mr-version-compare-dropdown"
+      />
+    </div>
+  </div>
+</template>

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

+<script>
+import Icon from '~/vue_shared/components/icon.vue';
+import { n__, __ } from '~/locale';
+import TimeAgo from '~/vue_shared/components/time_ago_tooltip.vue';
+
+export default {
+  components: {
+    Icon,
+    TimeAgo,
+  },
+  props: {
+    otherVersions: {
+      type: Array,
+      required: false,
+      default: () => [],
+    },
+    mergeRequestVersion: {
+      type: Object,
+      required: false,
+      default: null,
+    },
+    startVersion: {
+      type: Object,
+      required: false,
+      default: null,
+    },
+    targetBranch: {
+      type: Object,
+      required: false,
+      default: null,
+    },
+    showCommitCount: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+  },
+  computed: {
+    baseVersion() {
+      return {
+        name: 'hii',
+        versionIndex: -1,
+      };
+    },
+    targetVersions() {
+      if (this.mergeRequestVersion) {
+        return this.otherVersions;
+      }
+      return [...this.otherVersions, this.targetBranch];
+    },
+    selectedVersionName() {
+      const selectedVersion = this.startVersion || this.targetBranch || this.mergeRequestVersion;
+      return this.versionName(selectedVersion);
+    },
+  },
+  methods: {
+    commitsText(version) {
+      return n__(
+        `${version.commitsCount} commit,`,
+        `${version.commitsCount} commits,`,
+        version.commitsCount,
+      );
+    },
+    href(version) {
+      if (this.showCommitCount) {
+        return version.versionPath;
+      }
+      return version.comparePath;
+    },
+    versionName(version) {
+      if (this.isLatest(version)) {
+        return __('latest version');
+      }
+      if (this.targetBranch && (this.isBase(version) || !version)) {
+        return this.targetBranch.branchName;
+      }
+      return `version ${version.versionIndex}`;
+    },
+    isActive(version) {
+      if (!version) {
+        return false;
+      }
+
+      if (this.targetBranch) {
+        return (
+          (this.isBase(version) && !this.startVersion) ||
+          (this.startVersion && this.startVersion.versionIndex === version.versionIndex)
+        );
+      }
+
+      return version.versionIndex === this.mergeRequestVersion.versionIndex;
+    },
+    isBase(version) {
+      if (!version || !this.targetBranch) {
+        return false;
+      }
+      return version.versionIndex === -1;
+    },
+    isLatest(version) {
+      return (
+        this.mergeRequestVersion && version.versionIndex === this.targetVersions[0].versionIndex
+      );
+    },
+  },
+};
+</script>
+
+<template>
+  <span class="dropdown inline">
+    <a
+      class="dropdown-toggle btn btn-default"
+      data-toggle="dropdown"
+      aria-expanded="false"
+    >
+      <span>
+        {{ selectedVersionName }}
+      </span>
+      <Icon
+        :size="12"
+        name="angle-down"
+      />
+    </a>
+    <div class="dropdown-menu dropdown-select dropdown-menu-selectable">
+      <div class="dropdown-content">
+        <ul>
+          <li
+            v-for="version in targetVersions"
+            :key="version.id"
+          >
+            <a
+              :class="{ 'is-active': isActive(version) }"
+              :href="href(version)"
+            >
+              <div>
+                <strong>
+                  {{ versionName(version) }}
+                  <template v-if="isBase(version)">
+                    (base)
+                  </template>
+                </strong>
+              </div>
+              <div>
+                <small class="commit-sha">
+                  {{ version.truncatedCommitSha }}
+                </small>
+              </div>
+              <div>
+                <small>
+                  <template v-if="showCommitCount">
+                    {{ commitsText(version) }}
+                  </template>
+                  <time-ago
+                    v-if="version.createdAt"
+                    :time="version.createdAt"
+                    class="js-timeago js-timeago-render"
+                  />
+                </small>
+              </div>
+            </a>
+          </li>
+        </ul>
+      </div>
+    </div>
+  </span>
+</template>

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

+<script>
+import { mapGetters } from 'vuex';
+import InlineDiffView from './inline_diff_view.vue';
+import ParallelDiffView from './parallel_diff_view.vue';
+
+export default {
+  components: {
+    InlineDiffView,
+    ParallelDiffView,
+  },
+  props: {
+    diffFile: {
+      type: Object,
+      required: true,
+    },
+  },
+  computed: {
+    ...mapGetters(['isInlineView', 'isParallelView']),
+  },
+};
+</script>
+
+<template>
+  <div class="diff-content">
+    <div class="diff-viewer">
+      <inline-diff-view
+        v-if="isInlineView"
+        :diff-file="diffFile"
+        :diff-lines="diffFile.highlightedDiffLines || []"
+      />
+      <parallel-diff-view
+        v-if="isParallelView"
+        :diff-file="diffFile"
+        :diff-lines="diffFile.parallelDiffLines || []"
+      />
+    </div>
+  </div>
+</template>

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

+<script>
+import noteableDiscussion from '../../notes/components/noteable_discussion.vue';
+
+export default {
+  components: {
+    noteableDiscussion,
+  },
+  props: {
+    discussions: {
+      type: Array,
+      required: true,
+    },
+  },
+};
+</script>
+
+<template>
+  <div
+    v-if="discussions.length"
+  >
+    <div
+      v-for="discussion in discussions"
+      :key="discussion.id"
+      class="discussion-notes diff-discussions"
+    >
+      <ul
+        :data-discussion-id="discussion.id"
+        class="notes"
+      >
+        <noteable-discussion
+          :discussion="discussion"
+          :render-header="false"
+          :render-diff-file="false"
+          :always-expanded="true"
+        />
+      </ul>
+    </div>
+  </div>
+</template>

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

+<script>
+import { mapActions } from 'vuex';
+import _ from 'underscore';
+import { __, sprintf } from '~/locale';
+import createFlash from '~/flash';
+import LoadingIcon from '~/vue_shared/components/loading_icon.vue';
+import DiffFileHeader from './diff_file_header.vue';
+import DiffContent from './diff_content.vue';
+
+export default {
+  components: {
+    DiffFileHeader,
+    DiffContent,
+    LoadingIcon,
+  },
+  props: {
+    file: {
+      type: Object,
+      required: true,
+    },
+    currentUser: {
+      type: Object,
+      required: true,
+    },
+  },
+  data() {
+    return {
+      isActive: false,
+      isLoadingCollapsedDiff: false,
+      forkMessageVisible: false,
+    };
+  },
+  computed: {
+    isDiscussionsExpanded() {
+      return true; // TODO: @fatihacet - Fix this.
+    },
+    isCollapsed() {
+      return this.file.collapsed || false;
+    },
+    viewBlobLink() {
+      return sprintf(
+        __('You can %{linkStart}view the blob%{linkEnd} instead.'),
+        {
+          linkStart: `<a href="${_.escape(this.file.viewPath)}">`,
+          linkEnd: '</a>',
+        },
+        false,
+      );
+    },
+  },
+  mounted() {
+    document.addEventListener('scroll', this.handleScroll);
+  },
+  beforeDestroy() {
+    document.removeEventListener('scroll', this.handleScroll);
+  },
+  methods: {
+    ...mapActions(['loadCollapsedDiff']),
+    handleToggle() {
+      const { collapsed, highlightedDiffLines, parallelDiffLines } = this.file;
+
+      if (collapsed && !highlightedDiffLines && !parallelDiffLines.length) {
+        this.handleLoadCollapsedDiff();
+      } else {
+        this.file.collapsed = !this.file.collapsed;
+      }
+    },
+    handleScroll() {
+      if (!this.updating) {
+        requestAnimationFrame(this.scrollUpdate.bind(this));
+        this.updating = true;
+      }
+    },
+    scrollUpdate() {
+      const header = document.querySelector('.js-diff-files-changed');
+      if (!header) {
+        this.updating = false;
+        return;
+      }
+
+      const { top, bottom } = this.$el.getBoundingClientRect();
+      const { top: topOfFixedHeader, bottom: bottomOfFixedHeader } = header.getBoundingClientRect();
+
+      const headerOverlapsContent = top < topOfFixedHeader && bottom > bottomOfFixedHeader;
+      const fullyAboveHeader = bottom < bottomOfFixedHeader;
+      const fullyBelowHeader = top > topOfFixedHeader;
+
+      if (headerOverlapsContent && !this.isActive) {
+        this.$emit('setActive');
+        this.isActive = true;
+      } else if (this.isActive && (fullyAboveHeader || fullyBelowHeader)) {
+        this.$emit('unsetActive');
+        this.isActive = false;
+      }
+
+      this.updating = false;
+    },
+    handleLoadCollapsedDiff() {
+      this.isLoadingCollapsedDiff = true;
+
+      this.loadCollapsedDiff(this.file)
+        .then(() => {
+          this.isLoadingCollapsedDiff = false;
+          this.file.collapsed = false;
+        })
+        .catch(() => {
+          this.isLoadingCollapsedDiff = false;
+          createFlash(__('Something went wrong on our end. Please try again!'));
+        });
+    },
+    showForkMessage() {
+      this.forkMessageVisible = true;
+    },
+    hideForkMessage() {
+      this.forkMessageVisible = false;
+    },
+  },
+};
+</script>
+
+<template>
+  <div
+    :id="file.fileHash"
+    class="diff-file file-holder"
+  >
+    <diff-file-header
+      :current-user="currentUser"
+      :diff-file="file"
+      :collapsible="true"
+      :expanded="!isCollapsed"
+      :discussions-expanded="isDiscussionsExpanded"
+      :add-merge-request-buttons="true"
+      class="js-file-title file-title"
+      @toggleFile="handleToggle"
+      @showForkMessage="showForkMessage"
+    />
+
+    <div
+      v-if="forkMessageVisible"
+      class="js-file-fork-suggestion-section file-fork-suggestion">
+      <span class="file-fork-suggestion-note">
+        You're not allowed to <span class="js-file-fork-suggestion-section-action">edit</span>
+        files in this project directly. Please fork this project,
+        make your changes there, and submit a merge request.
+      </span>
+      <a
+        :href="file.forkPath"
+        class="js-fork-suggestion-button btn btn-grouped btn-inverted btn-success"
+      >
+        Fork
+      </a>
+      <button
+        class="js-cancel-fork-suggestion-button btn btn-grouped"
+        type="button"
+        @click="hideForkMessage"
+      >
+        Cancel
+      </button>
+    </div>
+
+    <diff-content
+      v-show="!isCollapsed"
+      :class="{ hidden: isCollapsed || file.tooLarge }"
+      :diff-file="file"
+    />
+    <loading-icon
+      v-if="isLoadingCollapsedDiff"
+      class="diff-content loading"
+    />
+    <div
+      v-show="isCollapsed && !isLoadingCollapsedDiff && !file.tooLarge"
+      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.tooLarge"
+      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>
+  </div>
+</template>

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

+<script>
+import _ from 'underscore';
+import ClipboardButton from '~/vue_shared/components/clipboard_button.vue';
+import Icon from '~/vue_shared/components/icon.vue';
+import Tooltip from '~/vue_shared/directives/tooltip';
+import { truncateSha } from '~/lib/utils/text_utility';
+import { __, s__, sprintf } from '~/locale';
+import EditButton from './edit_button.vue';
+
+export default {
+  components: {
+    ClipboardButton,
+    EditButton,
+    Icon,
+  },
+  directives: {
+    Tooltip,
+  },
+  props: {
+    diffFile: {
+      type: Object,
+      required: true,
+    },
+    collapsible: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    addMergeRequestButtons: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    expanded: {
+      type: Boolean,
+      required: false,
+      default: true,
+    },
+    discussionsExpanded: {
+      type: Boolean,
+      required: false,
+      default: true,
+    },
+    currentUser: {
+      type: Object,
+      required: true,
+    },
+  },
+  data() {
+    return {
+      blobForkSuggestion: null,
+    };
+  },
+  computed: {
+    icon() {
+      if (this.diffFile.submodule) {
+        return 'archive';
+      }
+
+      return this.diffFile.blob.icon;
+    },
+    titleLink() {
+      if (this.diffFile.submodule) {
+        return this.diffFile.submoduleTreeUrl || this.diffFile.submoduleLink;
+      }
+
+      return `#${this.diffFile.fileHash}`;
+    },
+    filePath() {
+      if (this.diffFile.submodule) {
+        return `${this.diffFile.filePath} @ ${truncateSha(this.diffFile.blob.id)}`;
+      }
+
+      if (this.diffFile.deletedFile) {
+        return sprintf(__('%{filePath} deleted'), { filePath: this.diffFile.filePath }, false);
+      }
+
+      return this.diffFile.filePath;
+    },
+    titleTag() {
+      return this.diffFile.fileHash ? 'a' : 'span';
+    },
+    isUsingLfs() {
+      return this.diffFile.storedExternally && this.diffFile.externalStorage === 'lfs';
+    },
+    collapseIcon() {
+      return this.expanded ? 'chevron-down' : 'chevron-right';
+    },
+    isDiscussionsExpanded() {
+      return this.discussionsExpanded && this.expanded;
+    },
+    viewFileButtonText() {
+      const truncatedContentSha = _.escape(truncateSha(this.diffFile.contentSha));
+      return sprintf(
+        s__('MergeRequests|View file @ %{commitId}'),
+        {
+          commitId: `<span class="commit-sha">${truncatedContentSha}</span>`,
+        },
+        false,
+      );
+    },
+    viewReplacedFileButtonText() {
+      const truncatedBaseSha = _.escape(truncateSha(this.diffFile.diffRefs.baseSha));
+      return sprintf(
+        s__('MergeRequests|View replaced file @ %{commitId}'),
+        {
+          commitId: `<span class="commit-sha">${truncatedBaseSha}</span>`,
+        },
+        false,
+      );
+    },
+  },
+  methods: {
+    handleToggle(e, checkTarget) {
+      if (!checkTarget || e.target === this.$refs.header) {
+        this.$emit('toggleFile');
+      }
+    },
+    showForkMessage() {
+      this.$emit('showForkMessage');
+    },
+  },
+};
+</script>
+
+<template>
+  <div
+    ref="header"
+    class="js-file-title file-title file-title-flex-parent"
+    @click="handleToggle($event, true)"
+  >
+    <div class="file-header-content">
+      <icon
+        v-if="collapsible"
+        :name="collapseIcon"
+        :size="16"
+        aria-hidden="true"
+        class="diff-toggle-caret"
+        @click.stop="handleToggle"
+      />
+      <a
+        ref="titleWrapper"
+        :href="titleLink"
+      >
+        <i
+          :class="`fa-${icon}`"
+          class="fa fa-fw"
+          aria-hidden="true"
+        ></i>
+        <span v-if="diffFile.renamedFile">
+          <strong
+            v-tooltip
+            :title="diffFile.oldPath"
+            class="file-title-name"
+            data-container="body"
+          >
+            {{ diffFile.oldPath }}
+          </strong>
+          →
+          <strong
+            v-tooltip
+            :title="diffFile.newPath"
+            class="file-title-name"
+            data-container="body"
+          >
+            {{ diffFile.newPath }}
+          </strong>
+        </span>
+
+        <strong
+          v-tooltip
+          v-else
+          :title="filePath"
+          class="file-title-name"
+          data-container="body"
+        >
+          {{ filePath }}
+        </strong>
+      </a>
+
+      <clipboard-button
+        :title="__('Copy file path to clipboard')"
+        :text="diffFile.filePath"
+        css-class="btn-default btn-transparent btn-clipboard"
+      />
+
+      <small
+        v-if="diffFile.modeChanged"
+        ref="fileMode"
+      >
+        {{ diffFile.aMode }} → {{ diffFile.bMode }}
+      </small>
+
+      <span
+        v-if="isUsingLfs"
+        class="label label-lfs append-right-5"
+      >
+        {{ __('LFS') }}
+      </span>
+    </div>
+
+    <div
+      v-if="!diffFile.submodule && addMergeRequestButtons"
+      class="file-actions d-none d-md-block"
+    >
+      <template
+        v-if="diffFile.blob && diffFile.blob.readableText"
+      >
+        <button
+          :class="{ active: isDiscussionsExpanded }"
+          :title="s__('MergeRequests|Toggle comments for this file')"
+          class="btn js-toggle-diff-comments"
+          type="button"
+        >
+          <icon name="comment" />
+        </button>
+
+        <edit-button
+          v-if="!diffFile.deletedFile"
+          :current-user="currentUser"
+          :edit-path="diffFile.editPath"
+          :can-modify-blob="diffFile.canModifyBlob"
+          @showForkMessage="showForkMessage"
+        />
+      </template>
+
+      <a
+        v-if="diffFile.replacedViewPath"
+        :href="diffFile.replacedViewPath"
+        class="btn view-file js-view-file"
+        v-html="viewReplacedFileButtonText"
+      >
+      </a>
+      <a
+        :href="diffFile.viewPath"
+        class="btn view-file js-view-file"
+        v-html="viewFileButtonText"
+      >
+      </a>
+
+      <a
+        v-tooltip
+        v-if="diffFile.externalUrl"
+        :href="diffFile.externalUrl"
+        :title="`View on ${diffFile.formattedExternalUrl}`"
+        target="_blank"
+        rel="noopener noreferrer"
+        class="btn btn-file-option"
+      >
+        <icon name="external-link" />
+      </a>
+    </div>
+  </div>
+</template>

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

+<script>
+import { mapActions } from 'vuex';
+import Icon from '~/vue_shared/components/icon.vue';
+import tooltip from '~/vue_shared/directives/tooltip';
+import { pluralize, truncate } from '~/lib/utils/text_utility';
+import UserAvatarImage from '~/vue_shared/components/user_avatar/user_avatar_image.vue';
+import { COUNT_OF_AVATARS_IN_GUTTER, LENGTH_OF_AVATAR_TOOLTIP } from '../constants';
+
+export default {
+  directives: {
+    tooltip,
+  },
+  components: {
+    Icon,
+    UserAvatarImage,
+  },
+  props: {
+    discussions: {
+      type: Array,
+      required: true,
+    },
+  },
+  computed: {
+    discussionsExpanded() {
+      return this.discussions.every(discussion => discussion.expanded);
+    },
+    allDiscussions() {
+      return this.discussions.reduce((acc, note) => acc.concat(note.notes), []);
+    },
+    notesInGutter() {
+      return this.allDiscussions.slice(0, COUNT_OF_AVATARS_IN_GUTTER).map(n => ({
+        note: n.note,
+        author: n.author,
+      }));
+    },
+    moreCount() {
+      return this.allDiscussions.length - this.notesInGutter.length;
+    },
+    moreText() {
+      if (this.moreCount === 0) {
+        return '';
+      }
+
+      return pluralize(`${this.moreCount} more comment`, this.moreCount);
+    },
+  },
+  methods: {
+    ...mapActions(['toggleDiscussion']),
+    getTooltipText(noteData) {
+      let note = noteData.note;
+
+      if (note.length > LENGTH_OF_AVATAR_TOOLTIP) {
+        note = truncate(note, LENGTH_OF_AVATAR_TOOLTIP);
+      }
+
+      return `${noteData.author.name}: ${note}`;
+    },
+    toggleDiscussions() {
+      this.discussions.forEach(discussion => {
+        this.toggleDiscussion({
+          discussionId: discussion.id,
+        });
+      });
+    },
+  },
+};
+</script>
+
+<template>
+  <div class="diff-comment-avatar-holders">
+    <button
+      v-if="discussionsExpanded"
+      type="button"
+      aria-label="Show comments"
+      class="diff-notes-collapse js-diff-comment-avatar js-diff-comment-button"
+      @click="toggleDiscussions"
+    >
+      <icon
+        :size="12"
+        name="collapse"
+      />
+    </button>
+    <template v-else>
+      <user-avatar-image
+        v-for="note in notesInGutter"
+        :key="note.id"
+        :img-src="note.author.avatar_url"
+        :tooltip-text="getTooltipText(note)"
+        :size="19"
+        class="diff-comment-avatar js-diff-comment-avatar"
+        @click.native="toggleDiscussions"
+      />
+      <span
+        v-tooltip
+        v-if="moreText"
+        :title="moreText"
+        class="diff-comments-more-count has-tooltip js-diff-comment-avatar js-diff-comment-plus"
+        data-container="body"
+        data-placement="top"
+        role="button"
+        @click="toggleDiscussions"
+      >+{{ moreCount }}</span>
+    </template>
+  </div>
+</template>

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

+<script>
+import createFlash from '~/flash';
+import { s__ } from '~/locale';
+import { mapState, mapGetters, mapActions } from 'vuex';
+import Icon from '~/vue_shared/components/icon.vue';
+import DiffGutterAvatars from './diff_gutter_avatars.vue';
+import {
+  MATCH_LINE_TYPE,
+  CONTEXT_LINE_TYPE,
+  OLD_NO_NEW_LINE_TYPE,
+  NEW_NO_NEW_LINE_TYPE,
+  LINE_POSITION_RIGHT,
+  UNFOLD_COUNT,
+} from '../constants';
+import * as utils from '../store/utils';
+
+export default {
+  components: {
+    DiffGutterAvatars,
+    Icon,
+  },
+  props: {
+    fileHash: {
+      type: String,
+      required: true,
+    },
+    contextLinesPath: {
+      type: String,
+      required: true,
+    },
+    lineType: {
+      type: String,
+      required: false,
+      default: '',
+    },
+    lineNumber: {
+      type: Number,
+      required: false,
+      default: 0,
+    },
+    lineCode: {
+      type: String,
+      required: false,
+      default: '',
+    },
+    linePosition: {
+      type: String,
+      required: false,
+      default: '',
+    },
+    metaData: {
+      type: Object,
+      required: false,
+      default: () => ({}),
+    },
+    showCommentButton: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    isBottom: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+  },
+  computed: {
+    ...mapState({
+      diffViewType: state => state.diffs.diffViewType,
+      diffFiles: state => state.diffs.diffFiles,
+    }),
+    ...mapGetters(['isLoggedIn', 'discussionsByLineCode']),
+    isMatchLine() {
+      return this.lineType === MATCH_LINE_TYPE;
+    },
+    isContextLine() {
+      return this.lineType === CONTEXT_LINE_TYPE;
+    },
+    isMetaLine() {
+      return this.lineType === OLD_NO_NEW_LINE_TYPE || this.lineType === NEW_NO_NEW_LINE_TYPE;
+    },
+    lineHref() {
+      return this.lineCode ? `#${this.lineCode}` : '#';
+    },
+    shouldShowCommentButton() {
+      return (
+        this.isLoggedIn &&
+        this.showCommentButton &&
+        !this.isMatchLine &&
+        !this.isContextLine &&
+        !this.hasDiscussions &&
+        !this.isMetaLine
+      );
+    },
+    discussions() {
+      return this.discussionsByLineCode[this.lineCode] || [];
+    },
+    hasDiscussions() {
+      return this.discussions.length > 0;
+    },
+    shouldShowAvatarsOnGutter() {
+      let render = this.hasDiscussions && this.showCommentButton;
+
+      if (!this.lineType && this.linePosition === LINE_POSITION_RIGHT) {
+        render = false;
+      }
+
+      return render;
+    },
+  },
+  methods: {
+    ...mapActions(['loadMoreLines']),
+    handleCommentButton() {
+      this.$emit('showCommentForm', { lineCode: this.lineCode });
+    },
+    handleLoadMoreLines() {
+      if (this.isRequesting) {
+        return;
+      }
+
+      this.isRequesting = true;
+      const endpoint = this.contextLinesPath;
+      const oldLineNumber = this.metaData.oldPos || 0;
+      const newLineNumber = this.metaData.newPos || 0;
+      const offset = newLineNumber - oldLineNumber;
+      const bottom = this.isBottom;
+      const fileHash = this.fileHash;
+      const view = this.diffViewType;
+      let unfold = true;
+      let lineNumber = newLineNumber - 1;
+      let since = lineNumber - UNFOLD_COUNT;
+      let to = lineNumber;
+
+      if (bottom) {
+        lineNumber = newLineNumber + 1;
+        since = lineNumber;
+        to = lineNumber + UNFOLD_COUNT;
+      } else {
+        const diffFile = utils.findDiffFile(this.diffFiles, this.fileHash);
+        const indexForInline = utils.findIndexInInlineLines(diffFile.highlightedDiffLines, {
+          oldLineNumber,
+          newLineNumber,
+        });
+        const prevLine = diffFile.highlightedDiffLines[indexForInline - 2];
+        const prevLineNumber = (prevLine && prevLine.newLine) || 0;
+
+        if (since <= prevLineNumber + 1) {
+          since = prevLineNumber + 1;
+          unfold = false;
+        }
+      }
+
+      const params = { since, to, bottom, offset, unfold, view };
+      const lineNumbers = { oldLineNumber, newLineNumber };
+      this.loadMoreLines({ endpoint, params, lineNumbers, fileHash })
+        .then(() => {
+          this.isRequesting = false;
+        })
+        .catch(() => {
+          createFlash(s__('Diffs|Something went wrong while fetching diff lines.'));
+          this.isRequesting = false;
+        });
+    },
+  },
+};
+</script>
+
+<template>
+  <div>
+    <span
+      v-if="isMatchLine"
+      class="context-cell"
+      role="button"
+      @click="handleLoadMoreLines"
+    >...</span>
+    <template
+      v-else
+    >
+      <button
+        v-show="shouldShowCommentButton"
+        type="button"
+        class="add-diff-note js-add-diff-note-button"
+        title="Add a comment to this line"
+        @click="handleCommentButton"
+      >
+        <icon
+          :size="12"
+          name="comment"
+        />
+      </button>
+      <a
+        v-if="lineNumber"
+        :data-linenumber="lineNumber"
+        :href="lineHref"
+      >
+      </a>
+      <diff-gutter-avatars
+        v-if="shouldShowAvatarsOnGutter"
+        :discussions="discussions"
+      />
+    </template>
+  </div>
+</template>

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

+<script>
+import { mapState, mapGetters, mapActions } from 'vuex';
+import createFlash from '~/flash';
+import { s__ } from '~/locale';
+import noteForm from '../../notes/components/note_form.vue';
+import { getNoteFormData } from '../store/utils';
+
+export default {
+  components: {
+    noteForm,
+  },
+  props: {
+    diffFile: {
+      type: Object,
+      required: true,
+    },
+    diffLines: {
+      type: Array,
+      required: true,
+    },
+    line: {
+      type: Object,
+      required: true,
+    },
+    position: {
+      type: String,
+      required: false,
+      default: '',
+    },
+    noteTargetLine: {
+      type: Object,
+      required: true,
+    },
+  },
+  computed: {
+    ...mapState({
+      noteableData: state => state.notes.noteableData,
+      diffViewType: state => state.diffs.diffViewType,
+    }),
+    ...mapGetters(['noteableType', 'getNotesDataByProp']),
+  },
+  methods: {
+    ...mapActions(['cancelCommentForm', 'saveNote', 'fetchDiscussions']),
+    handleCancelCommentForm() {
+      this.cancelCommentForm({
+        lineCode: this.line.lineCode,
+      });
+    },
+    handleSaveNote(note) {
+      const postData = getNoteFormData({
+        note,
+        noteableData: this.noteableData,
+        noteableType: this.noteableType,
+        noteTargetLine: this.noteTargetLine,
+        diffViewType: this.diffViewType,
+        diffFile: this.diffFile,
+        linePosition: this.position,
+      });
+
+      this.saveNote(postData)
+        .then(() => {
+          const endpoint = this.getNotesDataByProp('discussionsPath');
+
+          this.fetchDiscussions(endpoint)
+            .then(() => {
+              this.handleCancelCommentForm();
+            })
+            .catch(() => {
+              createFlash(s__('MergeRequests|Updating discussions failed'));
+            });
+        })
+        .catch(() => {
+          createFlash(s__('MergeRequests|Saving the comment failed'));
+        });
+    },
+  },
+};
+</script>
+
+<template>
+  <div
+    class="content discussion-form discussion-form-container discussion-notes"
+  >
+    <note-form
+      :is-editing="true"
+      :line-code="line.lineCode"
+      save-button-title="Comment"
+      class="diff-comment-form"
+      @cancelForm="handleCancelCommentForm"
+      @handleFormUpdate="handleSaveNote"
+    />
+  </div>
+</template>

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

+<script>
+export default {
+  props: {
+    editPath: {
+      type: String,
+      required: true,
+    },
+    currentUser: {
+      type: Object,
+      required: true,
+    },
+    canModifyBlob: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+  },
+  methods: {
+    handleEditClick(evt) {
+      if (!this.currentUser || this.canModifyBlob) {
+        // if we can Edit, do default Edit button behavior
+        return;
+      }
+
+      if (this.currentUser.canFork && this.currentUser.canCreateMergeRequest) {
+        evt.preventDefault();
+        this.$emit('showForkMessage');
+      }
+    },
+  },
+};
+</script>
+
+<template>
+  <a
+    :href="editPath"
+    class="btn btn-default js-edit-blob"
+    @click="handleEditClick"
+  >
+    Edit
+  </a>
+</template>

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

+<script>
+export default {
+  props: {
+    total: {
+      type: String,
+      required: true,
+    },
+    visible: {
+      type: Number,
+      required: true,
+    },
+    plainDiffPath: {
+      type: String,
+      required: true,
+    },
+    emailPatchPath: {
+      type: String,
+      required: true,
+    },
+  },
+};
+</script>
+
+<template>
+  <div class="alert alert-warning">
+    <h4>
+      {{ __('Too many changes to show.') }}
+      <div class="pull-right">
+        <a
+          :href="plainDiffPath"
+          class="btn btn-sm"
+        >
+          {{ __('Plain diff') }}
+        </a>
+        <a
+          :href="emailPatchPath"
+          class="btn btn-sm"
+        >
+          {{ __('Email patch') }}
+        </a>
+      </div>
+    </h4>
+    <p>
+      To preserve performance only
+      <strong>
+        {{ visible }} of {{ total }}
+      </strong>
+      files are displayed.
+    </p>
+  </div>
+</template>

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

+<script>
+import diffContentMixin from '../mixins/diff_content';
+import {
+  MATCH_LINE_TYPE,
+  CONTEXT_LINE_TYPE,
+  OLD_NO_NEW_LINE_TYPE,
+  NEW_NO_NEW_LINE_TYPE,
+  LINE_HOVER_CLASS_NAME,
+  LINE_UNFOLD_CLASS_NAME,
+} from '../constants';
+
+export default {
+  mixins: [diffContentMixin],
+  methods: {
+    handleMouse(lineCode, isOver) {
+      this.hoveredLineCode = isOver ? lineCode : null;
+    },
+    getLineClass(line) {
+      const isSameLine = this.hoveredLineCode && this.hoveredLineCode === line.lineCode;
+      const isMatchLine = line.type === MATCH_LINE_TYPE;
+      const isContextLine = line.type === CONTEXT_LINE_TYPE;
+      const isMetaLine = line.type === OLD_NO_NEW_LINE_TYPE || line.type === NEW_NO_NEW_LINE_TYPE;
+
+      return {
+        [line.type]: line.type,
+        [LINE_UNFOLD_CLASS_NAME]: isMatchLine,
+        [LINE_HOVER_CLASS_NAME]:
+          this.isLoggedIn && isSameLine && !isMatchLine && !isContextLine && !isMetaLine,
+      };
+    },
+  },
+};
+</script>
+
+<template>
+  <table
+    :class="userColorScheme"
+    :data-commit-id="commitId"
+    class="code diff-wrap-lines js-syntax-highlight text-file">
+    <tbody>
+      <template
+        v-for="(line, index) in normalizedDiffLines"
+      >
+        <tr
+          :id="line.lineCode || `${fileHash}_${line.oldLine}_${line.newLine}`"
+          :key="line.lineCode"
+          :class="getRowClass(line)"
+          class="line_holder"
+          @mouseover="handleMouse(line.lineCode, true)"
+          @mouseout="handleMouse(line.lineCode, false)"
+        >
+          <td
+            :class="getLineClass(line)"
+            class="diff-line-num old_line"
+          >
+            <diff-line-gutter-content
+              :file-hash="fileHash"
+              :line-type="line.type"
+              :line-code="line.lineCode"
+              :line-number="line.oldLine"
+              :meta-data="line.metaData"
+              :show-comment-button="true"
+              :context-lines-path="diffFile.contextLinesPath"
+              :is-bottom="index + 1 === diffLinesLength"
+              @showCommentForm="handleShowCommentForm"
+            />
+          </td>
+          <td
+            :class="getLineClass(line)"
+            class="diff-line-num new_line"
+          >
+            <diff-line-gutter-content
+              :file-hash="fileHash"
+              :line-type="line.type"
+              :line-code="line.lineCode"
+              :line-number="line.newLine"
+              :meta-data="line.metaData"
+              :is-bottom="index + 1 === diffLinesLength"
+              :context-lines-path="diffFile.contextLinesPath"
+            />
+          </td>
+          <td
+            :class="line.type"
+            class="line_content"
+            v-html="line.richText"
+          >
+          </td>
+        </tr>
+        <tr
+          v-if="isDiscussionExpanded(line.lineCode) || diffLineCommentForms[line.lineCode]"
+          :key="index"
+          :class="discussionsByLineCode[line.lineCode] ? '' : 'js-temp-notes-holder'"
+          class="notes_holder"
+        >
+          <td
+            class="notes_line"
+            colspan="2"
+          ></td>
+          <td class="notes_content">
+            <div class="content">
+              <diff-discussions
+                :discussions="discussionsByLineCode[line.lineCode] || []"
+              />
+              <diff-line-note-form
+                v-if="diffLineCommentForms[line.lineCode]"
+                :diff-file="diffFile"
+                :diff-lines="diffLines"
+                :line="line"
+                :note-target-line="diffLines[index]"
+              />
+            </div>
+          </td>
+        </tr>
+      </template>
+    </tbody>
+  </table>
+</template>

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

+<script>
+import { mapState } from 'vuex';
+import emptyImage from '~/../../views/shared/icons/_mr_widget_empty_state.svg';
+
+export default {
+  data() {
+    return {
+      emptyImage,
+    };
+  },
+  computed: {
+    ...mapState({
+      sourceBranch: state => state.notes.noteableData.source_branch,
+      targetBranch: state => state.notes.noteableData.target_branch,
+      newBlobPath: state => state.notes.noteableData.new_blob_path,
+    }),
+  },
+};
+</script>
+
+<template>
+  <div
+    class="row empty-state nothing-here-block"
+  >
+    <div class="col-xs-12">
+      <div class="svg-content">
+        <span
+          v-html="emptyImage"
+        ></span>
+      </div>
+    </div>
+    <div class="col-xs-12">
+      <div class="text-content text-center">
+        No changes between
+        <span class="ref-name">{{ sourceBranch }}</span>
+        and
+        <span class="ref-name">{{ targetBranch }}</span>
+        <div class="text-center">
+          <a
+            :href="newBlobPath"
+            class="btn btn-save"
+          >
+            {{ __('Create commit') }}
+          </a>
+        </div>
+      </div>
+    </div>
+  </div>
+</template>

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

+<script>
+import diffContentMixin from '../mixins/diff_content';
+import {
+  EMPTY_CELL_TYPE,
+  MATCH_LINE_TYPE,
+  CONTEXT_LINE_TYPE,
+  OLD_NO_NEW_LINE_TYPE,
+  NEW_NO_NEW_LINE_TYPE,
+  LINE_HOVER_CLASS_NAME,
+  LINE_UNFOLD_CLASS_NAME,
+  LINE_POSITION_RIGHT,
+} from '../constants';
+
+export default {
+  mixins: [diffContentMixin],
+  computed: {
+    parallelDiffLines() {
+      return this.normalizedDiffLines.map(line => {
+        if (!line.left) {
+          Object.assign(line, { left: { type: EMPTY_CELL_TYPE } });
+        } else if (!line.right) {
+          Object.assign(line, { right: { type: EMPTY_CELL_TYPE } });
+        }
+
+        return line;
+      });
+    },
+  },
+  methods: {
+    hasDiscussion(line) {
+      const discussions = this.discussionsByLineCode;
+      const hasDiscussion = discussions[line.left.lineCode] || discussions[line.right.lineCode];
+
+      return hasDiscussion;
+    },
+    getClassName(line, position) {
+      const { type, lineCode } = line[position];
+      const isMatchLine = type === MATCH_LINE_TYPE;
+      const isContextLine = !isMatchLine && type !== EMPTY_CELL_TYPE && type !== CONTEXT_LINE_TYPE;
+      const isMetaLine = type === OLD_NO_NEW_LINE_TYPE || type === NEW_NO_NEW_LINE_TYPE;
+      const isSameLine = this.hoveredLineCode && this.hoveredLineCode === lineCode;
+      const isSameSection = position === this.hoveredSection;
+
+      return {
+        [type]: type,
+        [LINE_UNFOLD_CLASS_NAME]: isMatchLine,
+        [LINE_HOVER_CLASS_NAME]:
+          this.isLoggedIn && isContextLine && isSameLine && isSameSection && !isMetaLine,
+      };
+    },
+    handleMouse(e, line, isHover) {
+      if (isHover) {
+        const cell = e.target.closest('td');
+
+        if (this.$refs.leftLines.indexOf(cell) > -1) {
+          this.hoveredLineCode = line.left.lineCode;
+          this.hoveredSection = 'left';
+        } else if (this.$refs.rightLines.indexOf(cell) > -1) {
+          this.hoveredLineCode = line.right.lineCode;
+          this.hoveredSection = 'right';
+        }
+      } else {
+        this.hoveredLineCode = null;
+        this.hoveredSection = null;
+      }
+    },
+    shouldRenderDiscussionsRow(line) {
+      const hasDiscussion = this.hasDiscussion(line) && this.hasAnyExpandedDiscussion(line);
+      const hasCommentFormOnLeft = this.diffLineCommentForms[line.left.lineCode];
+      const hasCommentFormOnRight = this.diffLineCommentForms[line.right.lineCode];
+
+      return hasDiscussion || hasCommentFormOnLeft || hasCommentFormOnRight;
+    },
+    shouldRenderDiscussions(line, position) {
+      const { lineCode } = line[position];
+      let render = this.discussionsByLineCode[lineCode] && this.isDiscussionExpanded(lineCode);
+
+      // Avoid rendering context line discussions on the right side in parallel view
+      if (position === LINE_POSITION_RIGHT) {
+        render = render && line.right.type;
+      }
+
+      return render;
+    },
+    hasAnyExpandedDiscussion(line) {
+      const isLeftExpanded = this.isDiscussionExpanded(line.left.lineCode);
+      const isRightExpanded = this.isDiscussionExpanded(line.right.lineCode);
+
+      return isLeftExpanded || isRightExpanded;
+    },
+    getLineCode(line, side) {
+      const lineCode = side.lineCode;
+      if (lineCode) {
+        return lineCode;
+      }
+
+      return `${this.fileHash}_${line.left.oldLine}_${line.right.newLine}`;
+    },
+  },
+};
+</script>
+
+<template>
+  <div
+    :class="userColorScheme"
+    :data-commit-id="commitId"
+    class="code diff-wrap-lines js-syntax-highlight text-file">
+    <table>
+      <tbody>
+        <template
+          v-for="(line, index) in parallelDiffLines"
+        >
+          <tr
+            :key="index"
+            :class="getRowClass(line)"
+            class="line_holder parallel"
+            @mouseover="handleMouse($event, line, true)"
+            @mouseout="handleMouse($event, line, false)"
+          >
+            <td
+              ref="leftLines"
+              :class="getClassName(line, 'left')"
+              class="diff-line-num old_line"
+            >
+              <diff-line-gutter-content
+                :file-hash="fileHash"
+                :line-type="line.left.type"
+                :line-code="line.left.lineCode"
+                :line-number="line.left.oldLine"
+                :meta-data="line.left.metaData"
+                :show-comment-button="true"
+                :context-lines-path="diffFile.contextLinesPath"
+                :is-bottom="index + 1 === diffLinesLength"
+                line-position="left"
+                @showCommentForm="handleShowCommentForm"
+              />
+            </td>
+            <td
+              ref="leftLines"
+              :class="getClassName(line, 'left')"
+              :id="getLineCode(line, line.left)"
+              class="line_content parallel left-side"
+              v-html="line.left.richText"
+            >
+            </td>
+            <td
+              ref="rightLines"
+              :class="getClassName(line, 'right')"
+              class="diff-line-num new_line"
+            >
+              <diff-line-gutter-content
+                :file-hash="fileHash"
+                :line-type="line.right.type"
+                :line-code="line.right.lineCode"
+                :line-number="line.right.newLine"
+                :meta-data="line.right.metaData"
+                :show-comment-button="true"
+                :context-lines-path="diffFile.contextLinesPath"
+                :is-bottom="index + 1 === diffLinesLength"
+                line-position="right"
+                @showCommentForm="handleShowCommentForm"
+              />
+            </td>
+            <td
+              ref="rightLines"
+              :class="getClassName(line, 'right')"
+              :id="getLineCode(line, line.right)"
+              class="line_content parallel right-side"
+              v-html="line.right.richText"
+            >
+            </td>
+          </tr>
+          <tr
+            v-if="shouldRenderDiscussionsRow(line)"
+            :key="line.left.lineCode || line.right.lineCode"
+            :class="hasDiscussion(line) ? '' : 'js-temp-notes-holder'"
+            class="notes_holder"
+          >
+            <td class="notes_line old"></td>
+            <td class="notes_content parallel old">
+              <div
+                v-if="shouldRenderDiscussions(line, 'left')"
+                class="content"
+              >
+                <diff-discussions
+                  :discussions="discussionsByLineCode[line.left.lineCode]"
+                />
+              </div>
+              <diff-line-note-form
+                v-if="diffLineCommentForms[line.left.lineCode] &&
+                diffLineCommentForms[line.left.lineCode]"
+                :diff-file="diffFile"
+                :diff-lines="diffLines"
+                :line="line.left"
+                :note-target-line="diffLines[index].left"
+                position="left"
+              />
+            </td>
+            <td class="notes_line new"></td>
+            <td class="notes_content parallel new">
+              <div
+                v-if="shouldRenderDiscussions(line, 'right')"
+                class="content"
+              >
+                <diff-discussions
+                  :discussions="discussionsByLineCode[line.right.lineCode]"
+                />
+              </div>
+              <diff-line-note-form
+                v-if="diffLineCommentForms[line.right.lineCode] &&
+                diffLineCommentForms[line.right.lineCode] && line.right.type"
+                :diff-file="diffFile"
+                :diff-lines="diffLines"
+                :line="line.right"
+                :note-target-line="diffLines[index].right"
+                position="right"
+              />
+            </td>
+          </tr>
+        </template>
+      </tbody>
+    </table>
+  </div>
+</template>

app/assets/javascripts/diffs/constants.js

+export const INLINE_DIFF_VIEW_TYPE = 'inline';
+export const PARALLEL_DIFF_VIEW_TYPE = 'parallel';
+export const MATCH_LINE_TYPE = 'match';
+export const OLD_NO_NEW_LINE_TYPE = 'old-nonewline';
+export const NEW_NO_NEW_LINE_TYPE = 'new-nonewline';
+export const CONTEXT_LINE_TYPE = 'context';
+export const EMPTY_CELL_TYPE = 'empty-cell';
+export const COMMENT_FORM_TYPE = 'commentForm';
+export const DIFF_NOTE_TYPE = 'DiffNote';
+export const NEW_LINE_TYPE = 'new';
+export const OLD_LINE_TYPE = 'old';
+export const TEXT_DIFF_POSITION_TYPE = 'text';
+
+export const LINE_POSITION_LEFT = 'left';
+export const LINE_POSITION_RIGHT = 'right';
+
+export const DIFF_VIEW_COOKIE_NAME = 'diff_view';
+export const LINE_HOVER_CLASS_NAME = 'is-over';
+export const LINE_UNFOLD_CLASS_NAME = 'unfold js-unfold';
+export const CONTEXT_LINE_CLASS_NAME = 'diff-expanded';
+
+export const UNFOLD_COUNT = 20;
+export const COUNT_OF_AVATARS_IN_GUTTER = 3;
+export const LENGTH_OF_AVATAR_TOOLTIP = 17;

app/assets/javascripts/diffs/index.js

+import Vue from 'vue';
+import { mapState } from 'vuex';
+import { convertObjectPropsToCamelCase } from '~/lib/utils/common_utils';
+import diffsApp from './components/app.vue';
+
+export default function initDiffsApp(store) {
+  return new Vue({
+    el: '#js-diffs-app',
+    name: 'MergeRequestDiffs',
+    components: {
+      diffsApp,
+    },
+    store,
+    data() {
+      const { dataset } = document.querySelector(this.$options.el);
+
+      return {
+        endpoint: dataset.endpoint,
+        currentUser: convertObjectPropsToCamelCase(JSON.parse(dataset.currentUserData), {
+          deep: true,
+        }),
+      };
+    },
+    computed: {
+      ...mapState({
+        activeTab: state => state.page.activeTab,
+      }),
+    },
+    render(createElement) {
+      return createElement('diffs-app', {
+        props: {
+          endpoint: this.endpoint,
+          currentUser: this.currentUser,
+          shouldShow: this.activeTab === 'diffs',
+        },
+      });
+    },
+  });
+}

app/assets/javascripts/diffs/mixins/changed_files.js

+export default {
+  props: {
+    diffFiles: {
+      type: Array,
+      required: true,
+    },
+  },
+  methods: {
+    fileChangedIcon(diffFile) {
+      if (diffFile.deletedFile) {
+        return 'file-deletion';
+      } else if (diffFile.newFile) {
+        return 'file-addition';
+      }
+      return 'file-modified';
+    },
+    fileChangedClass(diffFile) {
+      if (diffFile.deletedFile) {
+        return 'cred';
+      } else if (diffFile.newFile) {
+        return 'cgreen';
+      }
+
+      return '';
+    },
+    truncatedDiffPath(path) {
+      const maxLength = 60;
+
+      if (path.length > maxLength) {
+        const start = path.length - maxLength;
+        const end = start + maxLength;
+        return `...${path.slice(start, end)}`;
+      }
+
+      return path;
+    },
+  },
+};

app/assets/javascripts/diffs/mixins/diff_content.js

+import { mapState, mapGetters, mapActions } from 'vuex';
+import diffDiscussions from '../components/diff_discussions.vue';
+import diffLineGutterContent from '../components/diff_line_gutter_content.vue';
+import diffLineNoteForm from '../components/diff_line_note_form.vue';
+import { trimFirstCharOfLineContent } from '../store/utils';
+import { CONTEXT_LINE_TYPE, CONTEXT_LINE_CLASS_NAME } from '../constants';
+
+export default {
+  props: {
+    diffFile: {
+      type: Object,
+      required: true,
+    },
+    diffLines: {
+      type: Array,
+      required: true,
+    },
+  },
+  data() {
+    return {
+      hoveredLineCode: null,
+      hoveredSection: null,
+    };
+  },
+  components: {
+    diffDiscussions,
+    diffLineNoteForm,
+    diffLineGutterContent,
+  },
+  computed: {
+    ...mapState({
+      diffLineCommentForms: state => state.diffs.diffLineCommentForms,
+    }),
+    ...mapGetters(['discussionsByLineCode', 'isLoggedIn', 'commit']),
+    commitId() {
+      return this.commit && this.commit.id;
+    },
+    userColorScheme() {
+      return window.gon.user_color_scheme;
+    },
+    normalizedDiffLines() {
+      return this.diffLines.map(line => {
+        if (line.richText) {
+          return this.trimFirstChar(line);
+        }
+
+        if (line.left) {
+          Object.assign(line, { left: this.trimFirstChar(line.left) });
+        }
+
+        if (line.right) {
+          Object.assign(line, { right: this.trimFirstChar(line.right) });
+        }
+
+        return line;
+      });
+    },
+    diffLinesLength() {
+      return this.normalizedDiffLines.length;
+    },
+    fileHash() {
+      return this.diffFile.fileHash;
+    },
+  },
+  methods: {
+    ...mapActions(['showCommentForm', 'cancelCommentForm']),
+    getRowClass(line) {
+      const isContextLine = line.left
+        ? line.left.type === CONTEXT_LINE_TYPE
+        : line.type === CONTEXT_LINE_TYPE;
+
+      return {
+        [line.type]: line.type,
+        [CONTEXT_LINE_CLASS_NAME]: isContextLine,
+      };
+    },
+    trimFirstChar(line) {
+      return trimFirstCharOfLineContent(line);
+    },
+    handleShowCommentForm(params) {
+      this.showCommentForm({ lineCode: params.lineCode });
+    },
+    isDiscussionExpanded(lineCode) {
+      const discussions = this.discussionsByLineCode[lineCode];
+
+      return discussions ? discussions.every(discussion => discussion.expanded) : false;
+    },
+  },
+};

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

+import Vue from 'vue';
+import axios from '~/lib/utils/axios_utils';
+import Cookies from 'js-cookie';
+import { handleLocationHash, historyPushState } from '~/lib/utils/common_utils';
+import { mergeUrlParams } from '~/lib/utils/url_utility';
+import * as types from './mutation_types';
+import {
+  PARALLEL_DIFF_VIEW_TYPE,
+  INLINE_DIFF_VIEW_TYPE,
+  DIFF_VIEW_COOKIE_NAME,
+} from '../constants';
+
+export const setEndpoint = ({ commit }, endpoint) => {
+  commit(types.SET_ENDPOINT, endpoint);
+};
+
+export const setLoadingState = ({ commit }, state) => {
+  commit(types.SET_LOADING, state);
+};
+
+export const fetchDiffFiles = ({ state, commit }) => {
+  commit(types.SET_LOADING, true);
+
+  return axios
+    .get(state.endpoint)
+    .then(res => {
+      commit(types.SET_LOADING, false);
+      commit(types.SET_MERGE_REQUEST_DIFFS, res.data.merge_request_diffs || []);
+      commit(types.SET_DIFF_DATA, res.data);
+      return Vue.nextTick();
+    })
+    .then(handleLocationHash);
+};
+
+export const setInlineDiffViewType = ({ commit }) => {
+  commit(types.SET_DIFF_VIEW_TYPE, INLINE_DIFF_VIEW_TYPE);
+
+  Cookies.set(DIFF_VIEW_COOKIE_NAME, INLINE_DIFF_VIEW_TYPE);
+  const url = mergeUrlParams({ view: INLINE_DIFF_VIEW_TYPE }, window.location.href);
+  historyPushState(url);
+};
+
+export const setParallelDiffViewType = ({ commit }) => {
+  commit(types.SET_DIFF_VIEW_TYPE, PARALLEL_DIFF_VIEW_TYPE);
+
+  Cookies.set(DIFF_VIEW_COOKIE_NAME, PARALLEL_DIFF_VIEW_TYPE);
+  const url = mergeUrlParams({ view: PARALLEL_DIFF_VIEW_TYPE }, window.location.href);
+  historyPushState(url);
+};
+
+export const showCommentForm = ({ commit }, params) => {
+  commit(types.ADD_COMMENT_FORM_LINE, params);
+};
+
+export const cancelCommentForm = ({ commit }, params) => {
+  commit(types.REMOVE_COMMENT_FORM_LINE, params);
+};
+
+export const loadMoreLines = ({ commit }, options) => {
+  const { endpoint, params, lineNumbers, fileHash } = options;
+
+  params.from_merge_request = true;
+
+  return axios.get(endpoint, { params }).then(res => {
+    const contextLines = res.data || [];
+
+    commit(types.ADD_CONTEXT_LINES, {
+      lineNumbers,
+      contextLines,
+      params,
+      fileHash,
+    });
+  });
+};
+
+export const loadCollapsedDiff = ({ commit }, file) =>
+  axios.get(file.loadCollapsedDiffUrl).then(res => {
+    commit(types.ADD_COLLAPSED_DIFFS, {
+      file,
+      data: res.data,
+    });
+  });
+
+export const expandAllFiles = ({ commit }) => {
+  commit(types.EXPAND_ALL_FILES);
+};
+
+export default {
+  setEndpoint,
+  setLoadingState,
+  fetchDiffFiles,
+  setInlineDiffViewType,
+  setParallelDiffViewType,
+  showCommentForm,
+  cancelCommentForm,
+  loadMoreLines,
+  loadCollapsedDiff,
+  expandAllFiles,
+};

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

+import { PARALLEL_DIFF_VIEW_TYPE, INLINE_DIFF_VIEW_TYPE } from '../constants';
+
+export default {
+  isParallelView(state) {
+    return state.diffViewType === PARALLEL_DIFF_VIEW_TYPE;
+  },
+  isInlineView(state) {
+    return state.diffViewType === INLINE_DIFF_VIEW_TYPE;
+  },
+  areAllFilesCollapsed(state) {
+    return state.diffFiles.every(file => file.collapsed);
+  },
+  commit(state) {
+    return state.commit;
+  },
+};

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

+import Vue from 'vue';
+import Vuex from 'vuex';
+import diffsModule from './modules';
+
+Vue.use(Vuex);
+
+export default new Vuex.Store({
+  modules: {
+    diffs: diffsModule,
+  },
+});

app/assets/javascripts/diffs/store/modules/index.js

+import Cookies from 'js-cookie';
+import { getParameterValues } from '~/lib/utils/url_utility';
+import actions from '../actions';
+import getters from '../getters';
+import mutations from '../mutations';
+import { INLINE_DIFF_VIEW_TYPE, DIFF_VIEW_COOKIE_NAME } from '../../constants';
+
+const viewTypeFromQueryString = getParameterValues('view')[0];
+const viewTypeFromCookie = Cookies.get(DIFF_VIEW_COOKIE_NAME);
+const defaultViewType = INLINE_DIFF_VIEW_TYPE;
+
+export default {
+  state: {
+    isLoading: true,
+    endpoint: '',
+    commit: null,
+    diffFiles: [],
+    mergeRequestDiffs: [],
+    diffLineCommentForms: {},
+    diffViewType: viewTypeFromQueryString || viewTypeFromCookie || defaultViewType,
+  },
+  getters,
+  actions,
+  mutations,
+};

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

+export const SET_ENDPOINT = 'SET_ENDPOINT';
+export const SET_LOADING = 'SET_LOADING';
+export const SET_DIFF_DATA = 'SET_DIFF_DATA';
+export const SET_DIFF_FILES = 'SET_DIFF_FILES';
+export const SET_DIFF_VIEW_TYPE = 'SET_DIFF_VIEW_TYPE';
+export const SET_MERGE_REQUEST_DIFFS = 'SET_MERGE_REQUEST_DIFFS';
+export const ADD_COMMENT_FORM_LINE = 'ADD_COMMENT_FORM_LINE';
+export const REMOVE_COMMENT_FORM_LINE = 'REMOVE_COMMENT_FORM_LINE';
+export const ADD_CONTEXT_LINES = 'ADD_CONTEXT_LINES';
+export const ADD_COLLAPSED_DIFFS = 'ADD_COLLAPSED_DIFFS';
+export const EXPAND_ALL_FILES = 'EXPAND_ALL_FILES';

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

+import Vue from 'vue';
+import _ from 'underscore';
+import { convertObjectPropsToCamelCase } from '~/lib/utils/common_utils';
+import { findDiffFile, addLineReferences, removeMatchLine, addContextLines } from './utils';
+import * as types from './mutation_types';
+
+export default {
+  [types.SET_ENDPOINT](state, endpoint) {
+    Object.assign(state, { endpoint });
+  },
+
+  [types.SET_LOADING](state, isLoading) {
+    Object.assign(state, { isLoading });
+  },
+
+  [types.SET_DIFF_DATA](state, data) {
+    Object.assign(state, {
+      ...convertObjectPropsToCamelCase(data, { deep: true }),
+    });
+  },
+
+  [types.SET_DIFF_FILES](state, diffFiles) {
+    Object.assign(state, {
+      diffFiles: convertObjectPropsToCamelCase(diffFiles, { deep: true }),
+    });
+  },
+
+  [types.SET_MERGE_REQUEST_DIFFS](state, mergeRequestDiffs) {
+    Object.assign(state, {
+      mergeRequestDiffs: convertObjectPropsToCamelCase(mergeRequestDiffs, { deep: true }),
+    });
+  },
+
+  [types.SET_DIFF_VIEW_TYPE](state, diffViewType) {
+    Object.assign(state, { diffViewType });
+  },
+
+  [types.ADD_COMMENT_FORM_LINE](state, { lineCode }) {
+    Vue.set(state.diffLineCommentForms, lineCode, true);
+  },
+
+  [types.REMOVE_COMMENT_FORM_LINE](state, { lineCode }) {
+    Vue.delete(state.diffLineCommentForms, lineCode);
+  },
+
+  [types.ADD_CONTEXT_LINES](state, options) {
+    const { lineNumbers, contextLines, fileHash } = options;
+    const { bottom } = options.params;
+    const diffFile = findDiffFile(state.diffFiles, fileHash);
+    const { highlightedDiffLines, parallelDiffLines } = diffFile;
+
+    removeMatchLine(diffFile, lineNumbers, bottom);
+    const lines = addLineReferences(contextLines, lineNumbers, bottom);
+    addContextLines({
+      inlineLines: highlightedDiffLines,
+      parallelLines: parallelDiffLines,
+      contextLines: lines,
+      bottom,
+      lineNumbers,
+    });
+  },
+
+  [types.ADD_COLLAPSED_DIFFS](state, { file, data }) {
+    const normalizedData = convertObjectPropsToCamelCase(data, { deep: true });
+    const [newFileData] = normalizedData.diffFiles.filter(f => f.fileHash === file.fileHash);
+
+    if (newFileData) {
+      const index = _.findIndex(state.diffFiles, f => f.fileHash === file.fileHash);
+      state.diffFiles.splice(index, 1, newFileData);
+    }
+  },
+
+  [types.EXPAND_ALL_FILES](state) {
+    const diffFiles = [];
+
+    state.diffFiles.forEach((file) => {
+      diffFiles.push({
+        ...file,
+        collapsed: false,
+      });
+    });
+
+    Object.assign(state, { diffFiles });
+  },
+};

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

+import _ from 'underscore';
+import { convertObjectPropsToCamelCase } from '~/lib/utils/common_utils';
+import {
+  LINE_POSITION_LEFT,
+  LINE_POSITION_RIGHT,
+  TEXT_DIFF_POSITION_TYPE,
+  DIFF_NOTE_TYPE,
+  NEW_LINE_TYPE,
+  OLD_LINE_TYPE,
+  MATCH_LINE_TYPE,
+} from '../constants';
+
+export function findDiffFile(files, hash) {
+  return files.filter(file => file.fileHash === hash)[0];
+}
+
+export const getReversePosition = linePosition => {
+  if (linePosition === LINE_POSITION_RIGHT) {
+    return LINE_POSITION_LEFT;
+  }
+
+  return LINE_POSITION_RIGHT;
+};
+
+export function getNoteFormData(params) {
+  const {
+    note,
+    noteableType,
+    noteableData,
+    diffFile,
+    noteTargetLine,
+    diffViewType,
+    linePosition,
+  } = params;
+
+  const position = JSON.stringify({
+    base_sha: diffFile.diffRefs.baseSha,
+    start_sha: diffFile.diffRefs.startSha,
+    head_sha: diffFile.diffRefs.headSha,
+    old_path: diffFile.oldPath,
+    new_path: diffFile.newPath,
+    position_type: TEXT_DIFF_POSITION_TYPE,
+    old_line: noteTargetLine.oldLine,
+    new_line: noteTargetLine.newLine,
+  });
+
+  const postData = {
+    view: diffViewType,
+    line_type: linePosition === LINE_POSITION_RIGHT ? NEW_LINE_TYPE : OLD_LINE_TYPE,
+    merge_request_diff_head_sha: diffFile.diffRefs.headSha,
+    in_reply_to_discussion_id: '',
+    note_project_id: '',
+    target_type: noteableData.targetType,
+    target_id: noteableData.id,
+    note: {
+      note,
+      position,
+      noteable_type: noteableType,
+      noteable_id: noteableData.id,
+      commit_id: '',
+      type: DIFF_NOTE_TYPE,
+      line_code: noteTargetLine.lineCode,
+    },
+  };
+
+  return {
+    endpoint: noteableData.create_note_path,
+    data: postData,
+  };
+}
+
+export const findIndexInInlineLines = (lines, lineNumbers) => {
+  const { oldLineNumber, newLineNumber } = lineNumbers;
+
+  return _.findIndex(
+    lines,
+    line => line.oldLine === oldLineNumber && line.newLine === newLineNumber,
+  );
+};
+
+export const findIndexInParallelLines = (lines, lineNumbers) => {
+  const { oldLineNumber, newLineNumber } = lineNumbers;
+
+  return _.findIndex(
+    lines,
+    line =>
+      line.left &&
+      line.right &&
+      line.left.oldLine === oldLineNumber &&
+      line.right.newLine === newLineNumber,
+  );
+};
+
+export function removeMatchLine(diffFile, lineNumbers, bottom) {
+  const indexForInline = findIndexInInlineLines(diffFile.highlightedDiffLines, lineNumbers);
+  const indexForParallel = findIndexInParallelLines(diffFile.parallelDiffLines, lineNumbers);
+  const factor = bottom ? 1 : -1;
+
+  diffFile.highlightedDiffLines.splice(indexForInline + factor, 1);
+  diffFile.parallelDiffLines.splice(indexForParallel + factor, 1);
+}
+
+export function addLineReferences(lines, lineNumbers, bottom) {
+  const { oldLineNumber, newLineNumber } = lineNumbers;
+  const lineCount = lines.length;
+  let matchLineIndex = -1;
+
+  const linesWithNumbers = lines.map((l, index) => {
+    const line = convertObjectPropsToCamelCase(l);
+
+    if (line.type === MATCH_LINE_TYPE) {
+      matchLineIndex = index;
+    } else {
+      Object.assign(line, {
+        oldLine: bottom ? oldLineNumber + index + 1 : oldLineNumber + index - lineCount,
+        newLine: bottom ? newLineNumber + index + 1 : newLineNumber + index - lineCount,
+      });
+    }
+
+    return line;
+  });
+
+  if (matchLineIndex > -1) {
+    const line = linesWithNumbers[matchLineIndex];
+    const targetLine = bottom
+      ? linesWithNumbers[matchLineIndex - 1]
+      : linesWithNumbers[matchLineIndex + 1];
+
+    Object.assign(line, {
+      metaData: {
+        oldPos: targetLine.oldLine,
+        newPos: targetLine.newLine,
+      },
+    });
+  }
+
+  return linesWithNumbers;
+}
+
+export function addContextLines(options) {
+  const { inlineLines, parallelLines, contextLines, lineNumbers } = options;
+  const normalizedParallelLines = contextLines.map(line => ({
+    left: line,
+    right: line,
+  }));
+
+  if (options.bottom) {
+    inlineLines.push(...contextLines);
+    parallelLines.push(...normalizedParallelLines);
+  } else {
+    const inlineIndex = findIndexInInlineLines(inlineLines, lineNumbers);
+    const parallelIndex = findIndexInParallelLines(parallelLines, lineNumbers);
+    inlineLines.splice(inlineIndex, 0, ...contextLines);
+    parallelLines.splice(parallelIndex, 0, ...normalizedParallelLines);
+  }
+}
+
+export function trimFirstCharOfLineContent(line) {
+  if (!line.richText) {
+    return line;
+  }
+
+  const firstChar = line.richText.charAt(0);
+
+  if (firstChar === ' ' || firstChar === '+' || firstChar === '-') {
+    Object.assign(line, {
+      richText: line.richText.substring(1),
+    });
+  }
+
+  return line;
+}

app/assets/javascripts/lib/utils/dom_utils.js

-import $ from 'jquery';
-import { isInIssuePage, isInMRPage, isInEpicPage, hasVueMRDiscussionsCookie } from './common_utils';
-
-const isVueMRDiscussions = () => isInMRPage() && hasVueMRDiscussionsCookie() && !$('#diffs').is(':visible');
+import { isInIssuePage, isInMRPage, isInEpicPage } from './common_utils';
 
 export const addClassIfElementExists = (element, className) => {
   if (element) {
@@ -9,4 +6,4 @@ export const addClassIfElementExists = (element, className) => {
   }
 };
 
-export const isInVueNoteablePage = () => isInIssuePage() || isInEpicPage() || isVueMRDiscussions();
+export const isInVueNoteablePage = () => isInIssuePage() || isInEpicPage() || isInMRPage();

app/assets/javascripts/lib/utils/text_utility.js

@@ -57,6 +57,14 @@ export const slugify = str => str.trim().toLowerCase();
  */
 export const truncate = (string, maxLength) => `${string.substr(0, maxLength - 3)}...`;
 
+/**
+ * Truncate SHA to 8 characters
+ *
+ * @param {String} sha
+ * @returns {String}
+ */
+export const truncateSha = sha => sha.substr(0, 8);
+
 /**
  * Capitalizes first character
  *
@@ -98,3 +106,16 @@ export const convertToSentenceCase = string => {
 
   return splitWord.join(' ');
 };
+
+/**
+ * Splits camelCase or PascalCase words
+ * e.g. HelloWorld => Hello World
+ *
+ * @param {*} string
+*/
+export const splitCamelCase = string => (
+  string
+  .replace(/([A-Z]+)([A-Z][a-z])/g, ' $1 $2')
+  .replace(/([a-z\d])([A-Z])/g, '$1 $2')
+  .trim()
+);

app/assets/javascripts/merge_request.js

@@ -49,6 +49,7 @@ MergeRequest.prototype.initTabs = function() {
   if (window.mrTabs) {
     window.mrTabs.unbindEvents();
   }
+
   window.mrTabs = new MergeRequestTabs(this.opts);
 };
 

app/assets/javascripts/merge_request_tabs.js

 /* eslint-disable no-new, class-methods-use-this */
 
 import $ from 'jquery';
+import Vue from 'vue';
 import Cookies from 'js-cookie';
 import axios from './lib/utils/axios_utils';
 import flash from './flash';
@@ -8,6 +9,7 @@ import BlobForkSuggestion from './blob/blob_fork_suggestion';
 import initChangesDropdown from './init_changes_dropdown';
 import bp from './breakpoints';
 import { parseUrlPathname, handleLocationHash, isMetaClick } from './lib/utils/common_utils';
+import { isInVueNoteablePage } from './lib/utils/dom_utils';
 import { getLocationHash } from './lib/utils/url_utility';
 import initDiscussionTab from './image_diff/init_discussion_tab';
 import Diff from './diff';
@@ -70,11 +72,13 @@ export default class MergeRequestTabs {
     const navbar = document.querySelector('.navbar-gitlab');
     const peek = document.getElementById('js-peek');
     const paddingTop = 16;
+    this.commitsTab = document.querySelector('.tab-content .commits.tab-pane');
 
     this.diffsLoaded = false;
     this.pipelinesLoaded = false;
     this.commitsLoaded = false;
     this.fixedLayoutPref = null;
+    this.eventHub = new Vue();
 
     this.setUrl = setUrl !== undefined ? setUrl : true;
     this.setCurrentAction = this.setCurrentAction.bind(this);
@@ -149,7 +153,9 @@ export default class MergeRequestTabs {
       this.resetViewContainer();
       this.destroyPipelinesView();
     } else if (this.isDiffAction(action)) {
+      if (!isInVueNoteablePage()) {
         this.loadDiff($target.attr('href'));
+      }
       if (bp.getBreakpointSize() !== 'lg') {
         this.shrinkView();
       }
@@ -157,6 +163,7 @@ export default class MergeRequestTabs {
         this.expandViewContainer();
       }
       this.destroyPipelinesView();
+      this.commitsTab.classList.remove('active');
     } else if (action === 'pipelines') {
       this.resetViewContainer();
       this.mountPipelinesView();
@@ -172,6 +179,8 @@ export default class MergeRequestTabs {
     if (this.setUrl) {
       this.setCurrentAction(action);
     }
+
+    this.eventHub.$emit('MergeRequestTabChange', this.getCurrentAction());
   }
 
   scrollToElement(container) {

app/assets/javascripts/mr_notes/index.js

+import $ from 'jquery';
 import Vue from 'vue';
+import { mapActions, mapState, mapGetters } from 'vuex';
+import initDiffsApp from '../diffs';
 import notesApp from '../notes/components/notes_app.vue';
 import discussionCounter from '../notes/components/discussion_counter.vue';
-import store from '../notes/stores';
+import store from './stores';
+import MergeRequest from '../merge_request';
 
 export default function initMrNotes() {
+  const mrShowNode = document.querySelector('.merge-request');
+  // eslint-disable-next-line no-new
+  new MergeRequest({
+    action: mrShowNode.dataset.mrAction,
+  });
+
   // eslint-disable-next-line no-new
   new Vue({
     el: '#js-vue-mr-discussions',
+    name: 'MergeRequestDiscussions',
     components: {
       notesApp,
     },
+    store,
     data() {
-      const notesDataset = document.getElementById('js-vue-mr-discussions')
-        .dataset;
+      const notesDataset = document.getElementById('js-vue-mr-discussions').dataset;
       const noteableData = JSON.parse(notesDataset.noteableData);
       noteableData.noteableType = notesDataset.noteableType;
+      noteableData.targetType = notesDataset.targetType;
 
       return {
         noteableData,
@@ -22,12 +34,42 @@ export default function initMrNotes() {
         notesData: JSON.parse(notesDataset.notesData),
       };
     },
+    computed: {
+      ...mapGetters(['discussionTabCounter']),
+      ...mapState({
+        activeTab: state => state.page.activeTab,
+      }),
+    },
+    watch: {
+      discussionTabCounter() {
+        this.updateDiscussionTabCounter();
+      },
+    },
+    mounted() {
+      this.notesCountBadge = $('.issuable-details').find('.notes-tab .badge');
+      this.setActiveTab(window.mrTabs.getCurrentAction());
+
+      window.mrTabs.eventHub.$on('MergeRequestTabChange', tab => {
+        this.setActiveTab(tab);
+      });
+      $(document).on('visibilitychange', this.updateDiscussionTabCounter);
+    },
+    beforeDestroy() {
+      $(document).off('visibilitychange', this.updateDiscussionTabCounter);
+    },
+    methods: {
+      ...mapActions(['setActiveTab']),
+      updateDiscussionTabCounter() {
+        this.notesCountBadge.text(this.discussionTabCounter);
+      },
+    },
     render(createElement) {
       return createElement('notes-app', {
         props: {
           noteableData: this.noteableData,
           notesData: this.notesData,
           userData: this.currentUserData,
+          shouldShow: this.activeTab === 'show',
         },
       });
     },
@@ -36,6 +78,7 @@ export default function initMrNotes() {
   // eslint-disable-next-line no-new
   new Vue({
     el: '#js-vue-discussion-counter',
+    name: 'DiscussionCounter',
     components: {
       discussionCounter,
     },
@@ -44,4 +87,6 @@ export default function initMrNotes() {
       return createElement('discussion-counter');
     },
   });
+
+  initDiffsApp(store);
 }

app/assets/javascripts/mr_notes/stores/actions.js

+import types from './mutation_types';
+
+export default {
+  setActiveTab({ commit }, tab) {
+    commit(types.SET_ACTIVE_TAB, tab);
+  },
+};

app/assets/javascripts/mr_notes/stores/getters.js

+export default {
+  isLoggedIn(state, getters) {
+    return !!getters.getUserData.id;
+  },
+};

app/assets/javascripts/mr_notes/stores/index.js

+import Vue from 'vue';
+import Vuex from 'vuex';
+import notesModule from '~/notes/stores/modules';
+import diffsModule from '~/diffs/store/modules';
+import mrPageModule from './modules';
+
+Vue.use(Vuex);
+
+export default new Vuex.Store({
+  modules: {
+    page: mrPageModule,
+    notes: notesModule,
+    diffs: diffsModule,
+  },
+});

app/assets/javascripts/mr_notes/stores/modules/index.js

+import actions from '../actions';
+import getters from '../getters';
+import mutations from '../mutations';
+
+export default {
+  state: {
+    activeTab: null,
+  },
+  actions,
+  getters,
+  mutations,
+};

app/assets/javascripts/mr_notes/stores/mutation_types.js

+export default {
+  SET_ACTIVE_TAB: 'SET_ACTIVE_TAB',
+};

app/assets/javascripts/mr_notes/stores/mutations.js

+import types from './mutation_types';
+
+export default {
+  [types.SET_ACTIVE_TAB](state, tab) {
+    Object.assign(state, { activeTab: tab });
+  },
+};

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

@@ -10,6 +10,7 @@ import TaskList from '../../task_list';
 import {
   capitalizeFirstCharacter,
   convertToCamelCase,
+  splitCamelCase,
 } from '../../lib/utils/text_utility';
 import * as constants from '../constants';
 import eventHub from '../event_hub';
@@ -56,21 +57,23 @@ export default {
     ]),
     ...mapState(['isToggleStateButtonLoading']),
     noteableDisplayName() {
-      return this.noteableType.replace(/_/g, ' ');
+      return splitCamelCase(this.noteableType).toLowerCase();
     },
     isLoggedIn() {
       return this.getUserData.id;
     },
     commentButtonTitle() {
-      return this.noteType === constants.COMMENT
-        ? 'Comment'
-        : 'Start discussion';
+      return this.noteType === constants.COMMENT ? 'Comment' : 'Start discussion';
+    },
+    startDiscussionDescription() {
+      let text = 'Discuss a specific suggestion or question';
+      if (this.getNoteableData.noteableType === constants.MERGE_REQUEST_NOTEABLE_TYPE) {
+        text += ' that needs to be resolved';
+      }
+      return `${text}.`;
     },
     isOpen() {
-      return (
-        this.openState === constants.OPENED ||
-        this.openState === constants.REOPENED
-      );
+      return this.openState === constants.OPENED || this.openState === constants.REOPENED;
     },
     canCreateNote() {
       return this.getNoteableData.current_user.can_create_note;
@@ -117,6 +120,11 @@ export default {
     endpoint() {
       return this.getNoteableData.create_note_path;
     },
+    issuableTypeTitle() {
+      return this.noteableType === constants.MERGE_REQUEST_NOTEABLE_TYPE
+        ? 'merge request'
+        : 'issue';
+    },
   },
   watch: {
     note(newNote) {
@@ -129,9 +137,7 @@ export default {
   mounted() {
     // jQuery is needed here because it is a custom event being dispatched with jQuery.
     $(document).on('issuable:change', (e, isClosed) => {
-      this.toggleIssueLocalState(
-        isClosed ? constants.CLOSED : constants.REOPENED,
-      );
+      this.toggleIssueLocalState(isClosed ? constants.CLOSED : constants.REOPENED);
     });
 
     this.initAutoSave();
@@ -168,6 +174,7 @@ export default {
               noteable_id: this.getNoteableData.id,
               note: this.note,
             },
+            merge_request_diff_head_sha: this.getNoteableData.diff_head_sha,
           },
         };
 
@@ -227,9 +234,7 @@ Please check your network connection and try again.`;
             this.toggleStateButtonLoading(false);
             Flash(
               sprintf(
-                __(
-                  'Something went wrong while closing the %{issuable}. Please try again later',
-                ),
+                __('Something went wrong while closing the %{issuable}. Please try again later'),
                 { issuable: this.noteableDisplayName },
               ),
             );
@@ -242,9 +247,7 @@ Please check your network connection and try again.`;
             this.toggleStateButtonLoading(false);
             Flash(
               sprintf(
-                __(
-                  'Something went wrong while reopening the %{issuable}. Please try again later',
-                ),
+                __('Something went wrong while reopening the %{issuable}. Please try again later'),
                 { issuable: this.noteableDisplayName },
               ),
             );
@@ -281,9 +284,7 @@ Please check your network connection and try again.`;
     },
     initAutoSave() {
       if (this.isLoggedIn) {
-        const noteableType = capitalizeFirstCharacter(
-          convertToCamelCase(this.noteableType),
-        );
+        const noteableType = capitalizeFirstCharacter(convertToCamelCase(this.noteableType));
 
         this.autosave = new Autosave($(this.$refs.textarea), [
           'Note',
@@ -312,8 +313,8 @@ Please check your network connection and try again.`;
   <div>
     <note-signed-out-widget v-if="!isLoggedIn" />
     <discussion-locked-widget
-      v-else-if="isLocked(getNoteableData) && !canCreateNote"
-      issuable-type="issue"
+      v-else-if="!canCreateNote"
+      :issuable-type="issuableTypeTitle"
     />
     <ul
       v-else-if="canCreateNote"
@@ -357,7 +358,7 @@ Please check your network connection and try again.`;
                   v-model="note"
                   :disabled="isSubmitting"
                   name="note[note]"
-                  class="note-textarea js-vue-comment-form
+                  class="note-textarea js-vue-comment-form js-note-text
 js-gfm-input js-autosize markdown-area js-vue-textarea"
                   data-supports-quick-actions="true"
                   aria-label="Description"
@@ -423,7 +424,7 @@ append-right-10 comment-type-dropdown js-comment-type-dropdown droplab-dropdown"
                         <div class="description">
                           <strong>Start discussion</strong>
                           <p>
-                            Discuss a specific suggestion or question.
+                            {{ startDiscussionDescription }}
                           </p>
                         </div>
                       </button>

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

 <script>
-import $ from 'jquery';
-import syntaxHighlight from '~/syntax_highlight';
+import { mapState, mapActions } from 'vuex';
 import imageDiffHelper from '~/image_diff/helpers/index';
 import { convertObjectPropsToCamelCase } from '~/lib/utils/common_utils';
-import DiffFileHeader from './diff_file_header.vue';
+import DiffFileHeader from '~/diffs/components/diff_file_header.vue';
+import SkeletonLoadingContainer from '~/vue_shared/components/skeleton_loading_container.vue';
+import { trimFirstCharOfLineContent } from '~/diffs/store/utils';
 
 export default {
   components: {
     DiffFileHeader,
+    SkeletonLoadingContainer,
   },
   props: {
     discussion: {
@@ -15,7 +17,24 @@ export default {
       required: true,
     },
   },
+  data() {
+    return {
+      error: false,
+    };
+  },
   computed: {
+    ...mapState({
+      noteableData: state => state.notes.noteableData,
+    }),
+    hasTruncatedDiffLines() {
+      return this.discussion.truncatedDiffLines && this.discussion.truncatedDiffLines.length !== 0;
+    },
+    isDiscussionsExpanded() {
+      return true; // TODO: @fatihacet - Fix this.
+    },
+    isCollapsed() {
+      return this.diffFile.collapsed || false;
+    },
     isImageDiff() {
       return !this.diffFile.text;
     },
@@ -23,36 +42,46 @@ export default {
       const { text } = this.diffFile;
       return text ? 'text-file' : 'js-image-file';
     },
-    diffRows() {
-      return $(this.discussion.truncatedDiffLines);
-    },
     diffFile() {
-      return convertObjectPropsToCamelCase(this.discussion.diffFile);
+      return convertObjectPropsToCamelCase(this.discussion.diffFile, { deep: true });
     },
     imageDiffHtml() {
       return this.discussion.imageDiffHtml;
     },
+    currentUser() {
+      return this.noteableData.current_user;
+    },
+    userColorScheme() {
+      return window.gon.user_color_scheme;
+    },
+    normalizedDiffLines() {
+      const lines = this.discussion.truncatedDiffLines || [];
+
+      return lines.map(line => trimFirstCharOfLineContent(convertObjectPropsToCamelCase(line)));
+    },
   },
   mounted() {
     if (this.isImageDiff) {
       const canCreateNote = false;
       const renderCommentBadge = true;
-      imageDiffHelper.initImageDiff(
-        this.$refs.fileHolder,
-        canCreateNote,
-        renderCommentBadge,
-      );
-    } else {
-      const fileHolder = $(this.$refs.fileHolder);
-      this.$nextTick(() => {
-        syntaxHighlight(fileHolder);
-      });
+      imageDiffHelper.initImageDiff(this.$refs.fileHolder, canCreateNote, renderCommentBadge);
+    } else if (!this.hasTruncatedDiffLines) {
+      this.fetchDiff();
     }
   },
   methods: {
+    ...mapActions(['fetchDiscussionDiffLines']),
     rowTag(html) {
       return html.outerHTML ? 'tr' : 'template';
     },
+    fetchDiff() {
+      this.error = false;
+      this.fetchDiscussionDiffLines(this.discussion)
+        .then(this.highlight)
+        .catch(() => {
+          this.error = true;
+        });
+    },
   },
 };
 </script>
@@ -63,23 +92,59 @@ export default {
     :class="diffFileClass"
     class="diff-file file-holder"
   >
-    <div class="js-file-title file-title file-title-flex-parent">
     <diff-file-header
       :diff-file="diffFile"
+      :current-user="currentUser"
+      :discussions-expanded="isDiscussionsExpanded"
+      :expanded="!isCollapsed"
     />
-    </div>
     <div
       v-if="diffFile.text"
-      class="diff-content code js-syntax-highlight"
+      :class="userColorScheme"
+      class="diff-content code"
     >
       <table>
-        <component
-          v-for="(html, index) in diffRows"
-          :is="rowTag(html)"
-          :class="html.className"
-          :key="index"
-          v-html="html.outerHTML"
-        />
+        <tr
+          v-for="line in normalizedDiffLines"
+          :key="line.lineCode"
+          class="line_holder"
+        >
+          <td class="diff-line-num old_line">{{ line.oldLine }}</td>
+          <td class="diff-line-num new_line">{{ line.newLine }}</td>
+          <td
+            :class="line.type"
+            class="line_content"
+            v-html="line.richText"
+          >
+          </td>
+        </tr>
+        <tr
+          v-if="!hasTruncatedDiffLines"
+          class="line_holder line-holder-placeholder"
+        >
+          <td class="old_line diff-line-num"></td>
+          <td class="new_line diff-line-num"></td>
+          <td
+            v-if="error"
+            class="js-error-lazy-load-diff diff-loading-error-block"
+          >
+            Unable to load the diff
+            <button
+              class="btn-link btn-link-retry btn-no-padding js-toggle-lazy-diff-retry-button"
+              @click="fetchDiff"
+            >
+              Try again
+            </button>
+          </td>
+          <td
+            v-else
+            class="line_content js-success-lazy-load"
+          >
+            <span></span>
+            <skeleton-loading-container />
+            <span></span>
+          </td>
+        </tr>
         <tr class="notes_holder">
           <td
             class="notes_line"

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

 <script>
-import { mapGetters } from 'vuex';
+import { mapActions, mapGetters } from 'vuex';
 import resolveSvg from 'icons/_icon_resolve_discussion.svg';
 import resolvedSvg from 'icons/_icon_status_success_solid.svg';
 import mrIssueSvg from 'icons/_icon_mr_issue.svg';
@@ -48,10 +48,14 @@ export default {
     this.nextDiscussionSvg = nextDiscussionSvg;
   },
   methods: {
-    jumpToFirstDiscussion() {
-      const el = document.querySelector(
-        `[data-discussion-id="${this.firstUnresolvedDiscussionId}"]`,
-      );
+    ...mapActions(['expandDiscussion']),
+    jumpToFirstUnresolvedDiscussion() {
+      const discussionId = this.firstUnresolvedDiscussionId;
+      if (!discussionId) {
+        return;
+      }
+
+      const el = document.querySelector(`[data-discussion-id="${discussionId}"]`);
       const activeTab = window.mrTabs.currentAction;
 
       if (activeTab === 'commits' || activeTab === 'pipelines') {
@@ -59,6 +63,7 @@ export default {
       }
 
       if (el) {
+        this.expandDiscussion({ discussionId });
         scrollToElement(el);
       }
     },
@@ -97,7 +102,7 @@ export default {
         <a
           v-tooltip
           :href="resolveAllDiscussionsIssuePath"
-          title="Resolve all discussions in new issue"
+          :title="s__('Resolve all discussions in new issue')"
           data-container="body"
           class="new-issue-for-discussion btn btn-default discussion-create-issue-btn">
           <span v-html="mrIssueSvg"></span>
@@ -112,7 +117,7 @@ export default {
           title="Jump to first unresolved discussion"
           data-container="body"
           class="btn btn-default discussion-next-btn"
-          @click="jumpToFirstDiscussion">
+          @click="jumpToFirstUnresolvedDiscussion">
           <span v-html="nextDiscussionSvg"></span>
         </button>
       </div>

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

@@ -27,6 +27,10 @@ export default {
       type: Number,
       required: true,
     },
+    noteUrl: {
+      type: String,
+      required: true,
+    },
     accessLevel: {
       type: String,
       required: false,
@@ -48,6 +52,11 @@ export default {
       type: Boolean,
       required: true,
     },
+    canResolve: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
     resolvable: {
       type: Boolean,
       required: false,
@@ -125,7 +134,7 @@ export default {
       {{ accessLevel }}
     </span>
     <div
-      v-if="resolvable"
+      v-if="canResolve"
       class="note-actions-item">
       <button
         v-tooltip
@@ -216,6 +225,15 @@ export default {
             Report as abuse
           </a>
         </li>
+        <li>
+          <button
+            :data-clipboard-text="noteUrl"
+            type="button"
+            css-class="btn-default btn-transparent"
+          >
+            Copy link
+          </button>
+        </li>
         <li v-if="canEdit">
           <button
             class="btn btn-transparent js-note-delete js-note-delete"

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

@@ -40,7 +40,7 @@ export default {
     this.initTaskList();
 
     if (this.isEditing) {
-      this.initAutoSave(this.note.noteable_type);
+      this.initAutoSave(this.note);
     }
   },
   updated() {
@@ -49,7 +49,7 @@ export default {
 
     if (this.isEditing) {
       if (!this.autosave) {
-        this.initAutoSave(this.note.noteable_type);
+        this.initAutoSave(this.note);
       } else {
         this.setAutoSave();
       }
@@ -72,7 +72,7 @@ export default {
       this.$emit('handleFormUpdate', note, parentElement, callback);
     },
     formCancelHandler(shouldConfirm, isDirty) {
-      this.$emit('cancelFormEdition', shouldConfirm, isDirty);
+      this.$emit('cancelForm', shouldConfirm, isDirty);
     },
   },
 };
@@ -93,7 +93,7 @@ export default {
       :note-body="noteBody"
       :note-id="note.id"
       @handleFormUpdate="handleFormUpdate"
-      @cancelFormEdition="formCancelHandler"
+      @cancelForm="formCancelHandler"
     />
     <textarea
       v-if="canEdit"
@@ -105,6 +105,7 @@ export default {
       :edited-at="note.last_edited_at"
       :edited-by="note.last_edited_by"
       action-text="Edited"
+      class="note_edited_ago"
     />
     <note-awards-list
       v-if="note.award_emoji.length"

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

@@ -11,14 +11,20 @@ export default {
       type: String,
       required: true,
     },
+    actionDetailText: {
+      type: String,
+      required: false,
+      default: '',
+    },
     editedAt: {
       type: String,
-      required: true,
+      required: false,
+      default: null,
     },
     editedBy: {
       type: Object,
       required: false,
-      default: () => ({}),
+      default: null,
     },
     className: {
       type: String,
@@ -33,13 +39,14 @@ export default {
   <div :class="className">
     {{ actionText }}
     <template v-if="editedBy">
-      {{ s__('ByAuthor|by') }}
+      by
       <a
         :href="editedBy.path"
         class="js-vue-author author_link">
         {{ editedBy.name }}
       </a>
     </template>
+    {{ actionDetailText }}
     <time-ago-tooltip
       :time="editedAt"
       tooltip-placement="bottom"

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

@@ -29,7 +29,7 @@ export default {
       required: false,
       default: 'Save comment',
     },
-    note: {
+    discussion: {
       type: Object,
       required: false,
       default: () => ({}),
@@ -38,6 +38,11 @@ export default {
       type: Boolean,
       required: true,
     },
+    lineCode: {
+      type: String,
+      required: false,
+      default: '',
+    },
   },
   data() {
     return {
@@ -66,9 +71,7 @@ export default {
       return this.getNotesDataByProp('markdownDocsPath');
     },
     quickActionsDocsPath() {
-      return !this.isEditing
-        ? this.getNotesDataByProp('quickActionsDocsPath')
-        : undefined;
+      return !this.isEditing ? this.getNotesDataByProp('quickActionsDocsPath') : undefined;
     },
     currentUserId() {
       return this.getUserDataByProp('id');
@@ -95,24 +98,17 @@ export default {
       const beforeSubmitDiscussionState = this.discussionResolved;
       this.isSubmitting = true;
 
-      this.$emit(
-        'handleFormUpdate',
-        this.updatedNoteBody,
-        this.$refs.editNoteForm,
-        () => {
+      this.$emit('handleFormUpdate', this.updatedNoteBody, this.$refs.editNoteForm, () => {
         this.isSubmitting = false;
 
         if (shouldResolve) {
           this.resolveHandler(beforeSubmitDiscussionState);
         }
-        },
-      );
+      });
     },
     editMyLastNote() {
       if (this.updatedNoteBody === '') {
-        const lastNoteInDiscussion = this.getDiscussionLastNote(
-          this.updatedNoteBody,
-        );
+        const lastNoteInDiscussion = this.getDiscussionLastNote(this.discussion);
 
         if (lastNoteInDiscussion) {
           eventHub.$emit('enterEditMode', {
@@ -123,11 +119,7 @@ export default {
     },
     cancelHandler(shouldConfirm = false) {
       // Sends information about confirm message and if the textarea has changed
-      this.$emit(
-        'cancelFormEdition',
-        shouldConfirm,
-        this.noteBody !== this.updatedNoteBody,
-      );
+      this.$emit('cancelForm', shouldConfirm, this.noteBody !== this.updatedNoteBody);
     },
   },
 };
@@ -136,7 +128,7 @@ export default {
 <template>
   <div
     ref="editNoteForm"
-    class="note-edit-form current-note-edit-form">
+    class="note-edit-form current-note-edit-form js-discussion-note-form">
     <div
       v-if="conflictWhileEditing"
       class="js-conflict-edit-warning alert alert-danger">
@@ -150,7 +142,10 @@ export default {
       to ensure information is not lost.
     </div>
     <div class="flash-container timeline-content"></div>
-    <form class="edit-note common-note-form js-quick-submit gfm-form">
+    <form
+      :data-line-code="lineCode"
+      class="edit-note common-note-form js-quick-submit gfm-form"
+    >
 
       <issue-warning
         v-if="hasWarning(getNoteableData)"
@@ -170,7 +165,7 @@ export default {
           :data-supports-quick-actions="!isEditing"
           v-model="updatedNoteBody"
           name="note[note]"
-          class="note-textarea js-gfm-input
+          class="note-textarea js-gfm-input js-note-text
 js-autosize markdown-area js-vue-issue-note-form js-vue-textarea"
           aria-label="Description"
           placeholder="Write a comment or drag your files here…"
@@ -184,19 +179,19 @@ js-autosize markdown-area js-vue-issue-note-form js-vue-textarea"
         <button
           :disabled="isDisabled"
           type="button"
-          class="js-vue-issue-save btn btn-save"
+          class="js-vue-issue-save btn btn-save js-comment-button "
           @click="handleUpdate()">
           {{ saveButtonTitle }}
         </button>
         <button
-          v-if="note.resolvable"
+          v-if="discussion.resolvable"
           class="btn btn-nr btn-default append-right-10 js-comment-resolve-button"
           @click.prevent="handleUpdate(true)"
         >
           {{ resolveButtonTitle }}
         </button>
         <button
-          class="btn btn-cancel note-edit-cancel"
+          class="btn btn-cancel note-edit-cancel js-close-discussion-note-form"
           type="button"
           @click="cancelHandler()">
           Cancel

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

@@ -20,11 +20,6 @@ export default {
       required: false,
       default: '',
     },
-    actionTextHtml: {
-      type: String,
-      required: false,
-      default: '',
-    },
     noteId: {
       type: Number,
       required: true,
@@ -88,10 +83,8 @@ export default {
         <template v-if="actionText">
           {{ actionText }}
         </template>
-        <span
-          v-if="actionTextHtml"
-          class="system-note-message"
-          v-html="actionTextHtml">
+        <span class="system-note-message">
+          <slot></slot>
         </span>
         <span class="system-note-separator">
           &middot;

app/assets/javascripts/notes/constants.js

@@ -11,7 +11,7 @@ export const EMOJI_THUMBSUP = 'thumbsup';
 export const EMOJI_THUMBSDOWN = 'thumbsdown';
 export const ISSUE_NOTEABLE_TYPE = 'issue';
 export const EPIC_NOTEABLE_TYPE = 'epic';
-export const MERGE_REQUEST_NOTEABLE_TYPE = 'merge_request';
+export const MERGE_REQUEST_NOTEABLE_TYPE = 'MergeRequest';
 export const UNRESOLVE_NOTE_METHOD_NAME = 'delete';
 export const RESOLVE_NOTE_METHOD_NAME = 'post';
 export const DESCRIPTION_TYPE = 'changed the description';

app/assets/javascripts/notes/index.js

 import Vue from 'vue';
 import notesApp from './components/notes_app.vue';
+import createStore from './stores';
 
-document.addEventListener(
-  'DOMContentLoaded',
-  () =>
-    new Vue({
+document.addEventListener('DOMContentLoaded', () => {
+  const store = createStore();
+
+  return new Vue({
     el: '#js-vue-notes',
     components: {
       notesApp,
     },
+    store,
     data() {
       const notesDataset = document.getElementById('js-vue-notes').dataset;
       const parsedUserData = JSON.parse(notesDataset.currentUserData);
@@ -16,6 +18,7 @@ document.addEventListener(
       let currentUserData = {};
 
       noteableData.noteableType = notesDataset.noteableType;
+      noteableData.targetType = notesDataset.targetType;
 
       if (parsedUserData) {
         currentUserData = {
@@ -42,5 +45,5 @@ document.addEventListener(
         },
       });
     },
-    }),
-);
+  });
+});

app/assets/javascripts/vue_shared/components/markdown/field.vue

@@ -150,7 +150,7 @@
     </div>
     <div
       v-show="previewMarkdown"
-      class="md md-preview-holder md-preview"
+      class="md md-preview-holder md-preview js-vue-md-preview"
     >
       <div
         ref="markdown-preview"