diff --git a/app/assets/javascripts/autosave.js b/app/assets/javascripts/autosave.js
index e8c59fab609..fa00a3cf386 100644
--- a/app/assets/javascripts/autosave.js
+++ b/app/assets/javascripts/autosave.js
@@ -53,8 +53,4 @@ export default class Autosave {
 
     return window.localStorage.removeItem(this.key);
   }
-
-  dispose() {
-    this.field.off('input');
-  }
 }
diff --git a/app/assets/javascripts/diffs/components/diff_discussions.vue b/app/assets/javascripts/diffs/components/diff_discussions.vue
index e64d5511d78..20483161033 100644
--- a/app/assets/javascripts/diffs/components/diff_discussions.vue
+++ b/app/assets/javascripts/diffs/components/diff_discussions.vue
@@ -30,7 +30,6 @@ export default {
           :render-header="false"
           :render-diff-file="false"
           :always-expanded="true"
-          :discussions-by-diff-order="true"
         />
       </ul>
     </div>
diff --git a/app/assets/javascripts/diffs/components/diff_line_gutter_content.vue b/app/assets/javascripts/diffs/components/diff_line_gutter_content.vue
index d184a76f038..ad838a32518 100644
--- a/app/assets/javascripts/diffs/components/diff_line_gutter_content.vue
+++ b/app/assets/javascripts/diffs/components/diff_line_gutter_content.vue
@@ -71,18 +71,13 @@ export default {
       required: false,
       default: false,
     },
-    discussions: {
-      type: Array,
-      required: false,
-      default: () => [],
-    },
   },
   computed: {
     ...mapState({
       diffViewType: state => state.diffs.diffViewType,
       diffFiles: state => state.diffs.diffFiles,
     }),
-    ...mapGetters(['isLoggedIn']),
+    ...mapGetters(['isLoggedIn', 'discussionsByLineCode']),
     lineHref() {
       return this.lineCode ? `#${this.lineCode}` : '#';
     },
@@ -92,19 +87,24 @@ export default {
         this.showCommentButton &&
         !this.isMatchLine &&
         !this.isContextLine &&
-        !this.isMetaLine &&
-        !this.hasDiscussions
+        !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) {
-        return false;
+        render = false;
       }
 
-      return this.hasDiscussions && this.showCommentButton;
+      return render;
     },
   },
   methods: {
@@ -189,6 +189,7 @@ export default {
       </button>
       <a
         v-if="lineNumber"
+        v-once
         :data-linenumber="lineNumber"
         :href="lineHref"
       >
diff --git a/app/assets/javascripts/diffs/components/diff_line_note_form.vue b/app/assets/javascripts/diffs/components/diff_line_note_form.vue
index cbe4551d06b..32f9516d332 100644
--- a/app/assets/javascripts/diffs/components/diff_line_note_form.vue
+++ b/app/assets/javascripts/diffs/components/diff_line_note_form.vue
@@ -1,17 +1,17 @@
 <script>
+import $ from 'jquery';
 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';
-import autosave from '../../notes/mixins/autosave';
-import { DIFF_NOTE_TYPE } from '../constants';
+import Autosave from '../../autosave';
+import { DIFF_NOTE_TYPE, NOTE_TYPE } from '../constants';
 
 export default {
   components: {
     noteForm,
   },
-  mixins: [autosave],
   props: {
     diffFileHash: {
       type: String,
@@ -41,35 +41,28 @@ export default {
   },
   mounted() {
     if (this.isLoggedIn) {
+      const noteableData = this.getNoteableData;
       const keys = [
-        this.noteableData.diff_head_sha,
+        NOTE_TYPE,
+        this.noteableType,
+        noteableData.id,
+        noteableData.diff_head_sha,
         DIFF_NOTE_TYPE,
-        this.noteableData.source_project_id,
+        noteableData.source_project_id,
         this.line.lineCode,
       ];
 
-      this.initAutoSave(this.noteableData, keys);
+      this.autosave = new Autosave($(this.$refs.noteForm.$refs.textarea), keys);
     }
   },
   methods: {
     ...mapActions('diffs', ['cancelCommentForm']),
     ...mapActions(['saveNote', 'refetchDiscussionById']),
-    handleCancelCommentForm(shouldConfirm, isDirty) {
-      if (shouldConfirm && isDirty) {
-        const msg = s__('Notes|Are you sure you want to cancel creating this comment?');
-
-        // eslint-disable-next-line no-alert
-        if (!window.confirm(msg)) {
-          return;
-        }
-      }
-
+    handleCancelCommentForm() {
+      this.autosave.reset();
       this.cancelCommentForm({
         lineCode: this.line.lineCode,
       });
-      this.$nextTick(() => {
-        this.resetAutoSave();
-      });
     },
     handleSaveNote(note) {
       const selectedDiffFile = this.getDiffFileByHash(this.diffFileHash);
diff --git a/app/assets/javascripts/diffs/components/diff_table_cell.vue b/app/assets/javascripts/diffs/components/diff_table_cell.vue
index e8e8ddc6c5e..5962f30d9bb 100644
--- a/app/assets/javascripts/diffs/components/diff_table_cell.vue
+++ b/app/assets/javascripts/diffs/components/diff_table_cell.vue
@@ -67,11 +67,6 @@ export default {
       required: false,
       default: false,
     },
-    discussions: {
-      type: Array,
-      required: false,
-      default: () => [],
-    },
   },
   computed: {
     ...mapGetters(['isLoggedIn']),
@@ -141,7 +136,6 @@ export default {
       :is-match-line="isMatchLine"
       :is-context-line="isContentLine"
       :is-meta-line="isMetaLine"
-      :discussions="discussions"
     />
   </td>
 </template>
diff --git a/app/assets/javascripts/diffs/components/inline_diff_comment_row.vue b/app/assets/javascripts/diffs/components/inline_diff_comment_row.vue
index 1b5ae5e9f75..ca265dd892c 100644
--- a/app/assets/javascripts/diffs/components/inline_diff_comment_row.vue
+++ b/app/assets/javascripts/diffs/components/inline_diff_comment_row.vue
@@ -1,5 +1,5 @@
 <script>
-import { mapState } from 'vuex';
+import { mapState, mapGetters } from 'vuex';
 import diffDiscussions from './diff_discussions.vue';
 import diffLineNoteForm from './diff_line_note_form.vue';
 
@@ -21,22 +21,18 @@ export default {
       type: Number,
       required: true,
     },
-    discussions: {
-      type: Array,
-      required: false,
-      default: () => [],
-    },
   },
   computed: {
     ...mapState({
       diffLineCommentForms: state => state.diffs.diffLineCommentForms,
     }),
+    ...mapGetters(['discussionsByLineCode']),
+    discussions() {
+      return this.discussionsByLineCode[this.line.lineCode] || [];
+    },
     className() {
       return this.discussions.length ? '' : 'js-temp-notes-holder';
     },
-    hasCommentForm() {
-      return this.diffLineCommentForms[this.line.lineCode];
-    },
   },
 };
 </script>
@@ -57,7 +53,7 @@ export default {
           :discussions="discussions"
         />
         <diff-line-note-form
-          v-if="hasCommentForm"
+          v-if="diffLineCommentForms[line.lineCode]"
           :diff-file-hash="diffFileHash"
           :line="line"
           :note-target-line="line"
diff --git a/app/assets/javascripts/diffs/components/inline_diff_table_row.vue b/app/assets/javascripts/diffs/components/inline_diff_table_row.vue
index 32d65ff994f..0197a510ef1 100644
--- a/app/assets/javascripts/diffs/components/inline_diff_table_row.vue
+++ b/app/assets/javascripts/diffs/components/inline_diff_table_row.vue
@@ -33,11 +33,6 @@ export default {
       required: false,
       default: false,
     },
-    discussions: {
-      type: Array,
-      required: false,
-      default: () => [],
-    },
   },
   data() {
     return {
@@ -94,7 +89,6 @@ export default {
       :is-bottom="isBottom"
       :is-hover="isHover"
       :show-comment-button="true"
-      :discussions="discussions"
       class="diff-line-num old_line"
     />
     <diff-table-cell
@@ -104,10 +98,10 @@ export default {
       :line-type="newLineType"
       :is-bottom="isBottom"
       :is-hover="isHover"
-      :discussions="discussions"
       class="diff-line-num new_line"
     />
     <td
+      v-once
       :class="line.type"
       class="line_content"
       v-html="line.richText"
diff --git a/app/assets/javascripts/diffs/components/inline_diff_view.vue b/app/assets/javascripts/diffs/components/inline_diff_view.vue
index 5f30cc57a59..9fd19b74cd7 100644
--- a/app/assets/javascripts/diffs/components/inline_diff_view.vue
+++ b/app/assets/javascripts/diffs/components/inline_diff_view.vue
@@ -20,11 +20,8 @@ export default {
     },
   },
   computed: {
-    ...mapGetters('diffs', [
-      'commitId',
-      'shouldRenderInlineCommentRow',
-      'singleDiscussionByLineCode',
-    ]),
+    ...mapGetters('diffs', ['commitId']),
+    ...mapGetters(['discussionsByLineCode']),
     ...mapState({
       diffLineCommentForms: state => state.diffs.diffLineCommentForms,
     }),
@@ -38,7 +35,18 @@ export default {
       return window.gon.user_color_scheme;
     },
   },
-  methods: {},
+  methods: {
+    shouldRenderCommentRow(line) {
+      if (this.diffLineCommentForms[line.lineCode]) return true;
+
+      const lineDiscussions = this.discussionsByLineCode[line.lineCode];
+      if (lineDiscussions === undefined) {
+        return false;
+      }
+
+      return lineDiscussions.every(discussion => discussion.expanded);
+    },
+  },
 };
 </script>
 
@@ -57,15 +65,13 @@ export default {
           :line="line"
           :is-bottom="index + 1 === diffLinesLength"
           :key="line.lineCode"
-          :discussions="singleDiscussionByLineCode(line.lineCode)"
         />
         <inline-diff-comment-row
-          v-if="shouldRenderInlineCommentRow(line)"
+          v-if="shouldRenderCommentRow(line)"
           :diff-file-hash="diffFile.fileHash"
           :line="line"
           :line-index="index"
           :key="index"
-          :discussions="singleDiscussionByLineCode(line.lineCode)"
         />
       </template>
     </tbody>
diff --git a/app/assets/javascripts/diffs/components/parallel_diff_comment_row.vue b/app/assets/javascripts/diffs/components/parallel_diff_comment_row.vue
index bb9a65c83fa..cc5248c25d9 100644
--- a/app/assets/javascripts/diffs/components/parallel_diff_comment_row.vue
+++ b/app/assets/javascripts/diffs/components/parallel_diff_comment_row.vue
@@ -1,5 +1,5 @@
 <script>
-import { mapState } from 'vuex';
+import { mapState, mapGetters } from 'vuex';
 import diffDiscussions from './diff_discussions.vue';
 import diffLineNoteForm from './diff_line_note_form.vue';
 
@@ -21,51 +21,48 @@ export default {
       type: Number,
       required: true,
     },
-    leftDiscussions: {
-      type: Array,
-      required: false,
-      default: () => [],
-    },
-    rightDiscussions: {
-      type: Array,
-      required: false,
-      default: () => [],
-    },
   },
   computed: {
     ...mapState({
       diffLineCommentForms: state => state.diffs.diffLineCommentForms,
     }),
+    ...mapGetters(['discussionsByLineCode']),
     leftLineCode() {
       return this.line.left.lineCode;
     },
     rightLineCode() {
       return this.line.right.lineCode;
     },
+    hasDiscussion() {
+      const discussions = this.discussionsByLineCode;
+
+      return discussions[this.leftLineCode] || discussions[this.rightLineCode];
+    },
     hasExpandedDiscussionOnLeft() {
-      const discussions = this.leftDiscussions;
+      const discussions = this.discussionsByLineCode[this.leftLineCode];
+
       return discussions ? discussions.every(discussion => discussion.expanded) : false;
     },
     hasExpandedDiscussionOnRight() {
-      const discussions = this.rightDiscussions;
+      const discussions = this.discussionsByLineCode[this.rightLineCode];
+
       return discussions ? discussions.every(discussion => discussion.expanded) : false;
     },
     hasAnyExpandedDiscussion() {
       return this.hasExpandedDiscussionOnLeft || this.hasExpandedDiscussionOnRight;
     },
     shouldRenderDiscussionsOnLeft() {
-      return this.leftDiscussions && this.hasExpandedDiscussionOnLeft;
+      return this.discussionsByLineCode[this.leftLineCode] && this.hasExpandedDiscussionOnLeft;
     },
     shouldRenderDiscussionsOnRight() {
-      return this.rightDiscussions && this.hasExpandedDiscussionOnRight && this.line.right.type;
-    },
-    showRightSideCommentForm() {
-      return this.line.right.type && this.diffLineCommentForms[this.rightLineCode];
+      return (
+        this.discussionsByLineCode[this.rightLineCode] &&
+        this.hasExpandedDiscussionOnRight &&
+        this.line.right.type
+      );
     },
     className() {
-      return this.leftDiscussions.length > 0 || this.rightDiscussions.length > 0
-        ? ''
-        : 'js-temp-notes-holder';
+      return this.hasDiscussion ? '' : 'js-temp-notes-holder';
     },
   },
 };
@@ -83,12 +80,13 @@ export default {
         class="content"
       >
         <diff-discussions
-          v-if="leftDiscussions.length"
-          :discussions="leftDiscussions"
+          v-if="discussionsByLineCode[leftLineCode].length"
+          :discussions="discussionsByLineCode[leftLineCode]"
         />
       </div>
       <diff-line-note-form
-        v-if="diffLineCommentForms[leftLineCode]"
+        v-if="diffLineCommentForms[leftLineCode] &&
+        diffLineCommentForms[leftLineCode]"
         :diff-file-hash="diffFileHash"
         :line="line.left"
         :note-target-line="line.left"
@@ -102,12 +100,13 @@ export default {
         class="content"
       >
         <diff-discussions
-          v-if="rightDiscussions.length"
-          :discussions="rightDiscussions"
+          v-if="discussionsByLineCode[rightLineCode].length"
+          :discussions="discussionsByLineCode[rightLineCode]"
         />
       </div>
       <diff-line-note-form
-        v-if="showRightSideCommentForm"
+        v-if="diffLineCommentForms[rightLineCode] &&
+        diffLineCommentForms[rightLineCode] && line.right.type"
         :diff-file-hash="diffFileHash"
         :line="line.right"
         :note-target-line="line.right"
diff --git a/app/assets/javascripts/diffs/components/parallel_diff_table_row.vue b/app/assets/javascripts/diffs/components/parallel_diff_table_row.vue
index d4e54c2bd00..ee5bb4d8d05 100644
--- a/app/assets/javascripts/diffs/components/parallel_diff_table_row.vue
+++ b/app/assets/javascripts/diffs/components/parallel_diff_table_row.vue
@@ -36,16 +36,6 @@ export default {
       required: false,
       default: false,
     },
-    leftDiscussions: {
-      type: Array,
-      required: false,
-      default: () => [],
-    },
-    rightDiscussions: {
-      type: Array,
-      required: false,
-      default: () => [],
-    },
   },
   data() {
     return {
@@ -126,10 +116,10 @@ export default {
       :is-hover="isLeftHover"
       :show-comment-button="true"
       :diff-view-type="parallelDiffViewType"
-      :discussions="leftDiscussions"
       class="diff-line-num old_line"
     />
     <td
+      v-once
       :id="line.left.lineCode"
       :class="parallelViewLeftLineType"
       class="line_content parallel left-side"
@@ -147,10 +137,10 @@ export default {
       :is-hover="isRightHover"
       :show-comment-button="true"
       :diff-view-type="parallelDiffViewType"
-      :discussions="rightDiscussions"
       class="diff-line-num new_line"
     />
     <td
+      v-once
       :id="line.right.lineCode"
       :class="line.right.type"
       class="line_content parallel right-side"
diff --git a/app/assets/javascripts/diffs/components/parallel_diff_view.vue b/app/assets/javascripts/diffs/components/parallel_diff_view.vue
index 4d97cb6d15d..32528c9e7ab 100644
--- a/app/assets/javascripts/diffs/components/parallel_diff_view.vue
+++ b/app/assets/javascripts/diffs/components/parallel_diff_view.vue
@@ -21,11 +21,8 @@ export default {
     },
   },
   computed: {
-    ...mapGetters('diffs', [
-      'commitId',
-      'singleDiscussionByLineCode',
-      'shouldRenderParallelCommentRow',
-    ]),
+    ...mapGetters('diffs', ['commitId']),
+    ...mapGetters(['discussionsByLineCode']),
     ...mapState({
       diffLineCommentForms: state => state.diffs.diffLineCommentForms,
     }),
@@ -55,6 +52,32 @@ export default {
       return window.gon.user_color_scheme;
     },
   },
+  methods: {
+    shouldRenderCommentRow(line) {
+      const leftLineCode = line.left.lineCode;
+      const rightLineCode = line.right.lineCode;
+      const discussions = this.discussionsByLineCode;
+      const leftDiscussions = discussions[leftLineCode];
+      const rightDiscussions = discussions[rightLineCode];
+      const hasDiscussion = leftDiscussions || rightDiscussions;
+
+      const hasExpandedDiscussionOnLeft = leftDiscussions
+        ? leftDiscussions.every(discussion => discussion.expanded)
+        : false;
+      const hasExpandedDiscussionOnRight = rightDiscussions
+        ? rightDiscussions.every(discussion => discussion.expanded)
+        : false;
+
+      if (hasDiscussion && (hasExpandedDiscussionOnLeft || hasExpandedDiscussionOnRight)) {
+        return true;
+      }
+
+      const hasCommentFormOnLeft = this.diffLineCommentForms[leftLineCode];
+      const hasCommentFormOnRight = this.diffLineCommentForms[rightLineCode];
+
+      return hasCommentFormOnLeft || hasCommentFormOnRight;
+    },
+  },
 };
 </script>
 
@@ -75,17 +98,13 @@ export default {
             :line="line"
             :is-bottom="index + 1 === diffLinesLength"
             :key="index"
-            :left-discussions="singleDiscussionByLineCode(line.left.lineCode)"
-            :right-discussions="singleDiscussionByLineCode(line.right.lineCode)"
           />
           <parallel-diff-comment-row
-            v-if="shouldRenderParallelCommentRow(line)"
+            v-if="shouldRenderCommentRow(line)"
             :key="`dcr-${index}`"
             :line="line"
             :diff-file-hash="diffFile.fileHash"
             :line-index="index"
-            :left-discussions="singleDiscussionByLineCode(line.left.lineCode)"
-            :right-discussions="singleDiscussionByLineCode(line.right.lineCode)"
           />
         </template>
       </tbody>
diff --git a/app/assets/javascripts/diffs/store/getters.js b/app/assets/javascripts/diffs/store/getters.js
index fc1d15b8d54..9aec117c236 100644
--- a/app/assets/javascripts/diffs/store/getters.js
+++ b/app/assets/javascripts/diffs/store/getters.js
@@ -1,7 +1,5 @@
 import _ from 'underscore';
-import { convertObjectPropsToCamelCase } from '~/lib/utils/common_utils';
 import { PARALLEL_DIFF_VIEW_TYPE, INLINE_DIFF_VIEW_TYPE } from '../constants';
-import { getDiffRefsByLineCode } from './utils';
 
 export const isParallelView = state => state.diffViewType === PARALLEL_DIFF_VIEW_TYPE;
 
@@ -66,87 +64,6 @@ export const getDiffFileDiscussions = (state, getters, rootState, rootGetters) =
       discussion.diff_discussion && _.isEqual(discussion.diff_file.file_hash, diff.fileHash),
   ) || [];
 
-/**
- * Returns an Object with discussions by their diff line code
- * To avoid rendering outdated discussions on the Changes tab we should do a bunch of SHA
- * comparisions. `note.position.formatter` have the current version diff refs but
- * `note.original_position.formatter` will have the first version's diff refs.
- * If line diff refs matches with one of them, we should render it as a discussion on Changes tab.
- *
- * @param {Object} diff
- * @returns {Array}
- */
-export const discussionsByLineCode = (state, getters, rootState, rootGetters) => {
-  const diffRefsByLineCode = getDiffRefsByLineCode(state.diffFiles);
-
-  return rootGetters.discussions.reduce((acc, note) => {
-    const isDiffDiscussion = note.diff_discussion;
-    const hasLineCode = note.line_code;
-    const isResolvable = note.resolvable;
-
-    if (isDiffDiscussion && hasLineCode && isResolvable) {
-      const diffRefs = diffRefsByLineCode[note.line_code];
-      if (diffRefs) {
-        const refs = convertObjectPropsToCamelCase(note.position.formatter);
-        const originalRefs = convertObjectPropsToCamelCase(note.original_position.formatter);
-
-        if (_.isEqual(refs, diffRefs) || _.isEqual(originalRefs, diffRefs)) {
-          const lineCode = note.line_code;
-
-          if (acc[lineCode]) {
-            acc[lineCode].push(note);
-          } else {
-            acc[lineCode] = [note];
-          }
-        }
-      }
-    }
-
-    return acc;
-  }, {});
-};
-
-export const singleDiscussionByLineCode = (state, getters) => lineCode => {
-  if (!lineCode) return [];
-  const discussions = getters.discussionsByLineCode;
-  return discussions[lineCode] || [];
-};
-
-export const shouldRenderParallelCommentRow = (state, getters) => line => {
-  const leftLineCode = line.left.lineCode;
-  const rightLineCode = line.right.lineCode;
-  const leftDiscussions = getters.singleDiscussionByLineCode(leftLineCode);
-  const rightDiscussions = getters.singleDiscussionByLineCode(rightLineCode);
-  const hasDiscussion = leftDiscussions.length || rightDiscussions.length;
-
-  const hasExpandedDiscussionOnLeft = leftDiscussions.length
-    ? leftDiscussions.every(discussion => discussion.expanded)
-    : false;
-  const hasExpandedDiscussionOnRight = rightDiscussions.length
-    ? rightDiscussions.every(discussion => discussion.expanded)
-    : false;
-
-  if (hasDiscussion && (hasExpandedDiscussionOnLeft || hasExpandedDiscussionOnRight)) {
-    return true;
-  }
-
-  const hasCommentFormOnLeft = state.diffLineCommentForms[leftLineCode];
-  const hasCommentFormOnRight = state.diffLineCommentForms[rightLineCode];
-
-  return hasCommentFormOnLeft || hasCommentFormOnRight;
-};
-
-export const shouldRenderInlineCommentRow = (state, getters) => line => {
-  if (state.diffLineCommentForms[line.lineCode]) return true;
-
-  const lineDiscussions = getters.singleDiscussionByLineCode(line.lineCode);
-  if (lineDiscussions.length === 0) {
-    return false;
-  }
-
-  return lineDiscussions.every(discussion => discussion.expanded);
-};
-
 // prevent babel-plugin-rewire from generating an invalid default during karma∂ tests
 export const getDiffFileByHash = state => fileHash =>
   state.diffFiles.find(file => file.fileHash === fileHash);
diff --git a/app/assets/javascripts/diffs/store/utils.js b/app/assets/javascripts/diffs/store/utils.js
index 82082ac508a..d9589baa76e 100644
--- a/app/assets/javascripts/diffs/store/utils.js
+++ b/app/assets/javascripts/diffs/store/utils.js
@@ -173,24 +173,3 @@ export function trimFirstCharOfLineContent(line = {}) {
 
   return parsedLine;
 }
-
-export function getDiffRefsByLineCode(diffFiles) {
-  return diffFiles.reduce((acc, diffFile) => {
-    const { baseSha, headSha, startSha } = diffFile.diffRefs;
-    const { newPath, oldPath } = diffFile;
-
-    // We can only use highlightedDiffLines to create the map of diff lines because
-    // highlightedDiffLines will also include every parallel diff line in it.
-    if (diffFile.highlightedDiffLines) {
-      diffFile.highlightedDiffLines.forEach(line => {
-        const { lineCode, oldLine, newLine } = line;
-
-        if (lineCode) {
-          acc[lineCode] = { baseSha, headSha, startSha, newPath, oldPath, oldLine, newLine };
-        }
-      });
-    }
-
-    return acc;
-  }, {});
-}
diff --git a/app/assets/javascripts/lib/utils/poll.js b/app/assets/javascripts/lib/utils/poll.js
index 04a6948f1f1..198711cf427 100644
--- a/app/assets/javascripts/lib/utils/poll.js
+++ b/app/assets/javascripts/lib/utils/poll.js
@@ -63,7 +63,6 @@ export default class Poll {
     const headers = normalizeHeaders(response.headers);
     const pollInterval = parseInt(headers[this.intervalHeader], 10);
     if (pollInterval > 0 && successCodes.indexOf(response.status) !== -1 && this.canPoll) {
-      clearTimeout(this.timeoutID);
       this.timeoutID = setTimeout(() => {
         this.makeRequest();
       }, pollInterval);
diff --git a/app/assets/javascripts/notes/components/discussion_counter.vue b/app/assets/javascripts/notes/components/discussion_counter.vue
index ad6e7cf501d..6385b75e557 100644
--- a/app/assets/javascripts/notes/components/discussion_counter.vue
+++ b/app/assets/javascripts/notes/components/discussion_counter.vue
@@ -5,20 +5,19 @@ import resolvedSvg from 'icons/_icon_status_success_solid.svg';
 import mrIssueSvg from 'icons/_icon_mr_issue.svg';
 import nextDiscussionSvg from 'icons/_next_discussion.svg';
 import { pluralize } from '../../lib/utils/text_utility';
-import discussionNavigation from '../mixins/discussion_navigation';
+import { scrollToElement } from '../../lib/utils/common_utils';
 import tooltip from '../../vue_shared/directives/tooltip';
 
 export default {
   directives: {
     tooltip,
   },
-  mixins: [discussionNavigation],
   computed: {
     ...mapGetters([
       'getUserData',
       'getNoteableData',
       'discussionCount',
-      'firstUnresolvedDiscussionId',
+      'unresolvedDiscussions',
       'resolvedDiscussionCount',
     ]),
     isLoggedIn() {
@@ -36,6 +35,11 @@ export default {
     resolveAllDiscussionsIssuePath() {
       return this.getNoteableData.create_issue_to_resolve_discussions_path;
     },
+    firstUnresolvedDiscussionId() {
+      const item = this.unresolvedDiscussions[0] || {};
+
+      return item.id;
+    },
   },
   created() {
     this.resolveSvg = resolveSvg;
@@ -46,10 +50,22 @@ export default {
   methods: {
     ...mapActions(['expandDiscussion']),
     jumpToFirstUnresolvedDiscussion() {
-      const diffTab = window.mrTabs.currentAction === 'diffs';
-      const discussionId = this.firstUnresolvedDiscussionId(diffTab);
+      const discussionId = this.firstUnresolvedDiscussionId;
+      if (!discussionId) {
+        return;
+      }
 
-      this.jumpToDiscussion(discussionId);
+      const el = document.querySelector(`[data-discussion-id="${discussionId}"]`);
+      const activeTab = window.mrTabs.currentAction;
+
+      if (activeTab === 'commits' || activeTab === 'pipelines') {
+        window.mrTabs.activateTab('show');
+      }
+
+      if (el) {
+        this.expandDiscussion({ discussionId });
+        scrollToElement(el);
+      }
     },
   },
 };
diff --git a/app/assets/javascripts/notes/components/note_form.vue b/app/assets/javascripts/notes/components/note_form.vue
index abcd4422d7c..26482a02e00 100644
--- a/app/assets/javascripts/notes/components/note_form.vue
+++ b/app/assets/javascripts/notes/components/note_form.vue
@@ -7,7 +7,7 @@ import issuableStateMixin from '../mixins/issuable_state';
 import resolvable from '../mixins/resolvable';
 
 export default {
-  name: 'NoteForm',
+  name: 'IssueNoteForm',
   components: {
     issueWarning,
     markdownField,
diff --git a/app/assets/javascripts/notes/components/noteable_discussion.vue b/app/assets/javascripts/notes/components/noteable_discussion.vue
index 0fe1c16854a..bee635398b3 100644
--- a/app/assets/javascripts/notes/components/noteable_discussion.vue
+++ b/app/assets/javascripts/notes/components/noteable_discussion.vue
@@ -1,11 +1,11 @@
 <script>
+import _ from 'underscore';
 import { mapActions, mapGetters } from 'vuex';
 import resolveDiscussionsSvg from 'icons/_icon_mr_issue.svg';
 import nextDiscussionsSvg from 'icons/_next_discussion.svg';
-import { convertObjectPropsToCamelCase } from '~/lib/utils/common_utils';
+import { convertObjectPropsToCamelCase, scrollToElement } from '~/lib/utils/common_utils';
 import { truncateSha } from '~/lib/utils/text_utility';
 import systemNote from '~/vue_shared/components/notes/system_note.vue';
-import { s__ } from '~/locale';
 import Flash from '../../flash';
 import { SYSTEM_NOTE } from '../constants';
 import userAvatarLink from '../../vue_shared/components/user_avatar/user_avatar_link.vue';
@@ -20,7 +20,6 @@ import placeholderSystemNote from '../../vue_shared/components/notes/placeholder
 import autosave from '../mixins/autosave';
 import noteable from '../mixins/noteable';
 import resolvable from '../mixins/resolvable';
-import discussionNavigation from '../mixins/discussion_navigation';
 import tooltip from '../../vue_shared/directives/tooltip';
 
 export default {
@@ -40,7 +39,7 @@ export default {
   directives: {
     tooltip,
   },
-  mixins: [autosave, noteable, resolvable, discussionNavigation],
+  mixins: [autosave, noteable, resolvable],
   props: {
     discussion: {
       type: Object,
@@ -61,11 +60,6 @@ export default {
       required: false,
       default: false,
     },
-    discussionsByDiffOrder: {
-      type: Boolean,
-      required: false,
-      default: false,
-    },
   },
   data() {
     return {
@@ -80,12 +74,7 @@ export default {
       'discussionCount',
       'resolvedDiscussionCount',
       'allDiscussions',
-      'unresolvedDiscussionsIdsByDiff',
-      'unresolvedDiscussionsIdsByDate',
       'unresolvedDiscussions',
-      'unresolvedDiscussionsIdsOrdered',
-      'nextUnresolvedDiscussionId',
-      'isLastUnresolvedDiscussion',
     ]),
     transformedDiscussion() {
       return {
@@ -136,10 +125,6 @@ export default {
     hasMultipleUnresolvedDiscussions() {
       return this.unresolvedDiscussions.length > 1;
     },
-    showJumpToNextDiscussion() {
-      return this.hasMultipleUnresolvedDiscussions &&
-        !this.isLastUnresolvedDiscussion(this.discussion.id, this.discussionsByDiffOrder);
-    },
     shouldRenderDiffs() {
       const { diffDiscussion, diffFile } = this.transformedDiscussion;
 
@@ -159,17 +144,19 @@ export default {
       return this.isDiffDiscussion ? '' : 'card discussion-wrapper';
     },
   },
-  watch: {
-    isReplying() {
-      if (this.isReplying) {
-        this.$nextTick(() => {
-          // Pass an extra key to separate reply and note edit forms
-          this.initAutoSave(this.transformedDiscussion, ['Reply']);
-        });
+  mounted() {
+    if (this.isReplying) {
+      this.initAutoSave(this.transformedDiscussion);
+    }
+  },
+  updated() {
+    if (this.isReplying) {
+      if (!this.autosave) {
+        this.initAutoSave(this.transformedDiscussion);
       } else {
-        this.disposeAutoSave();
+        this.setAutoSave();
       }
-    },
+    }
   },
   created() {
     this.resolveDiscussionsSvg = resolveDiscussionsSvg;
@@ -207,18 +194,16 @@ export default {
     showReplyForm() {
       this.isReplying = true;
     },
-    cancelReplyForm(shouldConfirm, isDirty) {
-      if (shouldConfirm && isDirty) {
-        const msg = s__('Notes|Are you sure you want to cancel creating this comment?');
-
+    cancelReplyForm(shouldConfirm) {
+      if (shouldConfirm && this.$refs.noteForm.isDirty) {
         // eslint-disable-next-line no-alert
-        if (!window.confirm(msg)) {
+        if (!window.confirm('Are you sure you want to cancel creating this comment?')) {
           return;
         }
       }
 
-      this.isReplying = false;
       this.resetAutoSave();
+      this.isReplying = false;
     },
     saveReply(noteText, form, callback) {
       const postData = {
@@ -256,10 +241,21 @@ Please check your network connection and try again.`;
         });
     },
     jumpToNextDiscussion() {
-      const nextId =
-        this.nextUnresolvedDiscussionId(this.discussion.id, this.discussionsByDiffOrder);
+      const discussionIds = this.allDiscussions.map(d => d.id);
+      const unresolvedIds = this.unresolvedDiscussions.map(d => d.id);
+      const currentIndex = discussionIds.indexOf(this.discussion.id);
+      const remainingAfterCurrent = discussionIds.slice(currentIndex + 1);
+      const nextIndex = _.findIndex(remainingAfterCurrent, id => unresolvedIds.indexOf(id) > -1);
 
-      this.jumpToDiscussion(nextId);
+      if (nextIndex > -1) {
+        const nextId = remainingAfterCurrent[nextIndex];
+        const el = document.querySelector(`[data-discussion-id="${nextId}"]`);
+
+        if (el) {
+          this.expandDiscussion({ discussionId: nextId });
+          scrollToElement(el);
+        }
+      }
     },
   },
 };
@@ -401,7 +397,7 @@ Please check your network connection and try again.`;
                           </a>
                         </div>
                         <div
-                          v-if="showJumpToNextDiscussion"
+                          v-if="hasMultipleUnresolvedDiscussions"
                           class="btn-group"
                           role="group">
                           <button
@@ -424,8 +420,7 @@ Please check your network connection and try again.`;
                     :is-editing="false"
                     save-button-title="Comment"
                     @handleFormUpdate="saveReply"
-                    @cancelForm="cancelReplyForm"
-                  />
+                    @cancelForm="cancelReplyForm" />
                   <note-signed-out-widget v-if="!canReply" />
                 </div>
               </div>
diff --git a/app/assets/javascripts/notes/mixins/autosave.js b/app/assets/javascripts/notes/mixins/autosave.js
index 4f45f912479..36cc8d5d056 100644
--- a/app/assets/javascripts/notes/mixins/autosave.js
+++ b/app/assets/javascripts/notes/mixins/autosave.js
@@ -4,18 +4,12 @@ import { capitalizeFirstCharacter } from '../../lib/utils/text_utility';
 
 export default {
   methods: {
-    initAutoSave(noteable, extraKeys = []) {
-      let keys = [
+    initAutoSave(noteable) {
+      this.autosave = new Autosave($(this.$refs.noteForm.$refs.textarea), [
         'Note',
-        capitalizeFirstCharacter(noteable.noteable_type || noteable.noteableType),
+        capitalizeFirstCharacter(noteable.noteable_type),
         noteable.id,
-      ];
-
-      if (extraKeys) {
-        keys = keys.concat(extraKeys);
-      }
-
-      this.autosave = new Autosave($(this.$refs.noteForm.$refs.textarea), keys);
+      ]);
     },
     resetAutoSave() {
       this.autosave.reset();
@@ -23,8 +17,5 @@ export default {
     setAutoSave() {
       this.autosave.save();
     },
-    disposeAutoSave() {
-      this.autosave.dispose();
-    },
   },
 };
diff --git a/app/assets/javascripts/notes/mixins/discussion_navigation.js b/app/assets/javascripts/notes/mixins/discussion_navigation.js
deleted file mode 100644
index f7c4deee1f8..00000000000
--- a/app/assets/javascripts/notes/mixins/discussion_navigation.js
+++ /dev/null
@@ -1,29 +0,0 @@
-import { scrollToElement } from '~/lib/utils/common_utils';
-
-export default {
-  methods: {
-    jumpToDiscussion(id) {
-      if (id) {
-        const activeTab = window.mrTabs.currentAction;
-        const selector =
-          activeTab === 'diffs'
-            ? `ul.notes[data-discussion-id="${id}"]`
-            : `div.discussion[data-discussion-id="${id}"]`;
-        const el = document.querySelector(selector);
-
-        if (activeTab === 'commits' || activeTab === 'pipelines') {
-          window.mrTabs.activateTab('show');
-        }
-
-        if (el) {
-          this.expandDiscussion({ discussionId: id });
-
-          scrollToElement(el);
-          return true;
-        }
-      }
-
-      return false;
-    },
-  },
-};
diff --git a/app/assets/javascripts/notes/stores/getters.js b/app/assets/javascripts/notes/stores/getters.js
index 0d8d197bf71..5c65e1c3bb5 100644
--- a/app/assets/javascripts/notes/stores/getters.js
+++ b/app/assets/javascripts/notes/stores/getters.js
@@ -28,6 +28,18 @@ export const notesById = state =>
     return acc;
   }, {});
 
+export const discussionsByLineCode = state =>
+  state.discussions.reduce((acc, note) => {
+    if (note.diff_discussion && note.line_code && note.resolvable) {
+      // For context about line notes: there might be multiple notes with the same line code
+      const items = acc[note.line_code] || [];
+      items.push(note);
+
+      Object.assign(acc, { [note.line_code]: items });
+    }
+    return acc;
+  }, {});
+
 export const noteableType = state => {
   const { ISSUE_NOTEABLE_TYPE, MERGE_REQUEST_NOTEABLE_TYPE, EPIC_NOTEABLE_TYPE } = constants;
 
@@ -70,9 +82,6 @@ export const allDiscussions = (state, getters) => {
   return Object.values(resolved).concat(unresolved);
 };
 
-export const allResolvableDiscussions = (state, getters) =>
-  getters.allDiscussions.filter(d => !d.individual_note && d.resolvable);
-
 export const resolvedDiscussionsById = state => {
   const map = {};
 
@@ -89,51 +98,6 @@ export const resolvedDiscussionsById = state => {
   return map;
 };
 
-// Gets Discussions IDs ordered by the date of their initial note
-export const unresolvedDiscussionsIdsByDate = (state, getters) =>
-  getters.allResolvableDiscussions
-    .filter(d => !d.resolved)
-    .sort((a, b) => {
-      const aDate = new Date(a.notes[0].created_at);
-      const bDate = new Date(b.notes[0].created_at);
-
-      if (aDate < bDate) {
-        return -1;
-      }
-
-      return aDate === bDate ? 0 : 1;
-    })
-    .map(d => d.id);
-
-// Gets Discussions IDs ordered by their position in the diff
-//
-// Sorts the array of resolvable yet unresolved discussions by
-// comparing file names first. If file names are the same, compares
-// line numbers.
-export const unresolvedDiscussionsIdsByDiff = (state, getters) =>
-  getters.allResolvableDiscussions
-    .filter(d => !d.resolved)
-    .sort((a, b) => {
-      if (!a.diff_file || !b.diff_file) {
-        return 0;
-      }
-
-      // Get file names comparison result
-      const filenameComparison = a.diff_file.file_path.localeCompare(b.diff_file.file_path);
-
-      // Get the line numbers, to compare within the same file
-      const aLines = [a.position.formatter.new_line, a.position.formatter.old_line];
-      const bLines = [b.position.formatter.new_line, b.position.formatter.old_line];
-
-      return filenameComparison < 0 ||
-        (filenameComparison === 0 &&
-          // .max() because one of them might be zero (if removed/added)
-          Math.max(aLines[0], aLines[1]) < Math.max(bLines[0], bLines[1]))
-        ? -1
-        : 1;
-    })
-    .map(d => d.id);
-
 export const resolvedDiscussionCount = (state, getters) => {
   const resolvedMap = getters.resolvedDiscussionsById;
 
@@ -150,42 +114,5 @@ export const discussionTabCounter = state => {
   return all.length;
 };
 
-// Returns the list of discussion IDs ordered according to given parameter
-// @param {Boolean} diffOrder - is ordered by diff?
-export const unresolvedDiscussionsIdsOrdered = (state, getters) => diffOrder => {
-  if (diffOrder) {
-    return getters.unresolvedDiscussionsIdsByDiff;
-  }
-  return getters.unresolvedDiscussionsIdsByDate;
-};
-
-// Checks if a given discussion is the last in the current order (diff or date)
-// @param {Boolean} discussionId - id of the discussion
-// @param {Boolean} diffOrder - is ordered by diff?
-export const isLastUnresolvedDiscussion = (state, getters) => (discussionId, diffOrder) => {
-  const idsOrdered = getters.unresolvedDiscussionsIdsOrdered(diffOrder);
-  const lastDiscussionId = idsOrdered[idsOrdered.length - 1];
-
-  return lastDiscussionId === discussionId;
-};
-
-// Gets the ID of the discussion following the one provided, respecting order (diff or date)
-// @param {Boolean} discussionId - id of the current discussion
-// @param {Boolean} diffOrder - is ordered by diff?
-export const nextUnresolvedDiscussionId = (state, getters) => (discussionId, diffOrder) => {
-  const idsOrdered = getters.unresolvedDiscussionsIdsOrdered(diffOrder);
-  const currentIndex = idsOrdered.indexOf(discussionId);
-
-  return idsOrdered.slice(currentIndex + 1, currentIndex + 2)[0];
-};
-
-// @param {Boolean} diffOrder - is ordered by diff?
-export const firstUnresolvedDiscussionId = (state, getters) => diffOrder => {
-  if (diffOrder) {
-    return getters.unresolvedDiscussionsIdsByDiff[0];
-  }
-  return getters.unresolvedDiscussionsIdsByDate[0];
-};
-
 // prevent babel-plugin-rewire from generating an invalid default during karma tests
 export default () => {};
diff --git a/app/assets/javascripts/notes/stores/mutations.js b/app/assets/javascripts/notes/stores/mutations.js
index e1b159142c9..ab6a95e2601 100644
--- a/app/assets/javascripts/notes/stores/mutations.js
+++ b/app/assets/javascripts/notes/stores/mutations.js
@@ -174,19 +174,27 @@ export default {
 
   [types.UPDATE_NOTE](state, note) {
     const noteObj = utils.findNoteObjectById(state.discussions, note.discussion_id);
+
     if (noteObj.individual_note) {
       noteObj.notes.splice(0, 1, note);
     } else {
       const comment = utils.findNoteObjectById(noteObj.notes, note.id);
-      Object.assign(comment, note);
+      noteObj.notes.splice(noteObj.notes.indexOf(comment), 1, note);
     }
   },
 
   [types.UPDATE_DISCUSSION](state, noteData) {
     const note = noteData;
-    const selectedDiscussion = state.discussions.find(n => n.id === note.id);
+    let index = 0;
+
+    state.discussions.forEach((n, i) => {
+      if (n.id === note.id) {
+        index = i;
+      }
+    });
+
     note.expanded = true; // override expand flag to prevent collapse
-    Object.assign(selectedDiscussion, note);
+    state.discussions.splice(index, 1, note);
   },
 
   [types.CLOSE_ISSUE](state) {
@@ -207,9 +215,12 @@ export default {
 
   [types.SET_DISCUSSION_DIFF_LINES](state, { discussionId, diffLines }) {
     const discussion = utils.findNoteObjectById(state.discussions, discussionId);
+    const index = state.discussions.indexOf(discussion);
 
-    Object.assign(discussion, {
+    const discussionWithDiffLines = Object.assign({}, discussion, {
       truncated_diff_lines: diffLines,
     });
+
+    state.discussions.splice(index, 1, discussionWithDiffLines);
   },
 };
diff --git a/app/assets/javascripts/notes/stores/utils.js b/app/assets/javascripts/notes/stores/utils.js
index c4a812c5af4..a0e096ebfaf 100644
--- a/app/assets/javascripts/notes/stores/utils.js
+++ b/app/assets/javascripts/notes/stores/utils.js
@@ -2,11 +2,13 @@ import AjaxCache from '~/lib/utils/ajax_cache';
 
 const REGEX_QUICK_ACTIONS = /^\/\w+.*$/gm;
 
-export const findNoteObjectById = (notes, id) => notes.find(n => n.id === id);
+export const findNoteObjectById = (notes, id) =>
+  notes.filter(n => n.id === id)[0];
 
 export const getQuickActionText = note => {
   let text = 'Applying command';
-  const quickActions = AjaxCache.get(gl.GfmAutoComplete.dataSources.commands) || [];
+  const quickActions =
+    AjaxCache.get(gl.GfmAutoComplete.dataSources.commands) || [];
 
   const executedCommands = quickActions.filter(command => {
     const commandRegex = new RegExp(`/${command.name}`);
@@ -27,4 +29,5 @@ export const getQuickActionText = note => {
 
 export const hasQuickActions = note => REGEX_QUICK_ACTIONS.test(note);
 
-export const stripQuickActions = note => note.replace(REGEX_QUICK_ACTIONS, '').trim();
+export const stripQuickActions = note =>
+  note.replace(REGEX_QUICK_ACTIONS, '').trim();
diff --git a/app/serializers/discussion_entity.rb b/app/serializers/discussion_entity.rb
index 6f95e6f9ca1..b8321037fa5 100644
--- a/app/serializers/discussion_entity.rb
+++ b/app/serializers/discussion_entity.rb
@@ -6,7 +6,6 @@ class DiscussionEntity < Grape::Entity
 
   expose :id, :reply_id
   expose :position, if: -> (d, _) { d.diff_discussion? && !d.legacy_diff_discussion? }
-  expose :original_position, if: -> (d, _) { d.diff_discussion? && !d.legacy_diff_discussion? }
   expose :line_code, if: -> (d, _) { d.diff_discussion? }
   expose :expanded?, as: :expanded
   expose :active?, as: :active, if: -> (d, _) { d.diff_discussion? }
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index b003f22f26c..7189d1fedaf 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -3622,9 +3622,6 @@ msgstr ""
 msgid "Note: Consider asking your GitLab administrator to configure %{github_integration_link}, which will allow login via GitHub and allow importing repositories without generating a Personal Access Token."
 msgstr ""
 
-msgid "Notes|Are you sure you want to cancel creating this comment?"
-msgstr ""
-
 msgid "Notification events"
 msgstr ""
 
diff --git a/spec/features/merge_request/user_resolves_diff_notes_and_discussions_resolve_spec.rb b/spec/features/merge_request/user_resolves_diff_notes_and_discussions_resolve_spec.rb
index 2d268ecab58..bf4d5396df9 100644
--- a/spec/features/merge_request/user_resolves_diff_notes_and_discussions_resolve_spec.rb
+++ b/spec/features/merge_request/user_resolves_diff_notes_and_discussions_resolve_spec.rb
@@ -342,9 +342,8 @@ describe 'Merge request > User resolves diff notes and discussions', :js do
         end
       end
 
-      it 'shows jump to next discussion button, apart from the last one' do
-        expect(page).to have_selector('.discussion-reply-holder', count: 2)
-        expect(page).to have_selector('.discussion-reply-holder .discussion-next-btn', count: 1)
+      it 'shows jump to next discussion button' do
+        expect(page.all('.discussion-reply-holder', count: 2)).to all(have_selector('.discussion-next-btn'))
       end
 
       it 'displays next discussion even if hidden' do
diff --git a/spec/javascripts/autosave_spec.js b/spec/javascripts/autosave_spec.js
index dcb1c781591..38ae5b7e00c 100644
--- a/spec/javascripts/autosave_spec.js
+++ b/spec/javascripts/autosave_spec.js
@@ -59,10 +59,12 @@ describe('Autosave', () => {
 
         Autosave.prototype.restore.call(autosave);
 
-        expect(field.trigger).toHaveBeenCalled();
+        expect(
+          field.trigger,
+        ).toHaveBeenCalled();
       });
 
-      it('triggers native event', done => {
+      it('triggers native event', (done) => {
         autosave.field.get(0).addEventListener('change', () => {
           done();
         });
@@ -79,7 +81,9 @@ describe('Autosave', () => {
       it('does not trigger event', () => {
         spyOn(field, 'trigger').and.callThrough();
 
-        expect(field.trigger).not.toHaveBeenCalled();
+        expect(
+          field.trigger,
+        ).not.toHaveBeenCalled();
       });
     });
   });
diff --git a/spec/javascripts/diffs/components/diff_line_gutter_content_spec.js b/spec/javascripts/diffs/components/diff_line_gutter_content_spec.js
index bdc94131fc2..2d136a63c52 100644
--- a/spec/javascripts/diffs/components/diff_line_gutter_content_spec.js
+++ b/spec/javascripts/diffs/components/diff_line_gutter_content_spec.js
@@ -18,12 +18,10 @@ describe('DiffLineGutterContent', () => {
   };
   const setDiscussions = component => {
     component.$store.dispatch('setInitialNotes', getDiscussionsMockData());
-    component.$store.commit('diffs/SET_DIFF_DATA', { diffFiles: [getDiffFileMock()] });
   };
 
   const resetDiscussions = component => {
     component.$store.dispatch('setInitialNotes', []);
-    component.$store.commit('diffs/SET_DIFF_DATA', {});
   };
 
   describe('computed', () => {
@@ -50,11 +48,7 @@ describe('DiffLineGutterContent', () => {
 
       it('should return discussions for the given lineCode', () => {
         const { lineCode } = getDiffFileMock().highlightedDiffLines[1];
-        const component = createComponent({
-          lineCode,
-          showCommentButton: true,
-          discussions: getDiscussionsMockData(),
-        });
+        const component = createComponent({ lineCode, showCommentButton: true });
 
         setDiscussions(component);
 
diff --git a/spec/javascripts/diffs/components/diff_line_note_form_spec.js b/spec/javascripts/diffs/components/diff_line_note_form_spec.js
index 6fe5fdaf7f9..4600aaea70b 100644
--- a/spec/javascripts/diffs/components/diff_line_note_form_spec.js
+++ b/spec/javascripts/diffs/components/diff_line_note_form_spec.js
@@ -3,7 +3,6 @@ import DiffLineNoteForm from '~/diffs/components/diff_line_note_form.vue';
 import store from '~/mr_notes/stores';
 import { createComponentWithStore } from 'spec/helpers/vue_mount_component_helper';
 import diffFileMockData from '../mock_data/diff_file';
-import { noteableDataMock } from '../../notes/mock_data';
 
 describe('DiffLineNoteForm', () => {
   let component;
@@ -22,9 +21,10 @@ describe('DiffLineNoteForm', () => {
       noteTargetLine: diffLines[0],
     });
 
-    Object.defineProperties(component, {
-      noteableData: { value: noteableDataMock },
-      isLoggedIn: { value: true },
+    Object.defineProperty(component, 'isLoggedIn', {
+      get() {
+        return true;
+      },
     });
 
     component.$mount();
@@ -32,37 +32,12 @@ describe('DiffLineNoteForm', () => {
 
   describe('methods', () => {
     describe('handleCancelCommentForm', () => {
-      it('should ask for confirmation when shouldConfirm and isDirty passed as truthy', () => {
-        spyOn(window, 'confirm').and.returnValue(false);
-
-        component.handleCancelCommentForm(true, true);
-        expect(window.confirm).toHaveBeenCalled();
-      });
-
-      it('should ask for confirmation when one of the params false', () => {
-        spyOn(window, 'confirm').and.returnValue(false);
-
-        component.handleCancelCommentForm(true, false);
-        expect(window.confirm).not.toHaveBeenCalled();
-
-        component.handleCancelCommentForm(false, true);
-        expect(window.confirm).not.toHaveBeenCalled();
-      });
-
-      it('should call cancelCommentForm with lineCode', done => {
-        spyOn(window, 'confirm');
+      it('should call cancelCommentForm with lineCode', () => {
         spyOn(component, 'cancelCommentForm');
-        spyOn(component, 'resetAutoSave');
         component.handleCancelCommentForm();
 
-        expect(window.confirm).not.toHaveBeenCalled();
-        component.$nextTick(() => {
-          expect(component.cancelCommentForm).toHaveBeenCalledWith({
-            lineCode: diffLines[0].lineCode,
-          });
-          expect(component.resetAutoSave).toHaveBeenCalled();
-
-          done();
+        expect(component.cancelCommentForm).toHaveBeenCalledWith({
+          lineCode: diffLines[0].lineCode,
         });
       });
     });
@@ -91,7 +66,7 @@ describe('DiffLineNoteForm', () => {
 
   describe('mounted', () => {
     it('should init autosave', () => {
-      const key = 'autosave/Note/Issue/98//DiffNote//1c497fbb3a46b78edf04cc2a2fa33f67e3ffbe2a_1_1';
+      const key = 'autosave/Note/issue///DiffNote//1c497fbb3a46b78edf04cc2a2fa33f67e3ffbe2a_1_1';
 
       expect(component.autosave).toBeDefined();
       expect(component.autosave.key).toEqual(key);
diff --git a/spec/javascripts/diffs/components/inline_diff_view_spec.js b/spec/javascripts/diffs/components/inline_diff_view_spec.js
index 90dfa5c5a58..b02328dd359 100644
--- a/spec/javascripts/diffs/components/inline_diff_view_spec.js
+++ b/spec/javascripts/diffs/components/inline_diff_view_spec.js
@@ -33,7 +33,6 @@ describe('InlineDiffView', () => {
     it('should render discussions', done => {
       const el = component.$el;
       component.$store.dispatch('setInitialNotes', getDiscussionsMockData());
-      component.$store.commit('diffs/SET_DIFF_DATA', { diffFiles: [getDiffFileMock()] });
 
       Vue.nextTick(() => {
         expect(el.querySelectorAll('.notes_holder').length).toEqual(1);
diff --git a/spec/javascripts/diffs/mock_data/diff_discussions.js b/spec/javascripts/diffs/mock_data/diff_discussions.js
index 8cd57d2248b..41d0dfd8939 100644
--- a/spec/javascripts/diffs/mock_data/diff_discussions.js
+++ b/spec/javascripts/diffs/mock_data/diff_discussions.js
@@ -12,17 +12,6 @@ export default {
       head_sha: 'c48ee0d1bf3b30453f5b32250ce03134beaa6d13',
     },
   },
-  original_position: {
-    formatter: {
-      old_line: null,
-      new_line: 2,
-      old_path: 'CHANGELOG',
-      new_path: 'CHANGELOG',
-      base_sha: 'e63f41fe459e62e1228fcef60d7189127aeba95a',
-      start_sha: 'd9eaefe5a676b820c57ff18cf5b68316025f7962',
-      head_sha: 'c48ee0d1bf3b30453f5b32250ce03134beaa6d13',
-    },
-  },
   line_code: '1c497fbb3a46b78edf04cc2a2fa33f67e3ffbe2a_1_2',
   expanded: true,
   notes: [
diff --git a/spec/javascripts/diffs/store/getters_spec.js b/spec/javascripts/diffs/store/getters_spec.js
index 987c4dbcb26..7706c32d24d 100644
--- a/spec/javascripts/diffs/store/getters_spec.js
+++ b/spec/javascripts/diffs/store/getters_spec.js
@@ -2,7 +2,6 @@ import * as getters from '~/diffs/store/getters';
 import state from '~/diffs/store/modules/diff_state';
 import { PARALLEL_DIFF_VIEW_TYPE, INLINE_DIFF_VIEW_TYPE } from '~/diffs/constants';
 import discussion from '../mock_data/diff_discussions';
-import diffFile from '../mock_data/diff_file';
 
 describe('Diffs Module Getters', () => {
   let localState;
@@ -222,38 +221,4 @@ describe('Diffs Module Getters', () => {
       expect(getters.getDiffFileByHash(localState)('123')).toBeUndefined();
     });
   });
-
-  describe('discussionsByLineCode', () => {
-    let mockState;
-
-    beforeEach(() => {
-      mockState = { diffFiles: [diffFile] };
-    });
-
-    it('should return a map of diff lines with their line codes', () => {
-      const mockGetters = { discussions: [discussionMock] };
-
-      const map = getters.discussionsByLineCode(mockState, {}, {}, mockGetters);
-      expect(map['1c497fbb3a46b78edf04cc2a2fa33f67e3ffbe2a_1_2']).toBeDefined();
-      expect(Object.keys(map).length).toEqual(1);
-    });
-
-    it('should have the diff discussion on the map if the original position matches', () => {
-      discussionMock.position.formatter.base_sha = 'ff9200';
-      const mockGetters = { discussions: [discussionMock] };
-
-      const map = getters.discussionsByLineCode(mockState, {}, {}, mockGetters);
-      expect(map['1c497fbb3a46b78edf04cc2a2fa33f67e3ffbe2a_1_2']).toBeDefined();
-      expect(Object.keys(map).length).toEqual(1);
-    });
-
-    it('should not add an outdated diff discussion to the returned map', () => {
-      discussionMock.position.formatter.base_sha = 'ff9200';
-      discussionMock.original_position.formatter.base_sha = 'ff9200';
-      const mockGetters = { discussions: [discussionMock] };
-
-      const map = getters.discussionsByLineCode(mockState, {}, {}, mockGetters);
-      expect(Object.keys(map).length).toEqual(0);
-    });
-  });
 });
diff --git a/spec/javascripts/diffs/store/utils_spec.js b/spec/javascripts/diffs/store/utils_spec.js
index 8e7bd8afca4..32136d9ebff 100644
--- a/spec/javascripts/diffs/store/utils_spec.js
+++ b/spec/javascripts/diffs/store/utils_spec.js
@@ -207,24 +207,4 @@ describe('DiffsStoreUtils', () => {
       expect(utils.trimFirstCharOfLineContent()).toEqual({});
     });
   });
-
-  describe('getDiffRefsByLineCode', () => {
-    it('should return diffRefs for all highlightedDiffLines', () => {
-      const diffFile = getDiffFileMock();
-      const map = utils.getDiffRefsByLineCode([diffFile]);
-      const { highlightedDiffLines } = diffFile;
-      const lineCodeCount = highlightedDiffLines.reduce(
-        (acc, line) => (line.lineCode ? acc + 1 : acc),
-        0,
-      );
-
-      const { baseSha, headSha, startSha } = diffFile.diffRefs;
-      const targetLine = map[highlightedDiffLines[4].lineCode];
-
-      expect(Object.keys(map).length).toEqual(lineCodeCount);
-      expect(targetLine.baseSha).toEqual(baseSha);
-      expect(targetLine.headSha).toEqual(headSha);
-      expect(targetLine.startSha).toEqual(startSha);
-    });
-  });
 });
diff --git a/spec/javascripts/notes/components/discussion_counter_spec.js b/spec/javascripts/notes/components/discussion_counter_spec.js
index d09bc5037ef..a3869cc6498 100644
--- a/spec/javascripts/notes/components/discussion_counter_spec.js
+++ b/spec/javascripts/notes/components/discussion_counter_spec.js
@@ -46,7 +46,7 @@ describe('DiscussionCounter component', () => {
           discussions,
         });
         setFixtures(`
-          <div class="discussion" data-discussion-id="${firstDiscussionId}"></div>
+          <div data-discussion-id="${firstDiscussionId}"></div>
         `);
 
         vm.jumpToFirstUnresolvedDiscussion();
diff --git a/spec/javascripts/notes/components/noteable_discussion_spec.js b/spec/javascripts/notes/components/noteable_discussion_spec.js
index 2a01bd85520..7da931fd9cb 100644
--- a/spec/javascripts/notes/components/noteable_discussion_spec.js
+++ b/spec/javascripts/notes/components/noteable_discussion_spec.js
@@ -14,7 +14,6 @@ describe('noteable_discussion component', () => {
   preloadFixtures(discussionWithTwoUnresolvedNotes);
 
   beforeEach(() => {
-    window.mrTabs = {};
     store = createStore();
     store.dispatch('setNoteableData', noteableDataMock);
     store.dispatch('setNotesData', notesDataMock);
@@ -47,15 +46,10 @@ describe('noteable_discussion component', () => {
 
     it('should toggle reply form', done => {
       vm.$el.querySelector('.js-vue-discussion-reply').click();
-
       Vue.nextTick(() => {
+        expect(vm.$refs.noteForm).not.toBeNull();
         expect(vm.isReplying).toEqual(true);
-
-        // There is a watcher for `isReplying` which will init autosave in the next tick
-        Vue.nextTick(() => {
-          expect(vm.$refs.noteForm).not.toBeNull();
-          done();
-        });
+        done();
       });
     });
 
@@ -107,29 +101,33 @@ describe('noteable_discussion component', () => {
 
   describe('methods', () => {
     describe('jumpToNextDiscussion', () => {
-      it('expands next unresolved discussion', done => {
-        const discussion2 = getJSONFixture(discussionWithTwoUnresolvedNotes)[0];
-        discussion2.resolved = false;
-        discussion2.id = 'next'; // prepare this for being identified as next one (to be jumped to)
-        vm.$store.dispatch('setInitialNotes', [discussionMock, discussion2]);
-        window.mrTabs.currentAction = 'show';
+      it('expands next unresolved discussion', () => {
+        spyOn(vm, 'expandDiscussion').and.stub();
+        const discussions = [
+          discussionMock,
+          {
+            ...discussionMock,
+            id: discussionMock.id + 1,
+            notes: [{ ...discussionMock.notes[0], resolvable: true, resolved: true }],
+          },
+          {
+            ...discussionMock,
+            id: discussionMock.id + 2,
+            notes: [{ ...discussionMock.notes[0], resolvable: true, resolved: false }],
+          },
+        ];
+        const nextDiscussionId = discussionMock.id + 2;
+        store.replaceState({
+          ...store.state,
+          discussions,
+        });
+        setFixtures(`
+          <div data-discussion-id="${nextDiscussionId}"></div>
+        `);
 
-        Vue.nextTick()
-          .then(() => {
-            spyOn(vm, 'expandDiscussion').and.stub();
+        vm.jumpToNextDiscussion();
 
-            const nextDiscussionId = discussion2.id;
-
-            setFixtures(`
-              <div class="discussion" data-discussion-id="${nextDiscussionId}"></div>
-            `);
-
-            vm.jumpToNextDiscussion();
-
-            expect(vm.expandDiscussion).toHaveBeenCalledWith({ discussionId: nextDiscussionId });
-          })
-          .then(done)
-          .catch(done.fail);
+        expect(vm.expandDiscussion).toHaveBeenCalledWith({ discussionId: nextDiscussionId });
       });
     });
   });
diff --git a/spec/javascripts/notes/mock_data.js b/spec/javascripts/notes/mock_data.js
index 67f6a9629d9..be2a8ba67fe 100644
--- a/spec/javascripts/notes/mock_data.js
+++ b/spec/javascripts/notes/mock_data.js
@@ -1168,87 +1168,3 @@ export const collapsedSystemNotes = [
     diff_discussion: false,
   },
 ];
-
-export const discussion1 = {
-  id: 'abc1',
-  resolvable: true,
-  resolved: false,
-  diff_file: {
-    file_path: 'about.md',
-  },
-  position: {
-    formatter: {
-      new_line: 50,
-      old_line: null,
-    },
-  },
-  notes: [
-    {
-      created_at: '2018-07-04T16:25:41.749Z',
-    },
-  ],
-};
-
-export const resolvedDiscussion1 = {
-  id: 'abc1',
-  resolvable: true,
-  resolved: true,
-  diff_file: {
-    file_path: 'about.md',
-  },
-  position: {
-    formatter: {
-      new_line: 50,
-      old_line: null,
-    },
-  },
-  notes: [
-    {
-      created_at: '2018-07-04T16:25:41.749Z',
-    },
-  ],
-};
-
-export const discussion2 = {
-  id: 'abc2',
-  resolvable: true,
-  resolved: false,
-  diff_file: {
-    file_path: 'README.md',
-  },
-  position: {
-    formatter: {
-      new_line: null,
-      old_line: 20,
-    },
-  },
-  notes: [
-    {
-      created_at: '2018-07-04T12:05:41.749Z',
-    },
-  ],
-};
-
-export const discussion3 = {
-  id: 'abc3',
-  resolvable: true,
-  resolved: false,
-  diff_file: {
-    file_path: 'README.md',
-  },
-  position: {
-    formatter: {
-      new_line: 21,
-      old_line: null,
-    },
-  },
-  notes: [
-    {
-      created_at: '2018-07-05T17:25:41.749Z',
-    },
-  ],
-};
-
-export const unresolvableDiscussion = {
-  resolvable: false,
-};
diff --git a/spec/javascripts/notes/stores/getters_spec.js b/spec/javascripts/notes/stores/getters_spec.js
index 7f8ede51508..41599e00122 100644
--- a/spec/javascripts/notes/stores/getters_spec.js
+++ b/spec/javascripts/notes/stores/getters_spec.js
@@ -5,11 +5,6 @@ import {
   noteableDataMock,
   individualNote,
   collapseNotesMock,
-  discussion1,
-  discussion2,
-  discussion3,
-  resolvedDiscussion1,
-  unresolvableDiscussion,
 } from '../mock_data';
 
 const discussionWithTwoUnresolvedNotes = 'merge_requests/resolved_diff_discussion.json';
@@ -114,154 +109,4 @@ describe('Getters Notes Store', () => {
       expect(getters.isNotesFetched(state)).toBeFalsy();
     });
   });
-
-  describe('allResolvableDiscussions', () => {
-    it('should return only resolvable discussions in same order', () => {
-      const localGetters = {
-        allDiscussions: [
-          discussion3,
-          unresolvableDiscussion,
-          discussion1,
-          unresolvableDiscussion,
-          discussion2,
-        ],
-      };
-
-      expect(getters.allResolvableDiscussions(state, localGetters)).toEqual([
-        discussion3,
-        discussion1,
-        discussion2,
-      ]);
-    });
-
-    it('should return empty array if there are no resolvable discussions', () => {
-      const localGetters = {
-        allDiscussions: [unresolvableDiscussion, unresolvableDiscussion],
-      };
-
-      expect(getters.allResolvableDiscussions(state, localGetters)).toEqual([]);
-    });
-  });
-
-  describe('unresolvedDiscussionsIdsByDiff', () => {
-    it('should return all discussions IDs in diff order', () => {
-      const localGetters = {
-        allResolvableDiscussions: [discussion3, discussion1, discussion2],
-      };
-
-      expect(getters.unresolvedDiscussionsIdsByDiff(state, localGetters)).toEqual([
-        'abc1',
-        'abc2',
-        'abc3',
-      ]);
-    });
-
-    it('should return empty array if all discussions have been resolved', () => {
-      const localGetters = {
-        allResolvableDiscussions: [resolvedDiscussion1],
-      };
-
-      expect(getters.unresolvedDiscussionsIdsByDiff(state, localGetters)).toEqual([]);
-    });
-  });
-
-  describe('unresolvedDiscussionsIdsByDate', () => {
-    it('should return all discussions in date ascending order', () => {
-      const localGetters = {
-        allResolvableDiscussions: [discussion3, discussion1, discussion2],
-      };
-
-      expect(getters.unresolvedDiscussionsIdsByDate(state, localGetters)).toEqual([
-        'abc2',
-        'abc1',
-        'abc3',
-      ]);
-    });
-
-    it('should return empty array if all discussions have been resolved', () => {
-      const localGetters = {
-        allResolvableDiscussions: [resolvedDiscussion1],
-      };
-
-      expect(getters.unresolvedDiscussionsIdsByDate(state, localGetters)).toEqual([]);
-    });
-  });
-
-  describe('unresolvedDiscussionsIdsOrdered', () => {
-    const localGetters = {
-      unresolvedDiscussionsIdsByDate: ['123', '456'],
-      unresolvedDiscussionsIdsByDiff: ['abc', 'def'],
-    };
-
-    it('should return IDs ordered by diff when diffOrder param is true', () => {
-      expect(getters.unresolvedDiscussionsIdsOrdered(state, localGetters)(true)).toEqual([
-        'abc',
-        'def',
-      ]);
-    });
-
-    it('should return IDs ordered by date when diffOrder param is not true', () => {
-      expect(getters.unresolvedDiscussionsIdsOrdered(state, localGetters)(false)).toEqual([
-        '123',
-        '456',
-      ]);
-      expect(getters.unresolvedDiscussionsIdsOrdered(state, localGetters)(undefined)).toEqual([
-        '123',
-        '456',
-      ]);
-    });
-  });
-
-  describe('isLastUnresolvedDiscussion', () => {
-    const localGetters = {
-      unresolvedDiscussionsIdsOrdered: () => ['123', '456', '789'],
-    };
-
-    it('should return true if the discussion id provided is the last', () => {
-      expect(getters.isLastUnresolvedDiscussion(state, localGetters)('789')).toBe(true);
-    });
-
-    it('should return false if the discussion id provided is not the last', () => {
-      expect(getters.isLastUnresolvedDiscussion(state, localGetters)('123')).toBe(false);
-      expect(getters.isLastUnresolvedDiscussion(state, localGetters)('456')).toBe(false);
-    });
-  });
-
-  describe('nextUnresolvedDiscussionId', () => {
-    const localGetters = {
-      unresolvedDiscussionsIdsOrdered: () => ['123', '456', '789'],
-    };
-
-    it('should return the ID of the discussion after the ID provided', () => {
-      expect(getters.nextUnresolvedDiscussionId(state, localGetters)('123')).toBe('456');
-      expect(getters.nextUnresolvedDiscussionId(state, localGetters)('456')).toBe('789');
-      expect(getters.nextUnresolvedDiscussionId(state, localGetters)('789')).toBe(undefined);
-    });
-  });
-
-  describe('firstUnresolvedDiscussionId', () => {
-    const localGetters = {
-      unresolvedDiscussionsIdsByDate: ['123', '456'],
-      unresolvedDiscussionsIdsByDiff: ['abc', 'def'],
-    };
-
-    it('should return the first discussion id by diff when diffOrder param is true', () => {
-      expect(getters.firstUnresolvedDiscussionId(state, localGetters)(true)).toBe('abc');
-    });
-
-    it('should return the first discussion id by date when diffOrder param is not true', () => {
-      expect(getters.firstUnresolvedDiscussionId(state, localGetters)(false)).toBe('123');
-      expect(getters.firstUnresolvedDiscussionId(state, localGetters)(undefined)).toBe('123');
-    });
-
-    it('should be falsy if all discussions are resolved', () => {
-      const localGettersFalsy = {
-        unresolvedDiscussionsIdsByDiff: [],
-        unresolvedDiscussionsIdsByDate: [],
-      };
-
-      expect(getters.firstUnresolvedDiscussionId(state, localGettersFalsy)(true)).toBeFalsy();
-      expect(getters.firstUnresolvedDiscussionId(state, localGettersFalsy)(false)).toBeFalsy();
-    });
-  });
 });