Enable "prefer-destructuring" in JS files

Partially addresses #47006.

68 files changed, 134 insertions, 131 deletions

diff --git a/app/assets/javascripts/ajax_loading_spinner.js b/app/assets/javascripts/ajax_loading_spinner.js
index bd08308904c..54e86f329e4 100644
--- a/app/assets/javascripts/ajax_loading_spinner.js
+++ b/app/assets/javascripts/ajax_loading_spinner.js
@@ -26,7 +26,7 @@ export default class AjaxLoadingSpinner {
   }
 
   static toggleLoadingIcon(iconElement) {
-    const classList = iconElement.classList;
+    const { classList } = iconElement;
     classList.toggle(iconElement.dataset.icon);
     classList.toggle('fa-spinner');
     classList.toggle('fa-spin');
diff --git a/app/assets/javascripts/behaviors/copy_to_clipboard.js b/app/assets/javascripts/behaviors/copy_to_clipboard.js
index 75834ba351d..00419e80cbb 100644
--- a/app/assets/javascripts/behaviors/copy_to_clipboard.js
+++ b/app/assets/javascripts/behaviors/copy_to_clipboard.js
@@ -52,7 +52,7 @@ export default function initCopyToClipboard() {
    * data types to the intended values.
    */
   $(document).on('copy', 'body > textarea[readonly]', (e) => {
-    const clipboardData = e.originalEvent.clipboardData;
+    const { clipboardData } = e.originalEvent;
     if (!clipboardData) return;
 
     const text = e.target.value;
diff --git a/app/assets/javascripts/behaviors/markdown/copy_as_gfm.js b/app/assets/javascripts/behaviors/markdown/copy_as_gfm.js
index 9745e37acce..5d7a3bed301 100644
--- a/app/assets/javascripts/behaviors/markdown/copy_as_gfm.js
+++ b/app/assets/javascripts/behaviors/markdown/copy_as_gfm.js
@@ -321,7 +321,7 @@ export class CopyAsGFM {
   }
 
   static copyAsGFM(e, transformer) {
-    const clipboardData = e.originalEvent.clipboardData;
+    const { clipboardData } = e.originalEvent;
     if (!clipboardData) return;
 
     const documentFragment = getSelectedFragment();
@@ -338,7 +338,7 @@ export class CopyAsGFM {
   }
 
   static pasteGFM(e) {
-    const clipboardData = e.originalEvent.clipboardData;
+    const { clipboardData } = e.originalEvent;
     if (!clipboardData) return;
 
     const text = clipboardData.getData('text/plain');
diff --git a/app/assets/javascripts/blob/balsamiq/balsamiq_viewer.js b/app/assets/javascripts/blob/balsamiq/balsamiq_viewer.js
index 766039404ce..7986287f7e7 100644
--- a/app/assets/javascripts/blob/balsamiq/balsamiq_viewer.js
+++ b/app/assets/javascripts/blob/balsamiq/balsamiq_viewer.js
@@ -84,7 +84,7 @@ class BalsamiqViewer {
   renderTemplate(preview) {
     const resource = this.getResource(preview.resourceID);
     const name = BalsamiqViewer.parseTitle(resource);
-    const image = preview.image;
+    const { image } = preview;
 
     const template = PREVIEW_TEMPLATE({
       name,
diff --git a/app/assets/javascripts/blob/balsamiq_viewer.js b/app/assets/javascripts/blob/balsamiq_viewer.js
index 06ef86ecb77..b88e69a07bf 100644
--- a/app/assets/javascripts/blob/balsamiq_viewer.js
+++ b/app/assets/javascripts/blob/balsamiq_viewer.js
@@ -12,7 +12,7 @@ export default function loadBalsamiqFile() {
 
   if (!(viewer instanceof Element)) return;
 
-  const endpoint = viewer.dataset.endpoint;
+  const { endpoint } = viewer.dataset;
 
   const balsamiqViewer = new BalsamiqViewer(viewer);
   balsamiqViewer.loadFile(endpoint).catch(onError);
diff --git a/app/assets/javascripts/blob/stl_viewer.js b/app/assets/javascripts/blob/stl_viewer.js
index 63236b6477f..339906adc34 100644
--- a/app/assets/javascripts/blob/stl_viewer.js
+++ b/app/assets/javascripts/blob/stl_viewer.js
@@ -5,7 +5,7 @@ export default () => {
 
   [].slice.call(document.querySelectorAll('.js-material-changer')).forEach((el) => {
     el.addEventListener('click', (e) => {
-      const target = e.target;
+      const { target } = e;
 
       e.preventDefault();
 
diff --git a/app/assets/javascripts/boards/components/sidebar/remove_issue.vue b/app/assets/javascripts/boards/components/sidebar/remove_issue.vue
index 806e038a95f..55278626ffc 100644
--- a/app/assets/javascripts/boards/components/sidebar/remove_issue.vue
+++ b/app/assets/javascripts/boards/components/sidebar/remove_issue.vue
@@ -23,7 +23,7 @@
     },
     methods: {
       removeIssue() {
-        const issue = this.issue;
+        const { issue } = this;
         const lists = issue.getLists();
         const listLabelIds = lists.map(list => list.label.id);
 
diff --git a/app/assets/javascripts/boards/index.js b/app/assets/javascripts/boards/index.js
index 2d9141bf71c..751a66f89c6 100644
--- a/app/assets/javascripts/boards/index.js
+++ b/app/assets/javascripts/boards/index.js
@@ -121,7 +121,7 @@ export default () => {
         this.filterManager.updateTokens();
       },
       updateDetailIssue(newIssue) {
-        const sidebarInfoEndpoint = newIssue.sidebarInfoEndpoint;
+        const { sidebarInfoEndpoint } = newIssue;
         if (sidebarInfoEndpoint && newIssue.subscribed === undefined) {
           newIssue.setFetchingState('subscriptions', true);
           BoardService.getIssueInfo(sidebarInfoEndpoint)
@@ -144,7 +144,7 @@ export default () => {
         Store.detail.issue = {};
       },
       toggleSubscription(id) {
-        const issue = Store.detail.issue;
+        const { issue } = Store.detail;
         if (issue.id === id && issue.toggleSubscriptionEndpoint) {
           issue.setFetchingState('subscriptions', true);
           BoardService.toggleIssueSubscription(issue.toggleSubscriptionEndpoint)
diff --git a/app/assets/javascripts/boards/stores/modal_store.js b/app/assets/javascripts/boards/stores/modal_store.js
index a4220cd840d..0d9ac367a70 100644
--- a/app/assets/javascripts/boards/stores/modal_store.js
+++ b/app/assets/javascripts/boards/stores/modal_store.js
@@ -26,7 +26,7 @@ class ModalStore {
 
   toggleIssue(issueObj) {
     const issue = issueObj;
-    const selected = issue.selected;
+    const { selected } = issue;
 
     issue.selected = !selected;
 
diff --git a/app/assets/javascripts/clusters/clusters_bundle.js b/app/assets/javascripts/clusters/clusters_bundle.js
index e42a3632e79..8139aa69fc7 100644
--- a/app/assets/javascripts/clusters/clusters_bundle.js
+++ b/app/assets/javascripts/clusters/clusters_bundle.js
@@ -81,7 +81,7 @@ export default class Clusters {
   }
 
   initApplications() {
-    const store = this.store;
+    const { store } = this;
     const el = document.querySelector('#js-cluster-applications');
 
     this.applications = new Vue({
diff --git a/app/assets/javascripts/commit/image_file.js b/app/assets/javascripts/commit/image_file.js
index 2d180e9903a..410580b4c25 100644
--- a/app/assets/javascripts/commit/image_file.js
+++ b/app/assets/javascripts/commit/image_file.js
@@ -122,7 +122,7 @@ export default class ImageFile {
       return $('.swipe.view', this.file).each((function(_this) {
         return function(index, view) {
           var $swipeWrap, $swipeBar, $swipeFrame, wrapPadding, ref;
-          ref = _this.prepareFrames(view), maxWidth = ref[0], maxHeight = ref[1];
+          ref = _this.prepareFrames(view), [maxWidth, maxHeight] = ref;
           $swipeFrame = $('.swipe-frame', view);
           $swipeWrap = $('.swipe-wrap', view);
           $swipeBar = $('.swipe-bar', view);
@@ -159,7 +159,7 @@ export default class ImageFile {
       return $('.onion-skin.view', this.file).each((function(_this) {
         return function(index, view) {
           var $frame, $track, $dragger, $frameAdded, framePadding, ref, dragging = false;
-          ref = _this.prepareFrames(view), maxWidth = ref[0], maxHeight = ref[1];
+          ref = _this.prepareFrames(view), [maxWidth, maxHeight] = ref;
           $frame = $('.onion-skin-frame', view);
           $frameAdded = $('.frame.added', view);
           $track = $('.drag-track', view);
diff --git a/app/assets/javascripts/create_merge_request_dropdown.js b/app/assets/javascripts/create_merge_request_dropdown.js
index f77a5730b77..02aa507ba03 100644
--- a/app/assets/javascripts/create_merge_request_dropdown.js
+++ b/app/assets/javascripts/create_merge_request_dropdown.js
@@ -281,7 +281,7 @@ export default class CreateMergeRequestDropdown {
 
     if (event.target === this.branchInput) {
       target = 'branch';
-      value = this.branchInput.value;
+      ({ value } = this.branchInput);
     } else if (event.target === this.refInput) {
       target = 'ref';
       value =
diff --git a/app/assets/javascripts/diff_notes/components/diff_note_avatars.js b/app/assets/javascripts/diff_notes/components/diff_note_avatars.js
index 40f7c2fe5f3..5528d2a542b 100644
--- a/app/assets/javascripts/diff_notes/components/diff_note_avatars.js
+++ b/app/assets/javascripts/diff_notes/components/diff_note_avatars.js
@@ -111,7 +111,7 @@ const DiffNoteAvatars = Vue.extend({
       });
     },
     addNoCommentClass() {
-      const notesCount = this.notesCount;
+      const { notesCount } = this;
 
       $(this.$el).closest('.js-avatar-container')
         .toggleClass('no-comment-btn', notesCount > 0)
diff --git a/app/assets/javascripts/diff_notes/components/jump_to_discussion.js b/app/assets/javascripts/diff_notes/components/jump_to_discussion.js
index 66b20cc8739..2b893e35b6d 100644
--- a/app/assets/javascripts/diff_notes/components/jump_to_discussion.js
+++ b/app/assets/javascripts/diff_notes/components/jump_to_discussion.js
@@ -73,7 +73,7 @@ const JumpToDiscussion = Vue.extend({
         }).toArray();
       };
 
-      const discussions = this.discussions;
+      const { discussions } = this;
 
       if (activeTab === 'diffs') {
         discussionsSelector = '.diffs .notes[data-discussion-id]';
diff --git a/app/assets/javascripts/diff_notes/diff_notes_bundle.js b/app/assets/javascripts/diff_notes/diff_notes_bundle.js
index a9800a11644..7dcf3594471 100644
--- a/app/assets/javascripts/diff_notes/diff_notes_bundle.js
+++ b/app/assets/javascripts/diff_notes/diff_notes_bundle.js
@@ -18,7 +18,7 @@ import './components/new_issue_for_discussion';
 export default () => {
   const projectPathHolder =
     document.querySelector('.merge-request') || document.querySelector('.commit-box');
-  const projectPath = projectPathHolder.dataset.projectPath;
+  const { projectPath } = projectPathHolder.dataset;
   const COMPONENT_SELECTOR =
     'resolve-btn, resolve-discussion-btn, jump-to-discussion, comment-and-resolve-btn, new-issue-for-discussion-btn';
 
diff --git a/app/assets/javascripts/diffs/components/diff_gutter_avatars.vue b/app/assets/javascripts/diffs/components/diff_gutter_avatars.vue
index 3193b18becb..7e50a0aed84 100644
--- a/app/assets/javascripts/diffs/components/diff_gutter_avatars.vue
+++ b/app/assets/javascripts/diffs/components/diff_gutter_avatars.vue
@@ -47,7 +47,7 @@ export default {
   methods: {
     ...mapActions(['toggleDiscussion']),
     getTooltipText(noteData) {
-      let note = noteData.note;
+      let { note } = noteData;
 
       if (note.length > LENGTH_OF_AVATAR_TOOLTIP) {
         note = truncate(note, LENGTH_OF_AVATAR_TOOLTIP);
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 05dca0cdd9a..8999fd2ac96 100644
--- a/app/assets/javascripts/diffs/components/diff_line_gutter_content.vue
+++ b/app/assets/javascripts/diffs/components/diff_line_gutter_content.vue
@@ -124,7 +124,7 @@ export default {
       const newLineNumber = this.metaData.newPos || 0;
       const offset = newLineNumber - oldLineNumber;
       const bottom = this.isBottom;
-      const fileHash = this.fileHash;
+      const { fileHash } = this;
       const view = this.diffViewType;
       let unfold = true;
       let lineNumber = newLineNumber - 1;
diff --git a/app/assets/javascripts/diffs/components/parallel_diff_view.vue b/app/assets/javascripts/diffs/components/parallel_diff_view.vue
index 2ddf8e6c6ed..60edbcbbda8 100644
--- a/app/assets/javascripts/diffs/components/parallel_diff_view.vue
+++ b/app/assets/javascripts/diffs/components/parallel_diff_view.vue
@@ -89,7 +89,7 @@ export default {
       return isLeftExpanded || isRightExpanded;
     },
     getLineCode(line, side) {
-      const lineCode = side.lineCode;
+      const { lineCode } = side;
       if (lineCode) {
         return lineCode;
       }
diff --git a/app/assets/javascripts/environments/components/environment_item.vue b/app/assets/javascripts/environments/components/environment_item.vue
index 866e91057ec..5ecdccf63ad 100644
--- a/app/assets/javascripts/environments/components/environment_item.vue
+++ b/app/assets/javascripts/environments/components/environment_item.vue
@@ -292,7 +292,7 @@
         if (this.model &&
           this.model.last_deployment &&
           this.model.last_deployment.deployable) {
-          const deployable = this.model.last_deployment.deployable;
+          const { deployable } = this.model.last_deployment;
           return `${deployable.name} #${deployable.id}`;
         }
         return '';
diff --git a/app/assets/javascripts/environments/stores/environments_store.js b/app/assets/javascripts/environments/stores/environments_store.js
index 5f2989ab854..5ce9225a4bb 100644
--- a/app/assets/javascripts/environments/stores/environments_store.js
+++ b/app/assets/javascripts/environments/stores/environments_store.js
@@ -146,7 +146,7 @@ export default class EnvironmentsStore {
    * @return {Array}
    */
   updateEnvironmentProp(environment, prop, newValue) {
-    const environments = this.state.environments;
+    const { environments } = this.state;
 
     const updatedEnvironments = environments.map((env) => {
       const updateEnv = Object.assign({}, env);
@@ -161,7 +161,7 @@ export default class EnvironmentsStore {
   }
 
   getOpenFolders() {
-    const environments = this.state.environments;
+    const { environments } = this.state;
 
     return environments.filter(env => env.isFolder && env.isOpen);
   }
diff --git a/app/assets/javascripts/filtered_search/dropdown_utils.js b/app/assets/javascripts/filtered_search/dropdown_utils.js
index 9bc36c1f9b6..27fff488603 100644
--- a/app/assets/javascripts/filtered_search/dropdown_utils.js
+++ b/app/assets/javascripts/filtered_search/dropdown_utils.js
@@ -35,7 +35,7 @@ export default class DropdownUtils {
 
     // Remove the symbol for filter
     if (value[0] === filterSymbol) {
-      symbol = value[0];
+      [symbol] = value;
       value = value.slice(1);
     }
 
@@ -162,7 +162,7 @@ export default class DropdownUtils {
 
   // Determines the full search query (visual tokens + input)
   static getSearchQuery(untilInput = false) {
-    const container = FilteredSearchContainer.container;
+    const { container } = FilteredSearchContainer;
     const tokens = [].slice.call(container.querySelectorAll('.tokens-container li'));
     const values = [];
 
@@ -220,7 +220,7 @@ export default class DropdownUtils {
   }
 
   static getInputSelectionPosition(input) {
-    const selectionStart = input.selectionStart;
+    const { selectionStart } = input;
     let inputValue = input.value;
     // Replace all spaces inside quote marks with underscores
     // (will continue to match entire string until an end quote is found if any)
diff --git a/app/assets/javascripts/filtered_search/filtered_search_dropdown_manager.js b/app/assets/javascripts/filtered_search/filtered_search_dropdown_manager.js
index d7e1de18d09..296571606d6 100644
--- a/app/assets/javascripts/filtered_search/filtered_search_dropdown_manager.js
+++ b/app/assets/javascripts/filtered_search/filtered_search_dropdown_manager.js
@@ -159,7 +159,7 @@ export default class FilteredSearchDropdownManager {
   load(key, firstLoad = false) {
     const mappingKey = this.mapping[key];
     const glClass = mappingKey.gl;
-    const element = mappingKey.element;
+    const { element } = mappingKey;
     let forceShowList = false;
 
     if (!mappingKey.reference) {
diff --git a/app/assets/javascripts/filtered_search/filtered_search_manager.js b/app/assets/javascripts/filtered_search/filtered_search_manager.js
index cf5ba1e1771..81286c54c4c 100644
--- a/app/assets/javascripts/filtered_search/filtered_search_manager.js
+++ b/app/assets/javascripts/filtered_search/filtered_search_manager.js
@@ -235,7 +235,7 @@ export default class FilteredSearchManager {
 
   checkForEnter(e) {
     if (e.keyCode === 38 || e.keyCode === 40) {
-      const selectionStart = this.filteredSearchInput.selectionStart;
+      const { selectionStart } = this.filteredSearchInput;
 
       e.preventDefault();
       this.filteredSearchInput.setSelectionRange(selectionStart, selectionStart);
@@ -496,7 +496,7 @@ export default class FilteredSearchManager {
           // Replace underscore with hyphen in the sanitizedkey.
           // e.g. 'my_reaction' => 'my-reaction'
           sanitizedKey = sanitizedKey.replace('_', '-');
-          const symbol = match.symbol;
+          const { symbol } = match;
           let quotationsToUse = '';
 
           if (sanitizedValue.indexOf(' ') !== -1) {
diff --git a/app/assets/javascripts/filtered_search/filtered_search_visual_tokens.js b/app/assets/javascripts/filtered_search/filtered_search_visual_tokens.js
index 600024c21c3..56fe1ab4e90 100644
--- a/app/assets/javascripts/filtered_search/filtered_search_visual_tokens.js
+++ b/app/assets/javascripts/filtered_search/filtered_search_visual_tokens.js
@@ -101,7 +101,7 @@ export default class FilteredSearchVisualTokens {
 
   static updateLabelTokenColor(tokenValueContainer, tokenValue) {
     const filteredSearchInput = FilteredSearchContainer.container.querySelector('.filtered-search');
-    const baseEndpoint = filteredSearchInput.dataset.baseEndpoint;
+    const { baseEndpoint } = filteredSearchInput.dataset;
     const labelsEndpoint = FilteredSearchVisualTokens.getEndpointWithQueryParams(
       `${baseEndpoint}/labels.json`,
       filteredSearchInput.dataset.endpointQueryParams,
@@ -215,7 +215,7 @@ export default class FilteredSearchVisualTokens {
   static addFilterVisualToken(tokenName, tokenValue, canEdit) {
     const { lastVisualToken, isLastVisualTokenValid }
       = FilteredSearchVisualTokens.getLastVisualTokenBeforeInput();
-    const addVisualTokenElement = FilteredSearchVisualTokens.addVisualTokenElement;
+    const { addVisualTokenElement } = FilteredSearchVisualTokens;
 
     if (isLastVisualTokenValid) {
       addVisualTokenElement(tokenName, tokenValue, false, canEdit);
diff --git a/app/assets/javascripts/filtered_search/recent_searches_root.js b/app/assets/javascripts/filtered_search/recent_searches_root.js
index f9338b82acf..c1efa9c86f4 100644
--- a/app/assets/javascripts/filtered_search/recent_searches_root.js
+++ b/app/assets/javascripts/filtered_search/recent_searches_root.js
@@ -29,7 +29,7 @@ class RecentSearchesRoot {
   }
 
   render() {
-    const state = this.store.state;
+    const { state } = this.store;
     this.vm = new Vue({
       el: this.wrapperElement,
       components: {
diff --git a/app/assets/javascripts/gfm_auto_complete.js b/app/assets/javascripts/gfm_auto_complete.js
index b0f674f2c05..09186a865e4 100644
--- a/app/assets/javascripts/gfm_auto_complete.js
+++ b/app/assets/javascripts/gfm_auto_complete.js
@@ -80,7 +80,7 @@ class GfmAutoComplete {
         let tpl = '/${name} ';
         let referencePrefix = null;
         if (value.params.length > 0) {
-          referencePrefix = value.params[0][0];
+          [[referencePrefix]] = value.params;
           if (/^[@%~]/.test(referencePrefix)) {
             tpl += '<%- referencePrefix %>';
           }
@@ -458,7 +458,7 @@ class GfmAutoComplete {
   static isLoading(data) {
     let dataToInspect = data;
     if (data && data.length > 0) {
-      dataToInspect = data[0];
+      [dataToInspect] = data;
     }
 
     const loadingState = GfmAutoComplete.defaultLoadingData[0];
diff --git a/app/assets/javascripts/gl_dropdown.js b/app/assets/javascripts/gl_dropdown.js
index 45889c2d604..8d231e6c405 100644
--- a/app/assets/javascripts/gl_dropdown.js
+++ b/app/assets/javascripts/gl_dropdown.js
@@ -613,7 +613,7 @@ GitLabDropdown = (function() {
   };
 
   GitLabDropdown.prototype.renderItem = function(data, group, index) {
-    var field, fieldName, html, selected, text, url, value, rowHidden;
+    var field, html, selected, text, url, value, rowHidden;
 
     if (!this.options.renderRow) {
       value = this.options.id ? this.options.id(data) : data.id;
@@ -651,7 +651,7 @@ GitLabDropdown = (function() {
       html = this.options.renderRow.call(this.options, data, this);
     } else {
       if (!selected) {
-        fieldName = this.options.fieldName;
+        const { fieldName } = this.options;
 
         if (value) {
           field = this.dropdown.parent().find(`input[name='${fieldName}'][value='${value}']`);
@@ -705,7 +705,8 @@ GitLabDropdown = (function() {
 
   GitLabDropdown.prototype.highlightTextMatches = function(text, term) {
     const occurrences = fuzzaldrinPlus.match(text, term);
-    const indexOf = [].indexOf;
+    const { indexOf } = [];
+
     return text.split('').map(function(character, i) {
       if (indexOf.call(occurrences, i) !== -1) {
         return "<b>" + character + "</b>";
@@ -721,9 +722,9 @@ GitLabDropdown = (function() {
   };
 
   GitLabDropdown.prototype.rowClicked = function(el) {
-    var field, fieldName, groupName, isInput, selectedIndex, selectedObject, value, isMarking;
+    var field, groupName, isInput, selectedIndex, selectedObject, value, isMarking;
 
-    fieldName = this.options.fieldName;
+    const { fieldName } = this.options;
     isInput = $(this.el).is('input');
     if (this.renderedData) {
       groupName = el.data('group');
diff --git a/app/assets/javascripts/groups/index.js b/app/assets/javascripts/groups/index.js
index 57eaac72906..83a9008a94b 100644
--- a/app/assets/javascripts/groups/index.js
+++ b/app/assets/javascripts/groups/index.js
@@ -29,7 +29,7 @@ export default () => {
       groupsApp,
     },
     data() {
-      const dataset = this.$options.el.dataset;
+      const { dataset } = this.$options.el;
       const hideProjects = dataset.hideProjects === 'true';
       const store = new GroupsStore(hideProjects);
       const service = new GroupsService(dataset.endpoint);
@@ -42,7 +42,7 @@ export default () => {
       };
     },
     beforeMount() {
-      const dataset = this.$options.el.dataset;
+      const { dataset } = this.$options.el;
       let groupFilterList = null;
       const form = document.querySelector(dataset.formSel);
       const filter = document.querySelector(dataset.filterSel);
diff --git a/app/assets/javascripts/ide/components/file_finder/item.vue b/app/assets/javascripts/ide/components/file_finder/item.vue
index a4cf3edb981..f5252ce7706 100644
--- a/app/assets/javascripts/ide/components/file_finder/item.vue
+++ b/app/assets/javascripts/ide/components/file_finder/item.vue
@@ -30,7 +30,7 @@ export default {
   },
   computed: {
     pathWithEllipsis() {
-      const path = this.file.path;
+      const { path } = this.file;
 
       return path.length < MAX_PATH_LENGTH
         ? path
diff --git a/app/assets/javascripts/ide/components/new_dropdown/upload.vue b/app/assets/javascripts/ide/components/new_dropdown/upload.vue
index 1814924be39..677b282bd61 100644
--- a/app/assets/javascripts/ide/components/new_dropdown/upload.vue
+++ b/app/assets/javascripts/ide/components/new_dropdown/upload.vue
@@ -23,6 +23,7 @@
         let { result } = target;
 
         if (!isText) {
+          // eslint-disable-next-line prefer-destructuring
           result = result.split('base64,')[1];
         }
 
diff --git a/app/assets/javascripts/ide/lib/diff/diff_worker.js b/app/assets/javascripts/ide/lib/diff/diff_worker.js
index f09930e8158..78b2eab6399 100644
--- a/app/assets/javascripts/ide/lib/diff/diff_worker.js
+++ b/app/assets/javascripts/ide/lib/diff/diff_worker.js
@@ -2,7 +2,7 @@ import { computeDiff } from './diff';
 
 // eslint-disable-next-line no-restricted-globals
 self.addEventListener('message', (e) => {
-  const data = e.data;
+  const { data } = e;
 
   // eslint-disable-next-line no-restricted-globals
   self.postMessage({
diff --git a/app/assets/javascripts/ide/stores/actions/file.js b/app/assets/javascripts/ide/stores/actions/file.js
index 74f9c112f5a..29995a29d1a 100644
--- a/app/assets/javascripts/ide/stores/actions/file.js
+++ b/app/assets/javascripts/ide/stores/actions/file.js
@@ -8,7 +8,7 @@ import { setPageTitle } from '../utils';
 import { viewerTypes } from '../../constants';
 
 export const closeFile = ({ commit, state, dispatch }, file) => {
-  const path = file.path;
+  const { path } = file;
   const indexOfClosedFile = state.openFiles.findIndex(f => f.key === file.key);
   const fileWasActive = file.active;
 
diff --git a/app/assets/javascripts/image_diff/helpers/dom_helper.js b/app/assets/javascripts/image_diff/helpers/dom_helper.js
index 12d56714b34..a319bcccb8f 100644
--- a/app/assets/javascripts/image_diff/helpers/dom_helper.js
+++ b/app/assets/javascripts/image_diff/helpers/dom_helper.js
@@ -2,7 +2,8 @@ export function setPositionDataAttribute(el, options) {
   // Update position data attribute so that the
   // new comment form can use this data for ajax request
   const { x, y, width, height } = options;
-  const position = el.dataset.position;
+  const { position } = el.dataset;
+
   const positionObject = Object.assign({}, JSON.parse(position), {
     x,
     y,
diff --git a/app/assets/javascripts/image_diff/helpers/utils_helper.js b/app/assets/javascripts/image_diff/helpers/utils_helper.js
index 28d9a969143..beec99e6934 100644
--- a/app/assets/javascripts/image_diff/helpers/utils_helper.js
+++ b/app/assets/javascripts/image_diff/helpers/utils_helper.js
@@ -40,8 +40,7 @@ export function getTargetSelection(event) {
   const x = event.offsetX;
   const y = event.offsetY;
 
-  const width = imageEl.width;
-  const height = imageEl.height;
+  const { width, height } = imageEl;
 
   const actualWidth = imageEl.naturalWidth;
   const actualHeight = imageEl.naturalHeight;
diff --git a/app/assets/javascripts/issuable/auto_width_dropdown_select.js b/app/assets/javascripts/issuable/auto_width_dropdown_select.js
index b2c2de9e5de..07cf1eff279 100644
--- a/app/assets/javascripts/issuable/auto_width_dropdown_select.js
+++ b/app/assets/javascripts/issuable/auto_width_dropdown_select.js
@@ -10,7 +10,7 @@ class AutoWidthDropdownSelect {
   }
 
   init() {
-    const dropdownClass = this.dropdownClass;
+    const { dropdownClass } = this;
     this.$selectElement.select2({
       dropdownCssClass: dropdownClass,
       ...AutoWidthDropdownSelect.selectOptions(this.dropdownClass),
diff --git a/app/assets/javascripts/jobs/job_details_bundle.js b/app/assets/javascripts/jobs/job_details_bundle.js
index f2939ad4dbe..0db7b95636c 100644
--- a/app/assets/javascripts/jobs/job_details_bundle.js
+++ b/app/assets/javascripts/jobs/job_details_bundle.js
@@ -4,7 +4,7 @@ import jobHeader from './components/header.vue';
 import detailsBlock from './components/sidebar_details_block.vue';
 
 export default () => {
-  const dataset = document.getElementById('js-job-details-vue').dataset;
+  const { dataset } = document.getElementById('js-job-details-vue');
   const mediator = new JobMediator({ endpoint: dataset.endpoint });
 
   mediator.fetchJob();
diff --git a/app/assets/javascripts/labels_select.js b/app/assets/javascripts/labels_select.js
index dfc3f7a94c8..37a45d1d1a2 100644
--- a/app/assets/javascripts/labels_select.js
+++ b/app/assets/javascripts/labels_select.js
@@ -56,7 +56,7 @@ export default class LabelsSelect {
         .map(function () {
           return this.value;
         }).get();
-      const handleClick = options.handleClick;
+      const { handleClick } = options;
 
       $sidebarLabelTooltip.tooltip();
 
@@ -215,7 +215,7 @@ export default class LabelsSelect {
           }
           else {
             if (label.color != null) {
-              color = label.color[0];
+              [color] = label.color;
             }
           }
           if (color) {
@@ -243,7 +243,8 @@ export default class LabelsSelect {
           var $dropdownParent = $dropdown.parent();
           var $dropdownInputField = $dropdownParent.find('.dropdown-input-field');
           var isSelected = el !== null ? el.hasClass('is-active') : false;
-          var title = selected.title;
+
+          var { title } = selected;
           var selectedLabels = this.selected;
 
           if ($dropdownInputField.length && $dropdownInputField.val().length) {
@@ -382,7 +383,7 @@ export default class LabelsSelect {
               }));
             }
             else {
-              var labels = gl.issueBoards.BoardsStore.detail.issue.labels;
+              var { labels } = gl.issueBoards.BoardsStore.detail.issue;
               labels = labels.filter(function (selectedLabel) {
                 return selectedLabel.id !== label.id;
               });
diff --git a/app/assets/javascripts/lib/utils/common_utils.js b/app/assets/javascripts/lib/utils/common_utils.js
index 68f92c7f08a..5c249f3068e 100644
--- a/app/assets/javascripts/lib/utils/common_utils.js
+++ b/app/assets/javascripts/lib/utils/common_utils.js
@@ -164,7 +164,7 @@ export const scrollToElement = element => {
   if (!(element instanceof $)) {
     $el = $(element);
   }
-  const top = $el.offset().top;
+  const { top } = $el.offset();
 
   return $('body, html').animate(
     {
@@ -203,9 +203,7 @@ export const getSelectedFragment = () => {
 
 export const insertText = (target, text) => {
   // Firefox doesn't support `document.execCommand('insertText', false, text)` on textareas
-  const selectionStart = target.selectionStart;
-  const selectionEnd = target.selectionEnd;
-  const value = target.value;
+  const { selectionStart, selectionEnd, value } = target;
 
   const textBefore = value.substring(0, selectionStart);
   const textAfter = value.substring(selectionEnd, value.length);
@@ -245,7 +243,8 @@ export const nodeMatchesSelector = (node, selector) => {
 
   // IE11 doesn't support `node.matches(selector)`
 
-  let parentNode = node.parentNode;
+  let { parentNode } = node;
+
   if (!parentNode) {
     parentNode = document.createElement('div');
     // eslint-disable-next-line no-param-reassign
@@ -281,6 +280,8 @@ export const normalizeCRLFHeaders = headers => {
 
   headersArray.forEach(header => {
     const keyValue = header.split(': ');
+
+    // eslint-disable-next-line prefer-destructuring
     headersObject[keyValue[0]] = keyValue[1];
   });
 
diff --git a/app/assets/javascripts/lib/utils/number_utils.js b/app/assets/javascripts/lib/utils/number_utils.js
index f086d962221..afbab59055b 100644
--- a/app/assets/javascripts/lib/utils/number_utils.js
+++ b/app/assets/javascripts/lib/utils/number_utils.js
@@ -13,7 +13,7 @@ export function formatRelevantDigits(number) {
   let relevantDigits = 0;
   let formattedNumber = '';
   if (!Number.isNaN(Number(number))) {
-    digitsLeft = number.toString().split('.')[0];
+    [digitsLeft] = number.toString().split('.');
     switch (digitsLeft.length) {
       case 1:
         relevantDigits = 3;
diff --git a/app/assets/javascripts/merge_conflicts/merge_conflict_store.js b/app/assets/javascripts/merge_conflicts/merge_conflict_store.js
index 70f185e3656..1501296ac4f 100644
--- a/app/assets/javascripts/merge_conflicts/merge_conflict_store.js
+++ b/app/assets/javascripts/merge_conflicts/merge_conflict_store.js
@@ -156,7 +156,7 @@ import Cookies from 'js-cookie';
         return 0;
       }
 
-      const files = this.state.conflictsData.files;
+      const { files } = this.state.conflictsData;
       let count = 0;
 
       files.forEach((file) => {
@@ -313,7 +313,7 @@ import Cookies from 'js-cookie';
     },
 
     isReadyToCommit() {
-      const files = this.state.conflictsData.files;
+      const { files } = this.state.conflictsData;
       const hasCommitMessage = $.trim(this.state.conflictsData.commitMessage).length;
       let unresolved = 0;
 
diff --git a/app/assets/javascripts/merge_conflicts/merge_conflicts_bundle.js b/app/assets/javascripts/merge_conflicts/merge_conflicts_bundle.js
index 491858c3602..7badd68089c 100644
--- a/app/assets/javascripts/merge_conflicts/merge_conflicts_bundle.js
+++ b/app/assets/javascripts/merge_conflicts/merge_conflicts_bundle.js
@@ -12,7 +12,7 @@ import syntaxHighlight from '../syntax_highlight';
 export default function initMergeConflicts() {
   const INTERACTIVE_RESOLVE_MODE = 'interactive';
   const conflictsEl = document.querySelector('#conflicts');
-  const mergeConflictsStore = gl.mergeConflicts.mergeConflictsStore;
+  const { mergeConflictsStore } = gl.mergeConflicts;
   const mergeConflictsService = new MergeConflictsService({
     conflictsPath: conflictsEl.dataset.conflictsPath,
     resolveConflictsPath: conflictsEl.dataset.resolveConflictsPath,
diff --git a/app/assets/javascripts/merge_request_tabs.js b/app/assets/javascripts/merge_request_tabs.js
index 83d326ef68f..329d4303132 100644
--- a/app/assets/javascripts/merge_request_tabs.js
+++ b/app/assets/javascripts/merge_request_tabs.js
@@ -64,7 +64,7 @@ import Notes from './notes';
 /* eslint-enable max-len */
 
 // Store the `location` object, allowing for easier stubbing in tests
-let location = window.location;
+let { location } = window;
 
 export default class MergeRequestTabs {
   constructor({ action, setUrl, stubLocation } = {}) {
@@ -279,7 +279,7 @@ export default class MergeRequestTabs {
 
   mountPipelinesView() {
     const pipelineTableViewEl = document.querySelector('#commit-pipeline-table-view');
-    const CommitPipelinesTable = gl.CommitPipelinesTable;
+    const { CommitPipelinesTable } = gl;
     this.commitPipelinesTable = new CommitPipelinesTable({
       propsData: {
         endpoint: pipelineTableViewEl.dataset.endpoint,
diff --git a/app/assets/javascripts/monitoring/utils/multiple_time_series.js b/app/assets/javascripts/monitoring/utils/multiple_time_series.js
index ed3a27dd68b..cee39fd0559 100644
--- a/app/assets/javascripts/monitoring/utils/multiple_time_series.js
+++ b/app/assets/javascripts/monitoring/utils/multiple_time_series.js
@@ -41,10 +41,10 @@ function queryTimeSeries(query, graphWidth, graphHeight, graphHeightOffset, xDom
     } else {
       const unusedColors = _.difference(defaultColorOrder, usedColors);
       if (unusedColors.length > 0) {
-        pick = unusedColors[0];
+        [pick] = unusedColors;
       } else {
         usedColors = [];
-        pick = defaultColorOrder[0];
+        [pick] = defaultColorOrder;
       }
     }
     usedColors.push(pick);
diff --git a/app/assets/javascripts/network/branch_graph.js b/app/assets/javascripts/network/branch_graph.js
index 6a8591692f1..94da1be4066 100644
--- a/app/assets/javascripts/network/branch_graph.js
+++ b/app/assets/javascripts/network/branch_graph.js
@@ -101,8 +101,8 @@ export default (function() {
   };
 
   BranchGraph.prototype.buildGraph = function() {
-    var cuday, cumonth, day, j, len, mm, r, ref;
-    r = this.r;
+    var cuday, cumonth, day, j, len, mm, ref;
+    const { r } = this;
     cuday = 0;
     cumonth = "";
     r.rect(0, 0, 40, this.barHeight).attr({
@@ -121,7 +121,7 @@ export default (function() {
           font: "12px Monaco, monospace",
           fill: "#BBB"
         });
-        cuday = day[0];
+        [cuday] = day;
       }
       if (cumonth !== day[1]) {
         // Months
@@ -129,6 +129,8 @@ export default (function() {
           font: "12px Monaco, monospace",
           fill: "#EEE"
         });
+
+        // eslint-disable-next-line prefer-destructuring
         cumonth = day[1];
       }
     }
@@ -169,8 +171,8 @@ export default (function() {
   };
 
   BranchGraph.prototype.bindEvents = function() {
-    var element;
-    element = this.element;
+    const { element } = this;
+
     return $(element).scroll((function(_this) {
       return function(event) {
         return _this.renderPartialGraph();
@@ -207,11 +209,13 @@ export default (function() {
   };
 
   BranchGraph.prototype.appendLabel = function(x, y, commit) {
-    var label, r, rect, shortrefs, text, textbox, triangle;
+    var label, rect, shortrefs, text, textbox, triangle;
+
     if (!commit.refs) {
       return;
     }
-    r = this.r;
+
+    const { r } = this;
     shortrefs = commit.refs;
     // Truncate if longer than 15 chars
     if (shortrefs.length > 17) {
@@ -242,11 +246,8 @@ export default (function() {
   };
 
   BranchGraph.prototype.appendAnchor = function(x, y, commit) {
-    var anchor, options, r, top;
-    r = this.r;
-    top = this.top;
-    options = this.options;
-    anchor = r.circle(x, y, 10).attr({
+    const { r, top, options } = this;
+    const anchor = r.circle(x, y, 10).attr({
       fill: "#000",
       opacity: 0,
       cursor: "pointer"
@@ -262,14 +263,15 @@ export default (function() {
   };
 
   BranchGraph.prototype.drawDot = function(x, y, commit) {
-    var avatar_box_x, avatar_box_y, r;
-    r = this.r;
+    const { r } = this;
     r.circle(x, y, 3).attr({
       fill: this.colors[commit.space],
       stroke: "none"
     });
-    avatar_box_x = this.offsetX + this.unitSpace * this.mspace + 10;
-    avatar_box_y = y - 10;
+
+    const avatar_box_x = this.offsetX + this.unitSpace * this.mspace + 10;
+    const avatar_box_y = y - 10;
+
     r.rect(avatar_box_x, avatar_box_y, 20, 20).attr({
       stroke: this.colors[commit.space],
       "stroke-width": 2
@@ -282,10 +284,10 @@ export default (function() {
   };
 
   BranchGraph.prototype.drawLines = function(x, y, commit) {
-    var arrow, color, i, j, len, offset, parent, parentCommit, parentX1, parentX2, parentY, r, ref, results, route;
-    r = this.r;
-    ref = commit.parents;
-    results = [];
+    var arrow, color, i, len, offset, parent, parentCommit, parentX1, parentX2, parentY, route;
+    const { r } = this;
+    const ref = commit.parents;
+    const results = [];
 
     for (i = 0, len = ref.length; i < len; i += 1) {
       parent = ref[i];
@@ -331,11 +333,10 @@ export default (function() {
   };
 
   BranchGraph.prototype.markCommit = function(commit) {
-    var r, x, y;
     if (commit.id === this.options.commit_id) {
-      r = this.r;
-      x = this.offsetX + this.unitSpace * (this.mspace - commit.space);
-      y = this.offsetY + this.unitTime * commit.time;
+      const { r } = this;
+      const x = this.offsetX + this.unitSpace * (this.mspace - commit.space);
+      const y = this.offsetY + this.unitTime * commit.time;
       r.path(["M", x + 5, y, "L", x + 15, y + 4, "L", x + 15, y - 4, "Z"]).attr({
         fill: "#000",
         "fill-opacity": .5,
diff --git a/app/assets/javascripts/new_branch_form.js b/app/assets/javascripts/new_branch_form.js
index 41ba5b28a1b..205d9766656 100644
--- a/app/assets/javascripts/new_branch_form.js
+++ b/app/assets/javascripts/new_branch_form.js
@@ -52,7 +52,7 @@ export default class NewBranchForm {
 
   validate() {
     var errorMessage, errors, formatter, unique, validator;
-    const indexOf = [].indexOf;
+    const { indexOf } = [];
 
     this.branchNameError.empty();
     unique = function(values, value) {
diff --git a/app/assets/javascripts/notes.js b/app/assets/javascripts/notes.js
index da1a52155d8..48cda28a1ae 100644
--- a/app/assets/javascripts/notes.js
+++ b/app/assets/javascripts/notes.js
@@ -311,7 +311,7 @@ export default class Notes {
         },
       })
       .then(({ data }) => {
-        const notes = data.notes;
+        const { notes } = data;
         this.last_fetched_at = data.last_fetched_at;
         this.setPollingInterval(data.notes.length);
         $.each(notes, (i, note) => this.renderNote(note));
diff --git a/app/assets/javascripts/notes/components/notes_app.vue b/app/assets/javascripts/notes/components/notes_app.vue
index 17b5e8d1ae8..98f8b9af168 100644
--- a/app/assets/javascripts/notes/components/notes_app.vue
+++ b/app/assets/javascripts/notes/components/notes_app.vue
@@ -72,7 +72,7 @@ export default {
   },
   mounted() {
     this.fetchNotes();
-    const parentElement = this.$el.parentElement;
+    const { parentElement } = this.$el;
 
     if (parentElement && parentElement.classList.contains('js-vue-notes-event')) {
       parentElement.addEventListener('toggleAward', event => {
diff --git a/app/assets/javascripts/notes/services/notes_service.js b/app/assets/javascripts/notes/services/notes_service.js
index ee7628840cf..f5dce94caad 100644
--- a/app/assets/javascripts/notes/services/notes_service.js
+++ b/app/assets/javascripts/notes/services/notes_service.js
@@ -28,7 +28,7 @@ export default {
   },
   poll(data = {}) {
     const endpoint = data.notesData.notesPath;
-    const lastFetchedAt = data.lastFetchedAt;
+    const { lastFetchedAt } = data;
     const options = {
       headers: {
         'X-Last-Fetched-At': lastFetchedAt ? `${lastFetchedAt}` : undefined,
diff --git a/app/assets/javascripts/pages/admin/users/components/delete_user_modal.vue b/app/assets/javascripts/pages/admin/users/components/delete_user_modal.vue
index cc2805a1901..d6aa4bb95d2 100644
--- a/app/assets/javascripts/pages/admin/users/components/delete_user_modal.vue
+++ b/app/assets/javascripts/pages/admin/users/components/delete_user_modal.vue
@@ -96,7 +96,7 @@
         this.enteredUsername = '';
       },
       onSecondaryAction() {
-        const form = this.$refs.form;
+        const { form } = this.$refs;
 
         form.action = this.blockUserUrl;
         this.$refs.method.value = 'put';
diff --git a/app/assets/javascripts/pages/dashboard/todos/index/todos.js b/app/assets/javascripts/pages/dashboard/todos/index/todos.js
index 6fc43af2623..ff19b9a9c30 100644
--- a/app/assets/javascripts/pages/dashboard/todos/index/todos.js
+++ b/app/assets/javascripts/pages/dashboard/todos/index/todos.js
@@ -61,7 +61,7 @@ export default class Todos {
     e.stopPropagation();
     e.preventDefault();
 
-    const target = e.target;
+    const { target } = e;
     target.setAttribute('disabled', true);
     target.classList.add('disabled');
 
diff --git a/app/assets/javascripts/pages/projects/graphs/show/stat_graph_contributors.js b/app/assets/javascripts/pages/projects/graphs/show/stat_graph_contributors.js
index ae72c8cb4d5..6c1788dc160 100644
--- a/app/assets/javascripts/pages/projects/graphs/show/stat_graph_contributors.js
+++ b/app/assets/javascripts/pages/projects/graphs/show/stat_graph_contributors.js
@@ -80,10 +80,11 @@ export default (function() {
   };
 
   ContributorsStatGraph.prototype.redraw_authors = function() {
-    var author_commits, x_domain;
     $("ol").html("");
-    x_domain = ContributorsGraph.prototype.x_domain;
-    author_commits = ContributorsStatGraphUtil.get_author_data(this.parsed_log, this.field, x_domain);
+
+    const { x_domain } = ContributorsGraph.prototype;
+    const author_commits = ContributorsStatGraphUtil.get_author_data(this.parsed_log, this.field, x_domain);
+
     return _.each(author_commits, (function(_this) {
       return function(d) {
         _this.redraw_author_commit_info(d);
@@ -102,7 +103,7 @@ export default (function() {
   };
 
   ContributorsStatGraph.prototype.change_date_header = function() {
-    const x_domain = ContributorsGraph.prototype.x_domain;
+    const { x_domain } = ContributorsGraph.prototype;
     const formattedDateRange = sprintf(
       s__('ContributorsPage|%{startDate} – %{endDate}'),
       {
diff --git a/app/assets/javascripts/pages/projects/settings/ci_cd/show/index.js b/app/assets/javascripts/pages/projects/settings/ci_cd/show/index.js
index 37ef77c8e43..1faa59fb45b 100644
--- a/app/assets/javascripts/pages/projects/settings/ci_cd/show/index.js
+++ b/app/assets/javascripts/pages/projects/settings/ci_cd/show/index.js
@@ -28,7 +28,7 @@ document.addEventListener('DOMContentLoaded', () => {
   const autoDevOpsExtraSettings = document.querySelector('.js-extra-settings');
 
   autoDevOpsSettings.addEventListener('click', event => {
-    const target = event.target;
+    const { target } = event;
     if (target.classList.contains('js-toggle-extra-settings')) {
       autoDevOpsExtraSettings.classList.toggle(
         'hidden',
diff --git a/app/assets/javascripts/pipelines/pipeline_details_bundle.js b/app/assets/javascripts/pipelines/pipeline_details_bundle.js
index b49a16a87e6..cf3ff48e608 100644
--- a/app/assets/javascripts/pipelines/pipeline_details_bundle.js
+++ b/app/assets/javascripts/pipelines/pipeline_details_bundle.js
@@ -10,7 +10,7 @@ import eventHub from './event_hub';
 Vue.use(Translate);
 
 export default () => {
-  const dataset = document.querySelector('.js-pipeline-details-vue').dataset;
+  const { dataset } = document.querySelector('.js-pipeline-details-vue');
 
   const mediator = new PipelinesMediator({ endpoint: dataset.endpoint });
 
diff --git a/app/assets/javascripts/pipelines/services/pipelines_service.js b/app/assets/javascripts/pipelines/services/pipelines_service.js
index 59c8b9c58e5..8317d3f4510 100644
--- a/app/assets/javascripts/pipelines/services/pipelines_service.js
+++ b/app/assets/javascripts/pipelines/services/pipelines_service.js
@@ -19,7 +19,7 @@ export default class PipelinesService {
 
   getPipelines(data = {}) {
     const { scope, page } = data;
-    const CancelToken = axios.CancelToken;
+    const { CancelToken } = axios;
 
     this.cancelationSource = CancelToken.source();
 
diff --git a/app/assets/javascripts/preview_markdown.js b/app/assets/javascripts/preview_markdown.js
index 45670584679..0e973cab4d2 100644
--- a/app/assets/javascripts/preview_markdown.js
+++ b/app/assets/javascripts/preview_markdown.js
@@ -43,7 +43,7 @@ MarkdownPreview.prototype.showPreview = function ($form) {
     this.fetchMarkdownPreview(mdText, url, (function (response) {
       var body;
       if (response.body.length > 0) {
-        body = response.body;
+        ({ body } = response);
       } else {
         body = this.emptyMessage;
       }
diff --git a/app/assets/javascripts/profile/gl_crop.js b/app/assets/javascripts/profile/gl_crop.js
index c6d809d84a6..cc9ded789db 100644
--- a/app/assets/javascripts/profile/gl_crop.js
+++ b/app/assets/javascripts/profile/gl_crop.js
@@ -85,11 +85,10 @@ import _ from 'underscore';
         cropBoxResizable: false,
         toggleDragModeOnDblclick: false,
         built: function() {
-          var $image, container, cropBoxHeight, cropBoxWidth;
-          $image = $(this);
-          container = $image.cropper('getContainerData');
-          cropBoxWidth = _this.cropBoxWidth;
-          cropBoxHeight = _this.cropBoxHeight;
+          const $image = $(this);
+          const container = $image.cropper('getContainerData');
+          const { cropBoxWidth, cropBoxHeight } = _this;
+
           return $image.cropper('setCropBoxData', {
             width: cropBoxWidth,
             height: cropBoxHeight,
@@ -136,7 +135,7 @@ import _ from 'underscore';
     }
 
     dataURLtoBlob(dataURL) {
-      var array, binary, i, k, len, v;
+      var array, binary, i, len, v;
       binary = atob(dataURL.split(',')[1]);
       array = [];
 
diff --git a/app/assets/javascripts/project_find_file.js b/app/assets/javascripts/project_find_file.js
index bcdb3f739fe..05485e352dc 100644
--- a/app/assets/javascripts/project_find_file.js
+++ b/app/assets/javascripts/project_find_file.js
@@ -88,7 +88,7 @@ export default class ProjectFindFile {
 
   // render result
   renderList(filePaths, searchText) {
-    var blobItemUrl, filePath, html, i, j, len, matches, results;
+    var blobItemUrl, filePath, html, i, len, matches, results;
     this.element.find(".tree-table > tbody").empty();
     results = [];
 
diff --git a/app/assets/javascripts/projects/tree/components/commit_pipeline_status_component.vue b/app/assets/javascripts/projects/tree/components/commit_pipeline_status_component.vue
index c772fca14bb..a4c7c143e56 100644
--- a/app/assets/javascripts/projects/tree/components/commit_pipeline_status_component.vue
+++ b/app/assets/javascripts/projects/tree/components/commit_pipeline_status_component.vue
@@ -47,7 +47,7 @@
     },
     methods: {
       successCallback(res) {
-        const pipelines = res.data.pipelines;
+        const { pipelines } = res.data;
         if (pipelines.length > 0) {
           // The pipeline entity always keeps the latest pipeline info on the `details.status`
           this.ciStatus = pipelines[0].details.status;
diff --git a/app/assets/javascripts/projects_dropdown/index.js b/app/assets/javascripts/projects_dropdown/index.js
index e1ca70c51a6..6056f12aa4f 100644
--- a/app/assets/javascripts/projects_dropdown/index.js
+++ b/app/assets/javascripts/projects_dropdown/index.js
@@ -31,7 +31,7 @@ document.addEventListener('DOMContentLoaded', () => {
       projectsDropdownApp,
     },
     data() {
-      const dataset = this.$options.el.dataset;
+      const { dataset } = this.$options.el;
       const store = new ProjectsStore();
       const service = new ProjectsService(dataset.userName);
 
diff --git a/app/assets/javascripts/registry/index.js b/app/assets/javascripts/registry/index.js
index 6fb125192b2..e15cd94a915 100644
--- a/app/assets/javascripts/registry/index.js
+++ b/app/assets/javascripts/registry/index.js
@@ -10,7 +10,7 @@ export default () => new Vue({
     registryApp,
   },
   data() {
-    const dataset = document.querySelector(this.$options.el).dataset;
+    const { dataset } = document.querySelector(this.$options.el);
     return {
       endpoint: dataset.endpoint,
     };
diff --git a/app/assets/javascripts/registry/stores/actions.js b/app/assets/javascripts/registry/stores/actions.js
index c0de03373d8..a78aa90b7b5 100644
--- a/app/assets/javascripts/registry/stores/actions.js
+++ b/app/assets/javascripts/registry/stores/actions.js
@@ -20,7 +20,7 @@ export const fetchList = ({ commit }, { repo, page }) => {
   commit(types.TOGGLE_REGISTRY_LIST_LOADING, repo);
 
   return Vue.http.get(repo.tagsPath, { params: { page } }).then(response => {
-    const headers = response.headers;
+    const { headers } = response;
 
     return response.json().then(resp => {
       commit(types.TOGGLE_REGISTRY_LIST_LOADING, repo);
diff --git a/app/assets/javascripts/smart_interval.js b/app/assets/javascripts/smart_interval.js
index 77ab7c964e6..5e385400747 100644
--- a/app/assets/javascripts/smart_interval.js
+++ b/app/assets/javascripts/smart_interval.js
@@ -42,8 +42,7 @@ export default class SmartInterval {
   /* public */
 
   start() {
-    const cfg = this.cfg;
-    const state = this.state;
+    const { cfg, state } = this;
 
     if (cfg.immediateExecution && !this.isLoading) {
       cfg.immediateExecution = false;
@@ -100,7 +99,7 @@ export default class SmartInterval {
   /* private */
 
   initInterval() {
-    const cfg = this.cfg;
+    const { cfg } = this;
 
     if (!cfg.lazyStart) {
       this.start();
@@ -151,7 +150,7 @@ export default class SmartInterval {
   }
 
   incrementInterval() {
-    const cfg = this.cfg;
+    const { cfg } = this;
     const currentInterval = this.getCurrentInterval();
     if (cfg.hiddenInterval && !this.isPageVisible()) return;
     let nextInterval = currentInterval * cfg.incrementByFactorOf;
@@ -166,7 +165,7 @@ export default class SmartInterval {
   isPageVisible() { return this.state.pageVisibility === 'visible'; }
 
   stopTimer() {
-    const state = this.state;
+    const { state } = this;
 
     state.intervalId = window.clearInterval(state.intervalId);
   }
diff --git a/app/assets/javascripts/test_utils/simulate_drag.js b/app/assets/javascripts/test_utils/simulate_drag.js
index e39213cb098..a5c18042ce7 100644
--- a/app/assets/javascripts/test_utils/simulate_drag.js
+++ b/app/assets/javascripts/test_utils/simulate_drag.js
@@ -38,14 +38,14 @@ function simulateEvent(el, type, options = {}) {
 
 function isLast(target) {
   const el = typeof target.el === 'string' ? document.getElementById(target.el.substr(1)) : target.el;
-  const children = el.children;
+  const { children } = el;
 
   return children.length - 1 === target.index;
 }
 
 function getTarget(target) {
   const el = typeof target.el === 'string' ? document.getElementById(target.el.substr(1)) : target.el;
-  const children = el.children;
+  const { children } = el;
 
   return (
     children[target.index] ||
diff --git a/app/assets/javascripts/users_select.js b/app/assets/javascripts/users_select.js
index 7abe7a6be5f..e3d7645040d 100644
--- a/app/assets/javascripts/users_select.js
+++ b/app/assets/javascripts/users_select.js
@@ -250,7 +250,6 @@ function UsersSelect(currentUser, els, options = {}) {
 
           let anyUser;
           let index;
-          let j;
           let len;
           let name;
           let obj;
@@ -501,7 +500,7 @@ function UsersSelect(currentUser, els, options = {}) {
           if (this.multiSelect) {
             selected = getSelected().find(u => user.id === u);
 
-            const fieldName = this.fieldName;
+            const { fieldName } = this;
             const field = $dropdown.closest('.selectbox').find("input[name='" + fieldName + "'][value='" + user.id + "']");
 
             if (field.length) {
@@ -553,7 +552,7 @@ function UsersSelect(currentUser, els, options = {}) {
         minimumInputLength: 0,
         query: function(query) {
           return _this.users(query.term, options, function(users) {
-            var anyUser, data, emailUser, index, j, len, name, nullUser, obj, ref;
+            var anyUser, data, emailUser, index, len, name, nullUser, obj, ref;
             data = {
               results: users
             };
diff --git a/app/assets/javascripts/vue_merge_request_widget/mr_widget_options.vue b/app/assets/javascripts/vue_merge_request_widget/mr_widget_options.vue
index e455c4d2cb5..09477da40b5 100644
--- a/app/assets/javascripts/vue_merge_request_widget/mr_widget_options.vue
+++ b/app/assets/javascripts/vue_merge_request_widget/mr_widget_options.vue
@@ -191,7 +191,7 @@ export default {
       if (data.ci_status === this.mr.ciStatus) return;
       if (!data.pipeline) return;
 
-      const label = data.pipeline.details.status.label;
+      const { label } = data.pipeline.details.status;
       const title = `Pipeline ${label}`;
       const message = `Pipeline ${label} for "${data.title}"`;
 
@@ -211,7 +211,7 @@ export default {
       // `params` should be an Array contains a Boolean, like `[true]`
       // Passing parameter as Boolean didn't work.
       eventHub.$on('SetBranchRemoveFlag', (params) => {
-        this.mr.isRemovingSourceBranch = params[0];
+        [this.mr.isRemovingSourceBranch] = params;
       });
 
       eventHub.$on('FailedToMerge', (mergeError) => {
diff --git a/app/assets/javascripts/vue_shared/components/content_viewer/viewers/image_viewer.vue b/app/assets/javascripts/vue_shared/components/content_viewer/viewers/image_viewer.vue
index 6851029018a..133bdbb54f7 100644
--- a/app/assets/javascripts/vue_shared/components/content_viewer/viewers/image_viewer.vue
+++ b/app/assets/javascripts/vue_shared/components/content_viewer/viewers/image_viewer.vue
@@ -42,7 +42,7 @@ export default {
   },
   methods: {
     onImgLoad() {
-      const contentImg = this.$refs.contentImg;
+      const { contentImg } = this.$refs;
 
       if (contentImg) {
         this.isZoomable =
diff --git a/app/assets/javascripts/vue_shared/components/content_viewer/viewers/markdown_viewer.vue b/app/assets/javascripts/vue_shared/components/content_viewer/viewers/markdown_viewer.vue
index 09e0094054d..a10deb93f0f 100644
--- a/app/assets/javascripts/vue_shared/components/content_viewer/viewers/markdown_viewer.vue
+++ b/app/assets/javascripts/vue_shared/components/content_viewer/viewers/markdown_viewer.vue
@@ -4,7 +4,7 @@ import { __ } from '~/locale';
 import $ from 'jquery';
 import SkeletonLoadingContainer from '~/vue_shared/components/skeleton_loading_container.vue';
 
-const CancelToken = axios.CancelToken;
+const { CancelToken } = axios;
 let axiosSource;
 
 export default {
diff --git a/app/assets/javascripts/vue_shared/components/table_pagination.vue b/app/assets/javascripts/vue_shared/components/table_pagination.vue
index 2370e59d017..8e9621c956f 100644
--- a/app/assets/javascripts/vue_shared/components/table_pagination.vue
+++ b/app/assets/javascripts/vue_shared/components/table_pagination.vue
@@ -55,7 +55,7 @@
       },
       getItems() {
         const total = this.pageInfo.totalPages;
-        const page = this.pageInfo.page;
+        const { page } = this.pageInfo;
         const items = [];
 
         if (page > 1) {