Enable no-multi-assignment in JS files

Partially addresses #47006.

17 files changed, 38 insertions, 13 deletions

diff --git a/.eslintrc.yml b/.eslintrc.yml
index 5b416c9bf1b..b9c5973d7ac 100644
--- a/.eslintrc.yml
+++ b/.eslintrc.yml
@@ -71,5 +71,3 @@ rules:
         body: 1
   ## Destructuring: https://eslint.org/docs/rules/prefer-destructuring
   prefer-destructuring: off
-  ## no-multi-assign: https://eslint.org/docs/rules/no-multi-assign
-  no-multi-assign: off
diff --git a/app/assets/javascripts/lib/utils/common_utils.js b/app/assets/javascripts/lib/utils/common_utils.js
index d55d0585031..d0b0e5e1ba1 100644
--- a/app/assets/javascripts/lib/utils/common_utils.js
+++ b/app/assets/javascripts/lib/utils/common_utils.js
@@ -197,7 +197,10 @@ export const insertText = (target, text) => {
   // eslint-disable-next-line no-param-reassign
   target.value = newText;
   // eslint-disable-next-line no-param-reassign
-  target.selectionStart = target.selectionEnd = selectionStart + insertedText.length;
+  target.selectionStart = selectionStart + insertedText.length;
+
+  // eslint-disable-next-line no-param-reassign
+  target.selectionEnd = selectionStart + insertedText.length;
 
   // Trigger autosave
   target.dispatchEvent(new Event('input'));
diff --git a/app/assets/javascripts/line_highlighter.js b/app/assets/javascripts/line_highlighter.js
index 232b59e199c..303c5d8a894 100644
--- a/app/assets/javascripts/line_highlighter.js
+++ b/app/assets/javascripts/line_highlighter.js
@@ -145,6 +145,8 @@ LineHighlighter.prototype.highlightRange = function(range) {
   var i, lineNumber, ref, ref1, results;
   if (range[1]) {
     results = [];
+
+    // eslint-disable-next-line no-multi-assign
     for (lineNumber = i = ref = range[0], ref1 = range[1]; ref <= ref1 ? i <= ref1 : i >= ref1; lineNumber = ref <= ref1 ? (i += 1) : (i -= 1)) {
       results.push(this.highlightLine(lineNumber));
     }
diff --git a/app/assets/javascripts/monitoring/components/dashboard.vue b/app/assets/javascripts/monitoring/components/dashboard.vue
index 21934021852..e1c8b6a6d4a 100644
--- a/app/assets/javascripts/monitoring/components/dashboard.vue
+++ b/app/assets/javascripts/monitoring/components/dashboard.vue
@@ -139,7 +139,7 @@ export default {
       this.updateAspectRatio = true;
     },
     toggleAspectRatio() {
-      this.updatedAspectRatios = this.updatedAspectRatios += 1;
+      this.updatedAspectRatios += 1;
       if (this.store.getMetricsCount() === this.updatedAspectRatios) {
         this.updateAspectRatio = !this.updateAspectRatio;
         this.updatedAspectRatios = 0;
diff --git a/app/assets/javascripts/monitoring/components/graph.vue b/app/assets/javascripts/monitoring/components/graph.vue
index 20400154100..e5680a0499f 100644
--- a/app/assets/javascripts/monitoring/components/graph.vue
+++ b/app/assets/javascripts/monitoring/components/graph.vue
@@ -154,7 +154,7 @@ export default {
       point.x = e.clientX;
       point.y = e.clientY;
       point = point.matrixTransform(this.$refs.graphData.getScreenCTM().inverse());
-      point.x = point.x += 7;
+      point.x += 7;
       const firstTimeSeries = this.timeSeries[0];
       const timeValueOverlay = firstTimeSeries.timeSeriesScaleX.invert(point.x);
       const overlayIndex = bisectDate(firstTimeSeries.values, timeValueOverlay, 1);
diff --git a/app/assets/javascripts/network/branch_graph.js b/app/assets/javascripts/network/branch_graph.js
index bd007c707f2..e4096ddb00d 100644
--- a/app/assets/javascripts/network/branch_graph.js
+++ b/app/assets/javascripts/network/branch_graph.js
@@ -112,6 +112,8 @@ export default (function() {
       fill: "#444"
     });
     ref = this.days;
+
+    // eslint-disable-next-line no-multi-assign
     for (mm = j = 0, len = ref.length; j < len; mm = (j += 1)) {
       day = ref[mm];
       if (cuday !== day[0] || cumonth !== day[1]) {
@@ -285,6 +287,8 @@ export default (function() {
     r = this.r;
     ref = commit.parents;
     results = [];
+
+    // eslint-disable-next-line no-multi-assign
     for (i = j = 0, len = ref.length; j < len; i = (j += 1)) {
       parent = ref[i];
       parentCommit = this.preparedCommits[parent[0]];
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 653e2502d01..37336a8cb69 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
@@ -36,7 +36,9 @@ export default (function() {
         var author_graph, author_header;
         author_header = _this.create_author_header(d);
         $(".contributors-list").append(author_header);
-        _this.authors[d.author_name] = author_graph = new ContributorsAuthorGraph(d.dates);
+
+        author_graph = new ContributorsAuthorGraph(d.dates);
+        _this.authors[d.author_name] = author_graph;
         return author_graph.draw();
       };
     })(this));
diff --git a/app/assets/javascripts/pages/projects/graphs/show/stat_graph_contributors_util.js b/app/assets/javascripts/pages/projects/graphs/show/stat_graph_contributors_util.js
index 77135ad1f0e..165446a4db6 100644
--- a/app/assets/javascripts/pages/projects/graphs/show/stat_graph_contributors_util.js
+++ b/app/assets/javascripts/pages/projects/graphs/show/stat_graph_contributors_util.js
@@ -111,10 +111,15 @@ export default {
   parse_log_entry: function(log_entry, field, date_range) {
     var parsed_entry;
     parsed_entry = {};
+
     parsed_entry.author_name = log_entry.author_name;
     parsed_entry.author_email = log_entry.author_email;
     parsed_entry.dates = {};
-    parsed_entry.commits = parsed_entry.additions = parsed_entry.deletions = 0;
+
+    parsed_entry.commits = 0;
+    parsed_entry.additions = 0;
+    parsed_entry.deletions = 0;
+
     _.each(_.omit(log_entry, 'author_name', 'author_email'), (function(_this) {
       return function(value, key) {
         if (_this.in_range(value.date, date_range)) {
diff --git a/app/assets/javascripts/profile/gl_crop.js b/app/assets/javascripts/profile/gl_crop.js
index 8f93156cdd1..ba120c4bbdf 100644
--- a/app/assets/javascripts/profile/gl_crop.js
+++ b/app/assets/javascripts/profile/gl_crop.js
@@ -139,6 +139,8 @@ import _ from 'underscore';
       var array, binary, i, k, len, v;
       binary = atob(dataURL.split(',')[1]);
       array = [];
+
+      // eslint-disable-next-line no-multi-assign
       for (k = i = 0, len = binary.length; i < len; k = (i += 1)) {
         v = binary[k];
         array.push(binary.charCodeAt(k));
diff --git a/app/assets/javascripts/project_find_file.js b/app/assets/javascripts/project_find_file.js
index 1fed200db49..17497283695 100644
--- a/app/assets/javascripts/project_find_file.js
+++ b/app/assets/javascripts/project_find_file.js
@@ -91,6 +91,8 @@ export default class ProjectFindFile {
     var blobItemUrl, filePath, html, i, j, len, matches, results;
     this.element.find(".tree-table > tbody").empty();
     results = [];
+
+    // eslint-disable-next-line no-multi-assign
     for (i = j = 0, len = filePaths.length; j < len; i = (j += 1)) {
       filePath = filePaths[i];
       if (i === 20) {
diff --git a/app/assets/javascripts/prometheus_metrics/prometheus_metrics.js b/app/assets/javascripts/prometheus_metrics/prometheus_metrics.js
index 1a75fdd75db..078ccbbbac2 100644
--- a/app/assets/javascripts/prometheus_metrics/prometheus_metrics.js
+++ b/app/assets/javascripts/prometheus_metrics/prometheus_metrics.js
@@ -107,7 +107,7 @@ export default class PrometheusMetrics {
           if (data && data.success) {
             stop(data);
           } else {
-            this.backOffRequestCounter = this.backOffRequestCounter += 1;
+            this.backOffRequestCounter += 1;
             if (this.backOffRequestCounter < 3) {
               next();
             } else {
diff --git a/app/assets/javascripts/users_select.js b/app/assets/javascripts/users_select.js
index cd954f75613..349614460e1 100644
--- a/app/assets/javascripts/users_select.js
+++ b/app/assets/javascripts/users_select.js
@@ -259,6 +259,7 @@ function UsersSelect(currentUser, els, options = {}) {
             showDivider = 0;
             if (firstUser) {
               // Move current user to the front of the list
+              // eslint-disable-next-line no-multi-assign
               for (index = j = 0, len = users.length; j < len; index = (j += 1)) {
                 obj = users[index];
                 if (obj.username === firstUser) {
@@ -561,6 +562,8 @@ function UsersSelect(currentUser, els, options = {}) {
               if (firstUser) {
                 // Move current user to the front of the list
                 ref = data.results;
+
+                // eslint-disable-next-line no-multi-assign
                 for (index = j = 0, len = ref.length; j < len; index = (j += 1)) {
                   obj = ref[index];
                   if (obj.username === firstUser) {
diff --git a/app/assets/javascripts/vue_merge_request_widget/components/memory_usage.vue b/app/assets/javascripts/vue_merge_request_widget/components/memory_usage.vue
index f012f9c6772..5e76f6b1cac 100644
--- a/app/assets/javascripts/vue_merge_request_widget/components/memory_usage.vue
+++ b/app/assets/javascripts/vue_merge_request_widget/components/memory_usage.vue
@@ -105,7 +105,7 @@ export default {
         MRWidgetService.fetchMetrics(this.metricsUrl)
           .then((res) => {
             if (res.status === statusCodes.NO_CONTENT) {
-              this.backOffRequestCounter = this.backOffRequestCounter += 1;
+              this.backOffRequestCounter += 1;
               /* eslint-disable no-unused-expressions */
               this.backOffRequestCounter < 3 ? next() : stop(res);
             } else {
diff --git a/spec/javascripts/gl_field_errors_spec.js b/spec/javascripts/gl_field_errors_spec.js
index 4e93fd91751..108e0064c47 100644
--- a/spec/javascripts/gl_field_errors_spec.js
+++ b/spec/javascripts/gl_field_errors_spec.js
@@ -8,7 +8,9 @@ describe('GL Style Field Errors', function() {
 
   beforeEach(function() {
     loadFixtures('static/gl_field_errors.html.raw');
-    const $form = this.$form = $('form.gl-show-field-errors');
+    const $form = $('form.gl-show-field-errors');
+
+    this.$form = $form;
     this.fieldErrors = new GlFieldErrors($form);
   });
 
diff --git a/spec/javascripts/helpers/user_mock_data_helper.js b/spec/javascripts/helpers/user_mock_data_helper.js
index 323fee3767e..f6c3ce5aecc 100644
--- a/spec/javascripts/helpers/user_mock_data_helper.js
+++ b/spec/javascripts/helpers/user_mock_data_helper.js
@@ -1,7 +1,7 @@
 export default {
   createNumberRandomUsers(numberUsers) {
     const users = [];
-    for (let i = 0; i < numberUsers; i = i += 1) {
+    for (let i = 0; i < numberUsers; i += 1) {
       users.push(
         {
           avatar: 'https://gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=80&d=identicon',
diff --git a/spec/javascripts/profile/account/components/update_username_spec.js b/spec/javascripts/profile/account/components/update_username_spec.js
index bac306edf5a..5311499fb73 100644
--- a/spec/javascripts/profile/account/components/update_username_spec.js
+++ b/spec/javascripts/profile/account/components/update_username_spec.js
@@ -90,7 +90,8 @@ describe('UpdateUsername component', () => {
   it('confirmation modal should escape usernames properly', done => {
     const { modalBody } = findElements();
 
-    vm.username = vm.newUsername = '<i>Italic</i>';
+    vm.username = '<i>Italic</i>';
+    vm.newUsername = vm.username;
 
     Vue.nextTick()
       .then(() => {
diff --git a/spec/javascripts/test_bundle.js b/spec/javascripts/test_bundle.js
index 2411d33a496..994011b262a 100644
--- a/spec/javascripts/test_bundle.js
+++ b/spec/javascripts/test_bundle.js
@@ -39,7 +39,8 @@ jasmine.getJSONFixtures().fixturesPath = FIXTURES_PATH;
 beforeAll(() => jasmine.addMatchers(customMatchers));
 
 // globalize common libraries
-window.$ = window.jQuery = $;
+window.$ = $;
+window.jQuery = window.$;
 
 // stub expected globals
 window.gl = window.gl || {};