Merge branch 'issue-boards-label-filter-fix' into 'master'

Fixed issue board label filtering not removing labels

## What does this MR do?

When trying to remove a label filter it would actually add it instead making it impossible to remove the label filter without modifying the URL. This fixes that by correctly removing the label from the filter.

## What are the relevant issue numbers?

Closes #21417

See merge request !6208

CHANGELOG

@@ -118,6 +118,7 @@ v 8.12.0
   - Change pipeline duration to be jobs running time instead of simple wall time from start to end !6084
   - Show queued time when showing a pipeline !6084
   - Remove unused mixins (ClemMakesApps)
+  - Fix issue board label filtering appending already filtered labels
   - Add search to all issue board lists
   - Scroll active tab into view on mobile
   - Fix groups sort dropdown alignment (ClemMakesApps)

app/assets/javascripts/labels_select.js

@@ -280,12 +280,12 @@
             if (page === 'projects:boards:show') {
               if (label.isAny) {
                 gl.issueBoards.BoardsStore.state.filters['label_name'] = [];
-              } else if (label.title) {
+              } else if ($el.hasClass('is-active')) {
                 gl.issueBoards.BoardsStore.state.filters['label_name'].push(label.title);
               } else {
                 var filters = gl.issueBoards.BoardsStore.state.filters['label_name'];
-                filters = filters.filter(function (label) {
-                  return label !== $el.text().trim();
+                filters = filters.filter(function (filteredLabel) {
+                  return filteredLabel !== label.title;
                 });
                 gl.issueBoards.BoardsStore.state.filters['label_name'] = filters;
               }

spec/features/boards/boards_spec.rb

@@ -466,6 +466,29 @@ describe 'Issue Boards', feature: true, js: true do
         end
       end
 
+      it 'removes filtered labels' do
+        wait_for_vue_resource
+        
+        page.within '.labels-filter' do
+          click_button('Label')
+          wait_for_ajax
+
+          page.within '.dropdown-menu-labels' do
+            click_link(testing.title)
+            wait_for_vue_resource(spinner: false)
+          end
+
+          expect(page).to have_css('input[name="label_name[]"]', visible: false)
+
+          page.within '.dropdown-menu-labels' do
+            click_link(testing.title)
+            wait_for_vue_resource(spinner: false)
+          end
+
+          expect(page).not_to have_css('input[name="label_name[]"]', visible: false)
+        end
+      end
+
       it 'infinite scrolls list with label filter' do
         50.times do
           create(:labeled_issue, project: project, labels: [testing])