Move clear search test to JS to reduce overkill

Part of https://gitlab.com/gitlab-org/gitlab-ce/issues/33661

spec/features/merge_requests/filter_by_labels_spec.rb

@@ -79,22 +79,6 @@ feature 'Merge Request filtering by Labels', :js do
     end
   end
 
-  context 'clear button' do
-    before do
-      input_filtered_search('label:~bug')
-    end
-
-    it 'allows user to remove filtered labels' do
-      first('.clear-search').click
-      filtered_search.send_keys(:enter)
-
-      expect(page).to have_issuable_counts(open: 3, closed: 0, all: 3)
-      expect(page).to have_content "Bugfix2"
-      expect(page).to have_content "Feature1"
-      expect(page).to have_content "Bugfix1"
-    end
-  end
-
   context 'filter dropdown' do
     it 'filters by label name' do
       init_label_search

spec/javascripts/filtered_search/filtered_search_manager_spec.js

@@ -396,6 +396,25 @@ describe('Filtered Search Manager', () => {
     });
   });
 
+  describe('Clearing search', () => {
+    beforeEach(() => {
+      initializeManager();
+    });
+
+    it('Clicking the "x" clear button, clears the input', () => {
+      const inputValue = 'label:~bug ';
+      manager.filteredSearchInput.value = inputValue;
+      manager.filteredSearchInput.dispatchEvent(new Event('input'));
+
+      expect(gl.DropdownUtils.getSearchQuery()).toEqual(inputValue);
+
+      manager.clearSearchButton.click();
+
+      expect(manager.filteredSearchInput.value).toEqual('');
+      expect(gl.DropdownUtils.getSearchQuery()).toEqual('');
+    });
+  });
+
   describe('toggleInputContainerFocus', () => {
     beforeEach(() => {
       initializeManager();