Code review feedbac

Disconnect mutationobserver when component is destroyed

app/assets/javascripts/tooltips/components/tooltips.vue

@@ -43,6 +43,9 @@ export default {
       });
     });
   },
+  beforeDestroy() {
+    this.observer.disconnect();
+  },
   methods: {
     addTooltips(elements, config) {
       const newTooltips = elements

spec/frontend/helpers/mock_dom_observer.js

@@ -84,7 +84,9 @@ const useMockObserver = (key, createMock) => {
     mockObserver.$_triggerObserve(...args);
   };
 
-  return { trigger };
+  const observersCount = () => mockObserver.$_observers.length;
+
+  return { trigger, observersCount };
 };
 
 export const useMockIntersectionObserver = () =>

spec/frontend/tooltips/components/tooltips_spec.js

 import { shallowMount } from '@vue/test-utils';
 import { GlTooltip } from '@gitlab/ui';
-import Tooltips from '~/tooltips/components/tooltips.vue';
 import { useMockMutationObserver } from 'helpers/mock_dom_observer';
+import Tooltips from '~/tooltips/components/tooltips.vue';
 
 describe('tooltips/components/tooltips.vue', () => {
-  const { trigger: triggerMutate } = useMockMutationObserver();
+  const { trigger: triggerMutate, observersCount } = useMockMutationObserver();
   let wrapper;
 
   const buildWrapper = () => {
@@ -147,4 +147,14 @@ describe('tooltips/components/tooltips.vue', () => {
       expect(allTooltips()).toHaveLength(1);
     });
   });
+
+  it('disconnects mutation observer on beforeDestroy', () => {
+    buildWrapper();
+    wrapper.vm.addTooltips([createTooltipTarget()]);
+
+    expect(observersCount()).toBe(1);
+
+    wrapper.destroy();
+    expect(observersCount()).toBe(0);
+  });
 });