fixed karma spec

spec/javascripts/ide/components/commit_sidebar/list_item_spec.js

@@ -93,14 +93,14 @@ describe('Multi-file editor commit sidebar list item', () => {
 
   describe('is active', () => {
     it('does not add active class when dont keys match', () => {
-      expect(vm.$el.classList).not.toContain('is-active');
+      expect(vm.$el.querySelector('.is-active')).toBe(null);
     });
 
     it('adds active class when keys match', done => {
       vm.keyPrefix = 'staged';
 
       vm.$nextTick(() => {
-        expect(vm.$el.classList).toContain('is-active');
+        expect(vm.$el.querySelector('.is-active')).not.toBe(null);
 
         done();
       });