fix errorHandler tests

test/unit/features/global-api/config.spec.js

@@ -35,6 +35,8 @@ describe('Global config', () => {
   })
 
   describe('errorHandler', () => {
+    it('should be called with correct args', () => {
+      const spy = jasmine.createSpy('errorHandler')
       Vue.config.errorHandler = spy
       const err = new Error()
       const vm = new Vue({
@@ -44,3 +46,4 @@ describe('Global config', () => {
       Vue.config.errorHandler = null
     })
   })
+})