fix: handle async components

packages/shared/stub-components.js

@@ -202,6 +202,11 @@ function stubComponents (
     const componentOptions = typeof cmp === 'function'
       ? cmp.extendOptions
       : cmp
+
+    if (!componentOptions) {
+      stubbedComponents[component] = createBlankStub({}, component)
+      return
+    }
     // Remove cached constructor
     delete componentOptions._Ctor
     if (!componentOptions.name) {

test/specs/mount.spec.js

@@ -162,6 +162,22 @@ describeRunIf(process.env.TEST_ENV !== 'node', 'mount', () => {
     expect(wrapper.html()).to.equal(`<div></div>`)
   })
 
+  itDoNotRunIf(
+    vueVersion < 2.4, // auto resolve of default export added in 2.4
+    'handles components as dynamic imports', (done) => {
+      const TestComponent = {
+        template: '<div><async-component /></div>',
+        components: {
+          AsyncComponent: () => import('~resources/components/component.vue')
+        }
+      }
+      const wrapper = mount(TestComponent)
+      setTimeout(() => {
+        expect(wrapper.find(Component).exists()).to.equal(true)
+        done()
+      })
+    })
+
   it('logs if component is extended', () => {
     const msg =
       `[vue-test-utils]: an extended child component <ChildComponent> ` +

test/specs/shallow-mount.spec.js

@@ -294,6 +294,19 @@ describeRunIf(process.env.TEST_ENV !== 'node', 'shallowMount', () => {
       .to.equal('hey')
   })
 
+  itDoNotRunIf(
+    vueVersion < 2.4, // auto resolve of default export added in 2.4
+    'handles component as dynamic import', () => {
+      const TestComponent = {
+        template: '<div><async-component /></div>',
+        components: {
+          AsyncComponent: () => import('~resources/components/component.vue')
+        }
+      }
+      const wrapper = shallowMount(TestComponent)
+      expect(wrapper.find({ name: 'AsyncComponent' }).exists()).to.equal(true)
+    })
+
   it('stubs components registered on localVue after multiple installs', () => {
     const myPlugin = function (_Vue, opts) {
       _Vue.mixin({ })