add create-component tests (#2928)

ref: #2872

test/unit/modules/vdom/create-component.spec.js

@@ -0,0 +1,113 @@
+import Vue from 'vue'
+import { createComponent } from 'core/vdom/create-component'
+
+describe('create-component', () => {
+  let vm
+  beforeEach(done => {
+    vm = new Vue({
+      template: '<p>{{msg}}</p>',
+      data () {
+        return { msg: 'hello, my children' }
+      }
+    }).$mount()
+    Vue.nextTick(done)
+  })
+
+  it('create a component basically', () => {
+    const child = {
+      name: 'child',
+      props: ['msg']
+    }
+    const data = {
+      props: { msg: 'hello world' },
+      attrs: { id: 1 },
+      staticAttrs: { class: 'foo' },
+      hook: { insert: function () {} },
+      on: { notify: 'onNotify' }
+    }
+    const vnode = createComponent(child, data, vm, vm)
+    expect(vnode.tag).toMatch(/vue-component-[0-9]+-child/)
+    expect(vnode.data.attrs).toEqual({ id: 1 })
+    expect(vnode.data.staticAttrs).toEqual({ class: 'foo' })
+    expect(vnode.componentOptions.propsData).toEqual({ msg: 'hello world' })
+    expect(vnode.componentOptions.listeners).toEqual({ notify: 'onNotify' })
+    expect(vnode.children).toBeUndefined()
+    expect(vnode.text).toBeUndefined()
+    expect(vnode.elm).toBeUndefined()
+    expect(vnode.ns).toBeUndefined()
+    expect(vnode.context).toEqual(vm)
+  })
+
+  it('create a component when resolved with async loading', done => {
+    let vnode = null
+    const data = {
+      props: {},
+      staticAttrs: { class: 'foo' }
+    }
+    spyOn(vm, '$forceUpdate')
+    function async (resolve, reject) {
+      setTimeout(() => {
+        resolve({
+          name: 'child',
+          props: ['msg']
+        })
+        Vue.nextTick(loaded)
+      }, 0)
+    }
+    function go () {
+      vnode = createComponent(async, data, vm, vm)
+      expect(vnode).toBeUndefined() // not to be loaded yet.
+    }
+    function loaded () {
+      vnode = createComponent(async, data, vm, vm)
+      expect(vnode.tag).toMatch(/vue-component-[0-9]+-child/)
+      expect(vnode.data.staticAttrs).toEqual({ class: 'foo' })
+      expect(vnode.children).toBeUndefined()
+      expect(vnode.text).toBeUndefined()
+      expect(vnode.elm).toBeUndefined()
+      expect(vnode.ns).toBeUndefined()
+      expect(vnode.context).toEqual(vm)
+      expect(vm.$forceUpdate).toHaveBeenCalled()
+      done()
+    }
+    go()
+  })
+
+  it('not create a component when rejected with async loading', done => {
+    let vnode = null
+    const data = {
+      props: { msg: 'hello world' },
+      attrs: { id: 1 }
+    }
+    const reason = 'failed!!'
+    function async (resolve, reject) {
+      setTimeout(() => {
+        reject(reason)
+        Vue.nextTick(failed)
+      }, 0)
+    }
+    function go () {
+      vnode = createComponent(async, data, vm, vm)
+      expect(vnode).toBeUndefined() // not to be loaded yet.
+    }
+    function failed () {
+      vnode = createComponent(async, data, vm, vm)
+      expect(vnode).toBeUndefined() // failed
+      expect(`Failed to resolve async component: ${async}\nReason: ${reason}`).toHaveBeenWarned()
+      done()
+    }
+    go()
+  })
+
+  it('not create a component when specified with falsy', () => {
+    const vnode = createComponent(null, {}, vm, vm)
+    expect(vnode).toBeUndefined()
+  })
+
+  it('warn component definition type', () => {
+    const Ctor = 'child'
+    const vnode = createComponent(Ctor, {}, vm, vm)
+    expect(vnode).toBeUndefined()
+    expect(`Invalid Component definition: ${Ctor}`).toHaveBeenWarned()
+  })
+})