feat: emit api (#181)

* Add print

* Add test

* Add better test

* Specs

* All passing

* Add flow optional type

* Update docs

* Update emitted.md

* Add types

Author: lmiller1990

docs/en/api/wrapper/emitted.md

@@ -31,3 +31,16 @@ expect(wrapper.emitted().foo.length).toBe(2)
 // assert event payload
 expect(wrapper.emitted().foo[1]).toEqual([123])
 ```
+
+You can also write the above as follows:
+
+```js
+// assert event has been emitted
+expect(wrapper.emitted('foo')).toBeTruthy()
+
+// assert event count
+expect(wrapper.emitted('foo').length).toBe(2)
+
+// assert event payload
+expect(wrapper.emitted('foo')[1]).toEqual([123])
+```

docs/ja/api/wrapper/emitted.md

@@ -31,3 +31,16 @@ expect(wrapper.emitted().foo.length).toBe(2)
 // イベントのペイロードを検証します
 expect(wrapper.emitted().foo[1]).toEqual([123])
 ```
+
+別の構文があります。
+
+```js
+// イベントが発行されたか検証します
+expect(wrapper.emitted('foo')).toBeTruthy()
+
+// イベントの数を検証します
+expect(wrapper.emitted('foo').length).toBe(2)
+
+// イベントのペイロードを検証します
+expect(wrapper.emitted('foo')[1]).toEqual([123])
+```

src/wrappers/wrapper.js

@@ -62,10 +62,13 @@ export default class Wrapper implements BaseWrapper {
   /**
    * Returns an object containing custom events emitted by the Wrapper vm
    */
-  emitted () {
+  emitted (event: ?string) {
     if (!this._emitted && !this.vm) {
       throwError('wrapper.emitted() can only be called on a Vue instance')
     }
+    if (event) {
+      return this._emitted[event]
+    }
     return this._emitted
   }
 

test/unit/specs/mount/Wrapper/emitted.spec.js

@@ -1,6 +1,28 @@
 import mount from '~src/mount'
 
 describe('emitted', () => {
+  it('captures emitted events with a different api', () => {
+    const wrapper = mount({
+      render: h => h('div')
+    })
+
+    wrapper.vm.$emit('foo')
+    expect(wrapper.emitted('foo')).to.exist
+    expect(wrapper.emitted('foo').length).to.equal(1)
+    expect(wrapper.emitted('foo')[0]).to.eql([])
+
+    expect(wrapper.emitted('bar')).not.to.exist
+    wrapper.vm.$emit('bar', 1, 2, 3)
+    expect(wrapper.emitted('bar')).to.exist
+    expect(wrapper.emitted('bar').length).to.equal(1)
+    expect(wrapper.emitted('bar')[0]).to.eql([1, 2, 3])
+
+    wrapper.vm.$emit('foo', 2, 3, 4)
+    expect(wrapper.emitted('foo')).to.exist
+    expect(wrapper.emitted('foo').length).to.equal(2)
+    expect(wrapper.emitted('foo')[1]).to.eql([2, 3, 4])
+  })
+
   it('captures emitted events', () => {
     const wrapper = mount({
       render: h => h('div')

types/index.d.ts

@@ -79,7 +79,7 @@ interface Wrapper<V extends Vue> extends BaseWrapper {
   text (): string
   name (): string
 
-  emitted (): { [name: string]: Array<Array<any>> }
+  emitted (string? event): { [name: string]: Array<Array<any>> }
   emittedByOrder (): Array<{ name: string, args: Array<any> }>
 }