fix: recursively call Vue.set in setData (#843)

Author: eddyerburgh

Diff for: docs/api/wrapper/setData.md

@@ -2,7 +2,7 @@
 
 Sets `Wrapper` `vm` data.
 
-setData works by merging existing properties, except for arrays which are overwritten.
+setData works by recursively calling Vue.set.
 
 **Note the Wrapper must contain a Vue instance.**
 

Diff for: packages/shared/util.js

@@ -34,3 +34,7 @@ export const hyphenate = (str: string): string =>
 export const vueVersion = Number(
   `${Vue.version.split('.')[0]}.${Vue.version.split('.')[1]}`
 )
+
+export function isPlainObject (obj: any): boolean {
+  return Object.prototype.toString.call(obj) === '[object Object]'
+}

Diff for: packages/test-utils/src/recursively-set-data.js

@@ -0,0 +1,12 @@
+import { isPlainObject } from 'shared/util'
+
+export function recursivelySetData (vm, target, obj) {
+  Object.keys(obj).forEach(key => {
+    const val = obj[key]
+    if (isPlainObject(val)) {
+      recursivelySetData(vm, target[key], val)
+    } else {
+      vm.$set(target, key, val)
+    }
+  })
+}

Diff for: packages/test-utils/src/wrapper.js

@@ -1,7 +1,6 @@
 // @flow
 
 import Vue from 'vue'
-import mergeWith from 'lodash/mergeWith'
 import getSelectorTypeOrThrow from './get-selector-type'
 import {
   REF_SELECTOR,
@@ -17,10 +16,11 @@ import {
 } from './find-vue-components'
 import WrapperArray from './wrapper-array'
 import ErrorWrapper from './error-wrapper'
-import { throwError, warn } from 'shared/util'
+import { throwError, warn } from '../../shared/util'
 import findAll from './find'
 import createWrapper from './create-wrapper'
 import { orderWatchers } from './order-watchers'
+import { recursivelySetData } from './recursively-set-data'
 
 export default class Wrapper implements BaseWrapper {
   +vnode: VNode | null;
@@ -510,27 +510,7 @@ export default class Wrapper implements BaseWrapper {
       )
     }
 
-    Object.keys(data).forEach(key => {
-      if (
-        typeof data[key] === 'object' &&
-        data[key] !== null &&
-        !Array.isArray(data[key])
-      ) {
-        const newObj = mergeWith(
-          // $FlowIgnore : Problem with possibly null this.vm
-          this.vm[key],
-          data[key],
-          (objValue, srcValue) => {
-            return Array.isArray(srcValue) ? srcValue : undefined
-          }
-        )
-        // $FlowIgnore : Problem with possibly null this.vm
-        this.vm.$set(this.vm, [key], newObj)
-      } else {
-        // $FlowIgnore : Problem with possibly null this.vm
-        this.vm.$set(this.vm, [key], data[key])
-      }
-    })
+    recursivelySetData(this.vm, this.vm, data)
   }
 
   /**

Diff for: test/specs/wrapper/setData.spec.js

@@ -33,7 +33,7 @@ describeWithShallowAndMount('setData', mountingMethod => {
     const wrapper = mountingMethod(Component)
     wrapper.setData({ show: true })
     expect(wrapper.element).to.equal(wrapper.vm.$el)
-    expect(wrapper.hasClass('some-class')).to.be.true
+    expect(wrapper.classes()).to.contain('some-class')
   })
 
   it('runs watch function when data is updated', () => {
@@ -117,7 +117,7 @@ describeWithShallowAndMount('setData', mountingMethod => {
     expect(wrapper.vm.basket[0]).to.equal('hello')
   })
 
-  it.skip('should not run watcher if data is null', () => {
+  it('should not run watcher if data is null', () => {
     const TestComponent = {
       template: `
       <div>
@@ -217,4 +217,50 @@ describeWithShallowAndMount('setData', mountingMethod => {
     expect(wrapper.text()).to.equal('10')
     expect(wrapper.vm.nested.nested.nestedArray).to.deep.equal([10])
   })
+
+  it('should append a new property to an object when the new property is referenced by a template', () => {
+    const TestComponent = {
+      data: () => ({
+        anObject: {
+          propA: 'a',
+          propB: 'b'
+        }
+      }),
+      computed: {
+        anObjectKeys () {
+          return Object.keys(this.anObject).join(',')
+        }
+      },
+      template: `<div>{{ anObjectKeys }}</div>`
+    }
+    const wrapper = mountingMethod(TestComponent)
+    wrapper.setData({
+      anObject: {
+        propC: 'c'
+      }
+    })
+
+    expect(wrapper.vm.anObject.propA).to.equal('a')
+    expect(wrapper.vm.anObject.propB).to.equal('b')
+    expect(wrapper.vm.anObject.propC).to.equal('c')
+    expect(wrapper.vm.anObjectKeys).to.equal('propA,propB,propC')
+    expect(wrapper.html()).to.equal('<div>propA,propB,propC</div>')
+  })
+
+  it('allows setting data of type Date synchronously', () => {
+    const TestComponent = {
+      template: `
+      <div>
+        {{selectedDate}}
+      </div>
+    `,
+      data: () => ({
+        selectedDate: undefined
+      })
+    }
+    const testDate = new Date()
+    const wrapper = mountingMethod(TestComponent)
+    wrapper.setData({ selectedDate: testDate })
+    expect(wrapper.vm.selectedDate).to.equal(testDate)
+  })
 })