Fix update()

src/lib/add-slots.js

@@ -31,10 +31,18 @@ function addSlotToVm (vm: Component, slotName: string, slotValue: Component | st
   } else {
     elem = vm.$createElement(slotValue)
   }
-  if (Array.isArray(vm.$slots[slotName])) {
-    vm.$slots[slotName].push(elem)
+  if (Array.isArray(elem)) {
+    if (Array.isArray(vm.$slots[slotName])) {
+      vm.$slots[slotName] = [...vm.$slots[slotName], ...elem]
+    } else {
+      vm.$slots[slotName] = [...elem]
+    }
   } else {
-    vm.$slots[slotName] = [elem]
+    if (Array.isArray(vm.$slots[slotName])) {
+      vm.$slots[slotName].push(elem)
+    } else {
+      vm.$slots[slotName] = [elem]
+    }
   }
 }
 

src/lib/create-instance.js

@@ -13,6 +13,7 @@ import createLocalVue from '../create-local-vue'
 import extractOptions from '../options/extract-options'
 import deleteMountingOptions from '../options/delete-mounting-options'
 import createFunctionalComponent from './create-functional-component'
+import cloneDeep from 'lodash/cloneDeep'
 
 export default function createConstructor (
   component: Component,
@@ -58,6 +59,9 @@ export default function createConstructor (
   addAttrs(vm, mountingOptions.attrs)
   addListeners(vm, mountingOptions.listeners)
 
+  vm.$_mountingOptionsSlots = mountingOptions.slots
+  vm.$_originalSlots = cloneDeep(vm.$slots)
+
   if (mountingOptions.slots) {
     addSlots(vm, mountingOptions.slots)
   }

src/wrappers/vue-wrapper.js

@@ -1,9 +1,19 @@
 // @flow
 
 import Wrapper from './wrapper'
+import addSlots from '../lib/add-slots'
+import cloneDeep from 'lodash/cloneDeep'
 
 function update () {
-  this._update(this._render())
+  // the only component made by mount()
+  if (this.$_originalSlots) {
+    this.$slots = cloneDeep(this.$_originalSlots)
+  }
+  if (this.$_mountingOptionsSlots) {
+    addSlots(this, this.$_mountingOptionsSlots)
+  }
+  const vnodes = this._render()
+  this._update(vnodes)
   this.$children.forEach(child => update.call(child))
 }
 

test/resources/components/component-with-slots.vue

@@ -1,5 +1,5 @@
 <template>
-  <div class="container">
+  <div class="container" @keydown="change">
     <header>
       <slot name="header"></slot>
     </header>
@@ -19,6 +19,11 @@
       return {
         'foo': 'bar'
       }
+    },
+    methods: {
+      change () {
+        this.foo = 'BAR'
+      }
     }
   }
 </script>

test/unit/specs/mount/options/slots.spec.js

@@ -58,6 +58,8 @@ describe('mount.slots', () => {
     expect(wrapper4.find('main').html()).to.equal('<main>123</main>')
     const wrapper5 = mount(ComponentWithSlots, { slots: { default: '1{{ foo }}2' }})
     expect(wrapper5.find('main').html()).to.equal('<main>1bar2</main>')
+    wrapper5.trigger('keydown')
+    expect(wrapper5.find('main').html()).to.equal('<main>1BAR2</main>')
   })
 
   it('throws error if passed string in default slot object and vue-template-compiler is undefined', () => {