fix: support multiple default slot nodes (#861)

Author: eddyerburgh

Diff for: packages/create-instance/create-slot-vnodes.js

@@ -22,10 +22,13 @@ function createVNodesForSlot (
   vm: Component,
   slotValue: SlotValue,
   name: string,
-): VNode | string {
+): VNode | Array<VNode> {
   let vnode
   if (typeof slotValue === 'string') {
     const vnodes = createVNodes(vm, slotValue)
+    if (vnodes.length > 1) {
+      return vnodes
+    }
     vnode = vnodes[0]
   } else {
     vnode = vm.$createElement(slotValue)
@@ -41,7 +44,7 @@ function createVNodesForSlot (
 export function createSlotVNodes (
   vm: Component,
   slots: SlotsObject
-): Array<VNode | string> {
+): Array<VNode | Array<VNode>> {
   return Object.keys(slots).reduce((acc, key) => {
     const content = slots[key]
     if (Array.isArray(content)) {

Diff for: packages/create-instance/validate-slots.js

@@ -15,8 +15,8 @@ function requiresTemplateCompiler (slot: any): void {
   if (typeof slot === 'string' && !compileToFunctions) {
     throwError(
       `vueTemplateCompiler is undefined, you must pass ` +
-        `precompiled components if vue-template-compiler is ` +
-        `undefined`
+      `precompiled components if vue-template-compiler is ` +
+      `undefined`
     )
   }
 }

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

@@ -42,9 +42,6 @@ export default function mount (
 
   const vm = parentVm.$mount(elm).$refs.vm
 
-  // Workaround for Vue < 2.5
-  vm._staticTrees = []
-
   const componentsWithError = findAllVueComponentsFromVm(vm).filter(
     c => c._error
   )

Diff for: test/specs/mounting-options/slots.spec.js

@@ -347,6 +347,19 @@ describeWithMountingMethods('options.slots', mountingMethod => {
     }
   )
 
+  it('supports multiple root nodes in default slot option', () => {
+    const wrapper = mountingMethod(ComponentWithSlots, {
+      slots: {
+        default: ['<time /><time />']
+      }
+    })
+    if (mountingMethod.name === 'renderToString') {
+      expect(wrapper).to.contain('<time></time><time></time>')
+    } else {
+      expect(wrapper.findAll('time').length).to.equal(2)
+    }
+  })
+
   itDoNotRunIf(
     process.env.TEST_ENV === 'node',
     'mounts component with named slot if passed string in slot object',