fix: check for errors on child components (#415)

Author: chriscasola

src/lib/find-vue-components.js

@@ -8,7 +8,7 @@ import {
     throwError
 } from './util'
 
-function findAllVueComponentsFromVm (
+export function findAllVueComponentsFromVm (
   vm: Component,
   components: Array<Component> = []
 ): Array<Component> {

src/mount.js

@@ -8,6 +8,7 @@ import createElement from './lib/create-element'
 import './lib/polyfills/matches-polyfill'
 import './lib/polyfills/object-assign-polyfill'
 import errorHandler from './lib/error-handler'
+import { findAllVueComponentsFromVm } from './lib/find-vue-components'
 
 Vue.config.productionTip = false
 Vue.config.errorHandler = errorHandler
@@ -25,8 +26,10 @@ export default function mount (component: Component, options: Options = {}): Vue
     vm.$mount()
   }
 
-  if (vm._error) {
-    throw (vm._error)
+  const componentsWithError = findAllVueComponentsFromVm(vm).filter(c => c._error)
+
+  if (componentsWithError.length > 0) {
+    throw (componentsWithError[0]._error)
   }
 
   return new VueWrapper(vm, { attachedToDocument: !!options.attachToDocument })

test/specs/mount.spec.js

@@ -175,7 +175,27 @@ describe('mount', () => {
     }
 
     const fn = () => mount(TestComponent)
-    expect(fn).to.throw()
+    expect(fn).to.throw('Error in mounted')
+  })
+
+  it('propagates errors when they are thrown by a nested component', () => {
+    const childComponent = {
+      template: '<div></div>',
+      mounted: function () {
+        throw new Error('Error in mounted')
+      }
+    }
+    const rootComponent = {
+      render: function (h) {
+        return h('div', [h(childComponent)])
+      }
+    }
+
+    const fn = () => {
+      mount(rootComponent)
+    }
+
+    expect(fn).to.throw('Error in mounted')
   })
 
   it('overwrites the component options with the options other than the mounting options when the options for mount contain those', () => {