Handle Promise rejection in guards (fix #2833)

.babelrc

@@ -1,4 +1,4 @@
 {
   "presets": ["env", "flow-vue"],
-  "plugins": ["syntax-dynamic-import"]
+  "plugins": ["syntax-dynamic-import", "transform-runtime"]
 }

package.json

@@ -58,6 +58,7 @@
     "babel-eslint": "^10.0.1",
     "babel-loader": "^7.1.3",
     "babel-plugin-syntax-dynamic-import": "^6.18.0",
+    "babel-plugin-transform-runtime": "^6.23.0",
     "babel-preset-env": "^1.6.1",
     "babel-preset-flow-vue": "^1.0.0",
     "browserstack-local": "^1.4.0",

src/history/base.js

@@ -126,12 +126,12 @@ export class History {
     )
 
     this.pending = route
-    const iterator = (hook: NavigationGuard, next) => {
+    const iterator = async (hook: NavigationGuard, next) => {
       if (this.pending !== route) {
         return abort()
       }
       try {
-        hook(route, current, (to: any) => {
+        await hook(route, current, (to: any) => {
           if (to === false || isError(to)) {
             // next(false) -> abort navigation, ensure current URL
             this.ensureURL(true)

test/unit/specs/error-handling.spec.js

@@ -52,4 +52,21 @@ describe('error handling', () => {
     expect(spy1).toHaveBeenCalledWith(err)
     expect(spy2).toHaveBeenCalledWith(err)
   })
+
+  // #2833
+  it('async router.beforeEach, handle onError', () => {
+    const router = new VueRouter()
+    const err = new Error('foo')
+    const spy = jasmine.createSpy('error')
+    router.onError(spy)
+
+    router.push('/')
+    router.beforeEach(async () => { throw err })
+
+    router.push('/foo', () => {
+      fail('onError function did not receive an error')
+    }, () => {
+      expect(spy).toHaveBeenCalledWith(err)
+    })
+  })
 })

yarn.lock

@@ -2017,6 +2017,13 @@ babel-plugin-transform-regenerator@^6.22.0:
   dependencies:
     regenerator-transform "^0.10.0"
 
+babel-plugin-transform-runtime@^6.23.0:
+  version "6.23.0"
+  resolved "https://registry.yarnpkg.com/babel-plugin-transform-runtime/-/babel-plugin-transform-runtime-6.23.0.tgz#88490d446502ea9b8e7efb0fe09ec4d99479b1ee"
+  integrity sha1-iEkNRGUC6puOfvsP4J7E2ZR5se4=
+  dependencies:
+    babel-runtime "^6.22.0"
+
 babel-plugin-transform-strict-mode@^6.24.1:
   version "6.24.1"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-strict-mode/-/babel-plugin-transform-strict-mode-6.24.1.tgz#d5faf7aa578a65bbe591cf5edae04a0c67020758"