From f06679e7ccd944e972c461dcd13e5d801a0548da Mon Sep 17 00:00:00 2001
From: Vito Laera <vito.laera@objectway.it>
Date: Fri, 31 May 2019 08:44:30 +0200
Subject: [PATCH] feat: allow Vue component to receive a VueRouter factory

---
 src/install.js                  |  2 +-
 test/unit/specs/factory.spec.js | 50 +++++++++++++++++++++++++++++++++
 types/vue.d.ts                  |  3 +-
 3 files changed, 53 insertions(+), 2 deletions(-)
 create mode 100644 test/unit/specs/factory.spec.js

diff --git a/src/install.js b/src/install.js
index ee8506aa8..565b3e7f9 100644
--- a/src/install.js
+++ b/src/install.js
@@ -22,7 +22,7 @@ export function install (Vue) {
     beforeCreate () {
       if (isDef(this.$options.router)) {
         this._routerRoot = this
-        this._router = this.$options.router
+        this._router = typeof this.$options.router === 'function' ? this.$options.router() : this.$options.router
         this._router.init(this)
         Vue.util.defineReactive(this, '_route', this._router.history.current)
       } else {
diff --git a/test/unit/specs/factory.spec.js b/test/unit/specs/factory.spec.js
new file mode 100644
index 000000000..a8c6f85c1
--- /dev/null
+++ b/test/unit/specs/factory.spec.js
@@ -0,0 +1,50 @@
+import Router from '../../../src/index'
+import Vue from 'vue'
+
+describe('router factory', () => {
+  let InstancedBasedApp, FactoryBasedApp
+
+  beforeEach(() => {
+    const routerFactory = () => new Router({
+      mode: 'abstract',
+      routes: [
+        {
+          path: '/a',
+          component: {
+            name: 'A'
+          }
+        }
+      ]
+    })
+
+    const router = routerFactory()
+
+    InstancedBasedApp = Vue.extend({
+      router,
+      render (h) { return h('div') }
+    })
+
+    FactoryBasedApp = Vue.extend({
+      router: routerFactory,
+      render (h) { return h('div') }
+    })
+  })
+
+  it('should initialize router from factory', () => {
+    const vm = new FactoryBasedApp()
+    expect(vm.$router instanceof Router).toBeTruthy()
+  })
+
+  it('should use different router instances on different app instances', () => {
+    const app = new FactoryBasedApp()
+    const app2 = new FactoryBasedApp()
+    expect(app.$router).not.toBe(app2.$router)
+  })
+
+  it('should allow to work as normal', () => {
+    const app = new InstancedBasedApp()
+    const app2 = new InstancedBasedApp()
+    expect(app.$router).toBe(app2.$router)
+  })
+})
+
diff --git a/types/vue.d.ts b/types/vue.d.ts
index 4e57eec79..5d322fca5 100644
--- a/types/vue.d.ts
+++ b/types/vue.d.ts
@@ -13,8 +13,9 @@ declare module "vue/types/vue" {
 }
 
 declare module "vue/types/options" {
+  type VueRouterFactory = () => VueRouter;
   interface ComponentOptions<V extends Vue> {
-    router?: VueRouter;
+    router?: VueRouter | VueRouterFactory;
     beforeRouteEnter?: NavigationGuard<V>;
     beforeRouteLeave?: NavigationGuard<V>;
     beforeRouteUpdate?: NavigationGuard<V>;