fix $route being observed + expose $route.matched

Author: yyx990803

src/index.js

@@ -267,6 +267,7 @@ class Router {
    */
 
   _addRoute (path, handler, segments) {
+    handler.path = path
     guardComponent(path, handler)
     segments.push({
       path: path,

src/route.js

@@ -35,6 +35,8 @@ export default class Route {
     this.path = path
     this.router = router
     // for internal use
-    this._matched = matched || router._notFoundHandler
+    this.matched = matched || router._notFoundHandler
+    // Important: freeze self to prevent observation
+    Object.freeze(this)
   }
 }

src/transition.js

@@ -32,8 +32,8 @@ export default class RouteTransition {
     this.deactivateQueue = router._views
 
     // check the default handler of the deepest match
-    let matched = to._matched
-      ? Array.prototype.slice.call(to._matched)
+    let matched = to.matched
+      ? Array.prototype.slice.call(to.matched)
       : []
 
     // the activate queue is an array of route handlers