refactor(router): cleanup, simplification

packages/router/src/directives/router_outlet.ts

@@ -37,8 +37,9 @@ import {PRIMARY_OUTLET} from '../shared';
  */
 @Directive({selector: 'router-outlet'})
 export class RouterOutlet implements OnDestroy {
-  private activated: ComponentRef<any>;
+  private activated: ComponentRef<any>|null = null;
-  private _activatedRoute: ActivatedRoute;
+  private _activatedRoute: ActivatedRoute|null = null;
+  private _outletName: string;
   public outletMap: RouterOutletMap;
 
   @Output('activate') activateEvents = new EventEmitter<any>();
@@ -46,11 +47,12 @@ export class RouterOutlet implements OnDestroy {
 
   constructor(
       private parentOutletMap: RouterOutletMap, private location: ViewContainerRef,
-      private resolver: ComponentFactoryResolver, @Attribute('name') private name: string) {
+      private resolver: ComponentFactoryResolver, @Attribute('name') name: string) {
-    parentOutletMap.registerOutlet(name ? name : PRIMARY_OUTLET, this);
+    this._outletName = name || PRIMARY_OUTLET;
+    parentOutletMap.registerOutlet(this._outletName, this);
   }
 
-  ngOnDestroy(): void { this.parentOutletMap.removeOutlet(this.name ? this.name : PRIMARY_OUTLET); }
+  ngOnDestroy(): void { this.parentOutletMap.removeOutlet(this._outletName); }
 
   /** @deprecated since v4 **/
   get locationInjector(): Injector { return this.location.injector; }
@@ -58,24 +60,32 @@ export class RouterOutlet implements OnDestroy {
   get locationFactoryResolver(): ComponentFactoryResolver { return this.resolver; }
 
   get isActivated(): boolean { return !!this.activated; }
+
   get component(): Object {
     if (!this.activated) throw new Error('Outlet is not activated');
     return this.activated.instance;
   }
+
   get activatedRoute(): ActivatedRoute {
     if (!this.activated) throw new Error('Outlet is not activated');
-    return this._activatedRoute;
+    return this._activatedRoute as ActivatedRoute;
   }
 
+  /**
+   * Called when the `RouteReuseStrategy` instructs to detach the subtree
+   */
   detach(): ComponentRef<any> {
     if (!this.activated) throw new Error('Outlet is not activated');
     this.location.detach();
-    const r = this.activated;
+    const cmp = this.activated;
-    this.activated = null !;
+    this.activated = null;
-    this._activatedRoute = null !;
+    this._activatedRoute = null;
-    return r;
+    return cmp;
   }
 
+  /**
+   * Called when the `RouteReuseStrategy` instructs to re-attach a previously detached subtree
+   */
   attach(ref: ComponentRef<any>, activatedRoute: ActivatedRoute) {
     this.activated = ref;
     this._activatedRoute = activatedRoute;
@@ -86,8 +96,8 @@ export class RouterOutlet implements OnDestroy {
     if (this.activated) {
       const c = this.component;
       this.activated.destroy();
-      this.activated = null !;
+      this.activated = null;
-      this._activatedRoute = null !;
+      this._activatedRoute = null;
       this.deactivateEvents.emit(c);
     }
   }
@@ -129,11 +139,11 @@ export class RouterOutlet implements OnDestroy {
     const component = <any>snapshot._routeConfig !.component;
 
     resolver = resolver || this.resolver;
-    const factory = resolver.resolveComponentFactory(component) !;
+    const factory = resolver.resolveComponentFactory(component);
 
     const injector = new OutletInjector(activatedRoute, outletMap, this.location.injector);
 
-    this.activated = this.location.createComponent(factory, this.location.length, injector, []);
+    this.activated = this.location.createComponent(factory, this.location.length, injector);
     this.activated.changeDetectorRef.detectChanges();
 
     this.activateEvents.emit(this.activated.instance);

packages/router/src/recognize.ts

@@ -43,7 +43,7 @@ class Recognizer {
 
       const rootNode = new TreeNode<ActivatedRouteSnapshot>(root, children);
       const routeState = new RouterStateSnapshot(this.url, rootNode);
-      this.inheriteParamsAndData(routeState._root);
+      this.inheritParamsAndData(routeState._root);
       return of (routeState);
 
     } catch (e) {
@@ -52,14 +52,14 @@ class Recognizer {
     }
   }
 
-  inheriteParamsAndData(routeNode: TreeNode<ActivatedRouteSnapshot>): void {
+  inheritParamsAndData(routeNode: TreeNode<ActivatedRouteSnapshot>): void {
     const route = routeNode.value;
 
     const i = inheritedParamsDataResolve(route);
     route.params = Object.freeze(i.params);
     route.data = Object.freeze(i.data);
 
-    routeNode.children.forEach(n => this.inheriteParamsAndData(n));
+    routeNode.children.forEach(n => this.inheritParamsAndData(n));
   }
 
   processSegmentGroup(config: Route[], segmentGroup: UrlSegmentGroup, outlet: string):

packages/router/src/route_reuse_strategy.ts

@@ -47,4 +47,17 @@ export abstract class RouteReuseStrategy {
 
   /** Determines if a route should be reused */
   abstract shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean;
-}
+}
+
+/**
+ * Does not detach any subtrees. Reuses routes as long as their route config is the same.
+ */
+export class DefaultRouteReuseStrategy implements RouteReuseStrategy {
+  shouldDetach(route: ActivatedRouteSnapshot): boolean { return false; }
+  store(route: ActivatedRouteSnapshot, detachedTree: DetachedRouteHandle): void {}
+  shouldAttach(route: ActivatedRouteSnapshot): boolean { return false; }
+  retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle|null { return null; }
+  shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean {
+    return future.routeConfig === curr.routeConfig;
+  }
+}

packages/router/src/router.ts

@@ -28,7 +28,7 @@ import {createUrlTree} from './create_url_tree';
 import {RouterOutlet} from './directives/router_outlet';
 import {Event, NavigationCancel, NavigationEnd, NavigationError, NavigationStart, RouteConfigLoadEnd, RouteConfigLoadStart, RoutesRecognized} from './events';
 import {recognize} from './recognize';
-import {DetachedRouteHandle, DetachedRouteHandleInternal, RouteReuseStrategy} from './route_reuse_strategy';
+import {DefaultRouteReuseStrategy, DetachedRouteHandleInternal, RouteReuseStrategy} from './route_reuse_strategy';
 import {RouterConfigLoader} from './router_config_loader';
 import {RouterOutletMap} from './router_outlet_map';
 import {ActivatedRoute, ActivatedRouteSnapshot, RouterState, RouterStateSnapshot, advanceActivatedRoute, createEmptyState, equalParamsAndUrlSegments, inheritedParamsDataResolve} from './router_state';
@@ -192,19 +192,6 @@ function defaultRouterHook(snapshot: RouterStateSnapshot): Observable<void> {
   return of (null) as any;
 }
 
-/**
- * Does not detach any subtrees. Reuses routes as long as their route config is the same.
- */
-export class DefaultRouteReuseStrategy implements RouteReuseStrategy {
-  shouldDetach(route: ActivatedRouteSnapshot): boolean { return false; }
-  store(route: ActivatedRouteSnapshot, detachedTree: DetachedRouteHandle): void {}
-  shouldAttach(route: ActivatedRouteSnapshot): boolean { return false; }
-  retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle|null { return null; }
-  shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean {
-    return future.routeConfig === curr.routeConfig;
-  }
-}
-
 /**
  * @whatItDoes Provides the navigation and url manipulation capabilities.
  *
@@ -493,10 +480,10 @@ export class Router {
   isActive(url: string|UrlTree, exact: boolean): boolean {
     if (url instanceof UrlTree) {
       return containsTree(this.currentUrlTree, url, exact);
-    } else {
-      const urlTree = this.urlSerializer.parse(url);
-      return containsTree(this.currentUrlTree, urlTree, exact);
     }
+
+    const urlTree = this.urlSerializer.parse(url);
+    return containsTree(this.currentUrlTree, urlTree, exact);
   }
 
   private removeEmptyProps(params: Params): Params {
@@ -637,6 +624,7 @@ export class Router {
 
       // run preactivation: guards and data resolvers
       let preActivation: PreActivation;
+
       const preactivationTraverse$ = map.call(
           beforePreactivationDone$,
           ({appliedUrl, snapshot}: {appliedUrl: string, snapshot: RouterStateSnapshot}) => {
@@ -771,10 +759,10 @@ class CanDeactivate {
   constructor(public component: Object|null, public route: ActivatedRouteSnapshot) {}
 }
 
-
 export class PreActivation {
   private canActivateChecks: CanActivate[] = [];
   private canDeactivateChecks: CanDeactivate[] = [];
+
   constructor(
       private future: RouterStateSnapshot, private curr: RouterStateSnapshot,
       private moduleInjector: Injector) {}
@@ -808,13 +796,16 @@ export class PreActivation {
       outletMap: RouterOutletMap|null, futurePath: ActivatedRouteSnapshot[]): void {
     const prevChildren = nodeChildrenAsMap(currNode);
 
+    // Process the children of the future route
     futureNode.children.forEach(c => {
       this.traverseRoutes(c, prevChildren[c.value.outlet], outletMap, futurePath.concat([c.value]));
       delete prevChildren[c.value.outlet];
     });
+
+    // Process any children left from the current route (not active for the future route)
     forEach(
         prevChildren, (v: TreeNode<ActivatedRouteSnapshot>, k: string) =>
-                          this.deactiveRouteAndItsChildren(v, outletMap !._outlets[k]));
+                          this.deactivateRouteAndItsChildren(v, outletMap !._outlets[k]));
   }
 
   private traverseRoutes(
@@ -847,7 +838,7 @@ export class PreActivation {
       }
     } else {
       if (curr) {
-        this.deactiveRouteAndItsChildren(currNode, outlet);
+        this.deactivateRouteAndItsChildren(currNode, outlet);
       }
 
       this.canActivateChecks.push(new CanActivate(futurePath));
@@ -879,18 +870,18 @@ export class PreActivation {
     }
   }
 
-  private deactiveRouteAndItsChildren(
+  private deactivateRouteAndItsChildren(
       route: TreeNode<ActivatedRouteSnapshot>, outlet: RouterOutlet|null): void {
     const prevChildren = nodeChildrenAsMap(route);
     const r = route.value;
 
     forEach(prevChildren, (v: TreeNode<ActivatedRouteSnapshot>, k: string) => {
       if (!r.component) {
-        this.deactiveRouteAndItsChildren(v, outlet);
+        this.deactivateRouteAndItsChildren(v, outlet);
-      } else if (!!outlet) {
+      } else if (outlet) {
-        this.deactiveRouteAndItsChildren(v, outlet.outletMap._outlets[k]);
+        this.deactivateRouteAndItsChildren(v, outlet.outletMap._outlets[k]);
       } else {
-        this.deactiveRouteAndItsChildren(v, null);
+        this.deactivateRouteAndItsChildren(v, null);
       }
     });
 
@@ -1020,74 +1011,112 @@ class ActivateRoutes {
     this.activateChildRoutes(futureRoot, currRoot, parentOutletMap);
   }
 
+  // De-activate the child route that are not re-used for the future state
   private deactivateChildRoutes(
       futureNode: TreeNode<ActivatedRoute>, currNode: TreeNode<ActivatedRoute>|null,
       outletMap: RouterOutletMap): void {
-    const prevChildren: {[key: string]: any} = nodeChildrenAsMap(currNode);
+    const prevChildren: {[outlet: string]: any} = nodeChildrenAsMap(currNode);
-    futureNode.children.forEach(c => {
+
-      this.deactivateRoutes(c, prevChildren[c.value.outlet], outletMap);
+    // Recurse on the routes active in the future state to de-activate deeper children
-      delete prevChildren[c.value.outlet];
+    futureNode.children.forEach(child => {
+      const childOutletName = child.value.outlet;
+      this.deactivateRoutes(child, prevChildren[childOutletName], outletMap);
+      delete prevChildren[childOutletName];
     });
-    forEach(prevChildren, (v: any, k: string) => this.deactiveRouteAndItsChildren(v, outletMap));
+
+    // De-activate the routes that will not be re-used
+    forEach(prevChildren, (v: any, k: string) => this.deactivateRouteAndItsChildren(v, outletMap));
+  }
+
+  private deactivateRoutes(
+      futureNode: TreeNode<ActivatedRoute>, currNode: TreeNode<ActivatedRoute>,
+      parentOutletMap: RouterOutletMap): void {
+    const future = futureNode.value;
+    const curr = currNode ? currNode.value : null;
+
+    if (future === curr) {
+      // Reusing the node, check to see of the children need to be de-activated
+      if (future.component) {
+        // If we have a normal route, we need to go through an outlet.
+        const outlet = getOutlet(parentOutletMap, future);
+        this.deactivateChildRoutes(futureNode, currNode, outlet.outletMap);
+      } else {
+        // if we have a componentless route, we recurse but keep the same outlet map.
+        this.deactivateChildRoutes(futureNode, currNode, parentOutletMap);
+      }
+    } else {
+      if (curr) {
+        this.deactivateRouteAndItsChildren(currNode, parentOutletMap);
+      }
+    }
+  }
+
+  private deactivateRouteAndItsChildren(
+      route: TreeNode<ActivatedRoute>, parentOutletMap: RouterOutletMap): void {
+    if (this.routeReuseStrategy.shouldDetach(route.value.snapshot)) {
+      this.detachAndStoreRouteSubtree(route, parentOutletMap);
+    } else {
+      this.deactivateRouteAndOutlet(route, parentOutletMap);
+    }
+  }
+
+  private detachAndStoreRouteSubtree(
+      route: TreeNode<ActivatedRoute>, parentOutletMap: RouterOutletMap): void {
+    const outlet = getOutlet(parentOutletMap, route.value);
+    const componentRef = outlet.detach();
+    this.routeReuseStrategy.store(route.value.snapshot, {componentRef, route});
+  }
+
+  private deactivateRouteAndOutlet(
+      route: TreeNode<ActivatedRoute>, parentOutletMap: RouterOutletMap): void {
+    const prevChildren: {[outletName: string]: any} = nodeChildrenAsMap(route);
+    let outlet: RouterOutlet;
+
+    // getOutlet throws when cannot find the right outlet,
+    // which can happen if an outlet was in an NgIf and was removed
+    try {
+      outlet = getOutlet(parentOutletMap, route.value);
+    } catch (e) {
+      return;
+    }
+
+    const outletMap = route.value.component ? outlet.outletMap : parentOutletMap;
+
+    forEach(
+        prevChildren, (v: any, k: string) => { this.deactivateRouteAndItsChildren(v, outletMap); });
+
+    outlet.deactivate();
   }
 
   private activateChildRoutes(
       futureNode: TreeNode<ActivatedRoute>, currNode: TreeNode<ActivatedRoute>|null,
       outletMap: RouterOutletMap): void {
-    const prevChildren: {[key: string]: any} = nodeChildrenAsMap(currNode);
+    const prevChildren: {[outlet: string]: any} = nodeChildrenAsMap(currNode);
     futureNode.children.forEach(
         c => { this.activateRoutes(c, prevChildren[c.value.outlet], outletMap); });
   }
 
-  deactivateRoutes(
+  private activateRoutes(
       futureNode: TreeNode<ActivatedRoute>, currNode: TreeNode<ActivatedRoute>,
       parentOutletMap: RouterOutletMap): void {
     const future = futureNode.value;
     const curr = currNode ? currNode.value : null;
 
-    // reusing the node
+    advanceActivatedRoute(future);
-    if (future === curr) {
-      // If we have a normal route, we need to go through an outlet.
-      if (future.component) {
-        const outlet = getOutlet(parentOutletMap, future);
-        this.deactivateChildRoutes(futureNode, currNode, outlet.outletMap);
-
-        // if we have a componentless route, we recurse but keep the same outlet map.
-      } else {
-        this.deactivateChildRoutes(futureNode, currNode, parentOutletMap);
-      }
-    } else {
-      if (curr) {
-        this.deactiveRouteAndItsChildren(currNode, parentOutletMap);
-      }
-    }
-  }
-
-  activateRoutes(
-      futureNode: TreeNode<ActivatedRoute>, currNode: TreeNode<ActivatedRoute>,
-      parentOutletMap: RouterOutletMap): void {
-    const future = futureNode.value;
-    const curr = currNode ? currNode.value : null;
 
     // reusing the node
     if (future === curr) {
-      // advance the route to push the parameters
-      advanceActivatedRoute(future);
-
-      // If we have a normal route, we need to go through an outlet.
       if (future.component) {
+        // If we have a normal route, we need to go through an outlet.
         const outlet = getOutlet(parentOutletMap, future);
         this.activateChildRoutes(futureNode, currNode, outlet.outletMap);
-
-        // if we have a componentless route, we recurse but keep the same outlet map.
       } else {
+        // if we have a componentless route, we recurse but keep the same outlet map.
         this.activateChildRoutes(futureNode, currNode, parentOutletMap);
       }
     } else {
-      // if we have a normal route, we need to advance the route
-      // and place the component into the outlet. After that recurse.
       if (future.component) {
-        advanceActivatedRoute(future);
+        // if we have a normal route, we need to place the component into the outlet and recurse.
         const outlet = getOutlet(parentOutletMap, futureNode.value);
 
         if (this.routeReuseStrategy.shouldAttach(future.snapshot)) {
@@ -1101,10 +1130,8 @@ class ActivateRoutes {
           this.placeComponentIntoOutlet(outletMap, future, outlet);
           this.activateChildRoutes(futureNode, null, outletMap);
         }
-
-        // if we have a componentless route, we recurse but keep the same outlet map.
       } else {
-        advanceActivatedRoute(future);
+        // if we have a componentless route, we recurse but keep the same outlet map.
         this.activateChildRoutes(futureNode, null, parentOutletMap);
       }
     }
@@ -1117,49 +1144,6 @@ class ActivateRoutes {
 
     outlet.activateWith(future, cmpFactoryResolver, outletMap);
   }
-
-  private deactiveRouteAndItsChildren(
-      route: TreeNode<ActivatedRoute>, parentOutletMap: RouterOutletMap): void {
-    if (this.routeReuseStrategy.shouldDetach(route.value.snapshot)) {
-      this.detachAndStoreRouteSubtree(route, parentOutletMap);
-    } else {
-      this.deactiveRouteAndOutlet(route, parentOutletMap);
-    }
-  }
-
-  private detachAndStoreRouteSubtree(
-      route: TreeNode<ActivatedRoute>, parentOutletMap: RouterOutletMap): void {
-    const outlet = getOutlet(parentOutletMap, route.value);
-    const componentRef = outlet.detach();
-    this.routeReuseStrategy.store(route.value.snapshot, {componentRef, route});
-  }
-
-  private deactiveRouteAndOutlet(route: TreeNode<ActivatedRoute>, parentOutletMap: RouterOutletMap):
-      void {
-    const prevChildren: {[key: string]: any} = nodeChildrenAsMap(route);
-    let outlet: RouterOutlet|null = null;
-
-    // getOutlet throws when cannot find the right outlet,
-    // which can happen if an outlet was in an NgIf and was removed
-    try {
-      outlet = getOutlet(parentOutletMap, route.value);
-    } catch (e) {
-      return;
-    }
-    const childOutletMap = outlet.outletMap;
-
-    forEach(prevChildren, (v: any, k: string) => {
-      if (route.value.component) {
-        this.deactiveRouteAndItsChildren(v, childOutletMap);
-      } else {
-        this.deactiveRouteAndItsChildren(v, parentOutletMap);
-      }
-    });
-
-    if (outlet && outlet.isActivated) {
-      outlet.deactivate();
-    }
-  }
 }
 
 function advanceActivatedRouteNodeAndItsChildren(node: TreeNode<ActivatedRoute>): void {
@@ -1188,8 +1172,9 @@ function closestLoadedConfig(snapshot: ActivatedRouteSnapshot): LoadedRouterConf
   return null;
 }
 
+// Return the list of T indexed by outlet name
 function nodeChildrenAsMap<T extends{outlet: string}>(node: TreeNode<T>| null) {
-  const map: {[key: string]: TreeNode<T>} = {};
+  const map: {[outlet: string]: TreeNode<T>} = {};
 
   if (node) {
     node.children.forEach(child => map[child.value.outlet] = child);

packages/router/src/router_outlet_map.ts

@@ -25,5 +25,5 @@ export class RouterOutletMap {
   /**
    * Removes an outlet from this map.
    */
-  removeOutlet(name: string): void { this._outlets[name] = undefined !; }
+  removeOutlet(name: string): void { this._outlets[name] = undefined as any; }
 }

packages/router/src/router_state.ts

@@ -51,7 +51,7 @@ export class RouterState extends Tree<ActivatedRoute> {
       /** The current snapshot of the router state */
       public snapshot: RouterStateSnapshot) {
     super(root);
-    setRouterStateSnapshot<RouterState, ActivatedRoute>(this, root);
+    setRouterState(<RouterState>this, root);
   }
 
   toString(): string { return this.snapshot.toString(); }
@@ -343,15 +343,15 @@ export class RouterStateSnapshot extends Tree<ActivatedRouteSnapshot> {
       /** The url from which this snapshot was created */
       public url: string, root: TreeNode<ActivatedRouteSnapshot>) {
     super(root);
-    setRouterStateSnapshot<RouterStateSnapshot, ActivatedRouteSnapshot>(this, root);
+    setRouterState(<RouterStateSnapshot>this, root);
   }
 
   toString(): string { return serializeNode(this._root); }
 }
 
-function setRouterStateSnapshot<U, T extends{_routerState: U}>(state: U, node: TreeNode<T>): void {
+function setRouterState<U, T extends{_routerState: U}>(state: U, node: TreeNode<T>): void {
   node.value._routerState = state;
-  node.children.forEach(c => setRouterStateSnapshot(state, c));
+  node.children.forEach(c => setRouterState(state, c));
 }
 
 function serializeNode(node: TreeNode<ActivatedRouteSnapshot>): string {
@@ -367,21 +367,22 @@ function serializeNode(node: TreeNode<ActivatedRouteSnapshot>): string {
 export function advanceActivatedRoute(route: ActivatedRoute): void {
   if (route.snapshot) {
     const currentSnapshot = route.snapshot;
-    route.snapshot = route._futureSnapshot;
+    const nextSnapshot = route._futureSnapshot;
-    if (!shallowEqual(currentSnapshot.queryParams, route._futureSnapshot.queryParams)) {
+    route.snapshot = nextSnapshot;
-      (<any>route.queryParams).next(route._futureSnapshot.queryParams);
+    if (!shallowEqual(currentSnapshot.queryParams, nextSnapshot.queryParams)) {
+      (<any>route.queryParams).next(nextSnapshot.queryParams);
     }
-    if (currentSnapshot.fragment !== route._futureSnapshot.fragment) {
+    if (currentSnapshot.fragment !== nextSnapshot.fragment) {
-      (<any>route.fragment).next(route._futureSnapshot.fragment);
+      (<any>route.fragment).next(nextSnapshot.fragment);
     }
-    if (!shallowEqual(currentSnapshot.params, route._futureSnapshot.params)) {
+    if (!shallowEqual(currentSnapshot.params, nextSnapshot.params)) {
-      (<any>route.params).next(route._futureSnapshot.params);
+      (<any>route.params).next(nextSnapshot.params);
     }
-    if (!shallowEqualArrays(currentSnapshot.url, route._futureSnapshot.url)) {
+    if (!shallowEqualArrays(currentSnapshot.url, nextSnapshot.url)) {
-      (<any>route.url).next(route._futureSnapshot.url);
+      (<any>route.url).next(nextSnapshot.url);
     }
-    if (!shallowEqual(currentSnapshot.data, route._futureSnapshot.data)) {
+    if (!shallowEqual(currentSnapshot.data, nextSnapshot.data)) {
-      (<any>route.data).next(route._futureSnapshot.data);
+      (<any>route.data).next(nextSnapshot.data);
     }
   } else {
     route.snapshot = route._futureSnapshot;

packages/router/src/utils/tree.ts

@@ -42,7 +42,7 @@ export class Tree<T> {
    * @internal
    */
   siblings(t: T): T[] {
-    const p = findPath(t, this._root, []);
+    const p = findPath(t, this._root);
     if (p.length < 2) return [];
 
     const c = p[p.length - 2].children.map(c => c.value);
@@ -52,26 +52,32 @@ export class Tree<T> {
   /**
    * @internal
    */
-  pathFromRoot(t: T): T[] { return findPath(t, this._root, []).map(s => s.value); }
+  pathFromRoot(t: T): T[] { return findPath(t, this._root).map(s => s.value); }
 }
 
-function findNode<T>(expected: T, c: TreeNode<T>): TreeNode<T>|null {
+
-  if (expected === c.value) return c;
+// DFS for the node matching the value
-  for (const cc of c.children) {
+function findNode<T>(value: T, node: TreeNode<T>): TreeNode<T>|null {
-    const r = findNode(expected, cc);
+  if (value === node.value) return node;
-    if (r) return r;
+
+  for (const child of node.children) {
+    const node = findNode(value, child);
+    if (node) return node;
   }
+
   return null;
 }
 
-function findPath<T>(expected: T, c: TreeNode<T>, collected: TreeNode<T>[]): TreeNode<T>[] {
+// Return the path to the node with the given value using DFS
-  collected.push(c);
+function findPath<T>(value: T, node: TreeNode<T>): TreeNode<T>[] {
-  if (expected === c.value) return collected;
+  if (value === node.value) return [node];
 
-  for (const cc of c.children) {
+  for (const child of node.children) {
-    const cloned = collected.slice(0);
+    const path = findPath(value, child);
-    const r = findPath(expected, cc, cloned);
+    if (path.length) {
-    if (r.length > 0) return r;
+      path.unshift(node);
+      return path;
+    }
   }
 
   return [];

packages/router/test/create_router_state.spec.ts

@@ -9,7 +9,7 @@
 import {Routes} from '../src/config';
 import {createRouterState} from '../src/create_router_state';
 import {recognize} from '../src/recognize';
-import {DefaultRouteReuseStrategy} from '../src/router';
+import {DefaultRouteReuseStrategy} from '../src/route_reuse_strategy';
 import {ActivatedRoute, RouterState, RouterStateSnapshot, advanceActivatedRoute, createEmptyState} from '../src/router_state';
 import {PRIMARY_OUTLET} from '../src/shared';
 import {DefaultUrlSerializer, UrlSegmentGroup, UrlTree} from '../src/url_tree';
@@ -80,7 +80,6 @@ describe('create router state', () => {
     const currP = state.firstChild(state.root) !;
     expect(prevP).toBe(currP);
 
-    const prevC = prevState.children(prevP);
     const currC = state.children(currP);
 
     expect(currP._futureSnapshot.params).toEqual({id: '2', p: '22'});