From 68b7847b4cfc486209236f86182dd081a33002de Mon Sep 17 00:00:00 2001
From: Jason Aden <jasonaden@google.com>
Date: Wed, 25 Jul 2018 17:33:47 -0700
Subject: [PATCH] refactor(router): create pipeable applyRedirects function
 (#25740)

PR Close #25740
---
 .../router/src/operators/apply_redirects.ts   | 31 +++++++++++++++++++
 packages/router/src/router.ts                 |  7 +++--
 2 files changed, 35 insertions(+), 3 deletions(-)
 create mode 100644 packages/router/src/operators/apply_redirects.ts

diff --git a/packages/router/src/operators/apply_redirects.ts b/packages/router/src/operators/apply_redirects.ts
new file mode 100644
index 0000000000..f79ff17d50
--- /dev/null
+++ b/packages/router/src/operators/apply_redirects.ts
@@ -0,0 +1,31 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {Injector} from '@angular/core';
+import {Observable, OperatorFunction} from 'rxjs';
+import {flatMap} from 'rxjs/operators';
+
+import {applyRedirects as applyRedirectsFn} from '../apply_redirects';
+import {Routes} from '../config';
+import {RouterConfigLoader} from '../router_config_loader';
+import {UrlSerializer, UrlTree} from '../url_tree';
+
+
+/**
+ * Returns the `UrlTree` with the redirection applied.
+ *
+ * Lazy modules are loaded along the way.
+ */
+export function applyRedirects(
+    moduleInjector: Injector, configLoader: RouterConfigLoader, urlSerializer: UrlSerializer,
+    config: Routes): OperatorFunction<UrlTree, UrlTree> {
+  return function(source: Observable<UrlTree>) {
+    return source.pipe(flatMap(
+        urlTree => applyRedirectsFn(moduleInjector, configLoader, urlSerializer, urlTree, config)));
+  };
+}
diff --git a/packages/router/src/router.ts b/packages/router/src/router.ts
index 544f46cd2f..7ca8a033cc 100644
--- a/packages/router/src/router.ts
+++ b/packages/router/src/router.ts
@@ -11,11 +11,11 @@ import {Compiler, Injector, NgModuleFactoryLoader, NgModuleRef, NgZone, Optional
 import {BehaviorSubject, Observable, Subject, Subscription, of } from 'rxjs';
 import {concatMap, map, mergeMap, tap} from 'rxjs/operators';
 
-import {applyRedirects} from './apply_redirects';
 import {LoadedRouterConfig, QueryParamsHandling, Route, Routes, standardizeConfig, validateConfig} from './config';
 import {createRouterState} from './create_router_state';
 import {createUrlTree} from './create_url_tree';
 import {ActivationEnd, ChildActivationEnd, Event, GuardsCheckEnd, GuardsCheckStart, NavigationCancel, NavigationEnd, NavigationError, NavigationStart, NavigationTrigger, ResolveEnd, ResolveStart, RouteConfigLoadEnd, RouteConfigLoadStart, RoutesRecognized} from './events';
+import {applyRedirects} from './operators/apply_redirects';
 import {recognize} from './operators/recognize';
 import {PreActivation} from './pre_activation';
 import {DefaultRouteReuseStrategy, DetachedRouteHandleInternal, RouteReuseStrategy} from './route_reuse_strategy';
@@ -29,6 +29,7 @@ import {forEach} from './utils/collection';
 import {TreeNode, nodeChildrenAsMap} from './utils/tree';
 
 
+
 /**
  * @description
  *
@@ -688,8 +689,8 @@ export class Router {
       let urlAndSnapshot$: Observable<NavStreamValue>;
       if (!precreatedState) {
         const moduleInjector = this.ngModule.injector;
-        const redirectsApplied$ =
-            applyRedirects(moduleInjector, this.configLoader, this.urlSerializer, url, this.config);
+        const redirectsApplied$ = applyRedirects(
+            moduleInjector, this.configLoader, this.urlSerializer, this.config)(of (url));
 
         urlAndSnapshot$ = redirectsApplied$.pipe(mergeMap(
             (appliedUrl: UrlTree) =>