fix(@angular/ssr): unblock route extraction with withEnabledBlockingInitialNavigation

This fix ensures that route extraction is not blocked when `withEnabledBlockingInitialNavigation` is used.

Closes #29400

(cherry picked from commit 4a1833d)

Author: alan-agius4

packages/angular/ssr/src/routes/ng-routes.ts

@@ -523,11 +523,17 @@ export async function getRoutesFromAngularRouterConfig(
       applicationRef = await bootstrap();
     }
 
+    const injector = applicationRef.injector;
+    const router = injector.get(Router);
+
+    // Workaround to unblock navigation when `withEnabledBlockingInitialNavigation()` is used.
+    // This is necessary because route extraction disables component bootstrapping.
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    (router as any).navigationTransitions.afterPreactivation()?.next?.();
+
     // Wait until the application is stable.
     await applicationRef.whenStable();
 
-    const injector = applicationRef.injector;
-    const router = injector.get(Router);
     const routesResults: RouteTreeNodeMetadata[] = [];
     const errors: string[] = [];
 

packages/angular/ssr/test/routes/ng-routes_spec.ts

@@ -12,6 +12,7 @@ import '@angular/compiler';
 /* eslint-enable import/no-unassigned-import */
 
 import { Component } from '@angular/core';
+import { Routes, provideRouter, withEnabledBlockingInitialNavigation } from '@angular/router';
 import { extractRoutesAndCreateRouteTree } from '../../src/routes/ng-routes';
 import { PrerenderFallback, RenderMode } from '../../src/routes/route-config';
 import { setAngularAppTestingManifest } from '../testing-utils';
@@ -495,4 +496,36 @@ describe('extractRoutesAndCreateRouteTree', () => {
     expect(errors).toHaveSize(0);
     expect(routeTree.toObject()).toHaveSize(2);
   });
+
+  it('should not bootstrap the root component when using `withEnabledBlockingInitialNavigation`', async () => {
+    @Component({
+      standalone: true,
+      selector: 'app-root',
+      template: '',
+    })
+    class RootComponent {
+      constructor() {
+        throw new Error('RootComponent should not be bootstrapped.');
+      }
+    }
+
+    const routes: Routes = [
+      { path: '', component: DummyComponent },
+      { path: 'home', component: DummyComponent },
+    ];
+
+    setAngularAppTestingManifest(
+      routes,
+      [{ path: '**', renderMode: RenderMode.Server }],
+      undefined,
+      undefined,
+      undefined,
+      RootComponent,
+      [provideRouter(routes, withEnabledBlockingInitialNavigation())],
+    );
+
+    const { routeTree, errors } = await extractRoutesAndCreateRouteTree({ url });
+    expect(errors).toHaveSize(0);
+    expect(routeTree.toObject()).toHaveSize(2);
+  });
 });

packages/angular/ssr/test/testing-utils.ts

@@ -6,7 +6,13 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import { Component, Type, provideExperimentalZonelessChangeDetection } from '@angular/core';
+import {
+  Component,
+  EnvironmentProviders,
+  Provider,
+  Type,
+  provideExperimentalZonelessChangeDetection,
+} from '@angular/core';
 import { bootstrapApplication } from '@angular/platform-browser';
 import { provideServerRendering } from '@angular/platform-server';
 import { RouterOutlet, Routes, provideRouter } from '@angular/router';
@@ -35,6 +41,8 @@ class AppComponent {}
  *                                  where the keys are asset paths and the values are asset details.
  * @param locale - An optional locale to configure for the application during testing.
  * @param rootComponent - The root Angular component to bootstrap the application.
+ * @param extraProviders - An optional array of additional providers that should be available to the
+ *                         root component and all its children.
  */
 export function setAngularAppTestingManifest(
   routes: Routes,
@@ -43,6 +51,7 @@ export function setAngularAppTestingManifest(
   additionalServerAssets: Record<string, ServerAsset> = {},
   locale?: string,
   rootComponent: Type<unknown> = AppComponent,
+  extraProviders: Array<Provider | EnvironmentProviders> = [],
 ): void {
   destroyAngularServerApp();
 
@@ -89,6 +98,7 @@ export function setAngularAppTestingManifest(
           provideExperimentalZonelessChangeDetection(),
           provideRouter(routes),
           provideServerRoutesConfig(serverRoutes),
+          ...extraProviders,
         ],
       });
     },