refactor(common): Add token to indicate whether precommit handler is supported

This commit adds a token that indicates whether the precommitHandler feature
is supported by the navigation api.

https://developer.mozilla.org/en-US/docs/Web/API/NavigateEvent/intercept#precommithandler

Author: atscott

packages/common/src/navigation/platform_navigation.ts

@@ -8,6 +8,7 @@
 
 import {
   Injectable,
+  InjectionToken,
   ɵNavigateEvent as NavigateEvent,
   ɵNavigation as Navigation,
   ɵNavigationCurrentEntryChangeEvent as NavigationCurrentEntryChangeEvent,
@@ -20,6 +21,19 @@ import {
   ɵNavigationUpdateCurrentEntryOptions as NavigationUpdateCurrentEntryOptions,
 } from '@angular/core';
 
+/**
+ * @see https://developer.mozilla.org/en-US/docs/Web/API/NavigationPrecommitController
+ * @see https://developer.mozilla.org/en-US/docs/Web/API/NavigateEvent/intercept#precommithandler
+ */
+export const PRECOMMIT_HANDLER_SUPPORTED = new InjectionToken<boolean>('', {
+  factory: () => {
+    return (
+      typeof window !== 'undefined' &&
+      typeof (window as any).NavigationPrecommitController !== 'undefined'
+    );
+  },
+});
+
 /**
  * This class wraps the platform Navigation API which allows server-specific and test
  * implementations.

packages/common/src/private_export.ts

@@ -12,3 +12,4 @@ export {
   setRootDomAdapter as ɵsetRootDomAdapter,
 } from './dom_adapter';
 export {NavigationAdapterForLocation as ɵNavigationAdapterForLocation} from './location/navigation_adapter_for_location';
+export {PRECOMMIT_HANDLER_SUPPORTED as ɵPRECOMMIT_HANDLER_SUPPORTED} from './navigation/platform_navigation';

packages/common/testing/src/navigation/provide_fake_platform_navigation.ts

@@ -8,6 +8,7 @@
 
 import {DOCUMENT, PlatformLocation, PlatformNavigation} from '../../../index';
 import {inject, InjectionToken, Provider} from '@angular/core';
+import {PRECOMMIT_HANDLER_SUPPORTED} from '../../../src/navigation/platform_navigation';
 
 import {
   FakeNavigationPlatformLocation,
@@ -38,5 +39,6 @@ export function provideFakePlatformNavigation(): Provider[] {
       useFactory: () => inject(FAKE_NAVIGATION),
     },
     {provide: PlatformLocation, useClass: FakeNavigationPlatformLocation},
+    {provide: PRECOMMIT_HANDLER_SUPPORTED, useValue: true},
   ];
 }

packages/router/src/statemanager/navigation_state_manager.ts

@@ -14,7 +14,11 @@ import {
   Injectable,
 } from '@angular/core';
 
-import {PlatformLocation, PlatformNavigation} from '@angular/common';
+import {
+  PlatformLocation,
+  PlatformNavigation,
+  ɵPRECOMMIT_HANDLER_SUPPORTED as PRECOMMIT_HANDLER_SUPPORTED,
+} from '@angular/common';
 import {StateManager} from './state_manager';
 import {RestoredState, Navigation as RouterNavigation} from '../navigation_transition';
 import {
@@ -59,6 +63,7 @@ export class NavigationStateManager extends StateManager {
   /** The root URL of the Angular application, considering the base href. */
   private readonly appRootURL = new URL(this.location.prepareExternalUrl?.('/') ?? '/', this.base)
     .href;
+  private readonly precommitHandlerSupported = inject(PRECOMMIT_HANDLER_SUPPORTED);
   /**
    * The `NavigationHistoryEntry` from the Navigation API that corresponds to the last successfully
    * activated router state. This is crucial for restoring the browser state if an ongoing navigation