feat(common): Add BrowserPlatformLocation to the public API (#48488)

`PlatformLocation` is already part of the public API so developers can
create their own. This means that developers would already be able to
access the existing `BrowserPlatformLocation` at runtime by injecting
it. The motivation for adding `BrowserPlatformLocation` to the public
API is because of those facts, but driven more by the fact that we are
looking to include `MockPlatformLocation` by default in TestBed.
Developers would need a way to revert back to the current behavior for
some tests that rely directly on browser interaction.

PR Close #48488

goldens/public-api/common/index.md

@@ -50,6 +50,48 @@ export class AsyncPipe implements OnDestroy, PipeTransform {
     static ɵpipe: i0.ɵɵPipeDeclaration<AsyncPipe, "async", true>;
 }
 
+// @public
+export class BrowserPlatformLocation extends PlatformLocation {
+    constructor(_doc: any);
+    // (undocumented)
+    back(): void;
+    // (undocumented)
+    forward(): void;
+    // (undocumented)
+    getBaseHrefFromDOM(): string;
+    // (undocumented)
+    getState(): unknown;
+    // (undocumented)
+    get hash(): string;
+    // (undocumented)
+    historyGo(relativePosition?: number): void;
+    // (undocumented)
+    get hostname(): string;
+    // (undocumented)
+    get href(): string;
+    // (undocumented)
+    onHashChange(fn: LocationChangeListener): VoidFunction;
+    // (undocumented)
+    onPopState(fn: LocationChangeListener): VoidFunction;
+    // (undocumented)
+    get pathname(): string;
+    set pathname(newPath: string);
+    // (undocumented)
+    get port(): string;
+    // (undocumented)
+    get protocol(): string;
+    // (undocumented)
+    pushState(state: any, title: string, url: string): void;
+    // (undocumented)
+    replaceState(state: any, title: string, url: string): void;
+    // (undocumented)
+    get search(): string;
+    // (undocumented)
+    static ɵfac: i0.ɵɵFactoryDeclaration<BrowserPlatformLocation, never>;
+    // (undocumented)
+    static ɵprov: i0.ɵɵInjectableDeclaration<BrowserPlatformLocation>;
+}
+
 // @public
 export class CommonModule {
     // (undocumented)

packages/common/src/location/index.ts

@@ -9,4 +9,4 @@
 export {HashLocationStrategy} from './hash_location_strategy';
 export {Location, PopStateEvent} from './location';
 export {APP_BASE_HREF, LocationStrategy, PathLocationStrategy} from './location_strategy';
-export {LOCATION_INITIALIZED, LocationChangeEvent, LocationChangeListener, PlatformLocation} from './platform_location';
+export {BrowserPlatformLocation, LOCATION_INITIALIZED, LocationChangeEvent, LocationChangeListener, PlatformLocation} from './platform_location';

packages/common/src/location/platform_location.ts

@@ -7,6 +7,7 @@
  */
 
 import {Inject, Injectable, InjectionToken, ɵɵinject} from '@angular/core';
+
 import {getDOM} from '../dom_adapter';
 import {DOCUMENT} from '../dom_tokens';
 
@@ -106,25 +107,21 @@ export interface LocationChangeListener {
  * `PlatformLocation` encapsulates all of the direct calls to platform APIs.
  * This class should not be used directly by an application developer. Instead, use
  * {@link Location}.
+ *
+ * @publicApi
  */
 @Injectable({
   providedIn: 'platform',
   // See #23917
   useFactory: createBrowserPlatformLocation,
 })
 export class BrowserPlatformLocation extends PlatformLocation {
-  public readonly location!: Location;
-  private _history!: History;
+  private _location: Location;
+  private _history: History;
 
   constructor(@Inject(DOCUMENT) private _doc: any) {
     super();
-    this._init();
-  }
-
-  // This is moved to its own method so that `MockPlatformLocationStrategy` can overwrite it
-  /** @internal */
-  _init() {
-    (this as {location: Location}).location = window.location;
+    this._location = window.location;
     this._history = window.history;
   }
 
@@ -145,43 +142,43 @@ export class BrowserPlatformLocation extends PlatformLocation {
   }
 
   override get href(): string {
-    return this.location.href;
+    return this._location.href;
   }
   override get protocol(): string {
-    return this.location.protocol;
+    return this._location.protocol;
   }
   override get hostname(): string {
-    return this.location.hostname;
+    return this._location.hostname;
   }
   override get port(): string {
-    return this.location.port;
+    return this._location.port;
   }
   override get pathname(): string {
-    return this.location.pathname;
+    return this._location.pathname;
   }
   override get search(): string {
-    return this.location.search;
+    return this._location.search;
   }
   override get hash(): string {
-    return this.location.hash;
+    return this._location.hash;
   }
   override set pathname(newPath: string) {
-    this.location.pathname = newPath;
+    this._location.pathname = newPath;
   }
 
   override pushState(state: any, title: string, url: string): void {
     if (supportsState()) {
       this._history.pushState(state, title, url);
     } else {
-      this.location.hash = url;
+      this._location.hash = url;
     }
   }
 
   override replaceState(state: any, title: string, url: string): void {
     if (supportsState()) {
       this._history.replaceState(state, title, url);
     } else {
-      this.location.hash = url;
+      this._location.hash = url;
     }
   }