fix(common): do not override locale provided on bootstrap (#13654)

Closes #13607

modules/@angular/core/src/application_module.ts

@@ -11,6 +11,7 @@ import {ApplicationInitStatus} from './application_init';
 import {ApplicationRef, ApplicationRef_} from './application_ref';
 import {APP_ID_RANDOM_PROVIDER} from './application_tokens';
 import {IterableDiffers, KeyValueDiffers, defaultIterableDiffers, defaultKeyValueDiffers} from './change_detection/change_detection';
+import {Inject, Optional, SkipSelf} from './di/metadata';
 import {LOCALE_ID} from './i18n/tokens';
 import {Compiler} from './linker/compiler';
 import {ViewUtils} from './linker/view_utils';
@@ -24,6 +25,10 @@ export function _keyValueDiffersFactory() {
   return defaultKeyValueDiffers;
 }
 
+export function _localeFactory(locale?: string): string {
+  return locale || 'en-US';
+}
+
 /**
  * This module includes the providers of @angular/core that are needed
  * to bootstrap components via `ApplicationRef`.
@@ -41,7 +46,11 @@ export function _keyValueDiffersFactory() {
     AnimationQueue,
     {provide: IterableDiffers, useFactory: _iterableDiffersFactory},
     {provide: KeyValueDiffers, useFactory: _keyValueDiffersFactory},
-    {provide: LOCALE_ID, useValue: 'en-US'},
+    {
+      provide: LOCALE_ID,
+      useFactory: _localeFactory,
+      deps: [[new Inject(LOCALE_ID), new Optional(), new SkipSelf()]]
+    },
   ]
 })
 export class ApplicationModule {

modules/@angular/core/test/application_module_spec.ts

@@ -14,4 +14,4 @@ export function main() {
     it('should set the default locale to "en-US"',
        inject([LOCALE_ID], (defaultLocale: string) => { expect(defaultLocale).toEqual('en-US'); }));
   });
-}
+}

modules/@angular/platform-browser/test/browser/bootstrap_spec.ts

@@ -6,12 +6,12 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {APP_INITIALIZER, CUSTOM_ELEMENTS_SCHEMA, Compiler, Component, Directive, ErrorHandler, Inject, Input, NgModule, OnDestroy, PLATFORM_INITIALIZER, Pipe, Provider, VERSION, createPlatformFactory} from '@angular/core';
+import {APP_INITIALIZER, CUSTOM_ELEMENTS_SCHEMA, Compiler, Component, Directive, ErrorHandler, Inject, Input, LOCALE_ID, NgModule, OnDestroy, PLATFORM_INITIALIZER, Pipe, Provider, VERSION, createPlatformFactory} from '@angular/core';
 import {ApplicationRef, destroyPlatform} from '@angular/core/src/application_ref';
 import {Console} from '@angular/core/src/console';
 import {ComponentRef} from '@angular/core/src/linker/component_factory';
 import {Testability, TestabilityRegistry} from '@angular/core/src/testability/testability';
-import {AsyncTestCompleter, Log, afterEach, beforeEach, beforeEachProviders, describe, iit, inject, it} from '@angular/core/testing/testing_internal';
+import {AsyncTestCompleter, Log, afterEach, beforeEach, beforeEachProviders, describe, inject, it} from '@angular/core/testing/testing_internal';
 import {BrowserModule} from '@angular/platform-browser';
 import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
 import {getDOM} from '@angular/platform-browser/src/dom/dom_adapter';
@@ -109,7 +109,8 @@ class DummyConsole implements Console {
 
 
 class TestModule {}
-function bootstrap(cmpType: any, providers: Provider[] = []): Promise<any> {
+function bootstrap(
+    cmpType: any, providers: Provider[] = [], platformProviders: Provider[] = []): Promise<any> {
   @NgModule({
     imports: [BrowserModule],
     declarations: [cmpType],
@@ -119,7 +120,7 @@ function bootstrap(cmpType: any, providers: Provider[] = []): Promise<any> {
   })
   class TestModule {
   }
-  return platformBrowserDynamic().bootstrapModule(TestModule);
+  return platformBrowserDynamic(platformProviders).bootstrapModule(TestModule);
 }
 
 export function main() {
@@ -281,6 +282,17 @@ export function main() {
          });
        }));
 
+    it('should not override locale provided during bootstrap',
+       inject([AsyncTestCompleter], (async: AsyncTestCompleter) => {
+         const refPromise =
+             bootstrap(HelloRootCmp, [testProviders], [{provide: LOCALE_ID, useValue: 'fr-FR'}]);
+
+         refPromise.then(ref => {
+           expect(ref.injector.get(LOCALE_ID)).toEqual('fr-FR');
+           async.done();
+         });
+       }));
+
     it('should avoid cyclic dependencies when root component requires Lifecycle through DI',
        inject([AsyncTestCompleter], (async: AsyncTestCompleter) => {
          const refPromise = bootstrap(HelloRootCmp4, testProviders);