fix(ivy): set LOCALE_ID when using the injector (#31566)

In `BrowserModule` the value of `LOCALE_ID` is defined in the `APPLICATION_MODULE_PROVIDERS` after `APP_INITIALIZER` has run.
This PR ensures that `LOCALE_ID` is also set for ivy at the same moment which allows the application to fetch the locale from a backend (for example).

Fixes #31465

FW-1436 #resolve

PR Close #31566

packages/core/src/application_module.ts

@@ -14,11 +14,14 @@ import {Console} from './console';
 import {Injector, StaticProvider} from './di';
 import {Inject, Optional, SkipSelf} from './di/metadata';
 import {ErrorHandler} from './error_handler';
+import {DEFAULT_LOCALE_ID} from './i18n/localization';
 import {LOCALE_ID} from './i18n/tokens';
+import {ivyEnabled} from './ivy_switch';
 import {ComponentFactoryResolver} from './linker';
 import {Compiler} from './linker/compiler';
 import {NgModule} from './metadata';
 import {SCHEDULER} from './render3/component_ref';
+import {setLocaleId} from './render3/i18n';
 import {NgZone} from './zone';
 
 export function _iterableDiffersFactory() {
@@ -31,15 +34,21 @@ export function _keyValueDiffersFactory() {
 
 export function _localeFactory(locale?: string): string {
   if (locale) {
+    if (ivyEnabled) {
+      setLocaleId(locale);
+    }
     return locale;
   }
   // Use `goog.LOCALE` as default value for `LOCALE_ID` token for Closure Compiler.
   // Note: default `goog.LOCALE` value is `en`, when Angular used `en-US`. In order to preserve
   // backwards compatibility, we use Angular default value over Closure Compiler's one.
   if (ngI18nClosureMode && typeof goog !== 'undefined' && goog.LOCALE !== 'en') {
+    if (ivyEnabled) {
+      setLocaleId(goog.LOCALE);
+    }
     return goog.LOCALE;
   }
-  return 'en-US';
+  return DEFAULT_LOCALE_ID;
 }
 
 /**

packages/core/src/application_ref.ts

@@ -8,15 +8,16 @@
 
 import {Observable, Observer, Subscription, merge} from 'rxjs';
 import {share} from 'rxjs/operators';
-
 import {ApplicationInitStatus} from './application_init';
 import {APP_BOOTSTRAP_LISTENER, PLATFORM_INITIALIZER} from './application_tokens';
 import {getCompilerFacade} from './compiler/compiler_facade';
 import {Console} from './console';
 import {Injectable, InjectionToken, Injector, StaticProvider} from './di';
 import {ErrorHandler} from './error_handler';
+import {DEFAULT_LOCALE_ID} from './i18n/localization';
 import {LOCALE_ID} from './i18n/tokens';
 import {Type} from './interface/type';
+import {ivyEnabled} from './ivy_switch';
 import {COMPILER_OPTIONS, CompilerFactory, CompilerOptions} from './linker/compiler';
 import {ComponentFactory, ComponentRef} from './linker/component_factory';
 import {ComponentFactoryBoundToModule, ComponentFactoryResolver} from './linker/component_factory_resolver';
@@ -26,7 +27,7 @@ import {isComponentResourceResolutionQueueEmpty, resolveComponentResources} from
 import {WtfScopeFn, wtfCreateScope, wtfLeave} from './profile/profile';
 import {assertNgModuleType} from './render3/assert';
 import {ComponentFactory as R3ComponentFactory} from './render3/component_ref';
-import {DEFAULT_LOCALE_ID, setLocaleId} from './render3/i18n';
+import {setLocaleId} from './render3/i18n';
 import {NgModuleFactory as R3NgModuleFactory} from './render3/ng_module_ref';
 import {Testability, TestabilityRegistry} from './testability/testability';
 import {isDevMode} from './util/is_dev_mode';
@@ -264,8 +265,10 @@ export class PlatformRef {
         throw new Error('No ErrorHandler. Is platform module (BrowserModule) included?');
       }
       // If the `LOCALE_ID` provider is defined at bootstrap we set the value for runtime i18n (ivy)
-      const localeId = moduleRef.injector.get(LOCALE_ID, DEFAULT_LOCALE_ID);
-      setLocaleId(localeId);
+      if (ivyEnabled) {
+        const localeId = moduleRef.injector.get(LOCALE_ID, DEFAULT_LOCALE_ID);
+        setLocaleId(localeId || DEFAULT_LOCALE_ID);
+      }
       moduleRef.onDestroy(() => remove(this._modules, moduleRef));
       ngZone !.runOutsideAngular(
           () => ngZone !.onError.subscribe(

packages/core/src/core_private_export.ts

@@ -16,6 +16,7 @@ export {Console as ɵConsole} from './console';
 export {inject, setCurrentInjector as ɵsetCurrentInjector, ɵɵinject} from './di/injector_compatibility';
 export {getInjectableDef as ɵgetInjectableDef, ɵɵInjectableDef, ɵɵInjectorDef} from './di/interface/defs';
 export {APP_ROOT as ɵAPP_ROOT} from './di/scope';
+export {DEFAULT_LOCALE_ID as ɵDEFAULT_LOCALE_ID} from './i18n/localization';
 export {ivyEnabled as ɵivyEnabled} from './ivy_switch';
 export {ComponentFactory as ɵComponentFactory} from './linker/component_factory';
 export {CodegenComponentFactoryResolver as ɵCodegenComponentFactoryResolver} from './linker/component_factory_resolver';
@@ -27,7 +28,6 @@ export {_sanitizeHtml as ɵ_sanitizeHtml} from './sanitization/html_sanitizer';
 export {_sanitizeStyle as ɵ_sanitizeStyle} from './sanitization/style_sanitizer';
 export {_sanitizeUrl as ɵ_sanitizeUrl} from './sanitization/url_sanitizer';
 export {global as ɵglobal} from './util/global';
-
 export {looseIdentical as ɵlooseIdentical,} from './util/comparison';
 export {stringify as ɵstringify} from './util/stringify';
 export {makeDecorator as ɵmakeDecorator} from './util/decorators';

packages/core/src/core_render3_private_export.ts

@@ -173,7 +173,6 @@ export {
   i18nConfigureLocalize as ɵi18nConfigureLocalize,
   ɵɵi18nLocalize,
   setLocaleId as ɵsetLocaleId,
-  DEFAULT_LOCALE_ID as ɵDEFAULT_LOCALE_ID,
   setClassMetadata as ɵsetClassMetadata,
   ɵɵresolveWindow,
   ɵɵresolveDocument,

packages/core/src/i18n/localization.ts

@@ -29,3 +29,8 @@ export function getPluralCase(value: any, locale: string): string {
       return 'other';
   }
 }
+
+/**
+ * The locale id that the application is using by default (for translations and ICU expressions).
+ */
+export const DEFAULT_LOCALE_ID = 'en-US';

packages/core/src/render3/i18n.ts

@@ -7,14 +7,12 @@
  */
 
 import '../util/ng_i18n_closure_mode';
-
-import {getPluralCase} from '../i18n/localization';
+import {DEFAULT_LOCALE_ID, getPluralCase} from '../i18n/localization';
 import {SRCSET_ATTRS, URI_ATTRS, VALID_ATTRS, VALID_ELEMENTS, getTemplateContent} from '../sanitization/html_sanitizer';
 import {InertBodyHelper} from '../sanitization/inert_body';
 import {_sanitizeUrl, sanitizeSrcset} from '../sanitization/url_sanitizer';
 import {addAllToArray} from '../util/array_utils';
 import {assertDataInRange, assertDefined, assertEqual, assertGreaterThan} from '../util/assert';
-
 import {attachPatchData} from './context_discovery';
 import {bind, setDelayProjection, ɵɵload} from './instructions/all';
 import {attachI18nOpCodesDebug} from './instructions/lview_debug';
@@ -1358,7 +1356,6 @@ export function ɵɵi18nLocalize(input: string, placeholders?: {[key: string]: s
  * This is the ivy version of `LOCALE_ID` that was defined as an injection token for the view engine
  * but is now defined as a global value.
  */
-export const DEFAULT_LOCALE_ID = 'en-US';
 let LOCALE_ID = DEFAULT_LOCALE_ID;
 
 /**
@@ -1369,7 +1366,10 @@ let LOCALE_ID = DEFAULT_LOCALE_ID;
  * @param localeId
  */
 export function setLocaleId(localeId: string) {
-  LOCALE_ID = localeId.toLowerCase().replace(/_/g, '-');
+  assertDefined(localeId, `Expected localeId to be defined`);
+  if (typeof localeId === 'string') {
+    LOCALE_ID = localeId.toLowerCase().replace(/_/g, '-');
+  }
 }
 
 /**

packages/core/src/render3/index.ts

@@ -142,7 +142,6 @@ export {
 } from './state';
 
 export {
-  DEFAULT_LOCALE_ID,
   ɵɵi18n,
   ɵɵi18nAttributes,
   ɵɵi18nExp,