fix(core): return StaticProvider for providePlatformInitializer

Returning `EnvironmentProviders` was never correct.
fixes angular#64277

Author: JeanMeche

goldens/public-api/core/index.api.md

@@ -1485,7 +1485,7 @@ export function provideEnvironmentInitializer(initializerFn: () => void): Enviro
 export function provideNgReflectAttributes(): EnvironmentProviders;
 
 // @public
-export function providePlatformInitializer(initializerFn: () => void): EnvironmentProviders;
+export function providePlatformInitializer(initializerFn: () => void): StaticProvider;
 
 // @public
 export type Provider = TypeProvider | ValueProvider | ClassProvider | ConstructorProvider | ExistingProvider | FactoryProvider | any[];

packages/core/src/platform/platform.ts

@@ -187,20 +187,23 @@ export function createOrReusePlatformInjector(providers: StaticProvider[] = []):
  *
  * Note that the provided initializer is run in the injection context.
  *
- * Previously, this was achieved using the `PLATFORM_INITIALIZER` token which is now deprecated.
+ * @usageNotes
+ * The platform initializer should be provided during platform creation:
  *
- * @see {@link PLATFORM_INITIALIZER}
+ * ```ts
+ * const platformRef = platformBrowser([ providePlatformInitializer(() =>  ...) ]);
+ *
+ * bootstrapApplication(App, appConfig, { platformRef })
+ * ```
  *
  * @publicApi
  */
-export function providePlatformInitializer(initializerFn: () => void): EnvironmentProviders {
-  return makeEnvironmentProviders([
-    {
-      provide: PLATFORM_INITIALIZER,
-      useValue: initializerFn,
-      multi: true,
-    },
-  ]);
+export function providePlatformInitializer(initializerFn: () => void): StaticProvider {
+  return {
+    provide: PLATFORM_INITIALIZER,
+    useValue: initializerFn,
+    multi: true,
+  };
 }
 
 function runPlatformInitializers(injector: Injector): void {

packages/platform-browser/test/browser/bootstrap_spec.ts

@@ -51,7 +51,7 @@ import {ɵLog as Log, inject, TestBed} from '@angular/core/testing';
 import {BrowserModule} from '../../index';
 import {provideAnimations, provideNoopAnimations} from '../../animations';
 import {expect} from '@angular/private/testing/matchers';
-import {isNode} from '@angular/private/testing';
+import {isNode, withBody} from '@angular/private/testing';
 
 import {bootstrapApplication, platformBrowser} from '../../src/browser';
 
@@ -920,28 +920,37 @@ describe('providePlatformInitializer', () => {
 
     createPlatformInjector([
       {provide: TEST_TOKEN, useValue: 'test'},
-      providePlatformInitializer(() => {
-        injectedValue = _inject(TEST_TOKEN);
-      }),
+      providePlatformInitializer(() => (injectedValue = _inject(TEST_TOKEN))),
     ]);
 
     expect(injectedValue).toBe('test');
   });
 
-  function createPlatformInjector(providers: Array<EnvironmentProviders | Provider>) {
-    /* TODO: should we change `createOrReusePlatformInjector` type to allow `EnvironmentProviders`?
-     */
-    return createOrReusePlatformInjector(providers as any);
+  function createPlatformInjector(providers: Array<StaticProvider>) {
+    return createOrReusePlatformInjector(providers);
   }
-});
 
-/**
- * Typing tests.
- */
-@Component({
-  template: '',
-  // @ts-expect-error: `providePlatformInitializer()` should not work with Component.providers, as
-  // it wouldn't be executed anyway.
-  providers: [providePlatformInitializer(() => {})],
-})
-class Test {}
+  it('should bootstrap with platform initializers', async () => {
+    return withBody('<app></app>', async () => {
+      @Component({
+        selector: 'app',
+        template: '',
+      })
+      class App {}
+
+      let platformInitializerCalls = 0;
+
+      const platformRef = platformBrowser([
+        providePlatformInitializer(() => {
+          platformInitializerCalls++;
+        }),
+      ]);
+
+      expect(platformInitializerCalls).toBe(0);
+      await bootstrapApplication(App, undefined, {platformRef});
+      expect(platformInitializerCalls).toBe(1);
+      await bootstrapApplication(App, undefined, {platformRef});
+      expect(platformInitializerCalls).toBe(1);
+    });
+  });
+});