feat(core): Expose Injector.destroy on Injector created with Injector.create (#60054)

There is no implementation change, this only expose `destroy` in a case where the injector can be owned in userland.

PR Close #60054

Author: JeanMeche

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

@@ -588,6 +588,12 @@ export class DefaultIterableDiffer<V> implements IterableDiffer<V>, IterableChan
 // @public @deprecated (undocumented)
 export const defineInjectable: typeof ɵɵdefineInjectable;
 
+// @public
+export interface DestroyableInjector extends Injector {
+    // (undocumented)
+    destroy(): void;
+}
+
 // @public
 export function destroyPlatform(): void;
 
@@ -949,7 +955,7 @@ export abstract class Injector {
         providers: Array<Provider | StaticProvider>;
         parent?: Injector;
         name?: string;
-    }): Injector;
+    }): DestroyableInjector;
     abstract get<T>(token: ProviderToken<T>, notFoundValue: undefined, options: InjectOptions & {
         optional?: false;
     }): T;

packages/core/src/di/index.ts

@@ -24,7 +24,7 @@ export {
 } from './interface/defs';
 export {forwardRef, resolveForwardRef, ForwardRefFn} from './forward_ref';
 export {Injectable, InjectableDecorator, InjectableProvider} from './injectable';
-export {Injector} from './injector';
+export {Injector, DestroyableInjector} from './injector';
 export {EnvironmentInjector} from './r3_injector';
 export {
   importProvidersFrom,

packages/core/src/di/injector.ts

@@ -117,7 +117,7 @@ export abstract class Injector {
     providers: Array<Provider | StaticProvider>;
     parent?: Injector;
     name?: string;
-  }): Injector;
+  }): DestroyableInjector;
 
   static create(
     options:
@@ -146,3 +146,12 @@ export abstract class Injector {
    */
   static __NG_ELEMENT_ID__ = InjectorMarkers.Injector;
 }
+
+/**
+ * An Injector that the owner can destroy and trigger the DestroyRef.destroy hooks.
+ *
+ * @publicApi
+ */
+export interface DestroyableInjector extends Injector {
+  destroy(): void;
+}

packages/core/src/di/r3_injector.ts

@@ -113,6 +113,8 @@ interface Record<T> {
 /**
  * An `Injector` that's part of the environment injector hierarchy, which exists outside of the
  * component tree.
+ *
+ * @publicApi
  */
 export abstract class EnvironmentInjector implements Injector {
   /**

packages/core/test/acceptance/di_spec.ts

@@ -60,6 +60,7 @@ import {
   ɵDEFAULT_LOCALE_ID as DEFAULT_LOCALE_ID,
   ɵINJECTOR_SCOPE,
   ɵInternalEnvironmentProviders as InternalEnvironmentProviders,
+  DestroyRef,
 } from '@angular/core';
 import {RuntimeError, RuntimeErrorCode} from '@angular/core/src/errors';
 import {ViewRef as ViewRefInternal} from '@angular/core/src/render3/view_ref';
@@ -6494,4 +6495,26 @@ describe('di', () => {
 
     expect(injector.get(token)).toBe('module');
   });
+
+  it('should be able to destroy programmatically created injectors', () => {
+    @Injectable()
+    class Service {
+      ngOnDestroy() {}
+    }
+
+    const parentInjector = Injector.create({
+      providers: [Service],
+      parent: TestBed.inject(Injector),
+    });
+
+    const childInjector = Injector.create({providers: [Service], parent: parentInjector});
+
+    const instance = childInjector.get(Service);
+    const destroySpy = spyOn(instance, 'ngOnDestroy');
+
+    parentInjector.get(DestroyRef).onDestroy(() => childInjector.destroy());
+    parentInjector.destroy();
+
+    expect(destroySpy).toHaveBeenCalled();
+  });
 });

packages/platform-browser/test/browser/tools/tools_spec.ts

@@ -34,7 +34,7 @@ describe('profiler', () => {
             deps: [],
           },
         ],
-      }),
+      }) as Injector,
     } as ComponentRef<any>);
   });