feat(effects): allow usage of empty forRoot array multiple times (#2774)

ngrx · Nov 14, 2020 · 5219ff5 · 5219ff5
1 parent a489b48
commit 5219ff5
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Showing 2 changed files with 50 additions and 9 deletions.
diff --git a/modules/effects/spec/integration.spec.ts b/modules/effects/spec/integration.spec.ts
@@ -20,7 +20,7 @@ import { mapTo, exhaustMap, tap } from 'rxjs/operators';
 import { Observable } from 'rxjs';
 
 describe('NgRx Effects Integration spec', () => {
- it('throws if forRoot() is used more than once', (done: any) => {
+ it('throws if forRoot() with Effects is used more than once', (done: any) => {
  TestBed.configureTestingModule({
  imports: [
  StoreModule.forRoot({}),
@@ -45,6 +45,30 @@ describe('NgRx Effects Integration spec', () => {
  });
  });
 
+ it('does not throw if forRoot() is used more than once with empty effects', (done: any) => {
+ TestBed.configureTestingModule({
+ imports: [
+ StoreModule.forRoot({}),
+ EffectsModule.forRoot([]),
+ RouterTestingModule.withRoutes([]),
+ ],
+ });
+
+ let router: Router = TestBed.inject(Router);
+ const loader: SpyNgModuleFactoryLoader = TestBed.inject(
+ NgModuleFactoryLoader
+ ) as SpyNgModuleFactoryLoader;
+
+ // empty forRoot([]) 👇
+ loader.stubbedModules = { feature: FeatModuleWithEmptyForRoot };
+ router.resetConfig([{ path: 'feature-path', loadChildren: 'feature' }]);
+
+ router.navigateByUrl('/feature-path').then(() => {
+ // success
+ done();
+ });
+ });
+
  describe('actions', () => {
  const createDispatchedReducer = (dispatchedActions: string[] = []) => (
  state = {},
@@ -386,11 +410,19 @@ describe('NgRx Effects Integration spec', () => {
  }
  }
 
+ @Injectable()
+ class SomeEffect {}
+
  @NgModule({
- imports: [EffectsModule.forRoot()],
+ imports: [EffectsModule.forRoot([SomeEffect])],
  })
  class FeatModuleWithForRoot {}
 
+ @NgModule({
+ imports: [EffectsModule.forRoot([])],
+ })
+ class FeatModuleWithEmptyForRoot {}
+
  @NgModule({
  imports: [
  EffectsModule.forFeature([FeatEffectFromLazyLoadedModuleWithInitAction]),

diff --git a/modules/effects/src/effects_module.ts b/modules/effects/src/effects_module.ts
@@ -3,6 +3,7 @@ import {
  ModuleWithProviders,
  NgModule,
  Optional,
+ Self,
  SkipSelf,
  Type,
 } from '@angular/core';
@@ -57,11 +58,6 @@ export class EffectsModule {
  return {
  ngModule: EffectsRootModule,
  providers: [
- {
- provide: _ROOT_EFFECTS_GUARD,
- useFactory: _provideForRootGuard,
- deps: [[EffectsRunner, new Optional(), new SkipSelf()]],
- },
  {
  provide: EFFECTS_ERROR_HANDLER,
  useValue: defaultEffectsErrorHandler,
@@ -74,6 +70,14 @@ export class EffectsModule {
  provide: _ROOT_EFFECTS,
  useValue: [rootEffects],
  },
+ {
+ provide: _ROOT_EFFECTS_GUARD,
+ useFactory: _provideForRootGuard,
+ deps: [
+ [EffectsRunner, new Optional(), new SkipSelf()],
+ [_ROOT_EFFECTS, new Self()],
+ ],
+ },
  {
  provide: USER_PROVIDED_EFFECTS,
  multi: true,
@@ -114,8 +118,13 @@ export function createEffectInstances(
  return effects.map((effect) => injector.get(effect));
 }
 
-export function _provideForRootGuard(runner: EffectsRunner): any {
- if (runner) {
+export function _provideForRootGuard(
+ runner: EffectsRunner,
+ rootEffects: any[][]
+): any {
+ // check whether any effects are actually passed
+ const hasEffects = !(rootEffects.length === 1 && rootEffects[0].length === 0);
+ if (hasEffects && runner) {
  throw new TypeError(
  `EffectsModule.forRoot() called twice. Feature modules should use EffectsModule.forFeature() instead.`
  );