feat(Effects): Add root effects init action (#473)

Closes #246

modules/effects/spec/effects_root_module.spec.ts

@@ -0,0 +1,55 @@
+import { TestBed } from '@angular/core/testing';
+import {
+  Store,
+  StoreModule,
+  ActionReducer,
+  MetaReducer,
+  Action,
+  INIT,
+} from '@ngrx/store';
+import { ROOT_EFFECTS_INIT } from '../src/effects_root_module';
+import { EffectsModule } from '../src/effects_module';
+
+describe('Effects Root Module', () => {
+  const foo = 'foo';
+  const reducer = jasmine.createSpy('reducer').and.returnValue(foo);
+
+  beforeEach(() => {
+    reducer.calls.reset();
+  });
+
+  it('dispatches the root effects init action', () => {
+    TestBed.configureTestingModule({
+      imports: [
+        StoreModule.forRoot({ reducer }, { initialState: { reducer: foo } }),
+        EffectsModule.forRoot([]),
+      ],
+    });
+
+    const store = TestBed.get(Store);
+
+    expect(reducer).toHaveBeenCalledWith(foo, {
+      type: INIT,
+    });
+    expect(reducer).toHaveBeenCalledWith(foo, {
+      type: ROOT_EFFECTS_INIT,
+    });
+  });
+
+  it("doesn't dispatch the root effects init action when EffectsModule isn't used", () => {
+    TestBed.configureTestingModule({
+      imports: [
+        StoreModule.forRoot({ reducer }, { initialState: { reducer: foo } }),
+      ],
+    });
+
+    const store = TestBed.get(Store);
+
+    expect(reducer).toHaveBeenCalledWith(foo, {
+      type: INIT,
+    });
+    expect(reducer).not.toHaveBeenCalledWith(foo, {
+      type: ROOT_EFFECTS_INIT,
+    });
+  });
+});

modules/effects/src/effects_root_module.ts

@@ -1,14 +1,17 @@
 import { NgModule, Inject, Optional } from '@angular/core';
-import { StoreModule } from '@ngrx/store';
+import { StoreModule, Store } from '@ngrx/store';
 import { EffectsRunner } from './effects_runner';
 import { EffectSources } from './effect_sources';
 import { ROOT_EFFECTS } from './tokens';
 
+export const ROOT_EFFECTS_INIT = '@ngrx/effects/init';
+
 @NgModule({})
 export class EffectsRootModule {
   constructor(
     private sources: EffectSources,
     runner: EffectsRunner,
+    store: Store<any>,
     @Inject(ROOT_EFFECTS) rootEffects: any[],
     @Optional() storeModule: StoreModule
   ) {
@@ -17,6 +20,8 @@ export class EffectsRootModule {
     rootEffects.forEach(effectSourceInstance =>
       sources.addEffects(effectSourceInstance)
     );
+
+    store.dispatch({ type: ROOT_EFFECTS_INIT });
   }
 
   addEffects(effectSourceInstance: any) {

modules/effects/src/index.ts

@@ -6,3 +6,4 @@ export { EffectSources } from './effect_sources';
 export { OnRunEffects } from './on_run_effects';
 export { toPayload } from './util';
 export { EffectNotification } from './effect_notification';
+export { ROOT_EFFECTS_INIT } from './effects_root_module';