Merge pull request #579 from matt1097/bug/578fix

Bugfix for aliased providers

lib/event-subscribers.loader.ts

@@ -45,7 +45,7 @@ export class EventSubscribersLoader
     const providers = this.discoveryService.getProviders();
     const controllers = this.discoveryService.getControllers();
     [...providers, ...controllers]
-      .filter(wrapper => wrapper.instance)
+      .filter(wrapper => wrapper.instance && !wrapper.isAlias)
       .forEach((wrapper: InstanceWrapper) => {
         const { instance } = wrapper;
         const prototype = Object.getPrototypeOf(instance) || {};

tests/e2e/module-e2e.spec.ts

@@ -8,6 +8,7 @@ import {
   TEST_EVENT_STRING_PAYLOAD,
 } from '../src/constants';
 import { EventsControllerConsumer } from '../src/events-controller.consumer';
+import { EventsProviderAliasedConsumer } from '../src/events-provider-aliased.consumer';
 import { EventsProviderPrependConsumer } from '../src/events-provider-prepend.consumer';
 import { EventsProviderConsumer } from '../src/events-provider.consumer';
 import { EventsProviderRequestScopedConsumer } from '../src/events-provider.request-scoped.consumer';
@@ -31,6 +32,15 @@ describe('EventEmitterModule - e2e', () => {
     expect(eventsConsumerRef.eventPayload).toEqual(TEST_EVENT_PAYLOAD);
   });
 
+  it(`aliased providers should receive an event only once`, async () => {
+    const eventsConsumerRef = app.get(EventsProviderAliasedConsumer);    
+    const eventSpy = jest.spyOn(eventsConsumerRef, 'eventPayload', 'set');
+    await app.init();
+
+    expect(eventSpy).toBeCalledTimes(1);
+    eventSpy.mockRestore();
+  });
+
   it(`should emit a "test-event" event to controllers`, async () => {
     const eventsConsumerRef = app.get(EventsControllerConsumer);
     await app.init();

tests/src/app.module.ts

@@ -1,6 +1,7 @@
 import { Module } from '@nestjs/common';
 import { EventEmitterModule } from '../../lib';
 import { EventsControllerConsumer } from './events-controller.consumer';
+import { EventsProviderAliasedConsumer } from './events-provider-aliased.consumer';
 import { EventsProviderPrependConsumer } from './events-provider-prepend.consumer';
 import { EventsProviderConsumer } from './events-provider.consumer';
 import { EventsProviderRequestScopedConsumer } from './events-provider.request-scoped.consumer';
@@ -20,6 +21,11 @@ import { TestProvider } from './test-provider';
     EventsProducer,
     TestProvider,
     EventsProviderRequestScopedConsumer,
+    EventsProviderAliasedConsumer,
+    {
+      provide: 'AnAliasedConsumer',
+      useExisting: EventsProviderAliasedConsumer,
+    },
   ],
 })
 export class AppModule {}

tests/src/events-provider-aliased.consumer.ts

@@ -0,0 +1,20 @@
+import { Injectable } from '@nestjs/common';
+import { OnEvent } from '../../lib';
+
+@Injectable()
+export class EventsProviderAliasedConsumer {
+  private _eventPayload = {};
+
+  set eventPayload(value) {
+    this._eventPayload = value;
+  }
+
+  get eventPayload() {
+    return this._eventPayload;
+  }
+
+  @OnEvent('test.*')
+  onTestEvent(payload: Record<string, any>) {
+    this.eventPayload = payload;
+  }
+}