Nestjs Hybrid application websocket + microservice - websocket

Question

I have a problem with Nestjs, with starting a microservice that listens to a messagebroker, while simultaneously starting a websocket server with which we can communicate with front-end clients.
So I am aware of hybrid nest applications, where the websocket gateway can be injected into the microservice. However I get errors about Nest not being able to resolve the Gateway import.
I configured the microservice in a ResultsModule, the websocket in UsersModule.
The error I get is:
ERROR [ExceptionHandler] Nest can't resolve dependencies of the ResultsController (ResultsService, ?). Please make sure that the argument UsersGateway at index [1] is available in the ResultsModule context.
These are the relevant pieces of code:
main.js
async function bootstrap() {
const app = await NestFactory.create(AppModule);
app.connectMicroservice<MicroserviceOptions>({
transport: Transport.RMQ,
options: {
urls: [
`amqp://${config.rabbitmq.username}:${config.rabbitmq.password}#${config.rabbitmq.host}:${config.rabbitmq.port}`,
],
queue: config.rabbitmq.channelListen,
noAck: false,
queueOptions: {
durable: false,
},
},
});
await app.startAllMicroservices();
await app.listen(82);
}
bootstrap();
app.module.ts
#Module({
imports: [UsersModule, ResultsModule],
controllers: [AppController],
providers: [AppService],
})
export class AppModule {}
results.module.ts
#Module({
imports: [UsersModule],
controllers: [ResultsController],
providers: [ResultsService],
})
export class ResultsModule {}
users.module.ts
#Module({
providers: [UsersGateway, UsersService],
})
export class UsersModule {}
users.gateway.ts
import {
WebSocketGateway,
SubscribeMessage,
MessageBody,
OnGatewayInit,
OnGatewayConnection,
OnGatewayDisconnect,
WebSocketServer,
ConnectedSocket,
} from '#nestjs/websockets';
import { Socket, Server } from 'socket.io';
import { UsersService } from './users.service';
import { CreateUserDto } from './dto/create-user.dto';
import { UpdateUserDto } from './dto/update-user.dto';
#WebSocketGateway(82)
export class UsersGateway
implements OnGatewayInit, OnGatewayConnection, OnGatewayDisconnect
{
constructor(private readonly usersService: UsersService) {}
#WebSocketServer() server: Server;
afterInit(server: Server) {
console.log('init');
}
handleDisconnect(client: Socket) {
console.log(`Client disconnected: ${client.id}`);
}
handleConnection(client: Socket, ...args: any[]) {
console.log(client.id);
}
#SubscribeMessage('resource')
create(
#MessageBody() createUserDto: CreateUserDto,
#ConnectedSocket() client: Socket,
) {
console.log(client.id);
console.log(createUserDto.resourceId)
}
}
I tried to move around the imports, not wrapping the gateway in a module.
Tried moving the results module out of the app.module. Which removes the error, however then I do not understand where to let nestjs know to use the resultsmodule for the microservice.
------------------------ANSWER-------------------------------------
Alright, we fixed it with the help of #yomateo , we were missing the export of the websocket gateway in the module. Thanks for the help!

Answer 1

You're close (you have it backwards).
Have your UsersGateway or UsersService call the ResultsService.