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To incorporate a ServerWritableStream in nest.js using gRPC, follow these steps:

1. Define a service and method in your proto file that requires a ServerWritableStream.

service MyService {
  rpc MyMethod(stream MyRequest) returns (MyResponse) {}
}

message MyRequest {
  string id = 1;
  string content = 2;
}

message MyResponse {
  bool success = 1;
}

1. Generate the TypeScript classes from the proto file using the grpctoolsnode_protoc command-line tool.

grpc_tools_node_protoc --plugin=protoc-gen-ts=./node_modules/.bin/protoc-gen-ts --ts_out=./src --grpc_out=./src --proto_path=./proto ./proto/my_service.proto

1. Implement the MyService interface in your nest.js service.

@Injectable()
export class MyService implements grpcService<MyService> {
  async myMethod(stream: ServerWritableStream<MyRequest, MyResponse>) {
    // Handle incoming requests from the client
    stream.on('data', (data: MyRequest) => {
      console.log('Received request:', data);
    });

    // Send response back to the client
    await stream.write({ success: true });

    // Close the stream
    stream.end();
  }
}

1. Add the MyService to your gRPC server in the main.ts file.

async function bootstrap() {
  const app = await NestFactory.createMicroservice(AppModule, {
    transport: Transport.GRPC,
    options: {
      package: 'my_package',
      protoPath: join(__dirname, './proto/my_service.proto'),
    },
  });

  await app.listenAsync();
}

1. Start the gRPC server and client to test the ServerWritableStream.

const client = new MyServiceClient('localhost:5000', credentials.createInsecure());

const stream = client.myMethod((error, response) => {
  console.log('Stream closed');
});

// Send multiple requests to the server and handle the responses
stream.write({ id: '1', content: 'Hello' });
stream.write({ id: '2', content: 'World' });

stream.on('data', (data: MyResponse) => {
  console.log('Received response:', data);
});

stream.on('end', () => {
  console.log('Stream ended');
});