看遍了koa,express以及其衍生框架之后，发现NodeJs的Web开发框架似乎跳不出一个固定的模式，这个问题也困扰着PHP，那就是能不能通过注解来简化开发？

示例代码

在介绍nestjs之前，先让大家看一看nestjs的示例代码。

1. HTTP接口

@Controller('socket')@UseGuards(AdminGuard)export class SocketController {  private logger: Logger = new Logger(SocketController.name);  constructor(private readonly gateway: SocketGateway,              private readonly salesmanService: SalesmanService,              private readonly hashidService: HashidService) {  }  @Post('interaction')  async send(@Query('salesman_id') salesmanId: number, @Query('user_id') userId: number, @Body('content') content: string) {    if (!salesmanId || !userId || !content) {      throw new BadRequestException('Bad Request');    }    const salesman = await this.salesmanService.findById(salesmanId);    if (!salesman) {      throw new NotFoundException('销售不存在');    }    const roomId = this.salesmanService.makeSyncRoomKey(salesman);    this.gateway.namespace.to(roomId).emit(SocketEvent.OnInteraction, { user_id: this.hashidService.encode(userId), content });    return { errmsg: 'ok', errcode: 0 };  }}

1. Socket.IO

@UseFilters(new WsExceptionFilter())@WebSocketGateway({ namespace: 'socket', adapter: adapter(appConfig.redis) })export class SocketGateway implements OnGatewayInit
    
     , OnGatewayConnection
     
       {  private logger: Logger = new Logger(SocketGateway.name);  @WebSocketServer() public readonly namespace: SocketIO.Namespace;  public adapter: adapter.RedisAdapter;  constructor(    private readonly salesmanService: SalesmanService,    private readonly corporationService: CorporationService,    private readonly hashidService: HashidService,    private readonly userService: UserService,    private readonly roomService: RoomService,    private readonly messageService: MessageService,    private readonly readService: ReadService,    private readonly memberService: MemberService,  ) {  }  afterInit(server: SocketIO.Namespace): any {    this.adapter = server.adapter as adapter.RedisAdapter;    this.logger.log(`initialized ${server.name}`);  }  /**   * 进入聊天室   * @param {SocketIO.Socket} client   * @returns {any}   */  async handleConnection(client: SocketIO.Socket): Promise
      
        {    const { user_id, token, corporation_id, sign } = qs.parse(url.parse(client.request.url).query) as {      [name: string]: string;    };    if (!user_id && !token && !corporation_id && !sign) {      client.disconnect(true);      return;    }    const realUserId = this.hashidService.decode(user_id);    await promisify(client.join.bind(client))(this.roomService.makePersonalRoomId(realUserId)),      client.emit(SocketEvent.Ready);  }  @SubscribeMessage(SocketEvent.Join)  handleJoin(client: SocketIO.Socket, data: any) {    if (JoinType.Chat === data.type) {      return this.handleJoinChat(client, data);    }    if (JoinType.Sync === data.type) {      return this.handleJoinSync(client, data);    }    client.disconnect(true);  }  @SubscribeMessage(SocketEvent.Leave)  async handleLeave(client: SocketIO.Socket, data: any) {    const { user_id, token, corporation_id, sign } = qs.parse(url.parse(client.request.url).query) as {      [name: string]: string;    };    if (JoinType.Chat === data.type) {      await promisify(client.leave.bind(client))(data.room_id);      return { event: SocketEvent.Leave, data };    }    const isPersonal = user_id && token;    const roomId = isPersonal      ? await this.salesmanService.getRoomId(user_id, token)      : await this.corporationService.getRoomId(corporation_id, sign);    if (roomId) {      await promisify(client.leave).bind(client)(roomId);    }    return { event: SocketEvent.Leave, data };  }// ...
      
     
    

写法是不是很像Java?或者说是Angular4?

介绍

实际上nestjs的架构源自于java的spring框架，而代码组织则借鉴与Angular4的Module。

nestjs模块架构图

开始开发

1. yarn global add @nestjs/cli
2. nest new projectName
3. cd projectName && yarn start

写在最后

由于篇幅关系，nestjs的详细文档可以前往官网查看，本文只是做个框架介绍，开启新世界的大门。