nestjs 本身已经集成了websocket的支持官方文档也有详细的描述:
官网
但是 他没有告诉你的是,他完全按照socket.io的方式设计的,遵从订阅、事件方式进行了处理,这个很好没有问题.
例如:

@SubscribeMessage('events')
handleEvent(
  @MessageBody() data: string,
  @ConnectedSocket() client: Socket,
): string {
  return data;
}

虽然有适配器说明,但是依然模糊不足以支撑自定义业务,因为要求的message格式必须是如下:

{
    "event": "message",
    "data": {
        "test": 123
    }
}

我的需求是对接的文档要求所有的动作都是cmd 因此需要支持的是 websocket方案

{"cmd":"ping","sn":"T78182","timestamp":1730734491}

自定义适配器如下:

ClockWsAdapter

// 
import { WsAdapter as OriginWsAdapter } from '@nestjs/platform-ws';
import { MessageMappingProperties } from '@nestjs/websockets';
import { CLOSE_EVENT } from '@nestjs/websockets/constants';
import { get } from 'lodash';
import {
  EMPTY,
  filter,
  first,
  fromEvent,
  mergeMap,
  Observable,
  share,
  takeUntil,
} from 'rxjs';

enum READY_STATE {
  CONNECTING_STATE = 0,
  OPEN_STATE = 1,
  CLOSING_STATE = 2,
  CLOSED_STATE = 3,
}

export class ClockWsAdapter extends OriginWsAdapter {
  public bindMessageHandlers(
    client: any,
    handlers: any,
    transform: (data: any) => Observable<any>,
  ) {
    const close$ = fromEvent(client, CLOSE_EVENT).pipe(share(), first());
    const source$ = fromEvent(client, 'message').pipe(
      mergeMap((data: any) =>
        this.bindMessageHandler(data.data, handlers, transform).pipe(
          filter((result: any) => result),
        ),
      ),
      takeUntil(close$),
    );
    const onMessage = (response: any) => {
      if (client.readyState !== READY_STATE.OPEN_STATE) {
        return;
      }
      client.send(response);
    };
    source$.subscribe(onMessage);
  }

  bindMessageHandler(
    buffer: string,
    handlersMap: any,
    transform: (data: any) => Observable<any>,
    // buffer: string | number | Buffer,
    // handlers: MessageMappingProperties[],
    // transform: (data: any) => Observable<any>,
  ) {
    try {
      const cmdObject = JSON.parse(buffer);
      // 对应获取  @SubscribeMessage('ping') name 自定义解析
      const handlerName = get(cmdObject, 'cmd', 'message');
      // this.logger.debug(cmdObject, handlerName, handlersMap);
      const messageHandler = (handlersMap as MessageMappingProperties[]).find(
        (p) => p.message === handlerName,
      );
      const { callback } = messageHandler;
      return transform(callback(buffer));
    } catch {
      return EMPTY;
    }
  }
}

TimeClockGateway

import { Logger } from '@nestjs/common';
import {
  MessageBody,
  SubscribeMessage,
  WebSocketGateway,
  WebSocketServer,
} from '@nestjs/websockets';
import { Server } from 'socket.io';

@WebSocketGateway({
  cors: {
    origin: '*',
    methods: ['GET', 'POST'],
    allowedHeaders: ['Content-Type'],
    credentials: true,
  },
})
export class TimeClockGateway {
  logger = new Logger(TimeClockGateway.name);

  @WebSocketServer()
  server: Server;
  //
  @SubscribeMessage('declare')
  handleDeclare(client: any, payload: any): void {
    this.logger.debug(payload);
    return;
  }

  @SubscribeMessage('ping')
  handleMessage(client: any, payload: any): string {
    // this.logger.debug(payload);
    return JSON.stringify({ cmd: 'pong' });
  }

  @SubscribeMessage('events')
  handleEvent(@MessageBody() data: string): string {
    // this.logger.debug(data);
    return data;
  }
}