trayanus1026/chat-server-nestjs-websocket

Chat server with nestJs and websocket

Chat server using WebSockets with Nest framework.

Installation

npm install

Running the app

# development
npm run start

# watch mode
npm run start:dev

Required packages

npm i --save @nestjs/websockets @nestjs/platform-socket.io ngx-socket-io
npm i --save-dev @types/socket.io

Web Socket Gateway

• Init:

  We add @WebSocketServer() server; inside of our ChatWebsocketGateway to attaches a native Web Socket Server to our property server and then we use the decorator @WebSocketGateway(port?: number)to mark our WebsocketGateway class as a Nest gateway that enables real-time, bidirectional and event-based communication between the browser and the server

• Handlers:

  In order de hand the connection and disconnection at our websocket server we need to implement interfaces OnGatewayConnection and OnGatewayDisconnect.

• Subscribers:

  We use decorator @SubscribeMessage('exmple-channel') on the method that handles our business rules on exmple-channel events, for example we use @SubscribeMessage('chat') to cap and handle the chat events. You can implement a custom subscriber as: @SubscribeMessage({channel: 'messages', type: 'group'}) in order to hand messages event of groups only.

APIs

RoomsController

• Create room:

  Resource:

    /api/v1/rooms
  

  Body:

    roomId: the room id (room name)
    creatorUsername: the username with creats the room
  

  Example:

  curl -X POST 'http://localhost:3000/api/v1/rooms' \
  --data-raw '{
      "roomId": "3XX",
      "creatorUsername": "idirnaitali"
  }'

  Error cases:

  • Invalid body:

  {
    "statusCode": 400,
    "message": [
      "roomId should not be empty",
      "creatorUsername should not be empty"
    ],
    "error": "Bad Request"
  }

  • Existing room id:

  {
    "code": "room.conflict",
    "message": "Room with 'exmple-room' already exists"
  }

• Get room messages:

  Resource:

    /api/v1/rooms/{roomId}/messages?fromIndex={fromIndex}&toIndex={fromIndex}
  

  Params:

    roomId: the room id
    fromIndex: the index of the first message to get
    fromIndex: the index of the last message to get
  

  Example:

  curl -X GET 'http://localhost:3000/api/v1/rooms/3XX/messages?fromIndex=1&toIndex=20'

  Error cases:

  • Invalid room id (ex: not found or closed):

  {
    "code": "access-forbidden",
    "message": "The access is forbidden"
  }

  • Missing fromIndex / toIndex:

  {
    "statusCode": 400,
    "message": "Validation failed (numeric string is expected)",
    "error": "Bad Request"
  }

  • Invalid fromIndex / toIndex:

  {
    "code": "req-params.validation",
    "message": "Invalid parameters, 'fromIndex' and 'toIndex' must be positive"
  }

  • Invalid fromIndex / toIndex:

  {
    "code": "req-params.validation",
    "message": "Invalid parameters, 'toIndex' must no not be less than 'fromIndex'"
  }

• Close room (Delete room):

  Resource:

    /api/v1/rooms/{roomId}
  

  Params:

    roomId: the room id
  

  Example:

  curl -X DELETE http://localhost:3000/api/v1/rooms/3XX 

  Error cases:

  • Invalid room id (ex: not found or closed):

  {
    "code": "room.not-fond",
    "message": "Room with '3XX' not found"
  }