fix: Non-JSON message from client causes uncaught ParameterParseJsonError error

[abourdin]

Description

When sending a message that isn't proper JSON to a socket controller expecting a @MessageBody(), server throws an uncaught exception.

Minimal code-snippet showcasing the problem

@SocketController('/chat')
export default class ChatSocketController {
  @OnConnect()
  public connection(@ConnectedSocket() socket: any) {
    logger.info('client connected');
  }

  @OnDisconnect()
  public disconnect(@ConnectedSocket() socket: any) {
    logger.info('client disconnected');
  }

  @OnMessage('send_message')
  @EmitOnFail('send_message_error')
  public save(@ConnectedSocket() socket: any, @MessageBody() message: any) {
    logger.info('received message:', message);
    socket.emit('message_received', message);
  }
}

Expected behavior

I would expect that either socket-controllers provides a way to gracefully handle this error (similar to an error handling middleware), or that this exception is simply logged and triggers the @EmitOnFail() decorator, instead of being uncaught.

Actual behavior

Following uncaught exception is thrown:

Error: 
    at new ParameterParseJsonError (/myproject/src/error/ParameterParseJsonError.ts:9:22)
    at SocketControllerExecutor.parseParamValue (/myproject/src/SocketControllerExecutor.ts:227:19)
    at SocketControllerExecutor.handleParamFormat (/myproject/src/SocketControllerExecutor.ts:212:34)
    at SocketControllerExecutor.handleParam (/myproject/src/SocketControllerExecutor.ts:181:26)
    at /myproject/src/SocketControllerExecutor.ts:163:33
    at Array.map (<anonymous>)
    at SocketControllerExecutor.handleAction (/myproject/src/SocketControllerExecutor.ts:136:14)
    at Socket.<anonymous> (/myproject/src/SocketControllerExecutor.ts:122:30)
    at Socket.emit (events.js:315:20)
    at Socket.EventEmitter.emit (domain.js:482:12)
    at /myproject/node_modules/socket.io/lib/socket.js:528:12
    at processTicksAndRejections (internal/process/task_queues.js:79:11)
[ERROR] 10:45:15 ParameterParseJsonError: Parameter is invalid. Value ("test") cannot be parsed to JSON

This uncaught exception that rises to the process level has the effect of crashing the entire express server.