Socket.use error drops server

[serhiisol]

You want to:

• report a bug

Current behaviour

Socket.use drops server in case if we'll pass error into the next function

Steps to reproduce (if the current behaviour is a bug)

Next snippet reproduces error easily:

let io = require('socket.io')(3000);

io.on('connection', (socket) => {
  socket.use((packet, next) => {
    next(new Error('Failed error, which drops server'));
  });
  socket.on('message', (message) => {
    console.log(message);
  });
});

Expected behaviour

Should send error packet back to the client and definitely shouldn't drop server

Setup

• OS: macOS Sierra 10.12.1
• browser: Chrome Version 54.0.2840.98 (64-bit)
• socket.io version: 1.7.1

Other information (e.g. stacktraces, related issues, suggestions how to fix)

events.js:165
      throw err;
      ^

Error: Uncaught, unspecified "error" event. (undefined)
    at Socket.emit (events.js:163:17)
    at Socket.emit (/Users/serhiysolonko/Google Drive/Projects/Code/@decorators/playground/socket/node_modules/socket.io/lib/socket.js:141:10)
    at /Users/serhiysolonko/Google Drive/Projects/Code/@decorators/playground/socket/node_modules/socket.io/lib/socket.js:501:21
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)

Possible place to debug

• https://nodejs.org/api/events.html#events_error_events
• https://github.com/socketio/socket.io/blob/master/lib/socket.js#L495

Result

Socket cannot use event error as fallback =), if I'll use socket.error instead, system works as expected