Pool connection failure doesn't emit error event

[topia]

Pool.query doesn't emit error event, when it failed with connection error.

index.js

var mysql = require('mysql');

var pool = mysql.createPool({host: 'unknown-host', port: 3306, user: 'test', password: 'test', database: 'test'});
var query;

query = pool.query('SELECT 1');
query.on('error', function (err) { console.log("error emitted", err); })

query = pool.query('SELECT 1', function (err) { console.log("error callbacked", err); });

query = pool.query('SELECT 1', function (err) { console.log("error callbacked, but bad style", err); });
query.on('error', function (err) { console.log("error emitted", err); })

package.json

{
  "name": "mysql-bug-temp",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "author": "",
  "license": "ISC",
  "dependencies": {
    "mysql": "^2.5.2"
  }
}

expected

error emitted { [Error: getaddrinfo ENOTFOUND]
  code: 'ENOTFOUND',
  errno: 'ENOTFOUND',
  syscall: 'getaddrinfo',
  fatal: true }
error callbacked { [Error: getaddrinfo ENOTFOUND]
  code: 'ENOTFOUND',
  errno: 'ENOTFOUND',
  syscall: 'getaddrinfo',
  fatal: true }
error callbacked, but bad style { [Error: getaddrinfo ENOTFOUND]
  code: 'ENOTFOUND',
  errno: 'ENOTFOUND',
  syscall: 'getaddrinfo',
  fatal: true }

actual

error callbacked { [Error: getaddrinfo ENOTFOUND]
  code: 'ENOTFOUND',
  errno: 'ENOTFOUND',
  syscall: 'getaddrinfo',
  fatal: true }
error callbacked, but bad style { [Error: getaddrinfo ENOTFOUND]
  code: 'ENOTFOUND',
  errno: 'ENOTFOUND',
  syscall: 'getaddrinfo',
  fatal: true }

[topia]

I think it will be fixed with use query.end(err); on https://github.com/felixge/node-mysql/blob/master/lib/Pool.js#L185

[dougwilson]

Ah, I see what you're saying: the connection error is only propagated to the returned query if you are using the callback interface. This is a bug indeed.

[topia]

I'm sorry to less description. I want to clarification:
connection error is only propagated to the specified callback function, but I want to use streaming (event) interface.
according to docs, I cannot specify callback on streaming interface, so I cannot catch connection error.

[dougwilson]

Right, I understood what you were asking, @topia :) The answer is that it's a bug and I have to fix it :)

[topia]

Thank you very match for fixing this!
🎉

[dougwilson]

No problem! I just published it to npm as 2.5.3 :)