uncatchable `uncaughtException` in `pool.execute` if `undefined` in query values

undefined in query values will cause TypeError: Bind parameters must not contain undefined. To pass SQL NULL specify JS null

with pool.execute, is there a place to catch the error?

the simplified test script:

// test-pool-execute-error.js

const Mysql = require('mysql2')

const CONFIG = {
  host: '127.0.0.1',
  port: 3306,
  user: 'root',
  database: 'mysql'
}

const testNormal = () => {
  console.log('[testNormal] start')
  const pool = Mysql.createPool(CONFIG)
  pool.execute(
    `SET @value = ?`,
    [ 0 ], // good value
    (error, resultList, fieldList) => console.log('[testNormal] from callback:', { error, resultList, fieldList })
  )
  setTimeout(() => pool.end(() => console.log('[testNormal] pool ended')), 1000)
}

const testError = () => {
  try {
    console.log('[testError] start')
    const pool = Mysql.createPool(CONFIG)
    pool.on('error', (error) => console.log('[testError] error from event', error))
    pool.execute(
      `SET @value = ?`,
      [ undefined ], // bad value
      (error, resultList, fieldList) => console.log('[testError] from callback:', { error, resultList, fieldList })
    )
    setTimeout(() => pool.end(() => console.log('[testError] pool ended')), 1000)
  } catch (error) { console.log('[testError] error from catch', error) }
}

process.on('uncaughtException', (error) => console.error('!!! error from uncaughtException', error))

testNormal()

setTimeout(() => { // wait first test pass
  testError()
}, 2000)

the output with mysql2@1.6.4: (testNormal pass, but testError throws and block the process exiting)

$ node test-pool-execute-error.js
[testNormal] start
[testNormal] from callback: { error: null,
  resultList:
   ResultSetHeader {
     fieldCount: 0,
     affectedRows: 0,
     insertId: 0,
     info: '',
     serverStatus: 2,
     warningStatus: 0 },
  fieldList: undefined }
[testNormal] pool ended
[testError] start
!!! error from uncaughtException TypeError: Bind parameters must not contain undefined. To pass SQL NULL specify JS null
    at ...\node_modules\mysql2\lib\connection.js:609:17
    at Array.forEach (<anonymous>)
    at PoolConnection.execute (...\node_modules\mysql2\lib\connection.js:607:22)
    at ...\node_modules\mysql2\lib\pool.js:171:31
    at Pool.<anonymous> (...\node_modules\mysql2\lib\pool.js:68:18)
    at PoolConnection.<anonymous> (...\node_modules\mysql2\lib\connection.js:753:13)
    at Object.onceWrapper (events.js:273:13)
    at PoolConnection.emit (events.js:182:13)
    at ClientHandshake.<anonymous> (...\node_modules\mysql2\lib\connection.js:108:20)
    at ClientHandshake.emit (events.js:182:13)

[hktr92]

it just happened to me, too. in a project that is supposed to go live sooner or later.

more time is wasted to overcome this issue by this method (implementing a strict type conversion + restart policy for a fallback in business logic) rather than having a try / catch in the library itself… which can be further caught and handled properly.

if the intention is to report an issue, then throw an error, don’t kill the process. it’s bad design imho and raises uncertainty for production.

also, the error reported is pretty ambiguous and doesn’t really tell what query caused this issue, which makes harder to debug + repair quickly (for reference, Doctrine (PHP library) reports which query failed in dev mode).

[damianobarbati]

Why was this closed? An unhandled rejection cause process exit/crash. This is pretty serious; there’s no way to catch this error, no matter where you put the try/catch .

@dr-js how did you solve?