Valid Pool options (e.g. `acquireTimeout`) trigger "Ignoring invalid configuration option passed to Connection" warning

[Cow258]

Bug Description

When using mysql2.createPoolCluster (or createPool) with valid pool-level options such as acquireTimeout, the library emits a warning indicating that the option is invalid for the Connection.

While acquireTimeout is a valid and necessary option for the Pool behavior, it seems the Pool implementation passes the entire configuration object down to the underlying Connection constructor without filtering out pool-specific keys. Since Connection now performs stricter validation (checking against a whitelist of known connection options), it flags acquireTimeout as invalid.

This creates a contradiction where a user provides a valid Pool configuration but receives warnings (which state they will become errors in future versions) because the underlying Connection doesn't recognize those Pool-specific settings.

Reproducible Example

const mysql = require('mysql2');

// Creating a pool cluster with valid pool options
const pool = mysql.createPoolCluster();

pool.add('MASTER', {
  host: 'localhost',
  user: 'root',
  database: 'test',
  // acquireTimeout is a valid Pool option (default 10000)
  // But passing it explicitly triggers the warning
  acquireTimeout: 10000 
});

pool.getConnection('MASTER', (err, connection) => {
  if (err) console.error(err);
  else {
    console.log('Connected!');
    connection.release();
  }
  pool.end();
});

Observed Behavior

The console outputs the following warning:

Ignoring invalid configuration option passed to Connection: acquireTimeout. This is currently a warning, but in future versions of MySQL2, an error will be thrown if you pass an invalid configuration option to a Connection

Expected Behavior

Pool-specific options like acquireTimeout, connectionLimit, queueLimit, etc., should be consumed by the Pool and not passed down (or should be filtered out) when creating a new Connection instance. Alternatively, the Connection validator should allow/ignore known Pool options without emitting a warning.

Environment

• Node.js Version: 20.x
• MySQL2 Version: 3.10+
• Operating System: macOS / Linux

[andryrochev]

This option is not implemented, see #673