DB transaction from a connection pool in node-mysql

pool-transaction.js

var mysql = require('mysql');

var pool = mysql.createPool('mysql://localhost');

inTransaction(pool, function(db, next) {
    db.query("DELETE * FROM stuff", function(err) {
        if (err) return next(err);

        db.query("INSERT INTO stuff VALUES (1,2,3)", function(err) {
            return next(err);
        });
    });
}, function(err) {

    console.log("All done, transaction ended and connection released");

});

/**
 * Convenience wrapper for database connection in a transaction
 */
function inTransaction(pool, body, callback) {
    withConnection(pool, function(db, done) {

        db.beginTransaction(function(err) {
            if (err) return done(err);

            body(db, finished)
        })

        // Commit or rollback transaction, then proxy callback
        function finished(err) {
            var context = this;
            var args = arguments;

            if (err) {
                if (err == 'rollback') {
                    args[0] = err = null;
                }
                db.rollback(function() { done.apply(context, args) });
            } else {
                db.commit(function(err) {
                    args[0] = err;
                    done.apply(context, args)
                })
            }
        }
    }, callback)
}

/**
 * Convenience wrapper for database connection from pool
 */
function withConnection(pool, body, callback) {
    pool.getConnection(function(err, db) {
        if (err) return callback(err);

        body(db, finished);

        function finished() {
            db.release();
            callback.apply(this, arguments);
        }
    })
}