ReferenceError: createDbConnection is not defined

Bom dia.

Ao executar a aplicação retorna o erro abaixo:

var mysql = require('mysql');

function createDBConnection(){
    if (!process.env.NODE_ENV || process.env.node == 'dev') {
        return mysql.createConnection({
            host: 'localhost',
            user: '<>',
            password: '<>',
            database: 'casadocodigonodejs'
        });
    }

    if (process.env.NODE_ENV == 'test') {
        return mysql.createConnection({
            host: 'localhost',
            user: '<>,
            password: '<>',
            database: 'casadocodigonodejs_teste'
        });
    }
}

module.exports = function(){
  return createDbConnection;

}

NodeJs\casadocodigo\app\infra\connectionFactory.js:35 return createDbConnection; ^

ReferenceError: createDbConnection is not defined