Erro ao refatorar a conexao com o banco de dados return = mysql.createConnection({

Apos refatorar , dá erro ao tentar pegar a conexao

var mysql = require('mysql');
module.exports = function(){

    return = mysql.createConnection({
                host:'localhost',
                user:'root',
                password:'123456',
                database:'casacodigo'
    });


}

I:\desenvolvimento\workspaces\work_web\work_node_js\teste-node\casadocodigo\app\infra\dbConnection.js:4
        return = mysql.createConnection({
               ^
SyntaxError: Unexpected token =
    at Object.exports.runInThisContext (vm.js:78:16)
    at Module._compile (module.js:543:28)
    at Object.Module._extensions..js (module.js:580:10)
    at Module.load (module.js:488:32)
    at tryModuleLoad (module.js:447:12)
    at Function.Module._load (module.js:439:3)
    at Module.require (module.js:498:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (I:\desenvolvimento\workspaces\work_web\work_node_js\teste-node\casadocodigo\app\routes\produtos.js:3:20)
    at Module._compile (module.js:571:32)
[nodemon] app crashed - waiting for file changes before starting...