var some_function = function(username, password)
{
return new Promise(function(resolve, reject)
{
/*stuff using username, password*/
if ( /* everything turned out fine */ )
{
resolve("Stuff worked!");
}
else
{
reject(Error("It broke"));
}
});
}
some_module.some_function(username, password).then(function(uid)
{
// stuff
})