Update only non-empty fields | Object spread

Question

I was wondering if there is a one liner is possible for something like

        let updatedUser;
        if (firstName) {
            updatedUser = { ...userData,         


        

Answer 1

Not really, however you could use a small helper:

 const assignDefined = (target, props) =>
   Object.entries(props).forEach(([k, v]) => v && (target[k] = v));

That allows you to write:

updateUser = assignDefined({...userData}, { firstName, lastName, password });

Answer 2

You can use

const updatedUser = Object.assign({},
     userData,
     firstName && {firstName},
     lastName && {lastName},
     password && {password}
);

or similar with object spread syntax:

const updatedUser = {
     ...userData,
     ...firstName && {firstName},
     ...lastName && {lastName},
     ...password && {password}
};

Falsy values will be ignored and not lead to the creation of any properties.