Shallow copy object leaving out one or more properties in ES6/ES7?

Question

This is how I've been doing it:

var props = { id: 1, name: 'test', children: [] }

//copy props but leave children out
var newProps = { ...props }
delete newProps.children

console.log(newProps) // { id: 1, name: 'test' }

Is there a cleaner, simpler way?

Answer 1

You could use a destructuring assignment:

var props = { id: 1, name: 'test', children: [] }

var {children:_, ...newProps} = props;
console.log(newProps) // { id: 1, name: 'test' }
console.log(_) // [] - as an "empty" placeholder

(with the same rest/spread properties proposal for ES7 that you were already using)

Answer 2

var props = { id: 1, name: 'test', children: [] }

function clone(orig, blacklistedProps) {
    var newProps = {};
    Object.keys(props).forEach(function(key) {
        if (!blacklistedProps || blacklistedProps.indexOf(key) == -1) {
            newProps[key] = props[key];
        }
    });
    return newProps;
}
var newProps = clone(props, ['children']); 
console.log(newProps) // { id: 1, name: 'test' }
var newProps1 = clone(props); 
console.log(newProps1) // { id: 1, name: 'test', children:[] }