Allows you to chain calls for void methods in third party objects

chain.js

exports.chain = function (subject) {
    const proxy = new Proxy(subject, {
        get(target, name, receiver) {
            const member = Reflect.get(target, name, receiver);

            if (typeof member === 'function') {
                return function () {
                    const value = member.apply(subject, arguments);
                    if (typeof value !== 'undefined')
                        return value;
                    return proxy;
                };
            }

            return member;
        }
    });

    return proxy;
};

const a = {
  doA: () => { console.log('A was done'); },
  doB: () => { console.log('B was done'); },
  doC: () => 'potato'
}

// you can now do:
chain(a)
  .doA()
  .doB()
  .doC();

// doA and doB are void, so we can chain, doC doesn't return void/undefined so we end up with the string "potato"