ECMA6 Class get all methods from all inherited classes

es6-get-prototype-methods.js

        function getClassMethods(className) {
            if (!className instanceof Object) {
                throw new Error("Not a class");
            }
            let ret = new Set();

            function methods(obj) {
                if (obj) {
                    let ps = Object.getOwnPropertyNames(obj);

                    ps.forEach(p => {
                        if (obj[p] instanceof Function) {
                            ret.add(p);
                        } else {
                            //can add properties if needed
                        }
                    });

                    methods(Object.getPrototypeOf(obj));
                }
            }

            methods(className.prototype);

            return Array.from(ret);
        }