SOURCE

function curry(fn) {
    return function curried(...args) {
        if (args.length >= fn.length) {
            return fn.apply(this, args);
        } else {
            return function (...nextArgs) {
                return curried.apply(this, args.concat(nextArgs));
            }
        }
    }
}

function sum(a, b, c) {
    return a + b + c;
}

const curriedSum = curry(sum);

console.log(curriedSum(1)(2)(3))