SOURCE

function curry(fn) {
    return function curried(...args1) {
        if (fn.length <= args1.length) {
            return fn.apply(this, args1)
        } else {
            return function(...args2) {
                return curried.apply(this, [...args1, ...args2])
            }
        }
    }
}

function sum(a, b, c) {
    return a + b + c
}
const curriedSum = curry(sum)
console.log(curriedSum(1, 2, 3))
console.log(curriedSum(1)(2, 3))