2632-curry.js

/**
 * @param {Function} fn
 * @return {Function}
 */
var curry = function (fn) {
  return function curried(...args) {
    if (fn.length === args.length) {
      return fn(...args);
    } else {
      return function (...newArgs) {
        return curried(...args, ...newArgs);
      };
    }
  };
};

/**
 * function sum(a, b) { return a + b; }
 * const csum = curry(sum);
 * csum(1)(2) // 3
 */