Simple and small wrapper to curry functions of any arity

curry.js

/**
 * Curry a function of any length. Note that a curried
 * function accepts only one argument at the time.
 *
 * @example <caption>Simple usage</caption>
 * let addTwoNumbers = curry((x, y) => x + y);
 * addTwoNumbers(1); // => Function[y => 1 + y]
 * addTwoNumbers(1)(3); // => 4
 *
 * @example <caption>Incorrect usage</caption>
 * let addTwoNumbers = curry((x, y) => x + y);
 * addTwoNumbers(1, 3); // => Function[y => 1 + y]  |  The second argument is ignored
 * addTwoNumbers(1, 3)(3); // => 4
 *
 * @param {Function} fn The function to curry.
 * @return {Function} The curried function.
 * @license The-Unlicense
 */
function curry(fn) {
  // Check if the provided argument is a function
  if (typeof fn !== 'function') throw Error('Curry should be provided with a function');

  // Get the arity of the function to curry
  const arity = fn.length;

  // Return the return value of resolver() which is the curried function
  return (function resolver() {
    // Create *local* memory to allow for reuse of the curried function
    const memory = Array.from(arguments);

    // Return the curried function
    return function(x) {
      // Add the provided argument to the memory
      let args = memory.slice(0);
      args.push(x);

      // Call fn if enough arguments have been provided, otherwise return
      // another curried function
      const next = args.length >= arity ? fn : resolver;
      return next.apply(null, args);
    };
  }());
};