Test implementation for ES6 Name module

name.js

(function (undefined) {
  
  "use strict";

  const MIN_STR_LEN = 0x10;
  const MAX_STR_LEN = 0xF0 - MIN_STR_LEN;
  
  const MIN_CHAR_CODE = 0x0;
  const MAX_CHAR_CODE = 0xFFFF - MIN_CHAR_CODE;
  
  /**
   * Return an array of length length
   */
  let arrayOfLength = function (length) {
    return new Array(length + 1).join(" ").split("");
  };
  
  /**
   * Return a random number between upper and lower
   */
  let randomNumber = function (lower, upper) {
    return Math.round(Math.random() * upper + lower);
  };
  
  /**
   * Return a random char between min and max char codes
   */
  let randomChar = function () {
    return String.fromCharCode(randomNumber(MIN_CHAR_CODE, MAX_CHAR_CODE));
  };
  
  /**
   * Return a random string of length length
   */
  let randomString = function (length) {
    return arrayOfLength(length).map(randomChar).join("");
  };
  
  /**
   * Constructor for private read-only names. toString returns generated value
   */
  let Name = this.Name = function () {
    let value = randomString(randomNumber(MIN_STR_LEN, MAX_STR_LEN)) + (+new Date());
    
    return {
      toString: function () {
        return value;
      }
    };
  };

}).call(this);

test.js

(function (undefined) {
  
  "use strict";
  
  // testing collisions
  let o = {};
  let n = "";
  let i = 0;
  let z = 500;
  
  while (o[n = new Name()] === undefined && i < z) {
    o[n] = true;
    i++;
  }
  
  if (i === z) {
    console.log("no collisions; count === " + i);
  } else {
    console.log("collision at " + i + "; max(" + z + ")");
  }

}).call(this);