JavaScript utility belt

utility-belt.js

//github.com/jed/140bytes/wiki/Byte-saving-techniques

Number.prototype.isPrime = function(n) {
  var n = '1'.repeat(this);
  return !n.match(/^1?$|^(11+?)\1+$/gi);
};

//

String.prototype.repeat = function(n) {
  return Array(n + 1).join(this);
};

String.prototype.reverse = function() {
  return this.split('').reverse().join('');
};


Array.prototype.shuffle = function() {
  return this.sort(function() Math.random() - 0.5));
};
  
String.prototype.pad = function(n, padding) {
  padding = padding.repeat(Math.abs(this.length - n));
  return n > 0 ? this + padding : padding + this;
};

//

Math._random = Math.random;

Math.random = function(n, m) {
  return n === undefined ? Math._random() : Math.ceil(Math._random() * (n - m) + m - 1);
};

//

Object.forEach = function(object, fn) {
  for(var key in object) {
    if(object.hasOwnProperty(key)) {
      fn.apply(object, key, object[key]);
    }
  }
};

//developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/assign
Object.assign = Object.assign || function() {
    var hashes = [].slice.call(arguments)
      , target = hashes.shift();

    hashes.forEach(function(hash) {
      Object.forEach(hash, function(key, value) {
        target[key] = value;
      });
    });

    return target;
  };
};

//

Date.prototype.addTime = function(n) {
  return new Date(this.getTime() + n);
};

Date.prototype.addSeconds = (n) {
  return this.addTime(n * 1000);
}

Date.prototype.addMinutes = (n) {
  return this.addSeconds(n * 60);
}

Date.prototype.addHours = (n) {
  return this.addMinutes(n * 60);
};