set-now/set-now.js

Travel through time with Date.setNow()

var _Date = Date;

var delta = 0;

var getTimestamp = function () {
  return _Date.now() + delta;
}

Date = function Date () {
  if (arguments.length === 0) {
    return new _Date(getTimestamp());
  }
  // Unfortunately, Date.apply doesn't work:
  // return _Date.apply(this, arguments);
  switch (arguments.length) {
    case 1: return new _Date(arguments[0]);
    case 2: return new _Date(arguments[0], arguments[1]);
    case 3: return new _Date(arguments[0], arguments[1], arguments[2]);
    case 4: return new _Date(arguments[0], arguments[1], arguments[2], arguments[3]);
    case 5: return new _Date(arguments[0], arguments[1], arguments[2], arguments[3], arguments[4]);
    case 6: return new _Date(arguments[0], arguments[1], arguments[2], arguments[3], arguments[4], arguments[5]);
    case 7: return new _Date(arguments[0], arguments[1], arguments[2], arguments[3], arguments[4], arguments[5], arguments[6]);
  }
};

Date.prototype = _Date.prototype;

Date.now = function () {
  return new _Date(getTimestamp()).getTime();
};

Date.UTC = _Date.UTC;

Date.parse = _Date.parse;

Date.setNow = function (now) {
  if (typeof now === 'undefined') {
    delta = 0;
    return;
  }
  delta = (new _Date(now).getTime()) - _Date.now();
};

module.exports = Date;