jasmine/src/core/Clock.js

getJasmineRequireObj().Clock = function() {
  /**
   * _Note:_ Do not construct this directly, Jasmine will make one during booting. You can get the current clock with {@link jasmine.clock}.
   * @class Clock
   * @classdesc Jasmine's mock clock is used when testing time dependent code.
   */
  function Clock(global, delayedFunctionSchedulerFactory, mockDate) {
    var self = this,
      realTimingFunctions = {
        setTimeout: global.setTimeout,
        clearTimeout: global.clearTimeout,
        setInterval: global.setInterval,
        clearInterval: global.clearInterval
      },
      fakeTimingFunctions = {
        setTimeout: setTimeout,
        clearTimeout: clearTimeout,
        setInterval: setInterval,
        clearInterval: clearInterval
      },
      installed = false,
      delayedFunctionScheduler,
      timer;


    /**
     * Install the mock clock over the built-in methods.
     * @name Clock#install
     * @function
     * @return {Clock}
     */
    self.install = function() {
      if(!originalTimingFunctionsIntact()) {
        throw new Error('Jasmine Clock was unable to install over custom global timer functions. Is the clock already installed?');
      }
      replace(global, fakeTimingFunctions);
      timer = fakeTimingFunctions;
      delayedFunctionScheduler = delayedFunctionSchedulerFactory();
      installed = true;

      return self;
    };

    /**
     * Uninstall the mock clock, returning the built-in methods to their places.
     * @name Clock#uninstall
     * @function
     */
    self.uninstall = function() {
      delayedFunctionScheduler = null;
      mockDate.uninstall();
      replace(global, realTimingFunctions);

      timer = realTimingFunctions;
      installed = false;
    };

    /**
     * Execute a function with a mocked Clock
     *
     * The clock will be {@link Clock#install|install}ed before the function is called and {@link Clock#uninstall|uninstall}ed in a `finally` after the function completes.
     * @name Clock#withMock
     * @function
     * @param {closure} Function The function to be called.
     */
    self.withMock = function(closure) {
      this.install();
      try {
        closure();
      } finally {
        this.uninstall();
      }
    };

    /**
     * Instruct the installed Clock to also mock the date returned by `new Date()`
     * @name Clock#mockDate
     * @function
     * @param {Date} [initialDate=now] The `Date` to provide.
     */
    self.mockDate = function(initialDate) {
      mockDate.install(initialDate);
    };

    self.setTimeout = function(fn, delay, params) {
      if (legacyIE()) {
        if (arguments.length > 2) {
          throw new Error('IE < 9 cannot support extra params to setTimeout without a polyfill');
        }
        return timer.setTimeout(fn, delay);
      }
      return Function.prototype.apply.apply(timer.setTimeout, [global, arguments]);
    };

    self.setInterval = function(fn, delay, params) {
      if (legacyIE()) {
        if (arguments.length > 2) {
          throw new Error('IE < 9 cannot support extra params to setInterval without a polyfill');
        }
        return timer.setInterval(fn, delay);
      }
      return Function.prototype.apply.apply(timer.setInterval, [global, arguments]);
    };

    self.clearTimeout = function(id) {
      return Function.prototype.call.apply(timer.clearTimeout, [global, id]);
    };

    self.clearInterval = function(id) {
      return Function.prototype.call.apply(timer.clearInterval, [global, id]);
    };

    /**
     * Tick the Clock forward, running any enqueued timeouts along the way
     * @name Clock#tick
     * @function
     * @param {int} millis The number of milliseconds to tick.
     */
    self.tick = function(millis) {
      if (installed) {
        delayedFunctionScheduler.tick(millis, function(millis) { mockDate.tick(millis); });
      } else {
        throw new Error('Mock clock is not installed, use jasmine.clock().install()');
      }
    };

    return self;

    function originalTimingFunctionsIntact() {
      return global.setTimeout === realTimingFunctions.setTimeout &&
        global.clearTimeout === realTimingFunctions.clearTimeout &&
        global.setInterval === realTimingFunctions.setInterval &&
        global.clearInterval === realTimingFunctions.clearInterval;
    }

    function legacyIE() {
      //if these methods are polyfilled, apply will be present
      return !(realTimingFunctions.setTimeout || realTimingFunctions.setInterval).apply;
    }

    function replace(dest, source) {
      for (var prop in source) {
        dest[prop] = source[prop];
      }
    }

    function setTimeout(fn, delay) {
      return delayedFunctionScheduler.scheduleFunction(fn, delay, argSlice(arguments, 2));
    }

    function clearTimeout(id) {
      return delayedFunctionScheduler.removeFunctionWithId(id);
    }

    function setInterval(fn, interval) {
      return delayedFunctionScheduler.scheduleFunction(fn, interval, argSlice(arguments, 2), true);
    }

    function clearInterval(id) {
      return delayedFunctionScheduler.removeFunctionWithId(id);
    }

    function argSlice(argsObj, n) {
      return Array.prototype.slice.call(argsObj, n);
    }
  }

  return Clock;
};