¶MockDateSpec.js

describe("FakeDate", function() {
  it("does not fail if no global date is found", function() {
    var fakeGlobal = {},
      mockDate = new j$.MockDate(fakeGlobal);

    expect(function() {
      mockDate.install();
      mockDate.tick(0);
      mockDate.uninstall();
    }).not.toThrow();
  });

  it("replaces the global Date when it is installed", function() {
    var globalDate = jasmine.createSpy("global Date").and.callFake(function() {
        return {
          getTime: function() {}
        }
      }),
      fakeGlobal = { Date: globalDate },
      mockDate = new j$.MockDate(fakeGlobal);

    expect(fakeGlobal.Date).toEqual(globalDate);
    mockDate.install();

    expect(fakeGlobal.Date).not.toEqual(globalDate);
  });

  it("replaces the global Date on uninstall", function() {
    var globalDate = jasmine.createSpy("global Date").and.callFake(function() {
        return {
          getTime: function() {}
        }
      }),
      fakeGlobal = { Date: globalDate },
      mockDate = new j$.MockDate(fakeGlobal);

    mockDate.install();
    mockDate.uninstall();

    expect(fakeGlobal.Date).toEqual(globalDate);
  });

  it("takes the current time as the base when installing without parameters", function() {
    var globalDate = jasmine.createSpy("global Date").and.callFake(function() {
        return {
          getTime: function() {
            return 1000;
          }
        }
      }),
      fakeGlobal = { Date: globalDate },
      mockDate = new j$.MockDate(fakeGlobal);

    mockDate.install();

    globalDate.calls.reset();
    new fakeGlobal.Date();
    expect(globalDate).toHaveBeenCalledWith(1000);
  });

  it("can accept a date as time base when installing", function() {
    var fakeGlobal = { Date: Date },
      mockDate = new j$.MockDate(fakeGlobal),
      baseDate = new Date();

    spyOn(baseDate, 'getTime').and.returnValue(123);
    mockDate.install(baseDate);

    expect(new fakeGlobal.Date().getTime()).toEqual(123);
  });

  it("makes real dates", function() {
    var fakeGlobal = { Date: Date },
      mockDate = new j$.MockDate(fakeGlobal);

    mockDate.install();
    expect(new fakeGlobal.Date()).toEqual(jasmine.any(Date));
  });

  it("fakes current time when using Date.now()", function() {
    var globalDate = jasmine.createSpy("global Date").and.callFake(function() {
        return {
          getTime: function() {
            return 1000;
          }
        }
      }),
      fakeGlobal = { Date: globalDate };

    globalDate.now = function() {};
    var mockDate = new j$.MockDate(fakeGlobal);

    mockDate.install();

    expect(fakeGlobal.Date.now()).toEqual(1000);
  });

  it("does not stub Date.now() if it doesn't already exist", function() {
    var globalDate = jasmine.createSpy("global Date").and.callFake(function() {
        return {
          getTime: function() {
            return 1000;
          }
        }
      }),
      fakeGlobal = { Date: globalDate },
      mockDate = new j$.MockDate(fakeGlobal);

    mockDate.install();

    expect(fakeGlobal.Date.now).toThrowError("Browser does not support Date.now()");
  });

  it("makes time passes using tick", function() {
    var globalDate = jasmine.createSpy("global Date").and.callFake(function() {
        return {
          getTime: function() {
            return 1000;
          }
        }
      }),
      fakeGlobal = { Date: globalDate };

    globalDate.now = function() {};
    var mockDate = new j$.MockDate(fakeGlobal);

    mockDate.install();

    mockDate.tick(100);

    expect(fakeGlobal.Date.now()).toEqual(1100);

    mockDate.tick(1000);

    expect(fakeGlobal.Date.now()).toEqual(2100);
  });

  it("allows to increase 0 milliseconds using tick", function() {
    var globalDate = jasmine.createSpy("global Date").and.callFake(function() {
        return {
          getTime: function() {
            return 1000;
          }
        }
      }),
      fakeGlobal = { Date: globalDate };

    globalDate.now = function() {};
    var mockDate = new j$.MockDate(fakeGlobal);

    mockDate.install();

    mockDate.tick(0);
    expect(fakeGlobal.Date.now()).toEqual(1000);

    mockDate.tick();
    expect(fakeGlobal.Date.now()).toEqual(1000);
  });

  it("allows creation of a Date in a different time than the mocked time", function() {
    var fakeGlobal = { Date: Date },
      mockDate = new j$.MockDate(fakeGlobal);

    mockDate.install();

    var otherDate = new fakeGlobal.Date(2013, 9, 23, 0, 0, 1, 0);
    expect(otherDate.getTime()).toEqual(new Date(2013, 9, 23, 0, 0, 1, 0).getTime());
  });

  it("allows creation of a Date that isn't fully specified", function() {
    var fakeGlobal = { Date: Date },
      mockDate = new j$.MockDate(fakeGlobal);

    mockDate.install();

    var otherDate = new fakeGlobal.Date(2013, 9, 23);
    expect(otherDate.getTime()).toEqual(new Date(2013, 9, 23).getTime());
  });

  it('allows creation of a Date with millis', function() {
    var fakeGlobal = { Date: Date },
      mockDate = new j$.MockDate(fakeGlobal),
      now = new Date(2014, 3, 15).getTime();

    mockDate.install();

    var otherDate = new fakeGlobal.Date(now);
    expect(otherDate.getTime()).toEqual(now);
  });

  it("copies all Date properties to the mocked date", function() {
    var fakeGlobal = { Date: Date },
      mockDate = new j$.MockDate(fakeGlobal);

    mockDate.install();

    expect(fakeGlobal.Date.UTC(2013, 9, 23)).toEqual(Date.UTC(2013, 9, 23));
  });
});