public void IsValidReturnsFalseForEmptyGuid()
        {
            IValidationRule <FakeObjectToValidate> rule =
                new GuidMustBeValidRule <FakeObjectToValidate>(f => f.Guid, "FakeGuid");

            bool isValid = rule.IsValid(new FakeObjectToValidate());

            Assert.IsFalse(isValid, "IsValid returned true for empty guid.");
        }
        public void IsValidReturnsFalseWhenGivenNullObjectToCheck()
        {
            IValidationRule <FakeObjectToValidate> rule =
                new GuidMustBeValidRule <FakeObjectToValidate>(f => f.Guid, "FakeGuid");

            bool isValid = rule.IsValid(null);

            Assert.IsFalse(isValid, "IsValid returned true for null object.");
        }
        public void IsValidReturnsTrueForGuidThatIsNotEqualToEmptyGuid()
        {
            IValidationRule <FakeObjectToValidate> rule =
                new GuidMustBeValidRule <FakeObjectToValidate>(f => f.Guid, "FakeGuid");

            bool isValid = rule.IsValid(new FakeObjectToValidate {
                Guid = Guid.NewGuid()
            });

            Assert.IsTrue(isValid, "IsValid returned false for guid that did not equal empty guid.");
        }