public void WhenSettingAPropertyToAnInvalidValue_ThenEntityHasErrors() { var testEntity = new TestEntity(); testEntity.SomeValue = 5; Assert.IsTrue(testEntity.HasErrors); Assert.IsTrue(testEntity.GetErrors("SomeValue").Cast<object>().Any()); Assert.IsFalse(testEntity.GetErrors("SomeOtherValue").Cast<object>().Any()); }