I'm using Microsoft WebTest and want to be able to do something similar to NUnit's Assert.Fail(). The best i have come up with is to throw new webTestException() but this shows in the test results as an Error rather than a Failure. Other than reflecting on the WebTest to set a private member variable to indicate the failure, is there something I've missed? EDIT: I have also used the Assert.Fail() method, but this still shows up as an error rather than a failure when used from within WebTest, and the Outcome property is read-only (has no public setter). EDIT: well now I'm really stumped. I used reflection to set the Outcome property to Failed but the test still passes! Here's the code that sets the Oucome to failed: public static class WebTestExtensions { public static void Fail(this WebTest test) { var method = test.GetType().GetMethod("set_Outcome", BindingFlags.NonPublic | BindingFlags.Instance); method.Invoke(test, new object[] {Outcome.Fail}); } } and here's the code that I'm trying to fail: public override IEnumerator<WebTestRequest> GetRequestEnumerator() { this.Fail(); yield return new WebTestRequest("http://google.com"); } Outcome is getting set to Oucome.Fail but apparently the WebTest framework doesn't really use this to determine test pass/fail results.