Assert.Fail
The Assert.Fail method provides you with the ability to generate a failure based on tests that are not encapsulated by the other methods. It is also useful in developing your own project-specific assertions.
Assert.Fail();
Assert.Fail(string message);
Here's an example of its use to create a private assertion that tests whether a string contains an expected value.
public void AssertStringContains(string expected, string actual)
{
AssertStringContains(expected, actual, string.Empty);
}
public void AssertStringContains(string expected, string actual, string message)
{
if (actual.IndexOf(expected) < 0)
Assert.Fail(message);
}