Why is this an issue?

It should be clear to a casual reader what code a test is testing and what results are expected. Unfortunately, that’s not usually the case with the ExpectedException attribute since an exception could be thrown from almost any line in the method.

This rule detects MSTest and NUnit ExpectedException attribute.

Noncompliant code example

<TestMethod>
<ExpectedException(GetType(ArgumentNullException))> ' Noncompliant
Public Sub TestNullArg()
  '...
End Sub

Compliant solution

<TestMethod>
Public Sub TestNullArg()
    Dim CallFailed As Boolean = False
    Try
    ' ...
    Catch ex As Exception
        CallFailed = true
    End Try
    Assert.IsTrue(CallFailed, "Expected call to MyMethod to fail with ArgumentNullException")
End Sub

or

<TestMethod>
Public Sub TestNullArg()
    Assert.ThrowsException(Of ArgumentNullException)(Sub() ... )
End Sub

Exceptions

This rule ignores one-line test methods, since it is obvious in such methods where the exception is expected to be thrown.