Weird nUnit unit test failure

I have classX:

Sub New(ByVal item_line_no As String, ByVal item_text As String)

    ' check to ensure that the parameters do not exceed the file template limits
    Select Case item_line_no.Length
        Case Is > m_item_line_no_capacity
            Throw New ArgumentOutOfRangeException(item_line_no, "Line No exceeds 4 characters")
        Case Else
            Me.m_item_line_no = item_line_no
    End Select


    Select Case item_text.Length
        Case Is > m_item_free_text_capacity
            Throw New ArgumentOutOfRangeException("Free Text Exceeds 130 characters")
        Case Else
            Me.m_item_free_text = item_text
    End Select


End Sub

and the following unti to test one point of failure

<ExpectedException(GetType(ArgumentOutOfRangeException), "Line No exceeds 4 characters")> _
<Test()> _
Sub testLineNoExceedsMaxLength()
    Dim it As New X("aaaaa", "Test")

End Sub

When I run the test I expect to get the message thrown in the exception "Line No exceeds 4 characters"

However the unit test fails with the following message

RecordTests.testLineNoExceedsMaxLength : FailedExpected exception message: Line No exceeds 4 characters
                       got: Line No exceeds 4 characters
Parameter name: aaaaa

I think the something simple but it driving me insane.

NOTE: in the declaration of the ExpectedException I get an obsolete warning stating that instead of

<ExpectedException(GetType(ArgumentOutOfRangeException), "Line No exceeds 4 characters")>

it should be

<ExpectedException(GetType(ArgumentOutOfRangeException), ExpectedException="Line No exceeds 4 characters")>

However this throws a ExpectedException is not declared error!

From stackoverflow

• The ExpectedExceptionAttribute is deprecated - i.e. you shouldn't use it at all. The best reference I could quickly find about this was this post (the original article is here).

  Your unit test would be a lot clearer if it was re-written:

  <Test()> _
  Sub testLineNoExceedsMaxLength()
      Try
  
          Dim it As New X("aaaaa", "Test")
  
      Catch ex as ArgumentOutOfRangeExcpetion
  
          Assert.That ( ex.Message, Is.Equal("Line No exceeds 4 characters") )
  
      End Try
  
  End Sub
  

  See also these articles

  • This one, and
  • http://cgi.skizz.plus.com/blog/dev/archives/000075.html" title="Praise god for the Way Back Machine">This one.

• I'm not sure I agree with your comment of the ExpectedException attribute being deprecated.

  It is still supported perfectly fine in 2.4 (version I am using) it is the ExpectedMessage in this case which is causing the deprecation issue

  uUnit Exception Guide

• Ok. Just run this.

  The message for the exception is:

  Line No exceeds 4 characters

  Parameter name: aaaaa

  (Including the line break)

  You need to specify this all of this as the expected message:

  <ExpectedException(GetType(ArgumentOutOfRangeException), ExpectedMessage="Line No exceeds 4 characters" & VbCrLf & "Parameter name: aaaaa")>