From: Paul Brannan <pbrannan@...>
Date: 2001-11-10T00:04:47+09:00
Subject: [ruby-talk:24760] Re: assert_exception_and_message

On Fri, 9 Nov 2001, Robert Feldt wrote:

> Hi,
>
> I didn't find a way in RubyUnit to check both an exception and its error
> message. Maybe its there somewhere. If not here's one version:
>
>   def assert_exception_and_message(exception, eMessage, message = "")
>     exception_raised = true
>     begin
>       yield
>       exception_raised = false
>     rescue Exception => e
>       raise e unless exception === e
>       assert_equals(eMessage, e.message)
>     end
>     assert(exception_raised, message)
>   end

Another way to write this is to just use assert_exception, and provide a
default parameter.  It's also useful to be able to provide a regular
expression instead of having to provide the exact string:

  def assert_exception(exception, message="", pattern=//)
    exception_raised = true
    begin
      yield
      exception_raised = false
    rescue Exception => e
      raise e, e.message, e.backtrace unless exception === e
      assert(pattern === e.message, "<some appropriate message>")
    end
    assert(exception_raised, message)
  end

> Its not perfect but can easily be fixed. If something similar is not in
> Lapidary I'd propose its added to the merged Test::Unit.

I think I agree.  I use something similar to this often.

Paul