Re: AUnit: access to local procedure needed when asserting exception

[Georg Bauhaus <rm.dash-bauhaus@futureapps.de>]

On 06.12.11 13:25, Simon Wright wrote:
> Georg Bauhaus <rm.dash-bauhaus@futureapps.de> writes:
> 
>> Consequently, when seeing procedure Test_Null mostly reproduced below,
>> the compiler diagnoses (correctly, I think)
>>
>>     66.       AUnit.Assertions.Assert_Exception (Null_Raises'Access,
>>                                                  |
>>         >>> subprogram must not be deeper than access type
> 
> At this point I tend to just use 'Unrestricted_Access.
> 
> I've never quite understood the point of this facility, what's wrong
> with
> 
>    begin
>       --  do whatever should raise The_Exception
>       Assert (C, False, "should have raised The_Exception");
>    exception
>       when The_Exception => null;
>    end;

Nothing wrong. The line numbers will be one off or so.
Actually, this is very close to how it is implemented
for run-times that support exception handling.

The generic was easily added.

   generic
      with procedure Proc;
   procedure Generic_Assert_Exception
     (Message : String;
      Source  : String := GNAT.Source_Info.File;
      Line    : Natural := GNAT.Source_Info.Line);
   --  Generic equivalent of Assert_Exception.


   procedure Generic_Assert_Exception
     (Message : String;
      Source  : String := GNAT.Source_Info.File;
      Line    : Natural := GNAT.Source_Info.Line) is
   begin
      begin
         Proc;
      exception
         when others =>
            return;
      end;

      --  No exception raised: register the failure message
      Assert (False, Message, Source, Line);

   end Generic_Assert_Exception;

OTOH, specific Assert procedures made for exceptions will create a way
to collect tests into two groups; one group for tests that
compare values and another group for testing exceptional situations,
I/O error, failures expressed as pre/post/inv, ...