[vtk-developers] C++ unit tests

[David Gobbi]

On Tue, Jul 28, 2015 at 11:34 AM, David Thompson <david.thompson at kitware.com
> wrote:

> Hi David(s),
>
> I really like the single-header idea, especially the macros for testing
> whether values match to within a tolerance.
>
> My concerns are
>
> 1. The C++ Testing/Rendering/vtkTesting.h class which provides (or now
> that we have ExternalData, provided?) access to baseline images doesn't
> seem to fit into the FIXTURE macro. Is there a way to integrate it? Or a
> way to extend the vtkTesting class to be more usable by including methods
> similar to your macros?
>

The quick answer is, no, as it stands vtkTesting wouldn't fit into a
UnitTest.h fixture.  Your second suggestion sounds like the better
approach: add unit test macros and their associated code to vtkTesting.

I'm very fond of using macros, rather than methods, for the unit-test
assertions because a macro can easily print out the line number in the test
program where an assertion failed.


> 2. One thing I dislike about most/all of the C++ test frameworks is that
> the error messages are assumed to be fixed and the methods often do not
> present a way to include the incorrect result as part of the failure
> message. It is nice that your macros include that. However, given that
> tests often fail on machines I don't have access to, it is really nice to
> encourage people to write useful messages. Macros like CHECK_CLOSE would be
> better if they accepted a message as a final argument, especially if the
> argument was passed to a std::ostream object the way
> vtkGenericWarningMacro() does so that people can (are forced to) provide
> more context about where the two numbers being compared come from.
>

Something like that could be accommodated.

I can see about putting together a merge request that makes vtkTesting more
amenable to unit tests, rather than introducing yet another way of creating
tests for VTK.

 - David
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/vtk-developers/attachments/20150728/34f3a728/attachment.html>