Package Extensions for tests

[schnellecom]

As discussed with @ThomasBreuer on GAPDays 25 Summer:
It would be great, if there was an option to also include certain test files in the extensions record. These would then only run, if the package is loaded, and also be respected by e.g. testall.tst.
If somebody has a good suggestion how to implement this, I would be happy to try implementing it.

[ThomasBreuer]

As discussed with @schnellecom:
For packages using a TestDirectory call in tst/testall.g, one can proceed as follows.

• For each set of suggested packages, put those tests into a separate testfile that make sense only if these packages are loaded.
• Before calling TestDirectory, compute which of the suggested packages are currently loaded, and deduce which testfiles shall currently not be run.
• Use the exclude component of the second argument of TestDirectory to omit the testfiles in question.

The first of these steps is part of the package setup.

The other steps could be done automatically by TestDirectory, provided the information about testfiles to be excluded is available somewhere.

For example, we could support a component testfiles in the declarations of package extensions, whose value is a list of those filenames relative to the tst directory of the package which shall be processed only if the packages listed in the needed component are loaded.

Then it would suffice to exclude exactly those testfiles that are currently listed in the pending extensions of the package in question.

It would be possible to have an extension record for a combinations of packages for which a testfiles component but no filename component is needed.

(Would it make sense to support also the situation that certain tests shall be executed only if certain other packages are not loaded? Then one could check for different behaviour depending on which suggested packages are loaded, but perhaps this would be too exotic.)