paraview: add simple validation test

[mathstuf]

This uses ParaView's Examples directory to test an installed ParaView. Note that these are only really effective as of 5.11.0-RC2 due to Examples having been untested from the top-level prior to this (ParaView runs its example directories individually itself).

[mathstuf]

spack/spack#33369

[wspear]

Since this test is version-restricted the setup should specify something like:
spackLoadUnique paraview@5.11.0-RC2:
To ensure it only runs with compatible installs. (Note the open colon, meaning higher versions will also be selected)

[wspear]

@mathstuf I tried this test after installing paraview+examples@5.11.0. It looks like the tests compiled without complaint but the run output looks incorrect to me. No tests were found.

I think the setup script needs to load paraview like this:
spackLoadUnique paraview@5.11:
Leaving out the .0-etc suffix entirely should cover everything from 5.11 on including pre-releases.

Here's what the test run output looks like:

Internal ctest changing into directory: /home/wspear/Code/testsuite/validation_tests/paraview/build/paraview-examples/build-ninja
Test project /home/wspear/Code/testsuite/validation_tests/paraview/build/paraview-examples/build-ninja
No tests were found!!!
Internal ctest changing into directory: /home/wspear/Code/testsuite/validation_tests/paraview/build/paraview-examples/build-make
Test project /home/wspear/Code/testsuite/validation_tests/paraview/build/paraview-examples/build-make
No tests were found!!!

I can send the build output along if that will help.

[mathstuf]

Would the pattern found here be preferred? spack/spack#40112

[wspear]

@mathstuf I'm reviewing this test, hoping to get it committed soon, and we actually need to avoid downloading test code during the test. Some platforms don't have external networking available at test time. Can we commit a small chunk of test code directly to the testsuite instead?

[mathstuf]

Is the source directory still available? I suppose we could submodule/subrepo it.

The problem is likely to be getting the proper version for the installed ParaView. There's no guarantee that a committed Examples/ tree would work for any given ParaView version.

[wspear]

Nope, we can't rely on source being around in a finished spack-based deployment. This is a common problem for the testsuite. We typically target just versions used in e4s releases and update test code manually as necessary to match the latest release. It's a pain in the neck but very few projects include test code with their install.