CI tests take too much time

[campospinto]

As of today (March 13, 2025), the continuous integration tests take more than 1h.

We should reduce this time if possible. We could start by profiling the tests and see if some tests are expensive with no good reason.

[jowezarek]

@kvrigor once presented a tool during our Psydac meeting that was able to show which tests take up the most time! @kvrigor, could you let us know which tests take up the most time / how to use this tool?

[kvrigor]

@jowezarek this should be addressed by #458. Unfortunately I don't yet have time to implement this; but all the necessary info to replicate the tests should be in that PR.

[kvrigor]

How to run profiling and visualize the results:

# Install profiling tools
pip3 install pytest-profiling snakeviz

# Run profiling on one test
pytest --profile psydac/feec/tests/test_global_projectors.py -k "test_derham_projector_3d"

# Visualize profiling results on a web browser
snakeviz prof/test_derham_projector_3d/combined.prof

# Repeat for another slow test
pytest --profile psydac/feec/tests/test_commuting_projections.py -k "test_3d_commuting_pro_3"
snakeviz prof/test_3d_commuting_pro_3/combined.prof

[campospinto]

thanks @kvrigor ! This will be useful. We can probably gain some time already by running some tests on coarse grids. I will run some profiling.