Slow starting of unit tests

[GernotMaier]

pytest is very slow to start, even for very simple tests (>5 seconds on my laptop). Very hard to debug with this slow response.

After investigation, it is the same issue as realized recently with general.py (#681): any including of ctapipe means that tools slow down due to a large number of slow imports.

I suggest to consider removing the following two fixtures from conftest.py:

@pytest.fixture
def corsika_histograms_instance(io_handler, corsika_output_file_name):
    return CorsikaHistograms(
        corsika_output_file_name, output_path=io_handler.get_output_directory(dir_type="test")
    )


@pytest.fixture
def corsika_histograms_instance_set_histograms(db, io_handler, corsika_histograms_instance):
    corsika_histograms_instance.set_histograms()
    return corsika_histograms_instance

Victor, is this possible without a huge amount of work?

I will also investigate with ctapipe developers if this is a feature or an issue.

[GernotMaier]

See also cta-observatory/ctapipe#2476

[VictorBarbosaMartins]

Hi @GernotMaier. Yes, this should be simple, as the fixtures are likely used in only two different places. I see two options:

• Either we repeat the definition of the fixture
• Or we import one test*.py inside the other, which I don't see as a problem, as both are related to corsika histograms.

Should I go for option 2?

[GernotMaier]

I leave it to you what is best - less dublication is definitively good.