Convenient test for different schedulers

[kain88-de]

pmda can be used with different dask schedulers and in a single core variant. It would be nice if we have a pytest.fixture that is easy to use and runs a single test with all supported schedulers.

from pmda.testing import scheduler

def test_custom(scheduler):
    a = AnalysisFromFunction(...).run(scheduler=scheduler)

I think it should be possible to parametrize over a fixture.

[orbeckst]

pmda/pmda/test/test_parallel.py

Line 82 in 2ff3db2

def client(tmpdir_factory):

shows how to set-up a client with two workers as a session-scoped test fixture

[kain88-de]

https://docs.pytest.org/en/latest/fixture.html#fixture-parametrize

I thought of this. We can use it to generate multiple schedulers for different tests.

[orbeckst]

Yes, this is used in

pmda/pmda/test/test_parallel.py

Line 93 in 2ff3db2

@pytest.fixture(scope='session', params=('distributed', 'multiprocessing'))

pmda/pmda/test/test_parallel.py

Line 94 in 2ff3db2

def scheduler(request, client):

... so your original example might just work.