MRG, MAINT: Better notebook tests

[larsoner]

• Add nbexec fixture that can be used to run tests in an IPython kernel
• Encapsulate existing tests in separate tests
• Read test_3d.py and test_brain.py tests in test_notebook.py and use ipytest to run them (probably), need to figure out how to run only the notebook tests, using the notebook backend. Probably by replacing renderer_interactive with renderer_notebook using regex or so...

[larsoner]

From here up in this file is git mv / old code

[larsoner]

@GuillaumeFavelier can you take a look and see if you agree that test_notebook.py is a better testing infrastructure than test.ipynb? To me it will be easier to add stuff this way, but it has the disadvantage that you can't directly run the notebook.

[GuillaumeFavelier]

I'm fine not running in the notebook and updating test.ipynb directly is not convenient at all. I'll take a look and test locally

[GuillaumeFavelier]

Similarly to #9190 (comment), the notebook tests were skipped so I pushed b08647c to fix that.

[GuillaumeFavelier]

The tests are green for me locally and on Azure Notebook job:

...
mne/viz/_brain/tests/test_notebook.py::test_notebook_alignment[notebook] Coverage.py warning: --include is ignored because --source is set (include-ignored)
PASSED [ 17%]
mne/viz/_brain/tests/test_notebook.py::test_notebook_interactive[notebook] Coverage.py warning: --include is ignored because --source is set (include-ignored)
PASSED [ 17%]
mne/viz/_brain/tests/test_notebook.py::test_notebook_button_counts[notebook] Coverage.py warning: --include is ignored because --source is set (include-ignored)
PASSED [ 18%]
...

Is it still WIP? What is missing?

[larsoner]

Is it still WIP? What is missing?

Ready for merge except tests still aren't passing on Windows:

c:\miniconda\lib\asyncio\events.py:501: in add_reader
    raise NotImplementedError
E   NotImplementedError

I think we probably just need to skip if the platform is Windows because it's probably not supported in some part of the stack. But I think we can rely on it working in practice for people. I'll push a commit to skip there

[larsoner]

Feel free to rebase #9190 and incorporate tests there!