automated CI for testing napari plugins

How this works

To add a test case for a plugin, open a PR to add a new file to the cases directory, then add your plugin to the github actions matrix.

Here's an example test case, for napari-omero, which has a somewhat complicated installation, involving conda dependencies and non-default channels.

# cases/napari-omero.yml
deps: napari-omero  # pip dependencies
conda_channels: ome  # conda channels to use
conda_deps: omero-py  # deps to install from conda
plugins:
  - name: omero  # plugin names that should be found
    hooks:  # hooks that this plugin should have registered
      - napari_get_reader
      - napari_experimental_provide_dock_widget

This will extend the tox.ini in this directory with a test-case specific testenv:

[testenv:napari-omero]
conda_deps =
  omero-py
conda_channels =
  ome
deps =
  {[testenv]deps}
  napari-omero

and, using that environment, will run the tests in test_cases. Currently the default test will just ensure that the pacakge is discovered correctly, and that the expected hooks have been registered for each plugin namespace provided by the package, but this can expand with the TestCase schema.