Test harness in CATMAID

[clbarnes]

As discussed elsewhere, the integration tests should be done as part of CATMAID's build because it's not worth standing up a whole instance of CATMAID for testing this library, and any breaking API changes by CATMAID which affect this library will also affect users and so should be addressed by the CATMAID maintainers as a priority.

[clbarnes]

Alternatively, we could simply stand up an instance of CATMAID using the (eventual) docker image, but it would mean that the tests would be in a separate repo to the fixtures they've be asserting against.

[aschampion]

I like the docker image test idea. If we set up the docker image right, we should be able to keep the fixtures here in catpy. One of the goals of the docker image is easy DB import for the purpose of hosting published/curated exports.

[clbarnes]

Been thinking about this a bit more in the context of the extension apps - might it be sensible to have a catpy_integration_tests package in the catpy repo, which could be installed with an extra flag for the setup script? This could be a Django app with just an appconfig, fixtures and tests, and we can let Django run the tests. That way catpy has control over all the fixtures, and doesn't need to worry about setup of the CATMAID environment other than installing itself in there before collectstatic is called. On the downside, having server and client running in the same (potentially dockerised) python environment potentially isn't as isolated as we'd like, especially if there are version or dependency clashes.

I'm definitely all for separating unit tests and integration tests within catpy, just thought this might be a nice way of using django's infrastructure to make sure the database is getting sufficiently cleaned up.

[clbarnes]

Minor step relevant to this: pytest now accepts a --credentials_json=path/to/file.json argument. There is a credentials fixture which will skip the test if this argument is not given; otherwise it will return the deserialised object in the JSON file, which can be used to instantiate the CatmaidClient object. That will make it trivial to run tests against whatever instance of CATMAID we would want to use.