Use pytest for (unit)testing?

[mielvds]

RDFLib and many other libraries use pytest to run unittest. Currently, we only run the spec's test-suite, but we probably want to test specific parts of the code as well.
Introducing pytest will simplify this for developers, or do we stick to using unittest? In case we go for the former: do we migrate https://github.com/digitalbazaar/pyld/blob/master/tests/runtests.py as well.

@anatoly-scherbakov @BigBlueHat @davidlehn what are your thoughts about this?

[ioggstream]

I suggest the following approach:

1. add pytest dependency
2. add new pytest unittests
3. use test spec files (e.g., YAML files containing the input and the expected output)
4. measure code coverage
5. progressively remove tests from runtest.py

[mielvds]

Thanks for the input @ioggstream ! I agree with 1, 2 and 4, although I think 5 can also be included in this process. Most of the code is about running the tests, rather than actual tests (which are in de JSON-LD 1.1 test-suite).

3 seems complimentary to non-spec based tests and therefore the last step in the process.

[anatoly-scherbakov]

Agreed with a migration to pytest, and with a need of non-spec tests.