Port and rework tests

[rkoschmitzky]

Goal

Add tests.

Motivation

The proprietary predecessor of Trackteroid had good test coverage. We have to identify if those tests can be ported and potentially rework them, but obviously, we need tests.

Considerations

We want to consider going fully with pytest instead of unittest.

[99alfie]

in test_session.py, the following tests are failing:

test_reconnect_and_commit
test_get_cached_collections

both are reading a database file that has uncommitted operations in it and try to apply it. If the operations contain the creation of an entity (as is the case), there is no way to get rid of them with the same process (delete is not implemented), so they leave garbage in ftrack which will also fail the test the next time it is run (duplicate entry).

Since the database write/read feature seems incomplete I would assume it is barely used if at all. I started a discussion, and based on its outcome, either remove the functionality together with its tests or implement the missing feature.

[99alfie]

Tests were failing because of modifications done in branch fix/i10-pytests. Reverting them resolved the confusion. All tests are working now.