Make test suite run faster

[create-issue-branch]

closes #114

[Flix6x]

Test results

• Start of speed-up-tests branch off of main (8ed869d)

Results (296.89s):
     189 passed

• Avoid redundant queries in test suite (6c7ad68)

Results (296.76s):
     189 passed

• Reduce the use of autouse=True (30b3831)

Results (288.15s):
     189 passed

• Clean redis only in API and data package (fc08c60)

Results (288.04s):
     189 passed

Results (289.62s):
     189 passed

• Less setup of market prices (f7a8bff)

Results (288.22s):
     189 passed

• Set up charging stations only when tests need them (2a8449b)

Results (292.38s):
     189 passed

• Set up assets only when tests need them, and split off setup of asset types (reverted commit)

Results (268.68s):
     189 passed

• Set up assets only when tests need them (stop autouse), and split off setup of asset types (2622d28)

Results (249.87s):
     189 passed

• Setup database with module scope (31f4613)

Results (94.90s):
     189 passed

• Refactor test db setup at different scopes (407da74)

Results (96.12s):
     189 passed

[Flix6x]

To summarise: the main time savers are to:

• have tests reuse a database where possible
• avoid using autouse=True, especially in higher up conftest.py files.

[nhoening]

I commend you for this effort! I didn't check every test in itself, but they do still all pass, which is also some feedback, and some do so really fast. Kudos.

One thing I would want to see a little different concerns being explicit (as per usual):

As I see it, the biggest organisational change is that you divided many test files into the ones with function-level db creation, and the one with module-level db creation.

OI think that's fine, as it can guide future test authors to make a decision about this. We could even explicitly state that this is a part of writing tests now. A policy. Could be mentioned in the main conftest.

And the filenames go a little like this: test_fresh_api_v1.py . I would be more explicit (what is "fresh_api"?), e.g. test_api_v1_fresh_db.py

[Flix6x]

I renamed according to your suggestions and updated the developer documentation in our main conftest.

[nhoening]

I'd say "Re-use the database between the automated tests, if possible. This shaves 2/3rd off the time ..."