Improve test coverage

[fneum]

There are some modules where test coverage can improve. Let's target step by step:

io:

• import and export functionality, starts with Add rudimentary test for import and export functionality #229

components:

• madd()
• mremove()
• copy()
• __getitem__() aka network[:,:]
• consistency_check()

linopt:

• get_sol()
• get_dual()

linopf:

• ramp limits
• store constraints
• global constraints
• ilopf()

opf:

• ramp limits, shut down, start up

pf:

• sub_network_pf_singlebus()
• aggregate_multi_graph()

as well as

• networkclustering
• plots
• stats

[fneum]

See also https://codecov.io/gh/PyPSA/PyPSA/tree/master/pypsa

[rockstaedt]

Hey! I would like to contribute to this issue :) Can you recommend any unit/function I could start with?

[FabianHofmann]

Great @rockstaedt! It depends a bit on how deep you are in the pypsa code. I'd say for a first step try to tackle the functions madd and mremove.
For madd:

1. Test that components are actually added to the static as well as the time dependent dataframe (e.g. n.generators_t.p_max_pu). This can be done via checking the index.
2. Check that defaults are set correctly. These come from n.component_attrs and should fill values which are not specified in madd (only test one or two single values)
3. madd should fail with a misspelled component (something like 'Gnerators')
4. Re-adding the same generator name should fail
   ...

For mremove:

1. Check that components are actually removed from static and time-dependent
2. Removal of non-existent components should fail
3. Removal with misspelled component names should fail

The test functions could go into a new test script like test_components.py.

[rockstaedt]

Great! Thanks 👍🏼 I'm on it!

[rockstaedt]

In the above commit, I created the unit tests for mremove().

How do you want to proceed? Should I already open a pull request?

I would be happy about every feedback :)

[FabianHofmann]

Wonderful @rockstaedt, looks clean are usable! If you want, you can start a PR in draft mode and continue adding things (at least the madd would be good). As soon as you think you are ready we review and pull it in.

[rockstaedt]

Sounds good! I'll draft the pull request and continue with madd() 👍🏼

[rockstaedt]

Tests for madd() are also done 👍🏻

[pz-max]

@LukasFrankenQ and @pz-max will take care of at least one test as well

[rockstaedt]

Just finished my master thesis and have some time now. I could also do some unit tests. Any recommendations?

[FabianHofmann]

hey @rockstaedt, that would be wonderful! How about copy and __get_item__() for a start?

[FabianHofmann]

@rockstaedt, if you scroll down here https://app.codecov.io/gh/PyPSA/PyPSA and open up the pypsa folder, you see the coverage of the individual modules, e.g. descriptors and networkclustering have quite low coverage. That should be tackled as well