test: add AbstractGraph interface tests and CI fixes (#42 split)

[mahmudsudo]

No description provided.

[Krastanov]

This looks close to done, thanks for taking it on. I left a few comments on things that seem to be incorrect or potentially problematic.

It seems @nenadilic84 has started doing something related to the interface tests in PR #35 and has a bit more thorough interface tests.

Could you either remove your interface tests so I can also merge #35 or cherry-pick the tests and bug fix? Or is this something you are already trying to address in #44 (I think not, it seems fairly different).

Maybe the easiest way forward to incorporate all the improvements you guys are submitting is to merge this as only CI fixes, then merge a rebased #35, then proceed with rebasing and reviewing your #44 -- let me know what your preferences are.

This is of course assuming @nenadilic84 has the time to fix up #35

Given @nenadilic84 was first to start working on this bounty, I want to make sure he has a chance to clean up his PR as well. It is a bit messy when multiple folks start working on the same bounty, but the whole point is to provide an onboarding experience for more junior contributors, so the mess is worth it. I do suspect you guys would end up splitting the bounty given that you are working on various sides of the same issue.

[mahmudsudo]

This looks close to done, thanks for taking it on. I left a few comments on things that seem to be incorrect or potentially problematic.

It seems @nenadilic84 has started doing something related to the interface tests in PR #35 and has a bit more thorough interface tests.

Could you either remove your interface tests so I can also merge #35 or cherry-pick the tests and bug fix? Or is this something you are already trying to address in #44 (I think not, it seems fairly different).

Maybe the easiest way forward to incorporate all the improvements you guys are submitting is to merge this as only CI fixes, then merge a rebased #35, then proceed with rebasing and reviewing your #44 -- let me know what your preferences are.

This is of course assuming @nenadilic84 has the time to fix up #35

Given @nenadilic84 was first to start working on this bounty, I want to make sure he has a chance to clean up his PR as well. It is a bit messy when multiple folks start working on the same bounty, but the whole point is to provide an onboarding experience for more junior contributors, so the mess is worth it. I do suspect you guys would end up splitting the bounty given that you are working on various sides of the same issue.

i cherrypicked the interface tests and implemented other corrections and pushed to #45