@achingbrain let me know your thoughts. Specially, if we should keep the same interface testing behaviour of receiving the libp2p module instance for testing, or if we should change all the interface tests to receive the libp2p instance. This can also be a follow up PR to not break the consistency with the other interfaces now

Perhaps libp2p interface tests should receive an instance of libp2p instead of the module instance

My gut feeling here is that this is not a good idea as it turns interface tests into integration tests which may hinder our ability to completely exercise the interface during the test, if some aspects of the interface require certain setup or other conditions.

Unrelated but part of me thinks we should split the interface tests from the interfaces themselves, otherwise you end up with aegir being an undeclared dep of code that can be required when running in production.

My gut feeling here is that this is not a good idea as it turns interface tests into integration tests which may hinder our ability to completely exercise the interface during the test, if some aspects of the interface require certain setup or other conditions.

Yeah, I agree let's wait for testground for more complex integration tests.

The PR as it is now, moves the pubsub subsystem tests from libp2p to the interface, which is how libp2p expects the routers to work and to have consistent behaviours. So, while they were technically used as integration tests in libp2p, they really are interface tests.

Unrelated but part of me thinks we should split the interface tests from the interfaces themselves, otherwise you end up with aegir being an undeclared dep of code that can be required when running in production.

I have the same opinion. It is super weird to have the tests in the src folder but this is the result of past decisions. You already opened #58 in the past. I can also promote it to the maintenance weekly candidates of libp2p.