nodebuilder/tests: Investigate why event connectedness subscription isn't working in TestFullDiscoveryViaBootstrapper

[renaynay]

          Investigate why subscription isn't working in this test.

Originally posted by @renaynay in #2166 (comment)

[nodersteam]

@renaynay

Could you describe in a little more detail what exactly needs to be fixed?

I see that the tests are passing, and we don’t fully understand what exactly needs to be completed

[nodersteam]

Like this?

[walldiss]

Hi @nodersteam. It is minor issue with the test being inefficient on cpu. At some point tests wants to wait for connection to be succeeded. Currently it checks it in endless poll loop. There is an api in libp2p to subscribe to connectivity event, that should allow to catch such event once it happens. So it needs to be investigated how to setup subscription to catch connectivity event at given test stage reliably.