If someone were to put together a TAP test suite that covered all that and made for a meaningful improvement in psql's altogether-miserable code coverage report[1], I would think that that would be a useful expenditure of buildfarm time.
Ok, this is an interesting point.
What I'm objecting to is paying the overhead for such a suite in order to test just this one thing.
Well, it should start somewhere. Once something is running it is easier to add more tests.
think that that passes the bang-for-buck test; or in other words, this isn't the place I would start if I were creating a TAP suite for psql.
Sure, I would not have started with that either.
Note that from this patch point of view, it is somehow logical to start testing a given feature when this very feature is being developed...
The summary is that we agree that psql test coverage is abysmal, but you do not want to bootstrap a better test infrastructure for this particular and rather special new feature. Ok.
Maybe Corey can submit another patch with the exit 3 test removed.