internal high-level testing (gjs, gts)?

[NullVoxPopuli]

as a feature implementation person, I would like to have gjs and gts rendering tests, like what consuming apps have.

This may mean bringing in @ember/test-helpers in to this repo -- but I think this is a good thing. (I think we should do the same with @ember/test-waiters, too).

This way, it'll be way easier to provide reproduction issues for general things encountered by the community, as well as implement new features and starting with the end-user-style testing (basically: e2e).

If this already exists, and I missed it, lemme know <3

[kategengler]

Until we move to automated releasing #20759 I don't think it makes sense to move more packages into a monorepo here.

Until that time, more high-level tests can be achieved in the smoke-tests, either directly in the apps or in scenarios
https://github.com/emberjs/ember.js/tree/main/smoke-tests/scenarios