Self test appears to depend on some protocols

[i509VCB]

I noticed that the self test needs a way to create a surface, and bind a seat.

I'd think the self tests would make sense as a way to ensure the compositor can properly receive requests and send events (using a roundtrip and wl_callback) and ensuring the registry behaves properly.

I'd think the test that a surface can be made would be better placed inside of the wl_compositor tests?