Good point, though I don't like the idea of a setup where your test file's only executed if you remember to do that personally (if the tooling doesn't already do similar, I'd at least want to generate the list you describe by globbing the relevantly named/located files).

You could just copy that entrypoint into another untracked file, have its list include (or be only - quicker) the new untracked test file, and execute that instead of the normal one while bisecting.