If you have some requirements/specifications, and the piece of code fits them, then it runs.

Alternatively, if you have some vague idea [1] about what you expect to see/have, and the running code satisfies that idea, then it also runs.

Obviously, there are plenty of non-functional specs (e.g., security, cleanness, readability) that a code should probably fulfill before one finds it acceptable, but these are also not somehow impossible for state-of-the-art models to satisfy.

[1] Vibe, if you prefer, tho I dislike the term. Another related term is eyeball estimation.