The fact that your statement includes a qualifier ("if the module... was implemented as...") means it's never going to be preferable. Nothing should depend on a

The fact that your statement includes a qualifier ("if the module... was implemented as...") means it's never going to be preferable. Nothing should depend on a qualifier that isn't self-evident from syntax. As for what is preferable... const closeServer = () => server.close(); async.timeout(closeServer, 60000)(exit); Abstracting `server.close()` and naming it `closeServer` may seem to be a bit redundant, but the example given was slightly contrived so this would be almost always preferable in practice.