We rely on this feature when shutting down the logger during process.on('exit'): in this case the write will never finish, so we can't wait. Possibly this is ok, the fd will be closed by the process closing... wdyt?

Could you add a test? Mocking is ok.

We rely on this feature when shutting down the logger during process.on('exit'): in this case the write will never finish, so we can't wait. Possibly this is ok, the fd will be closed by the process closing... wdyt?

process closing should be sufficient.

Could you add a test? Mocking is ok.

Sure. Was hoping the assertion would be sufficient (tests fail now without the fix). But I can do a test as well.