Bad credentials (or missing) throws UnhandledPromiseRejectionWarning

[kidplug]

When creating a new SpeechClient (specifically using keyFilename), and the file does not exist:

' new speech.SpeechClient({keyFile:"my.json"});'

causes:
UnhandledPromiseRejectionWarning

How is the caller supposed to catch or handle this? Does the returned SpeechClient object expose a promise that can be acted upon?

[kidplug]

Maybe this issue/question belongs here?
https://github.com/googleapis/google-auth-library-nodejs/issues

[JustinBeckwith]

I actually tracked this down in gax. The offending code is here:
https://github.com/googleapis/gax-nodejs/blob/master/src/api_callable.ts#L400

The funcWithAuth function is throwing without a handler. I think this function is dynamically generated, which makes tracking this down very hard.

I'm adding another chip to #439

[alexander-fenster]

This is a dup of googleapis/gapic-generator#2065. I was under impression it can be fixed by changing the generated library code, hence the issue I referred to is in the generator. Do you feel comfortable if I close it here?

[alexander-fenster]

Fixed by googleapis/gapic-generator#2565.