Why would a Firebase background function on Node.js 8 complain about an event parameter?

Question

After a recent update, firebase-tools wants me to set my package.json engines setting to either node 6 or 8. When you set it to 6 it deploys the functions on Node 6 and otherwise Node 8.

With firebase-functions 1.0 the background function signature changed from event to data, context. I have migrated all my background functions long ago.

I noticed that according to the @gloud/functions docs (which differs from firebase-functions) you explicitly set the Node deployment target, and the distinction in API between the Node 6 and 8 runtimes is this same event vs data/context signature.

So in @gloud/functions the API change got rolled out in a different way than with firebase-functions.

Wat seems weird is that if I now deploy my firebase-functions with engines set to node 8, I get errors like this:

Cloud function needs to be called with an event parameter.

When I set engines to node 6, it says it is deploying my code on Node.js 6, and everything works as before.

Now that seems to be the opposite of what I would expect!

So I am using the up-to-date background functions API but I can't seem to run them properly on Node.js 8. Something seems to be messed up somewhere. Any clue?

Answer 1

The problem is the version of firebase-functions needs to be 2.0.0+ for node 8 runtime.

This error message appears in 1.x.x firebase-functions for me, and is gone after I upgrade it.

Note that firebase-admin also needs to be 5.13.0+.