Firebase Cloud Function does not terminate in functions:shell - firebase

Question

I'm trying to import a JSON into a collection. For testing purpose, I'm using emulators and document creation trigger.
The workflow is :
start emulators with firebase emulators:start
start functions shell in another terminal with firebase functions:shell (tells me that no emulator is running btw)
call my function with tempoCF()
it runs and add documents to collection but it seems that the function does not terminate. I cannot call another function and need to press CTRL+C to be able to write again in the shell.
Here is the function I use :
const functions = require("firebase-functions");
const admin = require('firebase-admin');
const fetch = require('node-fetch');
admin.initializeApp();
const db = admin.firestore();
exports.tempoCF = functions
.firestore.document('/tempo/{docId}')
.onCreate(async (snap, context) => {
console.log("onCreate");
let settings = { method: "Get" };
let url = "https://opendata.paris.fr/api/records/1.0/search/?dataset=sanisettesparis&q=&rows=-1";
try {
let response = await fetch(url, settings);
let json = await response.json();
// TODO for each json object, add new document
return Promise.all(json["records"].map(toiletJsonObject => {
console.log(toiletJsonObject);
return db.collection('toilets').doc(toiletJsonObject["recordid"]).set({});
}));
}
catch(error) {
console.log(error);
return null;
}
}
);
I know I can use the emulator UI to create a new document that trigger the tempoCF function and it works as well but I fear that my function isn't correct and could generate bugs in production.
Here is the screenshot of the terminal. It prints logs and at the end, there is no way to write anything on the last empty line in the screenshot. I run it in Android Studio but I don't think that it matters.

Answer 1

I'm not on Windows but on a Mac, and I can reproduce your problem in the Terminal by calling the function with tempoCF(). Somehow, by doing that, you are simulating the creation a Firestore document without data.
But if I pass some data when calling the Cloud Function, e.g. tempoCF({foo: "bar"}) (i.e. providing new test data for the onCreate operation) I'm able to write to the Terminal after the CF has completed. See the doc for more details.