firebase pubsub function invoked but not writing to firestore - firebase

Question

I have a simple pub sub cloud function
var serviceAccount = require("./serviceAccountKey.json");
admin.initializeApp({
credential: admin.credential.cert(serviceAccount)
});
exports.updateNews = functions.pubsub
.topic("firebase-schedule-cronForNews-us-central1")
.onPublish(message => {
axios
.get(
"https://newsapi.org/v2/top-headlines?apiKey=241414&sources=espn-cric-info"
)
.then(result => {
return result.data.articles.forEach(article => {
db.collection("news").add(article);
});
})
.then(result => {
console.log(result);
return result;
})
.catch(error => {
console.log(error);
return error;
});
return null;
});
The function is being invoked but it is not writing to firestore the same code works when I convert this to http function.

Answer 1

You may try returning the promises chain and using a batched write, as follows:
exports.updateNews = functions.pubsub
.topic("firebase-schedule-cronForNews-us-central1")
.onPublish(message => {
return axios // Note the return here
.get(
"https://newsapi.org/v2/top-headlines?apiKey=241414&sources=espn-cric-info"
)
.then(result => {
const batch = admin.firestore().batch();
result.data.articles.forEach(article => {
const docRef = admin.firestore().collection("news").doc();
batch.set(docRef, article);
});
return batch.commit();
})
.then(result => { // You don't need this then if you don't need the console.log
console.log(result);
return null;
});
});