Can't trigger Firebase pub/sub function from HTTPS function

Question

I've created two Firebase functions - one is an HTTPS where I am publishing a message to a topic, and a pub/sub function where I am responding to messages published to that topic.

testPubSub.ts

import { pubsub } from "firebase-functions";
export const testPubSub = pubsub
  .topic("high-scores")
  .onPublish(async (message, context) => {
    console.log("hit test pubsub");
    return null;
  });

testHttps.ts

import { https } from "firebase-functions";
import { messaging } from "firebase-admin";

export const testHookEndpoint = https.onRequest(async (request, response) => {
  const payload = {
    notification: {
      title: "Test title",
      body: "test body"
    }
  };

  const pubsubResponse = await messaging().sendToTopic("high-scores", payload);
  console.log("response from pubsub", pubsubResponse);
  response.send("success");
});

The HTTPS function appears to be running fine (200 response) and messaging is returning a message ID in the response, however I am not seeing the pub/sub function run in the Firebase Console.

When I look at GCP Console I see that "high-scores" has registered as a topic in the Pub/Sub tab, and I'm able to trigger other pub/sub functions in the project through Google Cloud Scheduler.

I'm not sure what step I'm missing for this.

so everything is working except for the logging in firebase console? — imjared
yeah i'm not getting any errors but that pubsub doesn't appear to running when i look at it either through the firebase console, or through GCP pubsub tab showing activity. — eaton9000

Doug Stevenson Doug Stevenson · Accepted Answer · 2019-09-11T17:31:16

messaging().sendToTopic("high-scores", payload) is using Firebase Cloud Messaging to send a message to mobile applications subscribed to the given topic. This is completely different than Cloud Pubsub messaging. These two products don't actually have anything in common - FCM is for mobile apps and pubsub is for servers.

What you'll need to do instead is use the node pubsub SDK to send the message to your pubsub topic.

Can't trigger Firebase pub/sub function from HTTPS function

1 Answers