`onConfigUpdated` emits error when the page becomes hidden

[noze12]

Operating System

macOS Sequoia

Environment (if applicable)

Chrome

Firebase SDK Version

12.6.0

Firebase SDK Product(s)

Remote-Config

Project Tooling

none.
(I use flutter firebase lib for flutter web and noticed this behavior: firebase/flutterfire#17901 )

Detailed Problem Description

onConfigUpdated with error handler emits the following error repeatedly when the page becomes hidden (e.g. switching tabs or minimizing the browser window):

FirebaseError: Remote Config: The stream was not able to connect to the backend: Unable to connect to the server. HTTP status code: undefined. (remoteconfig/stream-error).
    at RealtimeHandler.prepareAndBeginRealtimeHttpStream (realtime_handler.ts:633:35)

Since the SDK already tracks background state via isInBackground, would it make sense to guard this else block as well?

Steps and code to reproduce issue

import { initializeApp } from "https://www.gstatic.com/firebasejs/12.6.0/firebase-app.js"
import { getRemoteConfig, onConfigUpdate } from "https://www.gstatic.com/firebasejs/12.6.0/firebase-remote-config.js"

const firebaseConfig = {
  // config
};

const app = initializeApp(firebaseConfig);
const remoteConfig = getRemoteConfig(app);

onConfigUpdate(remoteConfig, {
  next: (configUpdate) => {
    console.log("Updated keys:", configUpdate.getUpdatedKeys());
  },
  error: (error) => {
    console.error(error);
  },
  complete: () => {
    console.log("Listening stopped.");
  }
});

1. Load js
2. Switch tab

[google-oss-bot]

I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.

[dlarocque]

Hi @noze12, thanks for submitting this detailed issue and for digging into the source code, this is very helpful. I was able to confirm the behaviour you observed with the code snippet you shared.

I'll label this as a bug since I believe we should not log an error to the console in this case. I think the ideal behaviour would be to not log an error if the page is not visible, and to hold off on reconnection attempts until the page is visible again.

[tusharkhandelwal8]

Hi @noze12, this situation is already handled in the SDK code. If you have a successful connection and then move the app to the background, you shouldn’t be seeing this error. Are you doing anything else in addition to this, such as closing the internet connection?