[🔥] Priority values missing from firebase realtime database DataSnapshot

[chetstone]

Issue

Describe your issue here

I'm switching my app from firebase web (V8) to react-native-firebase. (I figured it would be less work to refactor than going to web V9) But I have run into a problem.

I use Priority values to store a value that indicates ordering of objects in a realtime database container, and when I read the snapshot the priorities are not there. It seems like the top-level snapshot has a priority value, but when I access the child snapshots with snap.child("child1') or snap.forEach(), the child snapshots do not contain a .priority property.

This is the code has been working in my app for over 5 years (with added debugging printouts).

  subscribeFB() {
      if (!this.unlistenFB) {
        this.unlistenFB = this.user.child('Counternames').on(
          'value',
          (snap) => {
            // Need to also grab the current timestamps when 
            // Counternames changes.
            this.getTimestamps(snap);
          },
          (error) => {
            info('Counternames subscription cancelled because', error);
          }
        );
      }
    }

    getTimestamps(snap) {
      this.user.child('Timestamps').once(
        'value',
        (tsSnap) => {
          setTimeout(
            () =>
              MultiActions.setCounters({
                counterSnap: snap,
                timestamps: tsSnap.val(),
              }),
            0
          );
        },
        (error) => {
          info('Could not get timestamps because', error);
        }
      );
    }
// Then in setCounters I use both snaps

 setCounters(snaps) {
  [...]
       if ( timestamps.sequence > this.state.timestamps.sequence) {
          debug('Getting new sequence from FB');
          // get sequence from FB
          var CounternameSnap = snaps.counterSnap;
          var cns = CounternameSnap.exportVal();
          debug(`CounternameSnap exportVal ${JSON.stringify(cns, null, 2)}`);

          var ch = CounternameSnap.child('-MH3NnGU5iM0eakrd7ZS').exportVal();
          debug(`Counter 44 exportVal ${JSON.stringify(ch)}`);

          CounternameSnap.forEach((ctr) => {
            var p = ctr.getPriority();

            debug(`Counter priority ${p} has key ${ctr.key}, val ${ctr.val()}`);
            // Do something with priority...
          });
 

When I change the order of the counters on another device, my .on listener triggers and I get the following printout:

 LOG  MultiStore:debug Getting new sequence from FB +2ms
 LOG  MultiStore:debug CounternameSnap exportVal {
  ".value": {
    "-MH3MqLK32gCi0pqBUg3": "Counter 33",
    "-MH4yucF8rmeewGbPAVI": "Counter 55",
    "-MH3NnGU5iM0eakrd7ZS": "Counter 44",
    "-NuBYkNVlAUIUeoQQCKA": "Counter 66",
    "-MGQOBLgEvEekOg6geQI": "Counter 11",
    "-MGzzZXdUwpBr8RlLLE-": "Counter 22"
  },
  ".priority": null
} +1ms
 LOG  MultiStore:debug Counter 44 exportVal {".value":"Counter 44"} +1ms
 LOG  MultiStore:debug Counter priority undefined has key -MGzzZXdUwpBr8RlLLE-, val Counter 22 +2ms
 LOG  MultiStore:debug Counter priority undefined has key -MH4yucF8rmeewGbPAVI, val Counter 55 +1ms
 LOG  MultiStore:debug Counter priority undefined has key -MH3NnGU5iM0eakrd7ZS, val Counter 44 +1ms
 LOG  MultiStore:debug Counter priority undefined has key -MH3MqLK32gCi0pqBUg3, val Counter 33 +0ms
 LOG  MultiStore:debug Counter priority undefined has key -MGQOBLgEvEekOg6geQI, val Counter 11 +1ms
 LOG  MultiStore:debug Counter priority undefined has key -NuBYkNVlAUIUeoQQCKA, val Counter 66 +1ms

This shows the top-level snap contains a .priority value (null) but the "Counter 44" child does not have the property at all. I can verify that the other device successfully pushed the new priorities to firebase: although the firebase console does not show priorities, I can export and download the container, and it looks like this:

{
  "-MGQOBLgEvEekOg6geQI": {
    ".value": "Counter 11",
    ".priority": 4
  },
  "-MGzzZXdUwpBr8RlLLE-": {
    ".value": "Counter 22",
    ".priority": 0
  },
  "-MH3MqLK32gCi0pqBUg3": {
    ".value": "Counter 33",
    ".priority": 1
  },
  "-MH3NnGU5iM0eakrd7ZS": {
    ".value": "Counter 44",
    ".priority": 2
  },
  "-MH4yucF8rmeewGbPAVI": {
    ".value": "Counter 55",
    ".priority": 3
  },
  "-NuBYkNVlAUIUeoQQCKA": {
    ".value": "Counter 66",
    ".priority": 5
  }
}

Is this exposing a previously unknown bug in my program, is it a bug in RNFirebase, a change in underlying FB V9+ iOS/Android libraries (It has the same problem on both platforms), or ???

react-native: 0.70.15

react-native-firebase: 19.1.1

[UPDATE:] I wondered if offline persistence might have something to do with this so I enabled persistence and found the problem remains the same either way.

[NOTE:] I filed a StackOverflow question about this but since I'm pretty sure this is a bug I decided to go ahead and file an issue. The above is a copy-paste from that SO question.

I created a reproducible demo which is here.
This is the RNFB demo with just App.tsx changed to demonstrate the issue. Since the whole setup is the default, I have not included any of my own files below (Podfile, build.gradle, etc.) Note that I only tried the RNFB demo on iOS but I have confirmed the issue is the same on Android in my app.

When running my demo, you may want to edit make-demo.sh so it doesn't install all the RNFB modules. The only ones needed are app and database. Also, the default react-native run-ios build fails for me. I didn't investigate, I always prefer to use xcode. I just opened up xcode and ran on the simulator with no problem

---

Project Files

Javascript

Click To Expand

package.json:

# N/A

firebase.json for react-native-firebase v6:

# N/A

iOS

Click To Expand

ios/Podfile:

• I'm not using Pods
• I'm using Pods and my Podfile looks like:

# N/A

AppDelegate.m:

// N/A

---

Android

Click To Expand

Have you converted to AndroidX?

• my application is an AndroidX application?
• I am using android/gradle.settings jetifier=true for Android compatibility?
• I am using the NPM package jetifier for react-native compatibility?

android/build.gradle:

// N/A

android/app/build.gradle:

// N/A

android/settings.gradle:

// N/A

MainApplication.java:

// N/A

AndroidManifest.xml:

<!-- N/A -->

---

Environment

Click To Expand

react-native info output:

info Fetching system and libraries information...
System:
  OS: macOS 14.3.1
  CPU: (8) arm64 Apple M1 Pro
  Memory: 86.19 MB / 16.00 GB
  Shell:
    version: 3.2.57
    path: /bin/bash
Binaries:
  Node:
    version: 20.11.1
    path: ~/.nodenv/versions/20.11.1/bin/node
  Yarn:
    version: 1.22.19
    path: /opt/homebrew/bin/yarn
  npm:
    version: 10.2.4
    path: ~/.nodenv/versions/20.11.1/bin/npm
  Watchman:
    version: 2022.11.28.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.12.1
    path: /Users/chet/.rbenv/shims/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 23.2
      - iOS 17.2
      - macOS 14.2
      - tvOS 17.2
      - visionOS 1.0
      - watchOS 10.2
  Android SDK: Not Found
IDEs:
  Android Studio: 2022.1 AI-221.6008.13.2211.9514443
  Xcode:
    version: 15.2/15C500b
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 11.0.18
    path: /usr/bin/javac
  Ruby:
    version: 2.7.7
    path: /Users/chet/.rbenv/shims/ruby
npmPackages:
  "@react-native-community/cli": Not Found
  react:
    installed: 18.2.0
    wanted: 18.2.0
  react-native:
    installed: 0.73.6
    wanted: 0.73.6
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: false
iOS:
  hermesEnabled: true
  newArchEnabled: false

• Platform that you're experiencing the issue on:
  • iOS
  • Android
  • iOS but have not tested behavior on Android
  • Android but have not tested behavior on iOS
  • Both
• react-native-firebase version you're using that has this issue:
  • 19.1.1
• Firebase module(s) you're using that has the issue:
  • database
• Are you using TypeScript?
  • N & VERSION

---

• 👉 Check out React Native Firebase and Invertase on Twitter for updates on the library.

[mikehardy]

This does look like a bug here - I've marked it for examination

That said, the modular API is already implemented in react-native-firebase and the v8 API should be considered deprecated in all cases, in all ecosystems - so using react-native-firebase for what is sort of an "extended bridge" to continue using the deprecated v8 / non-modular API is technically possible but also not technically advisable

Having ported a few applications to the new style API, I can say it is almost completely mechanical. It's really just a matter of switching up the imports to import the functions (not just the desired module...) then doing a getAuth (or getApp or getNNN) first then just sending it in to the functions - but all the functions behave the same so it's just text moving around, not really functional change. Much easier than I personally feared at least

[chetstone]

Thanks Mike for looking at this. And thanks for the reassurance about switching to V9. I've noticed that things never turn out as bad as I fear (or as good as I hope :-)

I think I'll bite the bullet and do the switcheroo. It might take a while to fix this one in RNFB. I tried looking for low-hanging fruit-- I cloned and built your repo (Great build system: I was surprised it was so easy to build such a large project and run the tests). I wrote a test case and found the line in DatabaseDataSnapshot.js where it looked like priority was not being copied into the new snap. chetstone/react-native-firebase@main...chetstone:react-native-firebase:tryfix7719

But it didn't work.
So the problem may be in native code (though it's strange that it would affect both platforms.)