RN event loop stuck when using realm with an expo development build

[jayshah123]

How frequently does the bug occur?

Always

Description

I use an expo development build with realm "@realm/react": "0.6.2", and "realm": "12.6.2"
along with RN version: "react-native": "0.72.7"
When ever I tried to load the JS bundle via expo development client, the bundle is stuck at "Downloading 100%".

On diving deeper, the following code in ReactRealm.mm seems to be stuck in a infinite loop causing JS event loop/thread to block indefinitely:

          while (s_currentJSThread && !s_currentJSThread.finished) {
            [NSThread sleepForTimeInterval:0.1];
          }

Is there a known workaround or fix for this issue?

Stacktrace & log output

No response

Can you reproduce the bug?

Always

Reproduction Steps

1. Create an expo app repo with developmentClient: true for expo development build.
2. Add realm with following versions: "@realm/react": "0.6.2", and "realm": "12.6.2"
   along with RN version: "react-native": "0.72.7"
3. Try to load a JS bundle via development client.
4. Bundle is stuck at "Downloading 100%"

Version

0.6.2

What services are you using?

Local Database only

Are you using encryption?

No

Platform OS and version(s)

iOS 17

Build environment

System:
OS: macOS 14.5
CPU: (10) arm64 Apple M1 Max
Memory: 103.30 MB / 32.00 GB
Shell:
version: "5.9"
path: /bin/zsh
Binaries:
Node:
version: 18.13.0
path: ~/.nvm/versions/node/v18.13.0/bin/node
Yarn:
version: 1.18.0
path: ~/.nvm/versions/node/v18.13.0/bin/yarn
npm:
version: 8.19.3
path: ~/.nvm/versions/node/v18.13.0/bin/npm
Watchman:
version: 2024.01.22.00
path: /opt/homebrew/bin/watchman
Managers:
CocoaPods:
version: 1.14.3
path: /Users/jshah/.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: 2022.3 AI-223.8836.35.2231.10811636
Xcode:
version: 15.2/15C500b
path: /usr/bin/xcodebuild
Languages:
Java:
version: 17.0.11
path: /usr/bin/javac
Ruby:
version: 3.3.0
path: /Users/jshah/.rbenv/shims/ruby
npmPackages:
"@react-native-community/cli": Not Found
react:
installed: 18.2.0
wanted: 18.2.0
react-native:
installed: 0.72.7
wanted: 0.72.7
react-native-macos: Not Found
npmGlobalPackages:
"react-native": Not Found
Android:
hermesEnabled: true
newArchEnabled: false
iOS:
hermesEnabled: true
newArchEnabled: false

Cocoapods version

1.14.3

[sync-by-unito]

➤ PM Bot commented:

Jira ticket: RJS-2853

[kraenhansen]

Realm JS v12.11.0 deleted the code you're referring to and might very well resolve this issue as well 🤞 Please update to the latest version of our SDK and report back 👍

[jayshah123]

Thanks, will check and re-open if issue persists.

[elle-j]

May also be due to an older expo-dev-client/expo-dev-launcher used where you may be experiencing this issue that should be fixed.

[jayshah123]

For expo, I will have to do a full RN upgrade from 72 to 73 or 74 probably.
On the realm side I can go for "realm": "12.6.2" -> "12.11.0" as mentioned earlier.
What about "@realm/react" version?
How are they related? Is there any compatibility table needed between @realm/react and realm packages?

[elle-j]

Currently, for using realm v12 you need @realm/react v0.5.0 or later, but we recommend using the latest @realm/react 👍

[jayshah123]

Upgrading realm did not help, had to patch expo-dev-client/launcher.

[kraenhansen]

had to patch expo-dev-client/launcher.

How? What did you have to do? Could you open another issue here or on the expo repo, with a description of what you're seeing and instructions on how to reproduce this?

[jayshah123]

Technically the fix is in this PR - https://github.com/expo/expo/blob/main/packages/expo-dev-launcher/CHANGELOG.md#362---2024-01-10 which is available in 3.x and 4.x versions of expo-dev-launcher/client.

But I cannot upgrade to RN73 + Expo50 at the moment (which is the requirement to use 3.x versions of expo-dev-launcher/expo-dev-client). I've asked them to see if they can do patch releases on 2.x versions of expo-dev-client which is what I use with RN 72.

But for now, I have picked the fix present in expo/expo@54108e2 by using patch-package https://www.npmjs.com/package/patch-package which creates a local patch