Goals

Use Results/List Object listeners during development of a React Native app. This requires restarting the simulator or force-closing the app on device after a certain number of reloads.

Expected Results

Reloading the app during development (DEV mode) should not leak.

Actual Results

Memory leaks when dev-reloading the app with listeners on RealmResults and List objects. It does not leak on listeners on the Realm instance.

Steps to Reproduce

• Call addListener on either a RealmResults object or a List object.
• Reload the app (CMD+R)
• See that memory climb

Code Sample

I created a fresh React Native app to demonstrate the issue at https://github.com/dkpalmer/realm-rn-reload-leak/. Inside App.js there are 3 cases within componentWillMount:

Does not leak when reloading: (1) Realm listener

Does leak when reloading: (2) Results listener and (3) List object listener

Assuming you have the RN CLI and Xcode installed, app can be run by cloning, installing dependencies, and running react-native run-ios.

Version of Realm and Tooling

• Realm JS SDK Version: 2.27.0 and 2.28.0
• Node or React Native: RN 0.59
• Client OS & Version: iOS
• Which debugger for React Native: DEV Perf Monitor