Android crash on RN 0.84: react-native.config.js uses removed reactNativeHost

[myxmaster]

React Native 0.84 removed ReactNativeHost in favor of ReactHost. The autolinking config in react-native.config.js hardcodes:
packageInstance: 'new RNNotificationsPackage(reactNativeHost.getApplication())'

In RN 0.84, PackageList is constructed with Application directly, so reactNativeHost is null in the generated PackageList.java, causing an immediate crash on app launch:

java.lang.NullPointerException: Attempt to invoke virtual method 'android.app.Application com.facebook.react.ReactNativeHost.getApplication()' on a null object reference
    at com.facebook.react.PackageList.getPackages(PackageList.java)

Fix: Change reactNativeHost.getApplication() to application in react-native.config.js:
packageInstance: 'new RNNotificationsPackage(application)'

application is the field that PackageList sets when constructed with the Application overload.

[TwistedMinda]

@myxmaster Hey thanks for pointing that out
Do you think we can come up with a quick patch in case it takes some times before a new version comes out, or does it require a deeper rework than your proposed fix?

[myxmaster]

Yes, you can work around it with patch-package:

1. in node_modules/react-native-notifications/react-native.config.js change:
   packageInstance: 'new RNNotificationsPackage(reactNativeHost.getApplication())'
   into
   packageInstance: 'new RNNotificationsPackage(application)'

2. Run npx patch-package react-native-notifications -> this generates a patch file you commit to your repo

3. Delete android/build/generated/autolinking/ to force the autolinking cache to regenerate, then rebuild

Note: this only affects you if you follow the new RN 0.84 MainApplication template (using ReactHost directly without ReactNativeHost).