React-native-navigation: NPE in NavigationReactEventEmitter.java

[varungupta85]

I am observing multiple reports for below crash in the Google Play console for my app.

java.lang.NullPointerException: 
  at com.reactnativenavigation.bridge.NavigationReactEventEmitter.<init> (NavigationReactEventEmitter.java:17)
  at com.reactnativenavigation.react.NavigationReactGateway.onReactContextInitialized (NavigationReactGateway.java:114)
  at com.reactnativenavigation.react.NavigationReactGateway.access$000 (NavigationReactGateway.java:24)
  at com.reactnativenavigation.react.NavigationReactGateway$ReactNativeHostImpl.onReactContextInitialized (NavigationReactGateway.java:174)
  at com.facebook.react.ReactInstanceManager$6.run (ReactInstanceManager.java:1017)
  at android.os.Handler.handleCallback (Handler.java:742)
  at android.os.Handler.dispatchMessage (Handler.java:95)
  at android.os.Looper.loop (Looper.java:154)
  at android.app.ActivityThread.main (ActivityThread.java:5527)
  at java.lang.reflect.Method.invoke (Native Method)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:739)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:629)

I don't know what are the steps to reproduce. Below is the line in code on which the abort is occurring

public NavigationReactEventEmitter(ReactContext reactContext) {
        this.eventEmitter = reactContext.getJSModule(RCTDeviceEventEmitter.class);
}

So, it looks like the reactContext is null but I am not sure why would it be null.

---

Environment

• React Native Navigation version: 1.1.365
• React Native version: 0.52.4
• Platform(s) (iOS, Android, or both?): Android
• Device info (Simulator/Device? OS version? Debug/Release?): Device / Release

[guyca]

hmm that's really strange. I checked our crash logs and couldn't find a similar crash.
The event emitter is instantiated in onReactContextInitialized, one would assume react context won't be null at this point.

[varungupta85]

Yes. That confused me also. It is visible in the call stack also that the event emitter in the onReactContextInitialized, so it shouldn't be null which is why I didn't want to just add a null check there.

[marcmo]

I experience the same issue with RN 0.50.3 and RNN 1.1.389

Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'com.facebook.react.bridge.JavaScriptModule com.facebook.react.bridge.ReactContext.getJSModule(java.lang.Class)' on a null object reference
       at com.reactnativenavigation.bridge.NavigationReactEventEmitter.<init>(NavigationReactEventEmitter.java:17)
       at com.reactnativenavigation.react.NavigationReactGateway.onReactContextInitialized(NavigationReactGateway.java:114)
       at com.reactnativenavigation.react.NavigationReactGateway.access$000(NavigationReactGateway.java:24)
       at com.reactnativenavigation.react.NavigationReactGateway$ReactNativeHostImpl.onReactContextInitialized(NavigationReactGateway.java:174)
       at com.facebook.react.ReactInstanceManager$5.run(ReactInstanceManager.java:995)
       at android.os.Handler.handleCallback(Handler.java:790)
       at android.os.Handler.dispatchMessage(Handler.java:99)
       at android.os.Looper.loop(Looper.java:164)
       at android.app.ActivityThread.main(ActivityThread.java:6494)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

since it is not reproducible it could be a race condition. only happens from time to time on startup. looks to me like a RN bug.

[brunolemos]

Just had this too but only once.

D/ReactNative: CatalystInstanceImpl.runJSBundle()
D/ReactNative: ReactInstanceManager.runCreateReactContextOnNewThread()
D/ReactNative: ReactInstanceManager.setupReactContext()
D/ReactNative: CatalystInstanceImpl.initialize()
W/unknown:ReactNative: Packager connection already open, nooping.
E/BluetoothAdapter: Bluetooth binder is null
D/ReactNative: ReactInstanceManager.createReactContext()
D/ReactNative: ReactInstanceManager.onReloadWithJSDebugger()
D/ReactNative: ReactInstanceManager.recreateReactContextInBackground()
E/unknown:ReactNative: Unable to display loading message because react activity isn't available
D/FirebasePhoneAuth: initialized
D/ReactNative: Initializing React Xplat Bridge.
D/ReactNative: Initializing React Xplat Bridge before initializeBridge
D/ReactNative: Initializing React Xplat Bridge after initializeBridge
D/ReactNative: CatalystInstanceImpl.runJSBundle()
D/ReactNative: ReactInstanceManager.setupReactContext()
D/ReactNative: CatalystInstanceImpl.initialize()
E/BluetoothAdapter: Bluetooth binder is null
D/ReactNative: ReactInstanceManager.runCreateReactContextOnNewThread()
D/ReactNative: ReactInstanceManager.tearDownReactContext()
D/ReactNative: CatalystInstanceImpl.destroy() start
W/unknown:ReactNative: Packager connection already open, nooping.
W/unknown:ReactNative: Packager connection already open, nooping.
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.minderapps.minder, PID: 16267
                  java.lang.NullPointerException: Attempt to invoke virtual method 'com.facebook.react.bridge.JavaScriptModule com.facebook.react.bridge.ReactContext.getJSModule(java.lang.Class)' on a null object reference
                      at com.reactnativenavigation.bridge.NavigationReactEventEmitter.<init>(NavigationReactEventEmitter.java:17)
                      at com.reactnativenavigation.react.NavigationReactGateway.onReactContextInitialized(NavigationReactGateway.java:114)
                      at com.reactnativenavigation.react.NavigationReactGateway.access$000(NavigationReactGateway.java:24)
                      at com.reactnativenavigation.react.NavigationReactGateway$ReactNativeHostImpl.onReactContextInitialized(NavigationReactGateway.java:174)
                      at com.facebook.react.ReactInstanceManager$6.run(ReactInstanceManager.java:993)
                      at android.os.Handler.handleCallback(Handler.java:790)
                      at android.os.Handler.dispatchMessage(Handler.java:99)
                      at android.os.Looper.loop(Looper.java:164)
                      at android.app.ActivityThread.main(ActivityThread.java:6494)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
D/ReactNative: ReactInstanceManager.createReactContext()

"react-native": "0.54.0"
"react-native-navigation": "^1.1.365

[ankero]

Seeing the same thing on multiple devices (PlayStore reporting). For us we got a report that this happens when users are accessing camera/image storage. We are using package "react-native-image-picker" for that.

java.lang.NullPointerException: 
  at com.reactnativenavigation.bridge.NavigationReactEventEmitter.<init> (NavigationReactEventEmitter.java:17)
  at com.reactnativenavigation.react.NavigationReactGateway.onReactContextInitialized (NavigationReactGateway.java:114)
  at com.reactnativenavigation.react.NavigationReactGateway.access$000 (NavigationReactGateway.java:24)
  at com.reactnativenavigation.react.NavigationReactGateway$ReactNativeHostImpl.onReactContextInitialized (NavigationReactGateway.java:174)
  at com.facebook.react.ReactInstanceManager$5.run (ReactInstanceManager.java:1000)
  at android.os.Handler.handleCallback (Handler.java:761)
  at android.os.Handler.dispatchMessage (Handler.java:98)
  at android.os.Looper.loop (Looper.java:156)
  at android.app.ActivityThread.main (ActivityThread.java:6523)
  at java.lang.reflect.Method.invoke (Native Method)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:942)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:832)

"react-native": "^0.51.0",
"react-native-navigation": "^1.1.397",

[SudoPlz]

We're using react-native-image-picker too and we face the same issue.

[sapjax]

Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'com.facebook.react.bridge.JavaScriptModule com.facebook.react.bridge.ReactContext.getJSModule(java.lang.Class)' on a null object reference
       at com.reactnativenavigation.bridge.NavigationReactEventEmitter.<init>(NavigationReactEventEmitter.java:17)
       at com.reactnativenavigation.react.NavigationReactGateway.onReactContextInitialized(NavigationReactGateway.java:114)
       at com.reactnativenavigation.react.NavigationReactGateway.access$000(NavigationReactGateway.java:24)
       at com.reactnativenavigation.react.NavigationReactGateway$ReactNativeHostImpl.onReactContextInitialized(NavigationReactGateway.java:174)
       at com.facebook.react.ReactInstanceManager$5.run(ReactInstanceManager.java:1000)
       at android.os.Handler.handleCallback(Handler.java:754)
       at android.os.Handler.dispatchMessage(Handler.java:95)
       at android.os.Looper.loop(Looper.java:163)
       at android.app.ActivityThread.main(ActivityThread.java:6384)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:901)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:791)

"react-native": "^0.51.0",
"react-native-navigation": "^1.1.365",

android 7.1.1

[guyca]

Should be resolved by #2976