Android: "FATAL EXCEPTION: mqt_js" / Error calling function: RCTDeviceEventEmitter:emit / - malformed JSON parsing in RN's android native code

[GeoffreyPlitt]

Description

Calling fetch() and expecting JSON results (i.e. using response.json()) will crash if server sends malformed JSON. Error/logging system prints "Failed to create String from JSON:" and then does NOT print the JSON (the problem this ticket IS about).

#9117 promised to fix this, but did not.

Reproduction

Call fetch() and then response.json() with a server that returns bad JSON.

Additional Information

• React Native version: 0.36
• Platform: Android
• Operating System: MacOS

Here's an example log:

11-04 13:39:46.611  3509  3509 D EPDG -- [EPDGService]: onDataActivity: direction=3
11-04 13:39:46.611  7541  7836 D NetworkController.MobileSignalController(0/2): onDataActivity: direction=3
11-04 13:39:46.781 17917 17917 V MediaPlayer-JNI: getCurrentPosition: 617 (msec)
11-04 13:39:47.031 17917 17917 V MediaPlayer-JNI: getCurrentPosition: 617 (msec)
11-04 13:39:47.281 17917 17917 V MediaPlayer-JNI: getCurrentPosition: 617 (msec)
11-04 13:39:47.541 17917 17917 V MediaPlayer-JNI: getCurrentPosition: 617 (msec)
11-04 13:39:47.641  3509  3509 D EPDG -- [EPDGService]: onDataActivity: direction=1
11-04 13:39:47.641  7541  7836 D NetworkController.MobileSignalController(0/2): onDataActivity: direction=1
11-04 13:39:47.791 17917 17917 V MediaPlayer-JNI: getCurrentPosition: 617 (msec)
11-04 13:39:47.821 17917 17976 I System.out: (HTTPLog)-Static: isSBSettingEnabled false
11-04 13:39:47.821 17917 17976 I System.out: (HTTPLog)-Static: isSBSettingEnabled false
11-04 13:39:47.821  3079  3883 D EnterpriseController: netId is 0
11-04 13:39:47.821  3079  3883 D Netd    : getNetworkForDns: using netid 507 for uid 10726
11-04 13:39:47.821 17917 17968 E AndroidRuntime: FATAL EXCEPTION: mqt_js
11-04 13:39:47.821 17917 17968 E AndroidRuntime: Process: com.stardust, PID: 17917
11-04 13:39:47.821 17917 17968 E AndroidRuntime: java.lang.RuntimeException: Error calling function: RCTDeviceEventEmitter:emit
11-04 13:39:47.821 17917 17968 E AndroidRuntime: 	at com.facebook.react.bridge.queue.NativeRunnable.run(Native Method)
11-04 13:39:47.821 17917 17968 E AndroidRuntime: 	at android.os.Handler.handleCallback(Handler.java:739)
11-04 13:39:47.821 17917 17968 E AndroidRuntime: 	at android.os.Handler.dispatchMessage(Handler.java:95)
11-04 13:39:47.821 17917 17968 E AndroidRuntime: 	at com.facebook.react.bridge.queue.MessageQueueThreadHandler.dispatchMessage(MessageQueueThreadHandler.java:31)
11-04 13:39:47.821 17917 17968 E AndroidRuntime: 	at android.os.Looper.loop(Looper.java:158)
11-04 13:39:47.821 17917 17968 E AndroidRuntime: 	at com.facebook.react.bridge.queue.MessageQueueThreadImpl$3.run(MessageQueueThreadImpl.java:196)
11-04 13:39:47.821 17917 17968 E AndroidRuntime: 	at java.lang.Thread.run(Thread.java:818)
11-04 13:39:47.821 17917 17968 E AndroidRuntime: Caused by: java.lang.RuntimeException: Failed to create String from JSON: 
11-04 13:39:47.821 17917 17968 E AndroidRuntime: 	... 7 more
11-04 13:39:47.841  3509  4040 W ActivityManager:   Force finishing activity com.stardust/.MainActivity
11-04 13:39:47.851  3509  4040 D FocusedStackFrame: Set to : 0
11-04 13:39:47.851  3509  4040 D InputDispatcher: Focused application set to: xxxx
11-04 13:39:47.861  3509  4040 D InputDispatcher: Focus left window: 17917
11-04 13:39:47.861  3509  3638 D PointerIcon: setMouseIconStyle1 pointerType: 1001 iconType:101 flag:0 pid:3509 uid:1000
11-04 13:39:47.861  3509  3638 D PointerIcon: setMouseCustomIcon IconType is same.101
11-04 13:39:47.931  3509 18371 E android.os.Debug: ro.product_ship = true
11-04 13:39:47.931  3509 18371 E android.os.Debug: ro.debug_level = 0x4f4c
11-04 13:39:47.931  3509 18371 E android.os.Debug: sys.mobilecare.preload = false
11-04 13:39:47.971  3509  3610 D ViewRootImpl: #1 mView = com.android.internal.policy.PhoneWindow$DecorView{5822614 V.E...... R.....I. 0,0-0,0}
11-04 13:39:47.981  3509  3610 D ISSUE_DEBUG: InputChannelName : 1cdbcb2 Application Error: com.stardust
11-04 13:39:47.981  3509  3610 V MARsPolicyManager: handelAlertToastWindowStarted pkgName = android
11-04 13:39:47.981  3509  3610 D InputDispatcher: Focus entered window: 3509
11-04 13:39:47.981  3509  3638 D PointerIcon: setMouseIconStyle1 pointerType: 1001 iconType:101 flag:0 pid:3509 uid:1000
11-04 13:39:47.981  3509  3638 D PointerIcon: setMouseCustomIcon IconType is same.101
11-04 13:39:47.991  3067  3067 I SurfaceFlinger: id=2946 createSurf (193x193),1 flag=4, ttardust
11-04 13:39:48.001 18372 18372 E Zygote  : v2
11-04 13:39:48.001 18372 18372 I libpersona: KNOX_SDCARD checking this for 1000
11-04 13:39:48.001  3509  3609 I ActivityManager: Start proc 18372:com.samsung.android.sm/1000 for broadcast-3 com.samsung.android.sm/.common.SmartManagerReceiver
11-04 13:39:48.001 18372 18372 I libpersona: KNOX_SDCARD not a persona

Questions:

• What do we have to do to actually include the JSON so we can get to the bottom of this?
• Why does it say "... 7 more" ?

[brentvatne]

Hello! You're unlikely to get much help until you can provide a reproducible example :( Please keep trying and let us know when you have it.

[GeoffreyPlitt]

I narrowed it down.

BUG: Using fetch() and then doing response.json() when the server sends
malformed JSON causes a crash.

Expectation: JS exception, not crash.

On Nov 6, 2016 10:04 AM, "Brent Vatne" notifications@github.com wrote:

Hello! You're unlikely to get much help until you can provide a
reproducible example :( Please keep trying and let us know when you have it.

—
You are receiving this because you authored the thread.
Reply to this email directly, view it on GitHub
#10756 (comment),
or mute the thread
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.

[brentvatne]

@GeoffreyPlitt - that's no fun. Does that happen in release mode or debug or both?

[GeoffreyPlitt]

Both

On Nov 6, 2016 10:14 AM, "Brent Vatne" notifications@github.com wrote:

@GeoffreyPlitt https://github.com/GeoffreyPlitt - that's no fun. Does
that happen in release mode or debug or both?

—
You are receiving this because you were mentioned.
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#10756 (comment),
or mute the thread
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.

[brentvatne]

@lacker - any idea who this should be assigned to?

[lacker]

I don't have someone who is going to jump on and fix this, but if there is a pull request that fixes this I would be happy to prioritize its review.

[leeight]

@GeoffreyPlitt I tried to reproduce this case but failed ....

export default class Issue10756 extends Component {
  constructor(...args) {
    super(...args);
    this.state = {
      text: 'Welcome to React Native!'
    };
  }

  render() {
    return (
      <View style={styles.container}>
        <Text style={styles.welcome}>
          {this.state.text}
        </Text>
        <Button title="fetch()" onPress={this.sendRequest.bind(this)} />
      </View>
    );
  }

  sendRequest() {
    fetch('https://www.baidu.com/')
      .then(response => response.json())
      .then(response => this.setState({text: JSON.stringify(response, null, 2)}))
      .catch(error => this.setState({text: String(error)}));
  }
}

After click the <Button>, i got the JS Exception, and the app not crash...

[GeoffreyPlitt]

Update: Yeah I just re-tested this and you're right, it's not caused by fetch() / response.json(). I'm now convinced that this is some background android process. New crash logs from today:

1-09 12:05:20.698 16816 16850 E AndroidRuntime: FATAL EXCEPTION: mqt_js
11-09 12:05:20.698 16816 16850 E AndroidRuntime: Process: com.stardust, PID: 16816
11-09 12:05:20.698 16816 16850 E AndroidRuntime: java.lang.RuntimeException: Error calling function: RCTDeviceEventEmitter:emit
11-09 12:05:20.698 16816 16850 E AndroidRuntime:    at com.facebook.react.bridge.queue.NativeRunnable.run(Native Method)
11-09 12:05:20.698 16816 16850 E AndroidRuntime:    at android.os.Handler.handleCallback(Handler.java:751)
11-09 12:05:20.698 16816 16850 E AndroidRuntime:    at android.os.Handler.dispatchMessage(Handler.java:95)
11-09 12:05:20.698 16816 16850 E AndroidRuntime:    at com.facebook.react.bridge.queue.MessageQueueThreadHandler.dispatchMessage(MessageQueueThreadHandler.java:31)
11-09 12:05:20.698 16816 16850 E AndroidRuntime:    at android.os.Looper.loop(Looper.java:154)
11-09 12:05:20.698 16816 16850 E AndroidRuntime:    at com.facebook.react.bridge.queue.MessageQueueThreadImpl$3.run(MessageQueueThreadImpl.java:196)
11-09 12:05:20.698 16816 16850 E AndroidRuntime:    at java.lang.Thread.run(Thread.java:761)
11-09 12:05:20.698 16816 16850 E AndroidRuntime: Caused by: java.lang.RuntimeException: Failed to create String from JSON: 
11-09 12:05:20.698 16816 16850 E AndroidRuntime:    ... 7 more

What is mqt_js and how can we find out why it causes Error calling function: RCTDeviceEventEmitter:emit ?

[GeoffreyPlitt]

More: This seems to only happen in release-mode i.e. react-native run-android --variant=release or install via APK.

It does not happen in debug mode.

[lacker]

This is another case where reproducing it is going to make it easier to debug. What is the simplest app that reproduces this?