ScrollView crashing the app in release variant.

Is this a bug report?

Yes!

Have you read the Contributing Guidelines?

Yes.

Environment

OS: Windows 10 Node: 9.3.0 Yarn: 0.24.5 npm: 5.6.0 Watchman: Not Found Xcode: N/A Android Studio: Version 3.0.0.0 AI-171.4443003

Packages: (wanted => installed) react: 16.0.0 => 16.0.0 react-native: 0.50.4 => 0.50.4

Target Platform:

• Android (7.1.1)
• Android (6.0)

Steps to Reproduce

• Start a fresh react native project. Run react-native init Test --version 0.50.4
• Edit the App.js file with following changes

...

<View style={styles.container}>
   <ScrollView contentContainerStyle={{ flexGrow: 1 }}>
      <Text style={styles.welcome}>
         Welcome to React Native!
      </Text>
      <Text style={styles.instructions}>
         To get started, edit App.js
      </Text>
      <Text style={styles.instructions}>
            {instructions}
       </Text>

       ...

   </ScrollView>
</View>

...

• Extend the content a bit so it becomes scrollable.

• Follow the guide for generating signed .apk file. https://facebook.github.io/react-native/docs/signed-apk-android.html

• Run react-native run-android --variant=release

Expected Behavior

Expected the app to work normal in release version like in dev.

Actual Behavior

• App crashes on startup.
• Confirmed the issue on 2 different computers.
• Same issue persist on react-native version 51.0
• App works as expected on react-native version 49.5

Reproducible Demo

Download the project. Run npm install Run react-native run-android --variant=release

https://github.com/Aleksandar-FFWD/react-native-test

[Aleksandar-FFWD]

@aspidvip Its connected to #17348 as I can see.

There is an issue with ..\node_modules\react-native\Libraries\Components\Subscribable.js on componentWillUnmount function.

The workaround I did was to change this:

componentWillUnmount: function() {
    this._subscribableSubscriptions.forEach(
      (subscription) => subscription.remove()
    );
    this._subscribableSubscriptions = null;
},

To this:

componentWillUnmount: function() {
    this._subscribableSubscriptions && this._subscribableSubscriptions.forEach(
      (subscription) => subscription.remove()
    );
    this._subscribableSubscriptions = null;
},

[bridgewaterlabs]

I have huge issue with ScrollView not running properly in release mode … WTF in debug all works fine