react-native packager(or to be more precise - jest-haste-map) module resolution issue with 3rd party lib.

[nixoz]

Description

If react-native and react-native-windows installed together - the modules from latter considered being generic(g) by the packager(jest-haste-map). As result, we have broken app.

the initial discussion was started here: #13925

Reproduction Steps and Sample Code

1. react-native init test
2. cd test && yarn add react-native-windows
3. in the generated index.ios.js make a small modification so the render method of default exported component will look like that:

render() {
    return (
      <View style={styles.container}>
        <Text style={styles.welcome}>
          <Text style={styles.instructions}>
            To get started, edit index.ios.js
          </Text>
        </Text>
      </View>
    );
  }

4. react-native run-ios
5. ㅠㅠ

Solution

During investigating this, read a lot of code and eventually come to jest-haste-map - the one which required by react-native.

In the react-native packager defaults.js here is platforms array exported, looks like dat:

exports.platforms = ['ios', 'android', 'windows', 'web'];

at the same time, in jest-haste-map's lib/getPlatformExtension.js we have:

const SUPPORTED_PLATFORM_EXTS = {
  android: true,
  ios: true,
  native: true,
  web: true };

adding windows: true, to SUPPORTED_PLATFORM_EXTS dict will give us a fix:

Should I make a PR to jest-haste-map? or this thing was already addressed?
UPD: just in case, PR is below

Additional Information

• React Native version: 0.44
• Platform: iOS 10.0/10.3
• Development Operating System: macOSX 10.12.4(16E195)
• Dev tools: Xcode Version 8.3.2 (8E2002) / Simulator Version 10.0 (SimulatorApp-745.10

[skevy]

Hi there!

The packager no longer lives in this repo. It now lives in https://github.com/facebook/metro-bundler. The reasoning for the split is explained here: #13976.

If you're still interested in pursuing this issue, please open an issue on that repo! :)

Thanks!
-Adam