Unable to modify existing RN project to use single index.js entry point (both iOS and Android)

Is this a bug report?

Yes

Have you read the Contributing Guidelines?

Yes

Environment

Environment: OS: macOS High Sierra 10.13 Node: 8.6.0 Yarn: 1.2.0 npm: 5.5.1 Watchman: 4.9.0 Xcode: Xcode 9.0.1 Build version 9A1004 Android Studio: 2.3 AI-162.4069837

Packages: (wanted => installed) react: 16.0.0-beta.5 => 16.0.0-beta.5 react-native: 0.49.3 => 0.49.3

Steps to Reproduce

(Write your steps here:)

1. Have an existing React Native 0.48 project
2. Upgrade to React Native 0.49.3
3. Rename index.android.js to index.js, and delete index.ios.js
4. Use jsCodeLocation = [NSURL URLWithString:@"http://localhost:8081/index.bundle?platform=ios&dev=true"]; in AppDelegate.m

Expected Behavior

My expectation was that RN 0.49.* would know to use index.js as the entry point, but the packager and output suggested that it was still trying to use the old entry points (i.e. index.android.js).

Actual Behavior

The packager showed this output, suggesting that it was using old entry points:

Bundling `index.android.js`  [development, non-minified]  0.0% (0/1), failed.
error: bundling failed: Error
    at DependencyGraph._getAbsolutePath (/Users/sunw/Skale/Repos/skale-react-native/Skale/node_modules/metro-bundler/src/node-haste/DependencyGraph.js:305:11)
    at DependencyGraph.getDependencies (/Users/sunw/Skale/Repos/skale-react-native/Skale/node_modules/metro-bundler/src/node-haste/DependencyGraph.js:283:4236)
    at Resolver.getDependencies (/Users/sunw/Skale/Repos/skale-react-native/Skale/node_modules/metro-bundler/src/Resolver/index.js:129:5)
    at /Users/sunw/Skale/Repos/skale-react-native/Skale/node_modules/metro-bundler/src/Bundler/index.js:642:39
    at Generator.next (<anonymous>)
    at step (/Users/sunw/Skale/Repos/skale-react-native/Skale/node_modules/metro-bundler/src/Bundler/index.js:13:1336)
    at /Users/sunw/Skale/Repos/skale-react-native/Skale/node_modules/metro-bundler/src/Bundler/index.js:13:1496
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:188:7)

Screenshots (Android and iOS, respectively):

[achuvm]

I’m pretty sure this could’ve been done prior to the defaulting to only 1 index.js file

For Android, go to your Module: app’s build.gradle and add the following above the line: apply from: "../../node_modules/react-native/react.gradle"

project.ext.react = [
    entryFile: "index.js"
]

In MainApplication.java, you need to override another function in the anonymous ReactNativeHost class by adding this:

    @Override
    protected String getJSMainModuleName() {
      return "index";
    }

For iOS, go to your AppDelegate.m and change "index.ios" to "index" in this line:

  jsCodeLocation = [[RCTBundleURLProvider sharedSettings] jsBundleURLForBundleRoot:@"index.ios" fallbackResource:nil];

Depending on how old your project is, you might have a Build Phases Script that looks like this:

export NODE_BINARY=node

../node_modules/react-native/scripts/react-native-xcode.sh ../index.ios.js

In that case, you can remove the argument ../index.ios.js or simply rename it to index.js

These changes were tested with a new RN 47.2 project that I upgraded to RN 49.3 with a single index.js file. These instructions were also used to upgrade a RN 47.2 project w/ our Viro platform to a RN 49.3 project with a single index.js file too.

Hope that helps!

edit1: left out another android fix edit2: added possibly additional iOS changes

[sunweiyang]

Unfortunately @duailibe, the issue persists even after deleting ios/build/ and android/app/build/.