Enable JSX files extension

Summary:
JSX extension is much used in React, this would be a natural addition for React Native.
See: https://github.com/facebook/react-native/issues/2303
Closes https://github.com/facebook/react-native/pull/5233

Reviewed By: svcscm

Differential Revision: D2818888

Pulled By: mkonicek

fb-gh-sync-id: 856d1b8ba9ff88ba08a00923174e3284f359d774

packager/react-packager/src/DependencyResolver/DependencyGraph/ResolutionRequest.js

@@ -340,6 +340,8 @@ class ResolutionRequest {
         file = potentialModulePath + '.native.js';
       } else if (this._fastfs.fileExists(potentialModulePath + '.js')) {
         file = potentialModulePath + '.js';
+      } else if (this._fastfs.fileExists(potentialModulePath + '.jsx')) {
+        file = potentialModulePath + '.jsx';
       } else if (this._fastfs.fileExists(potentialModulePath + '.json')) {
         file = potentialModulePath + '.json';
       } else {

packager/react-packager/src/DependencyResolver/DependencyGraph/index.js

@@ -55,7 +55,7 @@ class DependencyGraph {
       platforms: platforms || [],
       preferNativePlatform: preferNativePlatform || false,
       cache,
-      extensions: extensions || ['js', 'json'],
+      extensions: extensions || ['js', 'jsx', 'json'],
       mocksPattern,
       extractRequires,
       shouldThrowOnUnresolvedErrors,

packager/react-packager/src/Server/index.js

@@ -151,6 +151,7 @@ class Server {
         dir: dir,
         globs: [
           '**/*.js',
+          '**/*.jsx',
           '**/*.json',
         ].concat(assetGlobs),
       };