Fallback to use lib when src doesn't exist.

Summary:
Changelog: [Internal] babel-plugin-codegen.js to fallback to use lib instead of src.

The bubel plugin uses react-native-codegen/src but it's not compatible when react-native-codegen is installed as a separate dependency (which is the case for OSS).

Reviewed By: cortinico

Differential Revision: D32908846

fbshipit-source-id: 1d3e3a3485e94e2f051e220d76dd2dbcdd8070a8

packages/babel-plugin-codegen/index.js

@@ -9,12 +9,21 @@
 
 'use strict';
 
-const {parseString} = require('react-native-codegen/src/parsers/flow');
-const RNCodegen = require('react-native-codegen/src/generators/RNCodegen');
+let flow, RNCodegen;
+
 const {basename} = require('path');
 
+try {
+  flow = require('react-native-codegen/src/parsers/flow');
+  RNCodegen = require('react-native-codegen/src/generators/RNCodegen');
+} catch (e) {
+  // Fallback to lib when source doesn't exit (e.g. when installed as a dev dependency)
+  flow = require('react-native-codegen/lib/parsers/flow');
+  RNCodegen = require('react-native-codegen/lib/generators/RNCodegen');
+}
+
 function generateViewConfig(filename, code) {
-  const schema = parseString(code);
+  const schema = flow.parseString(code);
 
   const libraryName = basename(filename).replace(/NativeComponent\.js$/, '');
   return RNCodegen.generateViewConfig({