Use a separate babel config for the local-cli and the packager

Summary:
This separates the babel config of the local-cli and the packager from the one used by the transforms of the packager since it doesn't run in the same environment and the local-cli/packager doesn't require react specific transforms and runs in node 4 so we can also avoid some es2015 transforms that node already supports.

I had to move the code in cli.js so it can still run in node 0.12 that doesn't support `const` since it is no longer transformed.

**Test plan**
Run the local-cli on node 0.12 and there should be a message saying that it requires at least node 4.
Run the local-cli on node 4 and 5 and everything should work the same as before.

I was also hoping for some perf gains but there was nothing noticeable. I did benchmark the babel-register call and it stayed pretty much the same. As for runtime performance it can help if there are optimisations for es2015 features in node.
Closes https://github.com/facebook/react-native/pull/6155

Reviewed By: bestander

Differential Revision: D3301008

Pulled By: davidaurelio

fbshipit-source-id: 504180d158a1e50bc03e28fb0d1e53d0731ce32f

local-cli/cli.js

@@ -8,164 +8,20 @@
  */
 'use strict';
 
+// This file must be able to run in node 0.12 without babel so we can show that
+// it is not supported. This is why the rest of the cli code is in `cliEntry.js`.
+require('./server/checkNodeVersion')();
+
 require('../packager/babelRegisterOnly')([
   /private-cli\/src/,
   /local-cli/,
   /react-packager\/src/
 ]);
 
-var bundle = require('./bundle/bundle');
+var cliEntry = require('./cliEntry');
-var childProcess = require('child_process');
-var Config = require('./util/Config');
-var defaultConfig = require('./default.config');
-var dependencies = require('./dependencies/dependencies');
-var generate = require('./generate/generate');
-var library = require('./library/library');
-var path = require('path');
-var Promise = require('promise');
-var runAndroid = require('./runAndroid/runAndroid');
-var runIOS = require('./runIOS/runIOS');
-var server = require('./server/server');
-var TerminalAdapter = require('yeoman-environment/lib/adapter.js');
-var yeoman = require('yeoman-environment');
-var unbundle = require('./bundle/unbundle');
-var upgrade = require('./upgrade/upgrade');
-var version = require('./version/version');
-
-var fs = require('fs');
-var gracefulFs = require('graceful-fs');
-
-// graceful-fs helps on getting an error when we run out of file
-// descriptors. When that happens it will enqueue the operation and retry it.
-gracefulFs.gracefulify(fs);
-
-var documentedCommands = {
-  'start': [server, 'starts the webserver'],
-  'bundle': [bundle, 'builds the javascript bundle for offline use'],
-  'unbundle': [unbundle, 'builds javascript as "unbundle" for offline use'],
-  'new-library': [library, 'generates a native library bridge'],
-  'android': [generateWrapper, 'generates an Android project for your app'],
-  'run-android': [runAndroid, 'builds your app and starts it on a connected Android emulator or device'],
-  'run-ios': [runIOS, 'builds your app and starts it on iOS simulator'],
-  'upgrade': [upgrade, 'upgrade your app\'s template files to the latest version; run this after ' +
-                       'updating the react-native version in your package.json and running npm install']
-};
-
-var exportedCommands = {dependencies: dependencies};
-Object.keys(documentedCommands).forEach(function(command) {
-  exportedCommands[command] = documentedCommands[command][0];
-});
-
-var undocumentedCommands = {
-  '--version': [version, ''],
-  'init': [printInitWarning, ''],
-};
-
-var commands = Object.assign({}, documentedCommands, undocumentedCommands);
-
-/**
- * Parses the command line and runs a command of the CLI.
- */
-function run() {
-  var args = process.argv.slice(2);
-  if (args.length === 0) {
-    printUsage();
-  }
-
-  var setupEnvScript = /^win/.test(process.platform)
-    ? 'setup_env.bat'
-    : 'setup_env.sh';
-  childProcess.execFileSync(path.join(__dirname, setupEnvScript));
-
-  var command = commands[args[0]];
-  if (!command) {
-    console.error('Command `%s` unrecognized', args[0]);
-    printUsage();
-    return;
-  }
-
-  command[0](args, Config.get(__dirname, defaultConfig)).done();
-}
-
-function generateWrapper(args, config) {
-  return generate([
-    '--platform', 'android',
-    '--project-path', process.cwd(),
-    '--project-name', JSON.parse(
-      fs.readFileSync('package.json', 'utf8')
-    ).name
-  ], config);
-}
-
-function printUsage() {
-  console.log([
-    'Usage: react-native <command>',
-    '',
-    'Commands:'
-  ].concat(Object.keys(documentedCommands).map(function(name) {
-    return '  - ' + name + ': ' + documentedCommands[name][1];
-  })).join('\n'));
-  process.exit(1);
-}
-
-// The user should never get here because projects are inited by
-// using `react-native-cli` from outside a project directory.
-function printInitWarning() {
-  return Promise.resolve().then(function() {
-    console.log([
-      'Looks like React Native project already exists in the current',
-      'folder. Run this command from a different folder or remove node_modules/react-native'
-    ].join('\n'));
-    process.exit(1);
-  });
-}
-
-class CreateSuppressingTerminalAdapter extends TerminalAdapter {
-  constructor() {
-    super();
-    // suppress 'create' output generated by yeoman
-    this.log.create = function() {};
-  }
-}
-
-/**
- * Creates the template for a React Native project given the provided
- * parameters:
- *   - projectDir: templates will be copied here.
- *   - argsOrName: project name or full list of custom arguments to pass to the
- *                 generator.
- */
-function init(projectDir, argsOrName) {
-  console.log('Setting up new React Native app in ' + projectDir);
-  var env = yeoman.createEnv(
-    undefined,
-    undefined,
-    new CreateSuppressingTerminalAdapter()
-  );
-
-  env.register(
-    require.resolve(path.join(__dirname, 'generator')),
-    'react:app'
-  );
-
-  // argv is for instance
-  // ['node', 'react-native', 'init', 'AwesomeApp', '--verbose']
-  // args should be ['AwesomeApp', '--verbose']
-  var args = Array.isArray(argsOrName)
-    ? argsOrName
-    : [argsOrName].concat(process.argv.slice(4));
-
-  var generator = env.create('react:app', {args: args});
-  generator.destinationRoot(projectDir);
-  generator.run();
-}
 
 if (require.main === module) {
-  run();
+  cliEntry.run();
 }
 
-module.exports = {
+module.exports = cliEntry;
-  run: run,
-  init: init,
-  commands: exportedCommands
-};

local-cli/cliEntry.js

@@ -0,0 +1,161 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+'use strict';
+
+const bundle = require('./bundle/bundle');
+const childProcess = require('child_process');
+const Config = require('./util/Config');
+const defaultConfig = require('./default.config');
+const dependencies = require('./dependencies/dependencies');
+const generate = require('./generate/generate');
+const library = require('./library/library');
+const path = require('path');
+const Promise = require('promise');
+const runAndroid = require('./runAndroid/runAndroid');
+const runIOS = require('./runIOS/runIOS');
+const server = require('./server/server');
+const TerminalAdapter = require('yeoman-environment/lib/adapter.js');
+const yeoman = require('yeoman-environment');
+const unbundle = require('./bundle/unbundle');
+const upgrade = require('./upgrade/upgrade');
+const version = require('./version/version');
+
+const fs = require('fs');
+const gracefulFs = require('graceful-fs');
+
+// graceful-fs helps on getting an error when we run out of file
+// descriptors. When that happens it will enqueue the operation and retry it.
+gracefulFs.gracefulify(fs);
+
+const documentedCommands = {
+  'start': [server, 'starts the webserver'],
+  'bundle': [bundle, 'builds the javascript bundle for offline use'],
+  'unbundle': [unbundle, 'builds javascript as "unbundle" for offline use'],
+  'new-library': [library, 'generates a native library bridge'],
+  'android': [generateWrapper, 'generates an Android project for your app'],
+  'run-android': [runAndroid, 'builds your app and starts it on a connected Android emulator or device'],
+  'run-ios': [runIOS, 'builds your app and starts it on iOS simulator'],
+  'upgrade': [upgrade, 'upgrade your app\'s template files to the latest version; run this after ' +
+                       'updating the react-native version in your package.json and running npm install']
+};
+
+const exportedCommands = {dependencies: dependencies};
+Object.keys(documentedCommands).forEach(function(command) {
+  exportedCommands[command] = documentedCommands[command][0];
+});
+
+const undocumentedCommands = {
+  '--version': [version, ''],
+  'init': [printInitWarning, ''],
+};
+
+const commands = Object.assign({}, documentedCommands, undocumentedCommands);
+
+/**
+ * Parses the command line and runs a command of the CLI.
+ */
+function run() {
+  const args = process.argv.slice(2);
+  if (args.length === 0) {
+    printUsage();
+  }
+
+  const setupEnvScript = /^win/.test(process.platform)
+    ? 'setup_env.bat'
+    : 'setup_env.sh';
+  childProcess.execFileSync(path.join(__dirname, setupEnvScript));
+
+  const command = commands[args[0]];
+  if (!command) {
+    console.error('Command `%s` unrecognized', args[0]);
+    printUsage();
+    return;
+  }
+
+  command[0](args, Config.get(__dirname, defaultConfig)).done();
+}
+
+function generateWrapper(args, config) {
+  return generate([
+    '--platform', 'android',
+    '--project-path', process.cwd(),
+    '--project-name', JSON.parse(
+      fs.readFileSync('package.json', 'utf8')
+    ).name
+  ], config);
+}
+
+function printUsage() {
+  console.log([
+    'Usage: react-native <command>',
+    '',
+    'Commands:'
+  ].concat(Object.keys(documentedCommands).map(function(name) {
+    return '  - ' + name + ': ' + documentedCommands[name][1];
+  })).join('\n'));
+  process.exit(1);
+}
+
+// The user should never get here because projects are inited by
+// using `react-native-cli` from outside a project directory.
+function printInitWarning() {
+  return Promise.resolve().then(function() {
+    console.log([
+      'Looks like React Native project already exists in the current',
+      'folder. Run this command from a different folder or remove node_modules/react-native'
+    ].join('\n'));
+    process.exit(1);
+  });
+}
+
+class CreateSuppressingTerminalAdapter extends TerminalAdapter {
+  constructor() {
+    super();
+    // suppress 'create' output generated by yeoman
+    this.log.create = function() {};
+  }
+}
+
+/**
+ * Creates the template for a React Native project given the provided
+ * parameters:
+ *   - projectDir: templates will be copied here.
+ *   - argsOrName: project name or full list of custom arguments to pass to the
+ *                 generator.
+ */
+function init(projectDir, argsOrName) {
+  console.log('Setting up new React Native app in ' + projectDir);
+  const env = yeoman.createEnv(
+    undefined,
+    undefined,
+    new CreateSuppressingTerminalAdapter()
+  );
+
+  env.register(
+    require.resolve(path.join(__dirname, 'generator')),
+    'react:app'
+  );
+
+  // argv is for instance
+  // ['node', 'react-native', 'init', 'AwesomeApp', '--verbose']
+  // args should be ['AwesomeApp', '--verbose']
+  const args = Array.isArray(argsOrName)
+    ? argsOrName
+    : [argsOrName].concat(process.argv.slice(4));
+
+  const generator = env.create('react:app', {args: args});
+  generator.destinationRoot(projectDir);
+  generator.run();
+}
+
+module.exports = {
+  run: run,
+  init: init,
+  commands: exportedCommands
+};

local-cli/server/checkNodeVersion.js

@@ -8,17 +8,17 @@
  */
 'use strict';
 
-const chalk = require('chalk');
+var chalk = require('chalk');
-const formatBanner = require('./formatBanner');
+var formatBanner = require('./formatBanner');
-const semver = require('semver');
+var semver = require('semver');
 
 module.exports = function() {
   if (!semver.satisfies(process.version, '>=4')) {
-    const engine = semver.satisfies(process.version, '<1 >=4')
+    var engine = semver.satisfies(process.version, '<1')
       ? 'Node'
       : 'io.js';
 
-    const message = 'You are currently running ' + engine + ' ' +
+    var message = 'You are currently running ' + engine + ' ' +
       process.version + '.\n' +
       '\n' +
       'React Native runs on Node 4.0 or newer. There are several ways to ' +

local-cli/server/server.js

@@ -9,7 +9,6 @@
 'use strict';
 
 const chalk = require('chalk');
-const checkNodeVersion = require('./checkNodeVersion');
 const formatBanner = require('./formatBanner');
 const parseCommandLine = require('../util/parseCommandLine');
 const path = require('path');
@@ -88,8 +87,6 @@ function _server(argv, config, resolve, reject) {
     )
     : config.getAssetRoots();
 
-  checkNodeVersion();
-
   console.log(formatBanner(
     'Running packager on port ' + args.port + '.\n\n' +
     'Keep this packager running while developing on any JS projects. ' +

package.json

@@ -131,7 +131,11 @@
     "art": "^0.10.0",
     "babel-core": "^6.6.4",
     "babel-plugin-external-helpers": "^6.5.0",
+    "babel-plugin-syntax-trailing-function-commas": "^6.5.0",
+    "babel-plugin-transform-flow-strip-types": "^6.6.5",
+    "babel-plugin-transform-object-rest-spread": "^6.6.5",
     "babel-polyfill": "^6.6.1",
+    "babel-preset-es2015-node": "^4.0.2",
     "babel-preset-react-native": "^1.8.0",
     "babel-register": "^6.6.0",
     "babel-types": "^6.6.4",

packager/babelRegisterOnly.js

@@ -12,20 +12,19 @@ Array.prototype.values || require('core-js/fn/array/values');
 Object.entries || require('core-js/fn/object/entries');
 Object.values || require('core-js/fn/object/values');
 
-var fs = require('fs');
-var path = require('path');
-
 var _only = [];
 
-function readBabelRC() {
-  var rcpath = path.join(__dirname, 'react-packager', 'rn-babelrc.json');
-  var source = fs.readFileSync(rcpath).toString();
-  return JSON.parse(source);
-}
-
 module.exports = function(onlyList) {
   _only = _only.concat(onlyList);
-  var config = readBabelRC();
+
-  config.only = _only;
+  require('babel-register')({
-  require('babel-register')(config);
+    presets: ['es2015-node'],
+    plugins: [
+      'transform-flow-strip-types',
+      'syntax-trailing-function-commas',
+      'transform-object-rest-spread',
+    ],
+    only: _only,
+    sourceMaps: 'inline',
+  });
 };

packager/package.json

@@ -1,5 +1,5 @@
 {
-  "version": "0.3.2",
+  "version": "0.4.0",
   "name": "react-native-packager",
   "description": "Build native apps with React!",
   "repository": {