diff --git a/private-cli/src/bundle/buildBundle.js b/private-cli/src/bundle/buildBundle.js
new file mode 100644
index 000000000..f57e2abc3
--- /dev/null
+++ b/private-cli/src/bundle/buildBundle.js
@@ -0,0 +1,59 @@
+/**
+ * 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 log = require('../util/log').out('bundle');
+const processBundle = require('./processBundle');
+const Promise = require('promise');
+const ReactPackager = require('../../../packager/react-packager');
+const saveBundleAndMap = require('./saveBundleAndMap');
+
+function buildBundle(args, config) {
+  return new Promise((resolve, reject) => {
+
+    // This is used by a bazillion of npm modules we don't control so we don't
+    // have other choice than defining it as an env variable here.
+    process.env.NODE_ENV = args.dev ? 'development' : 'production';
+
+    const options = {
+      projectRoots: config.getProjectRoots(),
+      assetRoots: config.getAssetRoots(),
+      blacklistRE: config.getBlacklistRE(),
+      transformModulePath: args.transformer,
+      verbose: args.verbose,
+    };
+
+    const requestOpts = {
+      entryFile: args['entry-file'],
+      dev: args.dev,
+      minify: !args.dev,
+      platform: args.platform,
+    };
+
+    resolve(ReactPackager.createClientFor(options).then(client => {
+      log('Created ReactPackager');
+      return client.buildBundle(requestOpts)
+        .then(outputBundle => {
+          log('Closing client');
+          client.close();
+          return outputBundle;
+        })
+        .then(outputBundle => processBundle(outputBundle, !args.dev))
+        .then(outputBundle => saveBundleAndMap(
+          outputBundle,
+          args.platform,
+          args['bundle-output'],
+          args['sourcemap-output'],
+          args['assets-dest']
+        ));
+    }));
+  });
+}
+
+module.exports = buildBundle;
diff --git a/private-cli/src/bundle/bundle.js b/private-cli/src/bundle/bundle.js
index 7a039cf4e..b4b8dafd8 100644
--- a/private-cli/src/bundle/bundle.js
+++ b/private-cli/src/bundle/bundle.js
@@ -8,99 +8,15 @@
  */
 'use strict';
 
-const log = require('../util/log').out('bundle');
+const buildBundle = require('./buildBundle');
+const bundleCommandLineArgs = require('./bundleCommandLineArgs');
 const parseCommandLine = require('../../../packager/parseCommandLine');
-const processBundle = require('./processBundle');
-const Promise = require('promise');
-const ReactPackager = require('../../../packager/react-packager');
-const saveBundleAndMap = require('./saveBundleAndMap');
 
 /**
  * Builds the bundle starting to look for dependencies at the given entry path.
  */
 function bundle(argv, config) {
-  return new Promise((resolve, reject) => {
-    _bundle(argv, config, resolve, reject);
-  });
-}
-
-function _bundle(argv, config, resolve, reject) {
-  const args = parseCommandLine([
-    {
-      command: 'entry-file',
-      description: 'Path to the root JS file, either absolute or relative to JS root',
-      type: 'string',
-      required: true,
-    }, {
-      command: 'platform',
-      description: 'Either "ios" or "android"',
-      type: 'string',
-      required: true,
-    }, {
-      command: 'transformer',
-      description: 'Specify a custom transformer to be used (absolute path)',
-      type: 'string',
-      default: require.resolve('../../../packager/transformer'),
-    }, {
-      command: 'dev',
-      description: 'If false, warnings are disabled and the bundle is minified',
-      default: true,
-    }, {
-      command: 'bundle-output',
-      description: 'File name where to store the resulting bundle, ex. /tmp/groups.bundle',
-      type: 'string',
-      required: true,
-    }, {
-      command: 'sourcemap-output',
-      description: 'File name where to store the sourcemap file for resulting bundle, ex. /tmp/groups.map',
-      type: 'string',
-    }, {
-      command: 'assets-dest',
-      description: 'Directory name where to store assets referenced in the bundle',
-      type: 'string',
-    }, {
-      command: 'verbose',
-      description: 'Enables logging',
-      default: false,
-    },
-  ], argv);
-
-  // This is used by a bazillion of npm modules we don't control so we don't
-  // have other choice than defining it as an env variable here.
-  process.env.NODE_ENV = args.dev ? 'development' : 'production';
-
-  const options = {
-    projectRoots: config.getProjectRoots(),
-    assetRoots: config.getAssetRoots(),
-    blacklistRE: config.getBlacklistRE(args.platform),
-    transformModulePath: args.transformer,
-    verbose: args.verbose,
-  };
-
-  const requestOpts = {
-    entryFile: args['entry-file'],
-    dev: args.dev,
-    minify: !args.dev,
-    platform: args.platform,
-  };
-
-  resolve(ReactPackager.createClientFor(options).then(client => {
-    log('Created ReactPackager');
-    return client.buildBundle(requestOpts)
-      .then(outputBundle => {
-        log('Closing client');
-        client.close();
-        return outputBundle;
-      })
-      .then(outputBundle => processBundle(outputBundle, !args.dev))
-      .then(outputBundle => saveBundleAndMap(
-        outputBundle,
-        args.platform,
-        args['bundle-output'],
-        args['sourcemap-output'],
-        args['assets-dest']
-      ));
-  }));
+  return buildBundle(parseCommandLine(bundleCommandLineArgs, argv), config);
 }
 
 module.exports = bundle;
diff --git a/private-cli/src/bundle/bundleCommandLineArgs.js b/private-cli/src/bundle/bundleCommandLineArgs.js
new file mode 100644
index 000000000..2eae48ef5
--- /dev/null
+++ b/private-cli/src/bundle/bundleCommandLineArgs.js
@@ -0,0 +1,49 @@
+/**
+ * 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';
+
+module.exports = [
+  {
+    command: 'entry-file',
+    description: 'Path to the root JS file, either absolute or relative to JS root',
+    type: 'string',
+    required: true,
+  }, {
+    command: 'platform',
+    description: 'Either "ios" or "android"',
+    type: 'string',
+    required: true,
+  }, {
+    command: 'transformer',
+    description: 'Specify a custom transformer to be used (absolute path)',
+    type: 'string',
+    default: require.resolve('../../../packager/transformer'),
+  }, {
+    command: 'dev',
+    description: 'If false, warnings are disabled and the bundle is minified',
+    default: true,
+  }, {
+    command: 'bundle-output',
+    description: 'File name where to store the resulting bundle, ex. /tmp/groups.bundle',
+    type: 'string',
+    required: true,
+  }, {
+    command: 'sourcemap-output',
+    description: 'File name where to store the sourcemap file for resulting bundle, ex. /tmp/groups.map',
+    type: 'string',
+  }, {
+    command: 'assets-dest',
+    description: 'Directory name where to store assets referenced in the bundle',
+    type: 'string',
+  }, {
+    command: 'verbose',
+    description: 'Enables logging',
+    default: false,
+  }
+];