old_contents: 'use strict';
  var path = require('path');
  var gutil = require('gulp-util');
  var through = require('through2');
  var react = require('react-tools');
  
  module.exports = function (options) {
  	return through.obj(function (file, enc, cb) {
  		if (file.isNull()) {
  			this.push(file);
  			return cb();
  		}
  
  		if (file.isStream()) {
  			this.emit('error', new gutil.PluginError('gulp-react', 'Streaming not supported'));
  			return cb();
  		}
  
  		var str = file.contents.toString();
  		var filePath = file.path;
  		// http://stackoverflow.com/a/15123777
  		var JS_COMMENTS_REGEX = /(?:\/\*(?:[\s\S]*?)\*\/)|(?:\/\/(?:.*)$)/gm;
  		var commentMatches = str.match(JS_COMMENTS_REGEX);
  		var hasJsxComment = commentMatches && (commentMatches[0].indexOf('/**') !== -1 && commentMatches[0].indexOf('@jsx') !== -1);
  
  		if (path.extname(filePath) === '.jsx' && !hasJsxComment) {
  			str = '/** @jsx React.DOM */\n' + str;
  		}
  
  		try {
  			file.contents = new Buffer(react.transform(str, options));
  			file.path = gutil.replaceExtension(filePath, '.js');
  			this.push(file);
  		} catch (err) {
  			err.fileName = err.fileName || filePath;
  			this.emit('error', new gutil.PluginError('gulp-react', err, {
  				fileName: filePath
  			}));
  		}
  
  		cb();
  	});
  };
  
new_contents: 'use strict';
  var path = require('path');
  var gutil = require('gulp-util');
  var through = require('through2');
  var react = require('react-tools');
  
  module.exports = function (options) {
  	return through.obj(function (file, enc, cb) {
  		if (file.isNull()) {
  			this.push(file);
  			return cb();
  		}
  
  		if (file.isStream()) {
  			this.emit('error', new gutil.PluginError('gulp-react', 'Streaming not supported'));
  			return cb();
  		}
  
  		var str = file.contents.toString();
  		var filePath = file.path;
  		// http://stackoverflow.com/a/15123777
  		var JS_COMMENTS_REGEX = /(?:\/\*(?:[\s\S]*?)\*\/)|(?:\/\/(?:.*)$)/gm;
  		var commentMatches = str.match(JS_COMMENTS_REGEX);
  		var hasJsxComment = commentMatches && (commentMatches[0].indexOf('/**') !== -1 && commentMatches[0].indexOf('@jsx') !== -1);
  
  		if (path.extname(filePath) === '.jsx' && !hasJsxComment) {
  			str = '/** @jsx React.DOM */\n' + str;
  		}
  
  		try {
  			file.contents = new Buffer(react.transform(str, options));
  			file.path = gutil.replaceExtension(filePath, '.js');
  			this.push(file);
  		} catch (err) {
  			this.emit('error', new gutil.PluginError('gulp-react', err, {
  				fileName: filePath
  			}));
  		}
  
  		cb();
  	});
  };
  
subject: remove moot line