Gruntfile.js

module.exports = function (grunt) { 
    require('jit-grunt')(grunt);
    grunt.initConfig({
        less: {
            development: {
                options: { 
                    compress: true,
                    yuicompress: true,
                    optimization: 2
                },
                files: {
                    "build/style.css": "src/style.less"
                } 
            }
        },
        browserify: {
            options: {
                // external: ["react", "d3", "lodash"],
                transform: [
                    ['babelify', {
                        stage: 1,
                        optional: ["runtime", "es7.classProperties"],
                        ignore: /bower_components/
                    }],
                    'browserify-shim',
                    // 'reactify', 
                    'debowerify'
                ],
                browserifyOptions: {
                    extensions: ['.jsx']
                }
            },
            dev: {
                options: {
                    debug: true,
                },
                src: 'src/main.jsx',
                dest: 'build/bundle.js'
            },
            production: {
                options: {
                    debug: false
                },
                src: '<%= browserify.dev.src %>',
                dest: 'build/bundle.js'
            } 
        },
        watch: {
            styles: {
                files: ['src/*.less'],
                tasks: ['less'],
                options: {
                    nospawn: true 
                }
            },
            browserify: {
                files: 'src/*.jsx',
                tasks: ['browserify:dev']
            } 
        }
    }); 
    grunt.registerTask('default',
                       ['less', 'browserify:dev', 'watch']);
};