FAST grunt + livereload + browserify + babelify

Gruntfile.js

module.exports = grunt => {

    const LIVERELOAD_PORT = 35729;

    require('load-grunt-tasks')(grunt, {});
    require('time-grunt')(grunt);

    grunt.initConfig({
        pkg: grunt.file.readJSON('package.json'),

        browserify: {
            watch: {
                files: {
                    'build/bundle.js': ['src/js/*.js']
                },
                options: {
                    watch: true,
                    transform: [
                        [
                            'babelify',
                            {
                                presets: [
                                    'es2015'
                                ]
                            }
                        ]
                    ]
                }
            }
        },

        eslint: {
            target: ['src/js/*.js'],
            options: {
                configFile: '.eslintrc',
                cache: true
            }
        },

        connect: {
            server: {
                options: {
                    port: 9090,
                    base: '.',
                    open: true,
                    livereload: LIVERELOAD_PORT,
                    hostname: 'localhost'
                    // keepalive: true
                }
            }
        },

        watch: {
            livereload: {
                files: ['build/**/*'],
                options: {
                    livereload: LIVERELOAD_PORT
                }
            }
        }
    });
    grunt.registerTask('default', [
        // 'eslint',
        'browserify:watch',
        'connect:server',
        'watch'
    ]);
};