gruntfile.js

module.exports = function(grunt) {
    require('load-grunt-tasks')(grunt);

    grunt.initConfig({
        clean: {
            js: ['static/build/js'],
            css: ['static/css/style.css', 'static/css/vendor/style-autoprefixer.css', 'static/build/css']
        },

        stylus: {
            compile: {
                options: {
                    paths: ['static/styl/'],
                    compress: false
                },
                files: {
                    'static/css/style.css': 'static/styl/style.styl'
                }
            }
        },

        autoprefixer: {
            dist: {
                files: {
                    'static/css/vendor/style-autoprefixer.css': 'static/css/style.css'
                }
            },
            options: {
                browsers: ['last 2 versions', 'ie 8', 'ie 9']
            }
        },

        concat: {
            js: {
               src: [
                   'static/js/lib/*.js',
                   'static/js/main.js'
               ],
               dest: 'static/build/js/production.js'

             },
             css: {
               src: 'static/css/vendor/*.css',
               dest: 'static/build/css/production.css'
             }
        },

        uglify: {
            my_target: {
                 options: {
                   sourceMap: true,
                   sourceMapName: 'static/build/js/production.map'
                 },
                 files: {
                   'static/build/js/production.min.js': ['static/build/js/production.js']
                 }
               }
        },

        cssmin: {
            css: {
                 src: 'static/build/css/production.css',
                 dest: 'static/build/css/production.min.css'
             }
        },

        express: {
            options: {
                livereload: true,
                nospawn: true
            },
            web: {
                options: {
                    script: 'server.js',
                }
            },
        },

        watch: {
            web: {
                files: ['*.js'],
                tasks: [
                    'express:web'
                ],
                options: {
                    nospawn: true,
                    atBegin: true
                }
            },
            js: {
                files: ['static/js/*.js'],
                tasks: ['clean:js','concat:js', 'uglify'],
                options: {
                    nospawn: true
                }
            },
            css: {
                files: ['static/styl/*.styl', 'static/css/vendor/*.css'],
                tasks: ['clean:css', 'stylus', 'autoprefixer', 'concat:css', 'cssmin'],
                options: {
                    nospawn: true
                }
            },
            frontend: {
                options: {
                    livereload: true
                },
                files: [
                    'static/build/css/*.css',
                    'static/build/js/*.js',
                    'static/img/**/*',
                    'static/fonts/**/*',
                    'static/bios/**/*',
                    'views/**/*',
                ]
            }
        },

        parallel: {
            web: {
                options: {
                    stream: true
                },
                tasks: [
                    {
                        grunt: true,
                        args: ['watch:web']
                    },
                    {
                        grunt: true,
                        args: ['watch:js']
                    },
                    {
                        grunt: true,
                        args: ['watch:css']
                    },
                    {
                        grunt: true,
                        args: ['watch:frontend']
                    }
                ]
            },
        }
    });

    grunt.registerTask('web', 'launch webserver and watch tasks', ['parallel:web']);
};