Grunt example

Gruntfile.js

module.exports = function (grunt)
{
    var files = {
        vendor: {
            css_src: 'vendor/css/bootstrap.css',
            css_dest: 'compiled/vendor.min.css',
            js_src: ['vendor/js/jquery.js', 'vendor/js/bootstrap.js'],
            js_dest: 'compiled/vendor.min.js'
        },
        app: {
            stylus_src: 'assets/stylus/index.styl',
            stylus_watch_src: 'assets/stylus/**/*.styl',
            stylus_dest: 'compiled/app.min.css',
            js_src: 'assets/js/**/*.js',
            js_dest: 'compiled/app.min.js'
        },
        public: {
            css: 'public/css/app.min.css',
            js: 'public/js/app.min.js'
        }
    };

    grunt.initConfig({
        cssmin: {
            options: {
                keepSpecialComments: 0
            },
            /** Minimize vendors CSS files. */
            vendor: {
                src: files.vendor.css_src,
                dest: files.vendor.css_dest
            }
        },

        stylus: {
            options: {
                compress: true
            },
            /** Compile stylus. */
            app: {
                src: files.app.stylus_src,
                dest: files.app.stylus_dest
            }
        },

        concat: {
            options: {
                separator: ''
            },
            /** Concatenate compiled CSS files and publish into public directory. */
            css: {
                src: [files.vendor.css_dest, files.app.stylus_dest],
                dest: files.public.css
            },
            /** Concatenate uglifyed JS files and publish into public directory */
            js: {
                src: [files.vendor.js_dest, files.app.js_dest],
                dest: files.public.js
            }
        },

        uglify: {
            vendor: {
                src: files.vendor.js_src,
                dest: files.vendor.js_dest
            },
            app: {
                src: files.app.js_src,
                dest: files.app.js_dest
            }
        },

        watch: {
            vendor_css: {
                files: files.vendor.css_src,
                tasks: ['cssmin:vendor', 'concat:css']
            },
            stylus: {
                files: files.app.stylus_watch_src,
                tasks: ['stylus:app', 'concat:css']
            },
            vendor_js: {
                files: files.vendor.js_src,
                tasks: ['uglify:vendor', 'concat:js']
            },
            app_js: {
                files: files.app.js_src,
                tasks: ['uglify:app', 'concat:js']
            },
            to_livereload: {
                options: {
                    livereload: true
                },
                files: [
                    'public/**/*',
                    '*.html'
                ]
            }
        }
    });
    // -- grunt.initConfig(...)

    // Load cool plugins
    grunt.loadNpmTasks('grunt-contrib-concat');
    grunt.loadNpmTasks('grunt-contrib-cssmin');
    grunt.loadNpmTasks('grunt-contrib-stylus');
    grunt.loadNpmTasks('grunt-contrib-uglify');
    grunt.loadNpmTasks('grunt-contrib-watch');

    grunt.registerTask('default', [
        'cssmin:vendor',
        'stylus:app',
        'concat:css',
        'uglify:vendor',
        'uglify:app',
        'concat:js',
        'watch'
    ]);
};