Warning: root path must be a string Use --force to continue.

/* global module, conf */
var modRewrite = require('connect-modrewrite');
var mountFolder = function(connect, dir) {
    return connect.static(require('path').resolve(dir));
};
module.exports = function(grunt) {

    grunt.initConfig({
        copy: {
            base: {
                files: [
                    {src: "index.html", dest: "BUILD/index.html"},
                    {expand: true, src: "app/**", dest: "BUILD/"},
                    {expand: true, src: "assets/**", dest: "BUILD/"}
                ]
            }
        },

        connect: {
            proxies: [
                {
                    context: "/wwff",
                    host:  "localhost",
                    port: "8080"
                }
            ],

            /**
            * Task defines a server at 9000,
            * watching the BUILD directory
            */
            dev: {
                options: {
                    port: "9000",
                    hostname: '*',
                    base: "BUILD",
                    middleware: function(connect, options) {
                        var proxySnippet = require('grunt-connect-proxy/lib/utils').proxyRequest;

                        return [
                            // include the proxy first
                            proxySnippet,
                            modRewrite([
                                '!\.html|\.js|\.swf|\.json|\.xml|\.css|\.png|\.jpg|\.gif|\.ico|\.aff|\.msi|\.zip|\.dic$ /index.html [L]'
                            ]),
                            // serve static files
                            connect.static(options.base),
                            // make empty directories browsable
                            connect.directory(options.base)
                        ];
                    }
                }
            }
        },

        /*
        * This task watches the application and asset directories and
        * deploys any changes to the dev server
        */
        watch: {
            static: {
                files: [ "app/**/*.js", "app/**/*.html"],
                tasks: ["build"]
            }
        },

        clean: {
            build: ["BUILD/"],
            temp: ["tmp"]
        }
    });

    grunt.loadNpmTasks('grunt-contrib-copy');
    grunt.loadNpmTasks('grunt-contrib-connect');
    grunt.loadNpmTasks('grunt-contrib-watch');
    grunt.loadNpmTasks('grunt-connect-proxy');
    grunt.loadNpmTasks('grunt-contrib-clean');

    /*
    * Main BUILD Task
    */
    grunt.registerTask("build", "Copies app and asset files to the BUILD directory.", function() {
        grunt.task.run("copy:base");
    });

    grunt.registerTask("server", "Stand up a node server for development.", function() {
        grunt.task.run(["build", "configureProxies:dev", "connect:dev", "watch"]);
    });

    grunt.event.on('watch', function(action, filepath, target) {
        grunt.log.writeln(target + ': ' + filepath + ' has ' + action);
    });

};

Verifying property connect.dev exists in config...OK
File: [no files]
Options: protocol="http", port="9000", hostname="*", base="BUILD", directory=null, keepalive=false, debug=false, livereload=false, open=false, useAvailablePort=false, onCreateServer=null, middleware=undefined