grunt uglify can't find my files in parent directory

Question

Unlike all of the other node projects i've written, this one needs the node server's folder to not be root. Here's the current folder hierarchy:

- Root/
  - build/
  - css/
  - im/
  - js/
  - nodeserver/   <-- gruntfile and package are here

GruntFile.js, package.json, and server.js are all located in nodeserver/

Here is my GruntFile:

module.exports = function(grunt) {

    // Project configuration.
    grunt.initConfig({
        pkg: grunt.file.readJSON('package.json'),
        uglify: {
            files: {
                '../build/all.min.js':['../js/config.js']
            },
            options: {
                banner: '/*! <%= pkg.name %> <%= grunt.template.today("yyyy-mm-dd") %> */\n',
                report: true
            }
        }
    });

    // Load the plugin that provides the "uglify" task.
    grunt.loadNpmTasks('grunt-contrib-uglify');

    // Default task(s).
    grunt.registerTask('default', ['uglify']);

};

When I run grunt, it can't find the file that I'm specifying. This is the response:

Running "uglify:files" (uglify) task
------------------------------------
Verifying property uglify.files exists in config...OK
File: [no files]
Options: banner="/*! demo-webservice 2014-03-28 */\n", footer="", compress={"warnings":false}, mangle={}, beautify=false, report

Why can't it see my js file?

Answer 1

Wrapping files: {} in my_target: {} solved my problem.

grunt.initConfig({
    pkg: grunt.file.readJSON('package.json'),
    uglify: {
        my_target: {
            files: {
                '../build/all.min.js':['../js/config.js']
            }
        },
        options: {
            banner: '/*! <%= pkg.name %> <%= grunt.template.today("yyyy-mm-dd") %> */\n',
            report: true
        }
    }
});

^--- the new version of that initConfig.

It should also be noted that my_target could be anything, and is used by default since it is the only uglify profile supplied. If i had supplied more than one profile, i.e. "test: {}, prod: {}, etc: {}", then I would refer to them after the task in the following way: uglify:test, uglify:prod, uglify:etc