A simple custom Grunt task to build a group of targets for a task based on a prefix. This allows for easy grouping, based on namespace.

build.js

/**
 * Build a group of targets based on a prefix
 * 
 * Ex: grunt build:less:debug
 *
 * This would run all less targets that begin with "debug_":
 *   debug_web
 *   debug_sidebar
 *   debug_self_help
 *   debug_self_help_theme
 *   ...
 */
module.exports = function (grunt) {
	grunt.registerTask(
		'build',
		'Build a set of targets for a given task based on a prefix.',
		function (task, prefix) {
			
		// Make sure the prefix ends with a delimiter to prevent accidental matches
		// of larger words. We don't want "dist" to match "distribution_"
		prefix += '_';

		var targets = Object.keys(grunt.config(task));

		var buildTargets = targets.filter(function (target) {
			return target.substring(0, prefix.length) === prefix;
		});

		grunt.task.run(buildTargets.map(function (target) {
			return task + ':' + target;
		}));
	});
};