module.exports = function (opts) { opts = opts || {}; var configName = opts.configName; var extensions = opts.extensions; if (!configName) { throw new Error('Please specify a configName.'); } if (configName instanceof RegExp) { return [configName]; } if (!Array.isArray(extensions)) { throw new Error('Please provide an array of valid extensions.'); } return extensions.map(function (ext) { return configName + ext; }); };