flagger.js

function flags(obj) {
    var res = { alias: { h: 'help' } };
    if (obj.length === 0) return res;
    let help = obj.help;
    delete obj.help;
    for (let key in obj) {
        res.alias[key[0]] = key;
    }
    if (help) {
        res.description = help.map((key) => {
            let desc = obj[key];
            return `-${key[0]}, --${key}: ${desc}`;
        });
    } else {
        res.description = Object.keys(obj).map((key) => {
            let desc = obj[key];
            return `-${key[0]}, --${key}: ${desc}`;
        });
    }
    res.description.length === 0
        ? (res.description = '')
        : res.description.length === 1
        ? (res.description = res.description[0])
        : (res.description = res.description.join('\n'));
    return res;
}