yubaba.js

const readline = require('readline');

class Yubaba{
  static keiyakusyo(){
    return new Promise((resolve, reject) => {
        const rl = readline.createInterface({input: process.stdin, output: process.stdout});

        rl.question('契約書だよ。そこに名前を書きな。\n', (name) => {
            console.log(`フン。${name}というのかい。贅沢な名だねぇ。`);

            var name_arr = Array.from(name);
            var new_name_index = Math.round(Math.random()*(name_arr.length -1));

            var new_name = name_arr[new_name_index];

            console.log(`今からお前の名前は${new_name}だ。いいかい、${new_name}だよ。分かったら返事をするんだ、${new_name}!!`);

            rl.close();
            resolve(new_name);
        });
    })
  }
}

async function main(){
  await Yubaba.keiyakusyo();
}

main();