fs = require('fs')

const needToPrint = ['name','description','version'];
const needToCopy  = needToPrint.concat('dependencies');
const newJson     = {};

fs.readFile('package.json', 'utf8', (err,data) => {

    if (err) {
        return console.log(err);
    }

    let json = JSON.parse(data);

    for(let key in json){
        if (needToPrint.indexOf(key) !== -1) {
            console.log(key, ':' , json[key]);
        }

        if (needToCopy.indexOf(key) !== -1) {
            newJson[key] = json[key];
        }
    }

    fs.writeFile('data.json', JSON.stringify(newJson), err => {
        if(err) {
            return console.log(err);
        }

        console.log("The file was saved as data.json");
    });
});