promise_es6.js

function calculateFibonacci(number) {
    if (number == 0 || number == 1)
        return number;
    return (calculateFibonacci(number - 1) + calculateFibonacci(number - 2));
}

function doStuff(serie) {
    return new Promise((resolve, reject) => {
        if (typeof serie === 'number') {
            var results = [];
            for (var i = 0; i > serie - 1; i++) {
                var result = calculateFibonacci(i);
                console.log(result);
                results.push(result);
            }
            console.log("for finished");
            resolve(results.join(", "));
        } else {
            reject(new Error('Argument serie must be a number'));
        }
    })
}

doStuff(10)
    .then(result => console.log(`Result: ${result}`))
    .catch(error => console.log(`Something bad happened: ${error}`));