ivals.promises.js

    let ivals = [/* lots of ivals here */];
    let c = new Ftp();

    function putItem(ftp, item) {
        return new Promise((resolve, reject) =>
            ftp.put(item, item, (err) => err ? reject(err) : resolve()));
    }

    ivals.reduce((promise, ival) =>
        promise.then(() => {
            console.log(`Transferring [${ival}]`);
            return putItem(c, ival)
                .catch(console.log); // Log errors!
        }), Promise.resolve()); // Start with an empty promise.