Q.sequential().js

/**
 * Runs an array of promises one after another instead of in parallel
 *
 * @param array
 * @param callback
 * 
 * @returns {*}
 */
function sequential(array, callback) {
    var result = [];
    return Q(array.reduce(function (previousPromise, item) {
        return previousPromise.then(function () {
            return callback(item);
        }).then(function (res) {
            result.push(res);
            return res;
        });
    }, Q([]))).then(function () {
        return result;
    });
}