Use of promises in loop (node)

I'm working on a NodeJS backend service, and use promises to load any data. Now, I want to make a combination (array) of items coming from different sources. I have the following solution, but I don't think this is the right way to get around something like this.

var results = [];
loop(items, index, data, results).then(function() {
    console.log(results);
});

function loop(items, index, data, results) {
    return utils.getPromise(function(resolve, reject) {
        if (index === items.length) {
            // Stop
            resolve();
        } else {
            doAction(items[index], data).then(function(result) {
                if (result) {
                    mergeResults(results, result)
                } else {
                    loop(items, index + 1, data, results).then(resolve, reject);
                }
            }, reject);
        }
    });
}

function doAction(item, data) {
    return utils.getPromise(function(resolve, reject) {
        item.doIt(data).then(resolve, reject);
    });
}

I think the right way would be to return a promise immediately, and add results on the fly, but I don't know exactly how to do this. Any suggestions?