bluebird.js then function not firing

Question

New to NodeJS, getting my head around promises. In this simple example below, I don't understand why the then function does not fire. The data variable is successfully set, but doesn't continue after this point.

What am I doing wrong?

var AWS = require('aws-sdk');
var Promise = require('bluebird');

var docClient = new AWS.DynamoDB.DocumentClient();
Promise.promisifyAll(Object.getPrototypeOf(docClient));

var tableQuery = {
    TableName : "Info",
    KeyConditionExpression: "#rt = :rt",
    ExpressionAttributeNames: { "#rt": "Type" },
    ExpressionAttributeValues: { ":rt": "Owner" }
}

docClient.queryAsync(tableQuery, function (err, data) {
    return data;
}).then(function(data) {
    //doesn't get here...
    return data.Items;
}).done(function (item) {
    console.log("Done." + item);
});

Answer 1

.done in bluebird is to terminate a chain, do not attempt to pass anything to it. In fact - it's probably a good idea to not use it at all except in special circumstance.

Promise fulfillment then handlers do not deal with errors - .catch does where you can find the error. methods is to not conflate errors with values - so your functions that take data should take a data parameter in the then handlers rather than (err, data):

const AWS = require('aws-sdk'); // prefer const in node
const Promise = require('bluebird');

const docClient = new AWS.DynamoDB.DocumentClient();
Promise.promisifyAll(Object.getPrototypeOf(docClient));

var tableQuery = {
    TableName : "Info",
    KeyConditionExpression: "#rt = :rt",
    ExpressionAttributeNames: { "#rt": "Type" },
    ExpressionAttributeValues: { ":rt": "Owner" }
}

docClient.queryAsync(tableQuery).then(data => data.Items).then(items => {
    console.log("Done." + items);
});

Your code failed because it confused bluebird - it made it pass an additional parameter after the callback (which you were manually passing). That effectively made the promise pending forever.