Javascript Promises returning strange object

Question

(function() {
"use strict";

var storage = chrome.storage.sync;
var localStorage = null;

function getOutsideScope(property) {
    if (localStorage.hasOwnProperty(property)) {
        return localStorage[property];
    }
}

function fulfill(data) {
    return data;
}

function rejected(err) {
    log(err);
}

window.app.storage = {
    get: function(storageKey, storageProp) {
        var promise = new Promise(function(fullfill, reject) {
            chrome.storage.sync.get(storageKey, function(data) {
                if (data.hasOwnProperty(storageKey)) {
                    fullfill(data[storageKey]);
                } else {
                    reject(new Error(storageKey + " does not exist in the storage values."));
                }
            });
        });
        return promise.then(fulfill, rejected);
    },
    set: function(storageKey, storageItem) {

    },
    onChanged: function(fn) {

    }
};

})();

So the above is my IIFE wrapper for chrome storage, and well the return is being a pain in the bleep. So I decided to give Promises a try, this is my first time so don't be too rough on me on this. Basically this is what I want to do

 var property = app.storage.get("properties");
 //property should equal "value"
 //except it returns undefined 

So adding the promises it does get the value except it returns this

Promise {[[PromiseStatus]]: "resolved", [[PromiseValue]]: "value"}

Am I doing something wrong with Promises I've tried reading HTML5Rocks, the MDN, and video tutorials except it doesn't really mention much of how to return a value. This does NOT work

get:function(storageKey,storageProp) {
    chrome.storage.sync.get(storageKey,function(data) {
        //for simplicity and no error checking -_-
        return data[storageKey];
    });
}

Answer 1

The function returns exactly what it is supposed to return: A promise. To get the value once the promise is fulfilled, you add a callback via .then:

app.storage.get("properties").then(function(property) {
    // property will be "value"
});

From MDN:

A Promise represents a proxy for a value not necessarily known when the promise is created. It allows you to associate handlers to an asynchronous action's eventual success value or failure reason. This lets asynchronous methods return values like synchronous methods: instead of the final value, the asynchronous method returns a promise of having a value at some point in the future.

[...]

A pending promise can become either fulfilled with a value, or rejected with a reason (error). When either of these happens, the associated handlers queued up by a promise's then method are called.