JavaScript Promise with immediate response

immediate.js

var Promise = require('promise');

// Always return a promise for immediate or delayed responses
var doAsync = function(nbr) {
    if (nbr === 1) {
        // use static function to resolve with data immediately
        return Promise.resolve('Success already!');
    }
    else if (nbr === 2) {
        // use static function to reject with an error immediately
        return Promise.reject('Rejected already!');
    }
    else {
        // create an instance of a promise which is resolved later
        var promise = new Promise(function (resolve, reject) {
            setTimeout(function() {
                resolve('Resolved later');
            }, 250);
        });
        return promise;
    }
};

var handleSuccess = function(result) {
    console.log('Success: ' + result);
};

var handleError = function(error) {
    console.log('Error: ' + error);
};

doAsync(1).then(handleSuccess, handleError);
doAsync(2).then(handleSuccess, handleError);
doAsync(3).then(handleSuccess, handleError);