JavaScript plugin architecture for multiple methods with the same parameters

I am writing a JavaScript plugin for fun. The plugin allows the user to pass options to initialize the plugin and perform actions. It is a simple alert/confirm plugin just for fun.

I am hoping to receive some architecture help with a little bit of code I am working on. It works as is, but I feel like there is a better or more efficient way of doing what I am doing below. ​ The ideal syntax that the user would use (when utilizing the plugin) would go something like this:

new Bulletin('success', 'a title', 'a description', { duration: 2000 }).notify();

​ Or:

new Bulletin('warning', 'a title', 'a description', { duration: 2000 }).ask();

​ The plugin has 2 parts:

1. Get a few base parameters (color, title, description) as well as some optional parameters (duration, size, class, etc.)
2. Pass what type of notification is being initialized: notify (alert) or ask (confirm)

The current plugin implementation is this:

import Notify from './notify';
import Ask from './ask';

var default = {};

var Bulletin = function(color, message, title, options) {
  this.settings = Object.assign(defaults, options);
  this.color = color;
  this.message = message;
  this.title = title;

  return this;
};

Bulletin.prototype.notify = function() {
    Notify(this.color, this.message, this.title, this.settings); 
};

Bulletin.prototype.ask = function() {
    Ask(this.color, this.message, this.title, this.settings); 
};

Question/Problem

As you can see, the code works. I am wondering if there is a better, more efficient way of achieving this though.

Put simple, is there a way to do something like this (maybe ES6 has something?):

• Use the constructor's properties without just referencing them with this
• Depending on which method is called from the constructor (i.e. .notify()), perform different logic
  • The user of the plugin will be able to call either a notify or ask method which will either show an alert or confirm (ask for user input) box - think native JavaScript alert() and confirm(). Therefore, the code that performs those actions would be different. One would simply show a div and the other would show a div but with buttons for the user to select yes or no. But at the end of the day, they would share a lot of the same options. So what I am trying to avoid is duplicating code that is shared between the notify and ask methods, if possible.

The code for these features (notify & ask) is not written yet. I maybe should've waited before asking for a review, but really what I am after, and what will possible drive the rest of the development, is how to create a public JavaScript API that shares parts of "setup" code (gathering params, merging objects, etc.) but then has separate logic depending on which method is called.

Another option is to make the usage something like Bulletin.notify(params), but then I would want to be able to perform things like extend on the options, without writing that code twice for the 2 different types (notify and ask).

My inspiration (if you haven't guessed by now) is notie.js if that gives you an idea of where I'm headed. That may provide a clearer picture of what this code will do eventually.