#ES6/ES2015 Modules Starter Project

Quick Start

1. Install the global packages.

   npm install gulp -g

2. Install the local packages for this demo.

   npm install

3. Run Gulp:

   gulp

4. Run the server, launch the browser, and transpile the ES6 to ES5 using Babel

   npm start

Details

The source code is located in the js folder and written in ES6/ES2015. We use gulp to transpile to ES5 using Babel. The gulp command runs the default Gulp task which transpiles the code and puts it in the dist folder and then watches for more changes. If you change the source, it will transpile again.

When you launch index.html (via npm start), SystemJS kicks in and looks for config.js for its settings. We tell SystemJS that the base URL for the code is in /dist. This is important so all import statements that were written assuming relative pathing in the src folder will still work. Finally, we tell SystemJS that import statements by default should assume they end with .js. This is accomplished by setting defaultExtension to js. See the code below for an example.

System.config({
    map: {
      main: 'dist' //Map "main" to the "dist" folder
    },
    packages: {
      //Define settings for loading files in "dist"
      dist: {
        main: 'main.js',
        format: 'system',
        defaultExtension: 'js'
      }
    }
});

We can now import the main starting module (main.js) like this:

System.import('main');

Now SystemJS gets /dist/main.js which in turn imports car and truck. Each of those import auto and extend it. SystemJS knows that the base URL is /dist and to assume an extension of .js, so it really gets /dist/car.js and /dist/truck.js which in turn get /dist/auto.js.