Webpack 2 how to polyfill a Promise asynchronously?

Question

webpack

Let's say:
webpack.config.js

, new webpack.ProvidePlugin({
    Promise: './bluebird-lazy.js'
  })

bluebird-lazy.js

exports default (function(w){
  if('Promise' in w){
    return w.Promise;
  }else{
    //return 
    import(bluebird).then(Promise => window.Promise); // вот тут и встает проблема асинхронности

  }
})(window);

I want to implement polyfill loading on demand!

Answer 1

Write a loadPolyfills function that accepts a callback (because you can't be sure at the time of calling it that the promises are implemented), and move all the entry point code into this callback. For purity, you can move this action into a self-written loader or plugin, or maybe there are already similar ones. Technically, this is the only correct way.
In your case, the function might look like this:

exports default function loadPolyfills(callback) {
  if (!window.Promise) {
    require.ensure([], function () {
      window.Promise = require('bluebird');

      callback();
    });
  } else {
    callback();
  }
};

If more polyfills are required, the logic will be more complicated.

Answer 2

RewriteRule ^blog/articles/([a-z0-9\-/]+) http://site.ru/blog/article.php\?id=$1 [L]