JavaScriptCore.swift

import JavaScriptCore
import Foundation

let context = JSContext()!

import JavaScriptCore

@objc protocol MovieJSExports: JSExport {
    var title: String { get set }
    var price: String { get set }
    var imageURL: String { get set }

    static func createWith(title: String, price: String, imageURL: String) -> Movie
}

final class Movie: NSObject, MovieJSExports {
    dynamic var title: String
    dynamic var price: String
    dynamic var imageURL: String

    init(title: String, price: String, imageURL: String) {
        self.title = title
        self.price = price
        self.imageURL = imageURL
    }

    class func createWith(title: String, price: String, imageURL: String) -> Movie {
        return Movie(title: title, price: price, imageURL: imageURL)
    }
}

context.setObject(Movie.self, forKeyedSubscript: "Movie" as NSString)
context.exceptionHandler =  { context, exception in
    print(exception!.toString()!)
}

let result = context.evaluateScript(#"""
class MovieService {
  constructor() {
    this._url = "https://itunes.apple.com/us/rss/topmovies/limit=50/json";
  }

  get url() {
    return this._url;
  }

  set url(url) {
    this._url = url
  }

  fetchMovies() {
    return new Promise(function(resolve, reject) {
        var request = new XMLHttpRequest();
        request.open('GET', url, true);
        request.responseType = "json";
        request.onload = function() {

          if (request.status >= 400 || request.status <= 599) {
            reject(Error(request.status));
          }

          var movies = JSON.parse(request.response).map((attributes) => {
            // Create a new Movie object
            return {
              "title": attributes['im:name']['label'],
              "price": Number(attributes['im:price']['attributes']['amount']).toFixed(2),
              "imageUrl": attributes['im:image'].reverse()[0]['label']
            };
          });

          resolve(movies);
        };

        request.send();
      });
  }
}
"""#)

context.evaluateScript("var service = new MovieService();")
context.evaluateScript(#"""
service.fetchMovies().then(function(value) {
  callback(value);
});

"""#
)