CreatePostCommand.js

export class CreatePostCommand extends Command {

   /**
   * Creates a command for adding new post to the system,
   * @param {Posts} posts - posts in system 
   */
  
  constructor(posts) {
    super();
    this.posts = posts;
  }
  
  /**
   * Creates new post in system
   * @param {Post} post - new post not yet added to system 
   * @param {string} id - id of newly created post
   */
  
  async execute(post) {
    post = await this.posts.add(post);
    return post.id();
  }

}