text: const Rule = require("html-validate").Rule;
  
  class HtmlTitle extends Rule {
    documentation(context) {
      return {
        description: "Title of the page must be defined"
      };
    }
  
    setup() {
      this.on("dom:ready", event => {
        const title = event.document.querySelector('html head title');
        if (title === null) {
          this.report(event.document.querySelector('html'), "Missing <title> tag in the <head>");
        }
        else if (!title.textContent || title.textContent.trim().length === 0) {
          this.report(title, "No title specified");
        }
        else if (title.textContent[0] === '-') {
          this.report(title, "Title starts with the dash `-`, add the `title` front matter to the Hugo content");
        }
        else if (title.textContent.startsWith('Untitled')) {
          this.report(title, "Title starts with the `Untitled` make sure that the Asciidoc file starts with level 1 heading");
        }
      });
    }
  }
  
  module.exports = {
    rules: {
      "hop/title": HtmlTitle
    }
  };
  