module Normalizers
  class TelegaBasicNormalizer < Normalizers::RssNormalizer
    protected

    def text
      Service::Html.post_excerpt(
        content,
        link: sanitized_link,
        separator: separator
      )
    end

    def sanitized_link
      entity.link.to_s.gsub(%r{^//}, 'https://')
    end

    def attachments
      image_url ? [image_url] : []
    end

    private

    def content
      (paragraphs[0..-1] || []).join("\n\n")
    end

    def paragraphs
      Service::Html.paragraphs(entity.description)
    end

    def image_url
      html = Nokogiri::HTML(entity.description)
      html.css('img').first.attributes['src'].value
    rescue StandardError
      nil
    end
  end
end

module Normalizers
  class TelegaBasicNormalizer < Normalizers::RssNormalizer
    protected

    def text
      Service::Html.post_excerpt(
        content,
        link: sanitized_link,
        separator: separator
      )
    end

    def sanitized_link
      entity.link.to_s.gsub(%r{^//}, 'https://')
    end

    private

    def content
      (paragraphs[0..-1] || []).join("\n\n")
    end

    def paragraphs
      Service::Html.paragraphs(entity.description)
    end
  end
end

--- 
+++ 
@@ -14,6 +14,10 @@
       entity.link.to_s.gsub(%r{^//}, 'https://')
     end
 
+    def attachments
+      image_url ? [image_url] : []
+    end
+
     private
 
     def content
@@ -23,5 +27,12 @@
     def paragraphs
       Service::Html.paragraphs(entity.description)
     end
+
+    def image_url
+      html = Nokogiri::HTML(entity.description)
+      html.css('img').first.attributes['src'].value
+    rescue StandardError
+      nil
+    end
   end
 end
Support images for the Telega normalizer
