Add image title for comment (#19586)

* Add image title for comment

* Break out boolean logic

app/models/comment.rb

@@ -104,6 +104,10 @@ class Comment < ApplicationRecord
     I18n.t("models.comment.hidden")
   end
 
+  def self.title_image_only
+    I18n.t("models.comment.image_only")
+  end
+
   def self.build_comment(params, &blk)
     includes(user: :profile).new(params, &blk)
   end
@@ -160,6 +164,8 @@ class Comment < ApplicationRecord
     return self.class.title_hidden if hidden_by_commentable_user
 
     text = ActionController::Base.helpers.strip_tags(processed_html).strip
+    return self.class.title_image_only if only_contains_image?(text)
+
     truncated_text = ActionController::Base.helpers.truncate(text, length: length).gsub("&#39;", "'").gsub("&amp;", "&")
     Nokogiri::HTML.fragment(truncated_text).text # unescapes all HTML entities
   end
@@ -389,4 +395,9 @@ class Comment < ApplicationRecord
   def parent_exists?
     parent_id && Comment.exists?(id: parent_id)
   end
+
+  def only_contains_image?(stripped_text)
+    # If stripped text is blank and processed html has <img> tags, then it's an image-only comment
+    stripped_text.blank? && processed_html.include?("<img")
+  end
 end

config/locales/models/en.yml

@@ -47,6 +47,7 @@ en:
       deleted: '[deleted]'
       has_been_deleted: '%{type} has been deleted.'
       hidden: '[hidden by post author]'
+      image_only: '[image]'
       is_not_valid: is not valid.
       locked: the discussion is locked on this Post
       published_article: is not a published article

config/locales/models/fr.yml

@@ -46,6 +46,7 @@ fr:
       deleted: '[supprimé]'
       has_been_deleted: '%{type} a été supprimé'
       hidden: "[caché par l'auteur du message]"
+      image_only: '[image]'
       is_not_valid: n'est pas valide.
       locked: la discussion est verrouillée sur ce message
       published_article: n'est pas un article publié

spec/models/comment_spec.rb

@@ -327,6 +327,12 @@ RSpec.describe Comment do
       expect(comment.title).to eq("[deleted]")
     end
 
+    it "is converted to image text if the comment is image" do
+      comment.body_markdown = "![image](https://myimage.com/image.png)"
+      comment.validate!
+      expect(comment.title).to eq("[image]")
+    end
+
     it "does not contain the wrong encoding" do
       comment.body_markdown = "It's the best post ever. It's so great."