Remove htmlentities gem (#15958)

Gemfile

@@ -45,7 +45,6 @@ gem "hairtrigger", "~> 0.2.24" # HairTrigger lets you create and manage database
 gem "honeybadger", "~> 4.9" # Used for tracking application errors
 gem "honeycomb-beeline", "~> 2.8.0" # Monitoring and Observability gem
 gem "html_truncator", "~> 0.4" # Truncate an HTML string properly
-gem "htmlentities", "~> 4.3", ">= 4.3.4" # A module for encoding and decoding (X)HTML entities
 gem "httparty", "~> 0.20" # Makes http fun! Also, makes consuming restful web services dead easy
 gem "httpclient", "~> 2.8.3" # Gives something like the functionality of libwww-perl (LWP) in Ruby
 gem "i18n-js", "~> 3.9.0" # Helps with internationalization in Rails.

Gemfile.lock

@@ -360,7 +360,6 @@ GEM
     html_tokenizer (0.0.7)
     html_truncator (0.4.2)
       nokogiri (~> 1.5)
-    htmlentities (4.3.4)
     http-2 (0.11.0)
     http (4.4.1)
       addressable (~> 2.3)
@@ -942,7 +941,6 @@ DEPENDENCIES
   honeybadger (~> 4.9)
   honeycomb-beeline (~> 2.8.0)
   html_truncator (~> 0.4)
-  htmlentities (~> 4.3, >= 4.3.4)
   httparty (~> 0.20)
   httpclient (~> 2.8.3)
   hypershield (~> 0.2.2)

app/models/comment.rb

@@ -57,7 +57,6 @@ class Comment < ApplicationRecord
   validates :positive_reactions_count, presence: true
   validates :public_reactions_count, presence: true
   validates :reactions_count, presence: true
-  validates :user_id, presence: true
   validates :commentable, on: :create, presence: {
     message: lambda do |object, _data|
       "#{object.commentable_type.presence || 'item'} has been deleted."
@@ -140,7 +139,7 @@ class Comment < ApplicationRecord
 
     text = ActionController::Base.helpers.strip_tags(processed_html).strip
     truncated_text = ActionController::Base.helpers.truncate(text, length: length).gsub("&#39;", "'").gsub("&amp;", "&")
-    HTMLEntities.new.decode(truncated_text)
+    Nokogiri::HTML.fragment(truncated_text).text # unescapes all HTML entities
   end
 
   def video

spec/models/comment_spec.rb

@@ -22,7 +22,6 @@ RSpec.describe Comment, type: :model do
       it { is_expected.to validate_presence_of(:positive_reactions_count) }
       it { is_expected.to validate_presence_of(:public_reactions_count) }
       it { is_expected.to validate_presence_of(:reactions_count) }
-      it { is_expected.to validate_presence_of(:user_id) }
     end
 
     it do
@@ -329,6 +328,14 @@ RSpec.describe Comment, type: :model do
       comment.validate!
       expect(comment.title).not_to include("'")
     end
+
+    # NOTE: example string taken from https://github.com/threedaymonk/htmlentities
+    # as this is the gem we're removing.
+    it "correctly decodes HTML entities" do
+      comment.body_markdown = "élan"
+      comment.validate!
+      expect(comment.title).to eq("élan")
+    end
   end
 
   describe "#custom_css" do