From a62d9a9a78cb1f3307470b6c4f4398c547ed5816 Mon Sep 17 00:00:00 2001
From: Claire <claire.github-309c@sitedethib.com>
Date: Wed, 30 Aug 2023 17:36:16 +0200
Subject: [PATCH] Change text extraction in `PlainTextFormatter` to be faster
 (#26727)

---
 app/lib/plain_text_formatter.rb | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/app/lib/plain_text_formatter.rb b/app/lib/plain_text_formatter.rb
index 6fa2bc5d2..d1ff6808b 100644
--- a/app/lib/plain_text_formatter.rb
+++ b/app/lib/plain_text_formatter.rb
@@ -1,9 +1,7 @@
 # frozen_string_literal: true
 
 class PlainTextFormatter
-  include ActionView::Helpers::TextHelper
-
-  NEWLINE_TAGS_RE = /(<br \/>|<br>|<\/p>)+/.freeze
+  NEWLINE_TAGS_RE = %r{(<br />|<br>|</p>)+}
 
   attr_reader :text, :local
 
@@ -18,7 +16,10 @@ class PlainTextFormatter
     if local?
       text
     else
-      html_entities.decode(strip_tags(insert_newlines)).chomp
+      node = Nokogiri::HTML.fragment(insert_newlines)
+      # Elements that are entirely removed with our Sanitize config
+      node.xpath('.//iframe|.//math|.//noembed|.//noframes|.//noscript|.//plaintext|.//script|.//style|.//svg|.//xmp').remove
+      node.text.chomp
     end
   end
 
@@ -27,8 +28,4 @@ class PlainTextFormatter
   def insert_newlines
     text.gsub(NEWLINE_TAGS_RE) { |match| "#{match}\n" }
   end
-
-  def html_entities
-    HTMLEntities.new
-  end
 end