Fix HTML validation (#10354)

* Fix HTML validation

* Report first HTML error instead on validation error

1 files changed, 7 insertions, 3 deletions

diff --git a/app/validators/html_validator.rb b/app/validators/html_validator.rb
index 882c35d41..b7caee5a9 100644
--- a/app/validators/html_validator.rb
+++ b/app/validators/html_validator.rb
@@ -3,12 +3,16 @@
 class HtmlValidator < ActiveModel::EachValidator
   def validate_each(record, attribute, value)
     return if value.blank?
-    record.errors.add(attribute, I18n.t('html_validator.invalid_markup')) unless valid_html?(value)
+    errors = html_errors(value)
+    unless errors.empty?
+      record.errors.add(attribute, I18n.t('html_validator.invalid_markup', error: errors.first.to_s))
+    end
   end
 
   private
 
-  def valid_html?(str)
-    Nokogiri::HTML.fragment(str).to_s == str
+  def html_errors(str)
+    fragment = Nokogiri::HTML.fragment(str)
+    fragment.errors
   end
 end