1 files changed, 51 insertions, 0 deletions
diff --git a/lib/gitlab/diff/suggestions_parser.rb b/lib/gitlab/diff/suggestions_parser.rb
new file mode 100644
index 00000000000..c8c03d5d001
--- /dev/null
+++ b/lib/gitlab/diff/suggestions_parser.rb
@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Diff
+    class SuggestionsParser
+      # Matches for instance "-1", "+1" or "-1+2".
+      SUGGESTION_CONTEXT = /^(\-(?<above>\d+))?(\+(?<below>\d+))?$/.freeze
+
+      class << self
+        # Returns an array of Gitlab::Diff::Suggestion which represents each
+        # suggestion in the given text.
+        #
+        def parse(text, position:, project:)
+          return [] unless position.complete?
+
+          html = Banzai.render(text, project: nil, no_original_data: true)
+          doc = Nokogiri::HTML(html)
+          suggestion_nodes = doc.search('pre.suggestion')
+
+          return [] if suggestion_nodes.empty?
+
+          diff_file = position.diff_file(project.repository)
+
+          suggestion_nodes.map do |node|
+            lang_param = node['data-lang-params']
+
+            lines_above, lines_below = nil
+
+            if lang_param && suggestion_params = fetch_suggestion_params(lang_param)
+              lines_above, lines_below =
+                suggestion_params[:above],
+                suggestion_params[:below]
+            end
+
+            Gitlab::Diff::Suggestion.new(node.text,
+                                         line: position.new_line,
+                                         above: lines_above.to_i,
+                                         below: lines_below.to_i,
+                                         diff_file: diff_file)
+          end
+        end
+
+        private
+
+        def fetch_suggestion_params(lang_param)
+          lang_param.match(SUGGESTION_CONTEXT)
+        end
+      end
+    end
+  end
+end