1 files changed, 18 insertions, 0 deletions
diff --git a/app/services/issuable/import_csv/base_service.rb b/app/services/issuable/import_csv/base_service.rb
index 9ef9fb76e3c..95338374ca6 100644
--- a/app/services/issuable/import_csv/base_service.rb
+++ b/app/services/issuable/import_csv/base_service.rb
@@ -23,6 +23,24 @@ module Issuable
 
         raise CSV::MalformedCSVError.new('Invalid CSV format - missing required headers.', 1)
       end
+
+      def preprocess!
+        preprocess_milestones!
+
+        raise PreprocessError if results[:preprocess_errors].any?
+      end
+
+      def preprocess_milestones!
+        # Pre-Process Milestone if header is present
+        return unless csv_data.lines.first.downcase.include?('milestone')
+
+        provided_titles = with_csv_lines.filter_map { |row| row[:milestone]&.strip&.downcase }.uniq
+        result = ::ImportCsv::PreprocessMilestonesService.new(user, project, provided_titles).execute
+        return if result.success?
+
+        # collate errors here and throw errors
+        results[:preprocess_errors][:milestone_errors] = result.payload
+      end
     end
   end
 end