1 files changed, 45 insertions, 0 deletions
diff --git a/lib/gitlab/import/errors.rb b/lib/gitlab/import/errors.rb
new file mode 100644
index 00000000000..b9e8c9135fd
--- /dev/null
+++ b/lib/gitlab/import/errors.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Import
+    module Errors
+      # Merges all nested subrelation errors into base errors object.
+      #
+      # @example
+      #   issue = Project.last.issues.new(
+      #     title: 'test',
+      #     author: User.first,
+      #     notes: [Note.new(
+      #               award_emoji: [AwardEmoji.new(name: 'test')]
+      #            )])
+      #
+      #   issue.validate
+      #   issue.errors.full_messages
+      #   => ["Notes is invalid"]
+      #
+      #   Gitlab::Import::Errors.merge_nested_errors(issue)
+      #   issue.errors.full_messages
+      #   => ["Notes is invalid",
+      #       "Award emoji is invalid",
+      #       "Awardable can't be blank",
+      #       "Name is not a valid emoji name",
+      #       ...
+      #      ]
+      def self.merge_nested_errors(object)
+        object.errors.each do |error|
+          association = object.class.reflect_on_association(error.attribute)
+
+          next unless association&.collection?
+
+          records = object.public_send(error.attribute).select(&:invalid?) # rubocop: disable GitlabSecurity/PublicSend
+
+          records.each do |record|
+            merge_nested_errors(record)
+
+            object.errors.merge!(record.errors)
+          end
+        end
+      end
+    end
+  end
+end