1 files changed, 41 insertions, 0 deletions
diff --git a/lib/gitlab/graphql/pagination/keyset/conditions/null_condition.rb b/lib/gitlab/graphql/pagination/keyset/conditions/null_condition.rb
new file mode 100644
index 00000000000..fa25181d663
--- /dev/null
+++ b/lib/gitlab/graphql/pagination/keyset/conditions/null_condition.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Graphql
+    module Pagination
+      module Keyset
+        module Conditions
+          class NullCondition < BaseCondition
+            def build
+              [first_attribute_condition, final_condition].join
+            end
+
+            private
+
+            # ex: "(relative_position IS NULL AND id > 500)"
+            def first_attribute_condition
+              condition = <<~SQL
+                (
+                  #{table_condition(order_list.first, nil, 'is_null').to_sql}
+                  AND
+                  #{table_condition(order_list[1], values[1], operators[1]).to_sql}
+                )
+              SQL
+
+              condition
+            end
+
+            # ex: " OR (relative_position IS NOT NULL)"
+            def final_condition
+              if before_or_after == :before
+                <<~SQL
+                  OR (#{table_condition(order_list.first, nil, 'is_not_null').to_sql})
+                SQL
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end