From b33ec96bd12722264f49daad7e641fc971b66eb8 Mon Sep 17 00:00:00 2001
From: Julien Duchesne <julien.duchesne@grafana.com>
Date: Fri, 10 Jan 2025 09:58:53 -0500
Subject: [PATCH] Add test to check that group isn't mutated

---
 pkg/ruler/rule_concurrency_test.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pkg/ruler/rule_concurrency_test.go b/pkg/ruler/rule_concurrency_test.go
index 9d18982ef4..e7c485db30 100644
--- a/pkg/ruler/rule_concurrency_test.go
+++ b/pkg/ruler/rule_concurrency_test.go
@@ -244,6 +244,10 @@ func TestSplitGroupIntoBatches(t *testing.T) {
 
 			batches := controller.SplitGroupIntoBatches(context.Background(), group)
 			requireConcurrentRulesEqual(t, tc.expectedGroups, batches)
+
+			// Make sure the group is not mutated and will still return the same batches when called again.
+			batches = controller.SplitGroupIntoBatches(context.Background(), group)
+			requireConcurrentRulesEqual(t, tc.expectedGroups, batches)
 		})
 	}
 }