Alerting: Don't validate rules on group update if they've only been reordered (#81841)

---------

Co-authored-by: Yuri Tseretyan <yuriy.tseretyan@grafana.com>

pkg/services/ngalert/api/api_ruler_test.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"net/url"
+	"slices"
 	"testing"
 	"time"
 
@@ -31,6 +32,7 @@ import (
 	"github.com/grafana/grafana/pkg/services/user"
 	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/util"
+	"github.com/grafana/grafana/pkg/util/cmputil"
 	"github.com/grafana/grafana/pkg/web"
 )
 
@@ -538,7 +540,24 @@ func TestValidateQueries(t *testing.T) {
 				New: models.AlertRuleGen(func(rule *models.AlertRule) {
 					rule.Condition = "Update_New"
 				})(),
-				Diff: nil,
+				Diff: cmputil.DiffReport{
+					cmputil.Diff{
+						Path: "SomeField",
+					},
+				},
+			},
+			{
+				Existing: models.AlertRuleGen(func(rule *models.AlertRule) {
+					rule.Condition = "Update_Index_Existing"
+				})(),
+				New: models.AlertRuleGen(func(rule *models.AlertRule) {
+					rule.Condition = "Update_Index_New"
+				})(),
+				Diff: cmputil.DiffReport{
+					cmputil.Diff{
+						Path: "RuleGroupIndex",
+					},
+				},
 			},
 		},
 		Delete: []*models.AlertRule{
@@ -548,12 +567,13 @@ func TestValidateQueries(t *testing.T) {
 		},
 	}
 
-	t.Run("should validate New and Updated only", func(t *testing.T) {
+	t.Run("should not validate deleted rules or updated rules with ignored fields", func(t *testing.T) {
 		validator := &recordingConditionValidator{}
 		err := validateQueries(context.Background(), &delta, validator, nil)
 		require.NoError(t, err)
+		noValidate := []string{"Deleted", "Update_Index_New"}
 		for _, condition := range validator.recorded {
-			if condition.Condition == "New" || condition.Condition == "Update_New" {
+			if !slices.Contains(noValidate, condition.Condition) {
 				continue
 			}
 			assert.Failf(t, "validated unexpected condition", "condition '%s' was validated but should not", condition.Condition)