Fix Group.Equals() to take in account the new queryOffset too (#14273)

Signed-off-by: Marco Pracucci <marco@pracucci.com>

rules/group.go

@@ -793,6 +793,10 @@ func (g *Group) Equals(ng *Group) bool {
 		return false
 	}
 
+	if ((g.queryOffset == nil) != (ng.queryOffset == nil)) || (g.queryOffset != nil && ng.queryOffset != nil && *g.queryOffset != *ng.queryOffset) {
+		return false
+	}
+
 	if len(g.rules) != len(ng.rules) {
 		return false
 	}

rules/group_test.go

@@ -0,0 +1,98 @@
+// Copyright 2013 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rules
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestGroup_Equals(t *testing.T) {
+	tests := map[string]struct {
+		first    *Group
+		second   *Group
+		expected bool
+	}{
+		"no query offset set on both groups": {
+			first: &Group{
+				name:     "group-1",
+				file:     "file-1",
+				interval: time.Minute,
+			},
+			second: &Group{
+				name:     "group-1",
+				file:     "file-1",
+				interval: time.Minute,
+			},
+			expected: true,
+		},
+		"query offset set only on the first group": {
+			first: &Group{
+				name:        "group-1",
+				file:        "file-1",
+				interval:    time.Minute,
+				queryOffset: pointerOf[time.Duration](time.Minute),
+			},
+			second: &Group{
+				name:     "group-1",
+				file:     "file-1",
+				interval: time.Minute,
+			},
+			expected: false,
+		},
+		"query offset set on both groups to the same value": {
+			first: &Group{
+				name:        "group-1",
+				file:        "file-1",
+				interval:    time.Minute,
+				queryOffset: pointerOf[time.Duration](time.Minute),
+			},
+			second: &Group{
+				name:        "group-1",
+				file:        "file-1",
+				interval:    time.Minute,
+				queryOffset: pointerOf[time.Duration](time.Minute),
+			},
+			expected: true,
+		},
+		"query offset set on both groups to different value": {
+			first: &Group{
+				name:        "group-1",
+				file:        "file-1",
+				interval:    time.Minute,
+				queryOffset: pointerOf[time.Duration](time.Minute),
+			},
+			second: &Group{
+				name:        "group-1",
+				file:        "file-1",
+				interval:    time.Minute,
+				queryOffset: pointerOf[time.Duration](2 * time.Minute),
+			},
+			expected: false,
+		},
+	}
+
+	for testName, testData := range tests {
+		t.Run(testName, func(t *testing.T) {
+			require.Equal(t, testData.expected, testData.first.Equals(testData.second))
+			require.Equal(t, testData.expected, testData.second.Equals(testData.first))
+		})
+	}
+}
+
+func pointerOf[T any](value T) *T {
+	return &value
+}