From 794937b3d6e5a9a75c71ad57600ebbe40722cf3c Mon Sep 17 00:00:00 2001
From: Holger Hans Peter Freyther <holger@moiji-mobile.com>
Date: Fri, 27 Aug 2021 13:44:46 +0800
Subject: [PATCH] promtool: Add testcase for detecting duplicates

Introduce a basic test for checking for duplicate rules.

Signed-off-by: Holger Hans Peter Freyther <holger@moiji-mobile.com>
---
 cmd/promtool/main_test.go                  | 33 ++++++++++++++++++++++
 cmd/promtool/testdata/rules_duplicates.yml | 24 ++++++++++++++++
 2 files changed, 57 insertions(+)
 create mode 100644 cmd/promtool/testdata/rules_duplicates.yml

diff --git a/cmd/promtool/main_test.go b/cmd/promtool/main_test.go
index 4949c467c1..6d8c02af6f 100644
--- a/cmd/promtool/main_test.go
+++ b/cmd/promtool/main_test.go
@@ -21,6 +21,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/prometheus/prometheus/pkg/rulefmt"
 	"github.com/stretchr/testify/require"
 )
 
@@ -118,3 +119,35 @@ func TestCheckSDFile(t *testing.T) {
 		})
 	}
 }
+
+func TestCheckDuplicates(t *testing.T) {
+	cases := []struct {
+		name         string
+		ruleFile     string
+		expectedDups []compareRuleType
+	}{
+		{
+			name:     "no duplicates",
+			ruleFile: "./testdata/rules.yml",
+		},
+		{
+			name:     "duplicate in other group",
+			ruleFile: "./testdata/rules_duplicates.yml",
+			expectedDups: []compareRuleType{
+				{
+					metric: "job:test:count_over_time1m",
+				},
+			},
+		},
+	}
+
+	for _, test := range cases {
+		c := test
+		t.Run(c.name, func(t *testing.T) {
+			rgs, err := rulefmt.ParseFile(c.ruleFile)
+			require.Empty(t, err)
+			dups := checkDuplicates(rgs.Groups)
+			require.Equal(t, c.expectedDups, dups)
+		})
+	}
+}
diff --git a/cmd/promtool/testdata/rules_duplicates.yml b/cmd/promtool/testdata/rules_duplicates.yml
new file mode 100644
index 0000000000..757006817b
--- /dev/null
+++ b/cmd/promtool/testdata/rules_duplicates.yml
@@ -0,0 +1,24 @@
+# This is a rules file with duplicate expressions
+
+groups:
+  - name: base
+    rules:
+      - record: job:test:count_over_time1m
+        expr: sum without(instance) (count_over_time(test[1m]))
+
+      # A recording rule that doesn't depend on input series.
+      - record: fixed_data
+        expr: 1
+
+      # Subquery with default resolution test.
+      - record: suquery_interval_test
+        expr: count_over_time(up[5m:])
+
+      # Duplicating
+      - record: job:test:count_over_time1m
+        expr: sum without(instance) (count_over_time(test[1m]))
+
+  - name: duplicate
+    rules:
+      - record: job:test:count_over_time1m
+        expr: sum without(instance) (count_over_time(test[1m]))