Add tests for AggregateBy

Author: gotjosh

pkg/rules/rules_test.go

@@ -0,0 +1,97 @@
+package rules
+
+import (
+	"testing"
+
+	"github.com/prometheus/prometheus/pkg/rulefmt"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestAggregateBy(t *testing.T) {
+	tt := []struct {
+		name            string
+		rn              RuleNamespace
+		expectedExpr    []string
+		count, modified int
+		expect          error
+	}{
+		{
+			name:  "with no rules",
+			rn:    RuleNamespace{},
+			count: 0, modified: 0, expect: nil,
+		},
+		{
+			name: "no modifcation",
+			rn: RuleNamespace{
+				Groups: []rulefmt.RuleGroup{rulefmt.RuleGroup{Name: "WithoutAggregation", Rules: []rulefmt.Rule{
+					{Alert: "WithoutAggregation", Expr: "up != 1"},
+				}}},
+			},
+			expectedExpr: []string{"up != 1"},
+			count:        1, modified: 0, expect: nil,
+		},
+		{
+			name: "no change in the query but lints with 'without' in the aggregation",
+			rn: RuleNamespace{
+				Groups: []rulefmt.RuleGroup{rulefmt.RuleGroup{Name: "SkipWithout", Rules: []rulefmt.Rule{
+					{Alert: "SkipWithout", Expr: `
+						min without(alertmanager) (
+							rate(prometheus_notifications_errors_total{job="default/prometheus"}[5m])
+						/
+							rate(prometheus_notifications_sent_total{job="default/prometheus"}[5m])
+						)
+						* 100
+						> 3
+					`},
+				}}},
+			},
+			expectedExpr: []string{`min without(alertmanager) (rate(prometheus_notifications_errors_total{job="default/prometheus"}[5m]) / rate(prometheus_notifications_sent_total{job="default/prometheus"}[5m])) * 100 > 3`},
+			count:        1, modified: 1, expect: nil,
+		},
+		{
+			name: "with an aggregation modification",
+			rn: RuleNamespace{
+				Groups: []rulefmt.RuleGroup{rulefmt.RuleGroup{Name: "WithAggregation", Rules: []rulefmt.Rule{
+					{Alert: "WithAggregation", Expr: `
+						sum(rate(cortex_prometheus_rule_evaluation_failures_total[1m])) by (namespace, job)
+						/
+						sum(rate(cortex_prometheus_rule_evaluations_total[1m])) by (namespace, job)
+						> 0.01
+					`},
+				}}},
+			},
+			expectedExpr: []string{"sum by(namespace, job, cluster) (rate(cortex_prometheus_rule_evaluation_failures_total[1m])) / sum by(namespace, job, cluster) (rate(cortex_prometheus_rule_evaluations_total[1m])) > 0.01"},
+			count:        1, modified: 1, expect: nil,
+		},
+		{
+			name: "with 'count' as the aggregation",
+			rn: RuleNamespace{
+				Groups: []rulefmt.RuleGroup{rulefmt.RuleGroup{Name: "CountAggregation", Rules: []rulefmt.Rule{
+					{Alert: "CountAggregation", Expr: `
+						count(count by (gitVersion) (label_replace(kubernetes_build_info{job!~"kube-dns|coredns"},"gitVersion","$1","gitVersion","(v[0-9]*.[0-9]*.[0-9]*).*"))) > 1	
+					`},
+				}}},
+			},
+			expectedExpr: []string{`count by(cluster) (count by(gitVersion, cluster) (label_replace(kubernetes_build_info{job!~"kube-dns|coredns"}, "gitVersion", "$1", "gitVersion", "(v[0-9]*.[0-9]*.[0-9]*).*"))) > 1`},
+			count:        1, modified: 1, expect: nil,
+		},
+	}
+
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			c, m, err := tc.rn.AggregateBy("cluster")
+
+			require.Equal(t, tc.expect, err)
+			assert.Equal(t, tc.count, c)
+			assert.Equal(t, tc.modified, m)
+
+			// Only verify the PromQL expression if it has been modified
+			for _, g := range tc.rn.Groups {
+				for i, r := range g.Rules {
+					require.Equal(t, tc.expectedExpr[i], r.Expr)
+				}
+			}
+		})
+	}
+}