Add first inhibition acceptance test.

inhibit.go

@@ -101,7 +101,7 @@ func NewInhibitRule(cr *config.InhibitRule) *InhibitRule {
 		targetm = append(targetm, m)
 	}
 
-	equal := make(map[model.LabelName]struct{})
+	equal := map[model.LabelName]struct{}{}
 	for _, ln := range cr.Equal {
 		equal[ln] = struct{}{}
 	}

test/acceptance/simple_test.go

@@ -172,3 +172,61 @@ notification_configs:
 
 	at.Run()
 }
+
+func TestInhibiting(t *testing.T) {
+	t.Parallel()
+
+	conf := `
+routes:
+- send_to: "default"
+  group_wait:     1s
+  group_interval: 1s
+
+notification_configs:
+- name: "default"
+  send_resolved: true
+  repeat_interval: 1s
+  webhook_configs:
+  - url: 'http://%s'
+
+inhibit_rules:
+- source_match:
+    alertname: JobDown
+  target_match:
+    alertname: InstanceDown
+  equal:
+    - job
+    - zone
+`
+
+	at := NewAcceptanceTest(t, &AcceptanceOpts{
+		Tolerance: 150 * time.Millisecond,
+	})
+
+	co := at.Collector("webhook")
+	wh := NewWebhook(co)
+
+	am := at.Alertmanager(fmt.Sprintf(conf, wh.Address()))
+
+	am.Push(At(1), Alert("alertname", "test1", "job", "testjob", "zone", "aa"))
+	am.Push(At(1), Alert("alertname", "InstanceDown", "job", "testjob", "zone", "aa"))
+	am.Push(At(1), Alert("alertname", "InstanceDown", "job", "testjob", "zone", "ab"))
+
+	// This JobDown in zone aa should inhibit InstanceDown in zone aa in the
+	// second batch of notifications.
+	am.Push(At(2.2), Alert("alertname", "JobDown", "job", "testjob", "zone", "aa"))
+
+	co.Want(Between(2, 2.5),
+		Alert("alertname", "test1", "job", "testjob", "zone", "aa"),
+		Alert("alertname", "InstanceDown", "job", "testjob", "zone", "aa"),
+		Alert("alertname", "InstanceDown", "job", "testjob", "zone", "ab"),
+	)
+
+	co.Want(Between(3, 3.5),
+		Alert("alertname", "test1", "job", "testjob", "zone", "aa"),
+		Alert("alertname", "InstanceDown", "job", "testjob", "zone", "ab"),
+		Alert("alertname", "JobDown", "job", "testjob", "zone", "aa"),
+	)
+
+	at.Run()
+}

test/collector.go

@@ -35,6 +35,8 @@ func batchesEqual(as, bs model.Alerts, opts *AcceptanceOpts) bool {
 
 	for i, a := range as {
 		if !equalAlerts(a, bs[i], opts) {
+			fmt.Println(a, bs[i])
+			fmt.Printf("%s != %s\n", a.StartsAt, bs[i].StartsAt)
 			return false
 		}
 	}