Thread Safety test for UpdateSubsSyncCounterStorage (#2918)

Introduces a test that ensure that the UpdateSubsSyncCounterStorage
function is thread safe and avoids concurrent map writes.

Signed-off-by: Alexander Greene <[email protected]>

Author: awgreene

pkg/metrics/metrics_test.go

@@ -0,0 +1,34 @@
+package metrics_test
+
+import (
+	"fmt"
+	"testing"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
+	operatorsv1alpha1 "github.com/operator-framework/api/pkg/operators/v1alpha1"
+	"github.com/operator-framework/operator-lifecycle-manager/pkg/metrics"
+)
+
+func TestUpdateSubsSyncCounterStorageThreadSafety(t *testing.T) {
+	for i := 0; i < 1000; i++ {
+		go func(ii int) {
+			sub := &operatorsv1alpha1.Subscription{
+				ObjectMeta: metav1.ObjectMeta{
+					Namespace: "foo",
+					Name:      "foo",
+				},
+				Spec: &operatorsv1alpha1.SubscriptionSpec{
+					Channel:             "foo",
+					Package:             "foo",
+					InstallPlanApproval: "automatic",
+				},
+				Status: operatorsv1alpha1.SubscriptionStatus{
+					InstalledCSV: "foo",
+				},
+			}
+			sub.Spec.Channel = fmt.Sprintf("bar-%v", ii)
+			metrics.UpdateSubsSyncCounterStorage(sub)
+		}(i)
+	}
+}