add negative test case

Author: paulyufan2

cns/middlewares/k8sSwiftV2_windows.go

@@ -1,8 +1,6 @@
 package middlewares
 
 import (
-	"fmt"
-
 	"github.com/Azure/azure-container-networking/cns"
 	"github.com/Azure/azure-container-networking/cns/middlewares/utils"
 	"github.com/Azure/azure-container-networking/crd/multitenancy/api/v1alpha1"
@@ -23,7 +21,6 @@ func (k *K8sSWIFTv2Middleware) setRoutes(podIPInfo *cns.PodIpInfo) error {
 
 		// add routes for infraNIC
 		routes, err := k.SetInfraRoutes(podIPInfo)
-		fmt.Printf("routes are %v", routes)
 		if err != nil {
 			return errors.Wrap(err, "failed to set routes for infraNIC interface")
 		}

cns/middlewares/k8sSwiftV2_windows_test.go

@@ -1,7 +1,6 @@
 package middlewares
 
 import (
-	"fmt"
 	"reflect"
 	"testing"
 
@@ -37,7 +36,6 @@ func TestSetRoutesSuccess(t *testing.T) {
 	}
 	for i := range podIPInfo {
 		ipInfo := &podIPInfo[i]
-		fmt.Printf("ipInfo is %v", ipInfo)
 		err := middleware.setRoutes(ipInfo)
 		assert.Equal(t, err, nil)
 		if ipInfo.NICType == cns.InfraNIC {
@@ -48,6 +46,27 @@ func TestSetRoutesSuccess(t *testing.T) {
 	}
 }
 
+func TestSetRoutesFailure(t *testing.T) {
+	// Failure due to env var not set
+	middleware := K8sSWIFTv2Middleware{Cli: mock.NewClient()}
+	podIPInfo := []cns.PodIpInfo{
+		{
+			PodIPConfig: cns.IPSubnet{
+				IPAddress:    "10.0.1.10",
+				PrefixLength: 32,
+			},
+			NICType: cns.InfraNIC,
+		},
+	}
+	for i := range podIPInfo {
+		ipInfo := &podIPInfo[i]
+		err := middleware.setRoutes(ipInfo)
+		if err == nil {
+			t.Errorf("SetRoutes should fail due to env var not set")
+		}
+	}
+}
+
 func TestAssignSubnetPrefixSuccess(t *testing.T) {
 	middleware := K8sSWIFTv2Middleware{Cli: mock.NewClient()}