feat(vol): add validation unit tests

apis/v1alpha1/instrumentation_webhook_test.go

@@ -19,11 +19,15 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
 	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
 
 	"github.com/open-telemetry/opentelemetry-operator/internal/config"
 )
 
+var defaultVolumeSize = resource.MustParse("200Mi")
+
 func TestInstrumentationDefaultingWebhook(t *testing.T) {
 	inst := &Instrumentation{}
 	err := InstrumentationWebhook{
@@ -113,6 +117,21 @@ func TestInstrumentationValidatingWebhook(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "with volume and volumeSizeLimit",
+			err:  "spec.nodejs.volume and spec.nodejs.volumeSizeLimit cannot both be defined",
+			inst: Instrumentation{
+				Spec: InstrumentationSpec{
+					NodeJS: NodeJS{
+						Volume: corev1.Volume{
+							Name: "vol1",
+						},
+						VolumeSizeLimit: &defaultVolumeSize,
+					},
+				},
+			},
+			warnings: []string{"sampler type not set"},
+		},
 	}
 
 	for _, test := range tests {