diff --git a/pkg/controller/controller_test.go b/pkg/controller/controller_test.go
new file mode 100644
index 000000000..5cb8c3e43
--- /dev/null
+++ b/pkg/controller/controller_test.go
@@ -0,0 +1,174 @@
+package controller
+
+import (
+	"context"
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/kubernetes-csi/external-resizer/pkg/csi"
+	"github.com/kubernetes-csi/external-resizer/pkg/resizer"
+
+	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/informers"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/kubernetes/fake"
+)
+
+func TestController(t *testing.T) {
+	for _, test := range []struct {
+		Name string
+		PVC  *v1.PersistentVolumeClaim
+		PV   *v1.PersistentVolume
+
+		CreateObjects bool
+		NodeResize    bool
+	}{
+		{
+			Name: "Invalid key",
+			PVC:  invalidPVC(),
+		},
+		{
+			Name: "PVC not found",
+			PVC:  createPVC(1, 1),
+		},
+		{
+			Name:          "PVC doesn't need resize",
+			PVC:           createPVC(1, 1),
+			CreateObjects: true,
+		},
+		{
+			Name:          "PV not found",
+			PVC:           createPVC(2, 1),
+			CreateObjects: true,
+		},
+		{
+			Name:          "PV doesn't need resize",
+			PVC:           createPVC(2, 1),
+			PV:            createPV(2),
+			CreateObjects: true,
+		},
+		{
+			Name:          "Resize PVC, no FS resize",
+			PVC:           createPVC(2, 1),
+			PV:            createPV(1),
+			CreateObjects: true,
+		},
+		{
+			Name:          "Resize PVC with FS resize",
+			PVC:           createPVC(2, 1),
+			PV:            createPV(1),
+			CreateObjects: true,
+			NodeResize:    true,
+		},
+	} {
+		client := csi.NewMockClient(test.NodeResize, true, true)
+		driverName, _ := client.GetDriverName(context.TODO())
+
+		initialObjects := []runtime.Object{}
+		if test.CreateObjects {
+			if test.PVC != nil {
+				initialObjects = append(initialObjects, test.PVC)
+			}
+			if test.PV != nil {
+				test.PV.Spec.PersistentVolumeSource.CSI.Driver = driverName
+				initialObjects = append(initialObjects, test.PV)
+			}
+		}
+
+		kubeClient, informerFactory := fakeK8s(initialObjects)
+		pvInformer := informerFactory.Core().V1().PersistentVolumes()
+		pvcInformer := informerFactory.Core().V1().PersistentVolumeClaims()
+
+		for _, obj := range initialObjects {
+			switch obj.(type) {
+			case *v1.PersistentVolume:
+				pvInformer.Informer().GetStore().Add(obj)
+			case *v1.PersistentVolumeClaim:
+				pvcInformer.Informer().GetStore().Add(obj)
+			default:
+				t.Fatalf("Test %s: Unknown initalObject type: %+v", test.Name, obj)
+			}
+		}
+
+		csiResizer, err := resizer.NewResizerFromClient(client, 15*time.Second, kubeClient, informerFactory)
+		if err != nil {
+			t.Fatalf("Test %s: Unable to create resizer: %v", test.Name, err)
+		}
+
+		controller := NewResizeController(driverName, csiResizer, kubeClient, time.Second, informerFactory)
+		err = controller.(*resizeController).syncPVC(fmt.Sprintf("%s/%s", test.PVC.Namespace, test.PVC.Name))
+		if err != nil {
+			t.Fatalf("Test %s: Unexpected error: %v", test.Name, err)
+		}
+	}
+}
+
+func invalidPVC() *v1.PersistentVolumeClaim {
+	pvc := createPVC(1, 1)
+	pvc.ObjectMeta.Name = ""
+	pvc.ObjectMeta.Namespace = ""
+
+	return pvc
+}
+
+func quantityGB(i int) resource.Quantity {
+	q := resource.NewQuantity(int64(i*1024*1024), resource.BinarySI)
+	return *q
+}
+
+func createPVC(requestGB, capacityGB int) *v1.PersistentVolumeClaim {
+	request := quantityGB(requestGB)
+	capacity := quantityGB(capacityGB)
+
+	return &v1.PersistentVolumeClaim{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "testPVC",
+			Namespace: "test",
+		},
+		Spec: v1.PersistentVolumeClaimSpec{
+			Resources: v1.ResourceRequirements{
+				Requests: map[v1.ResourceName]resource.Quantity{
+					v1.ResourceStorage: request,
+				},
+			},
+			VolumeName: "testPV",
+		},
+		Status: v1.PersistentVolumeClaimStatus{
+			Phase: v1.ClaimBound,
+			Capacity: map[v1.ResourceName]resource.Quantity{
+				v1.ResourceStorage: capacity,
+			},
+		},
+	}
+}
+
+func createPV(capacityGB int) *v1.PersistentVolume {
+	capacity := quantityGB(capacityGB)
+
+	return &v1.PersistentVolume{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "testPV",
+		},
+		Spec: v1.PersistentVolumeSpec{
+			Capacity: map[v1.ResourceName]resource.Quantity{
+				v1.ResourceStorage: capacity,
+			},
+			PersistentVolumeSource: v1.PersistentVolumeSource{
+				CSI: &v1.CSIPersistentVolumeSource{
+					Driver:       "foo",
+					VolumeHandle: "foo",
+				},
+			},
+		},
+	}
+}
+
+func fakeK8s(objs []runtime.Object) (kubernetes.Interface, informers.SharedInformerFactory) {
+	client := fake.NewSimpleClientset(objs...)
+	informerFactory := informers.NewSharedInformerFactory(client, 0)
+	return client, informerFactory
+}
diff --git a/pkg/resizer/csi_resizer.go b/pkg/resizer/csi_resizer.go
index 1c799a379..c7a7d31ea 100644
--- a/pkg/resizer/csi_resizer.go
+++ b/pkg/resizer/csi_resizer.go
@@ -56,10 +56,10 @@ func NewResizer(
 	if err != nil {
 		return nil, err
 	}
-	return newResizer(csiClient, timeout, k8sClient, informerFactory)
+	return NewResizerFromClient(csiClient, timeout, k8sClient, informerFactory)
 }
 
-func newResizer(
+func NewResizerFromClient(
 	csiClient csi.Client,
 	timeout time.Duration,
 	k8sClient kubernetes.Interface,
diff --git a/pkg/resizer/csi_resizer_test.go b/pkg/resizer/csi_resizer_test.go
index 1adaf447d..e5c08c5da 100644
--- a/pkg/resizer/csi_resizer_test.go
+++ b/pkg/resizer/csi_resizer_test.go
@@ -53,7 +53,7 @@ func TestNewResizer(t *testing.T) {
 	} {
 		client := csi.NewMockClient(c.SupportsNodeResize, c.SupportsControllerResize, c.SupportsPluginControllerService)
 		k8sClient, informerFactory := fakeK8s()
-		resizer, err := newResizer(client, 0, k8sClient, informerFactory)
+		resizer, err := NewResizerFromClient(client, 0, k8sClient, informerFactory)
 		if err != c.Error {
 			t.Errorf("Case %d: Unexpected error: wanted %v, got %v", i, c.Error, err)
 		}