// Metrics.  It serves as a placeholder for Volumes that do not yet support
// metrics.
type MetricsNil struct{}

// SupportsMetrics returns false for the MetricsNil type.
func (*MetricsNil) SupportsMetrics() bool {
	return false
}

// GetMetrics returns an empty Metrics and an error.
// See MetricsProvider.GetMetrics
func (*MetricsNil) GetMetrics() (*Metrics, error) {

	SELinuxRelabel   bool `json:"selinuxRelabel"`
	SupportsMetrics  bool `json:"supportsMetrics"`
	FSGroup          bool `json:"fsGroup"`
	RequiresFSResize bool `json:"requiresFSResize"`
}

func defaultCapabilities() *DriverCapabilities {
	return &DriverCapabilities{
		Attach:           true,
		SELinuxRelabel:   true,
		SupportsMetrics:  false,
		FSGroup:          true,
		RequiresFSResize: true,
	}

limitations under the License.
*/

package volume

import (
	"testing"
)

func TestMetricsNilSupportsMetrics(t *testing.T) {
	metrics := &MetricsNil{}
	supported := metrics.SupportsMetrics()
	if supported {
		t.Error("Expected no support for metrics")
	}
}

func TestMetricsNilGetCapacity(t *testing.T) {
	metrics := &MetricsNil{}
	actual, err := metrics.GetMetrics()
	expected := &Metrics{}

				// Some drivers inherit the MetricsProvider interface from Filesystem
				// mode volumes, but do not implement it for Block mode. Checking
				// SupportsMetrics() will prevent panics in that case.
				if v.SupportsMetrics() {
					metricVolumes[name] = v
				}
			}
		}
	}

	// Get volume specs for the pod - key'd by volume name
	volumesSpec := make(map[string]v1.Volume)

	if err != nil {
		return nil, err
	}

	readOnly, err := getReadOnly(spec)
	if err != nil {
		return nil, err
	}

	var metricsProvider volume.MetricsProvider
	if plugin.capabilities.SupportsMetrics {
		metricsProvider = volume.NewMetricsStatFS(plugin.host.GetPodVolumeDir(
			pod.UID, utilstrings.EscapeQualifiedName(sourceDriver), spec.Name()))
	} else {
		metricsProvider = &volume.MetricsNil{}
	}

func (v *fakeBlockVolume) GetGlobalMapPath(*volume.Spec) (string, error) { return "", nil }

func (v *fakeBlockVolume) GetPodDeviceMapPath() (string, string) { return "", "" }

func (v *fakeBlockVolume) SupportsMetrics() bool { return true }

func (v *fakeBlockVolume) GetMetrics() (*volume.Metrics, error) {
	return expectedBlockMetrics(), nil
}

func expectedBlockMetrics() *volume.Metrics {
	vMetrics := &volume.Metrics{