MetricsStatfs GetMetrics() function test

add test function to test GetMetrics() function in pkg/volume/metrics_statfs_test.go

pkg/volume/BUILD

@@ -50,6 +50,7 @@ go_test(
     name = "go_default_test",
     srcs = [
         "metrics_nil_test.go",
+        "metrics_statfs_test.go",
         "plugins_test.go",
         "util_test.go",
     ],
@@ -60,6 +61,7 @@ go_test(
         "//pkg/api/errors:go_default_library",
         "//pkg/api/resource:go_default_library",
         "//pkg/api/v1:go_default_library",
+        "//pkg/util/testing:go_default_library",
         "//pkg/watch:go_default_library",
     ],
 )

pkg/volume/metrics_statfs_test.go

@@ -0,0 +1,65 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package volume
+
+import (
+	"os"
+	"testing"
+
+	utiltesting "k8s.io/kubernetes/pkg/util/testing"
+)
+
+func TestGetMetricsStatFS(t *testing.T) {
+	metrics := NewMetricsStatFS("")
+	actual, err := metrics.GetMetrics()
+	expected := &Metrics{}
+	if *actual != *expected {
+		t.Errorf("Expected empty Metrics from uninitialized MetricsStatFS, actual %v", *actual)
+	}
+	if err == nil {
+		t.Errorf("Expected error when calling GetMetrics on uninitialized MetricsStatFS, actual nil")
+	}
+
+	metrics = NewMetricsStatFS("/not/a/real/directory")
+	actual, err = metrics.GetMetrics()
+	if *actual != *expected {
+		t.Errorf("Expected empty Metrics from incorrectly initialized MetricsStatFS, actual %v", *actual)
+	}
+	if err == nil {
+		t.Errorf("Expected error when calling GetMetrics on incorrectly initialized MetricsStatFS, actual nil")
+	}
+
+	tmpDir, err := utiltesting.MkTmpdir("metric_statfs_test")
+	if err != nil {
+		t.Fatalf("Can't make a tmp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	metrics = NewMetricsStatFS(tmpDir)
+	actual, err = metrics.GetMetrics()
+	if err != nil {
+		t.Errorf("Unexpected error when calling GetMetrics %v", err)
+	}
+
+	if a := actual.Capacity.Value(); a <= 0 {
+		t.Errorf("Expected Capacity %d to be greater than 0.", a)
+	}
+	if a := actual.Available.Value(); a <= 0 {
+		t.Errorf("Expected Available %d to be greater than 0.", a)
+	}
+
+}