adding checks for errors in root_test.go and removing extra comment

Author: vsoch

cmd/root.go

@@ -28,6 +28,7 @@ import (
 	pkgutil "github.com/GoogleContainerTools/container-diff/pkg/util"
 	"github.com/GoogleContainerTools/container-diff/util"
 	homedir "github.com/mitchellh/go-homedir"
+	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
@@ -151,7 +152,7 @@ func getCacheDir(imageName string) (string, error) {
 	if cacheDir == "" {
 		dir, err := homedir.Dir()
 		if err != nil {
-			return "", err
+			return "", errors.Wrap(err, "retrieving home dir")
 		} else {
 			cacheDir = dir
 		}

cmd/root_test.go

@@ -31,15 +31,18 @@ type testpair struct {
 }
 
 func TestCacheDir(t *testing.T) {
-	homeDir, _ := homedir.Dir()
+	homeDir, err := homedir.Dir()
+	if err != nil {
+		t.Errorf("\nError getting home dir")
+	}
+
 	tests := []struct {
 		name        string
 		cliFlag     string
 		envVar      string
 		expectedDir string
 		imageName   string
 	}{
-		// name, cliFlag, envVar, expectedDir
 		{
 			name:        "default cache is at $HOME",
 			cliFlag:     "",
@@ -80,7 +83,10 @@ func TestCacheDir(t *testing.T) {
 			cacheDir = tt.cliFlag
 
 			// call getCacheDir and make sure return is equal to expected
-			actualDir, _ := getCacheDir(tt.imageName)
+			actualDir, err := getCacheDir(tt.imageName)
+			if err != nil {
+				t.Errorf("%s\nError getting cache dir", tt.name)
+			}
 
 			if path.Dir(actualDir) != tt.expectedDir {
 				t.Errorf("%s\nExpected: %v\nGot: %v", tt.name, tt.expectedDir, actualDir)