prevent testing lib from being compiled in (#4742)

* remove testing dep from fsondisk

* code review

kyaml/filesys/fsondisk_test.go

@@ -58,7 +58,8 @@ func TestCleanedAbs_2(t *testing.T) {
 	req := require.New(t)
 	fSys, _ := makeTestDir(t)
 
-	root := getOSRoot(t)
+	root, err := getOSRoot()
+	req.NoError(err)
 	d, f, err := fSys.CleanedAbs(root)
 	req.NoError(err)
 	req.Equal(root, d.String())
@@ -122,7 +123,8 @@ func TestConfirmDirDisk(t *testing.T) {
 	err = os.Symlink(filepath.Join(wd, relDir), linkDir)
 	req.NoError(err)
 
-	root := getOSRoot(t)
+	root, err := getOSRoot()
+	req.NoError(err)
 	tests := map[string]*struct {
 		path     string
 		expected string

kyaml/filesys/fsondisk_unix.go

@@ -8,10 +8,8 @@ package filesys
 
 import (
 	"path/filepath"
-	"testing"
 )
 
-func getOSRoot(t *testing.T) string {
+func getOSRoot() (string, error) {
-	t.Helper()
+	return string(filepath.Separator), nil
-	return string(filepath.Separator)
 }

kyaml/filesys/fsondisk_windows.go

@@ -5,16 +5,14 @@ package filesys
 
 import (
 	"path/filepath"
-	"testing"
 
-	"github.com/stretchr/testify/require"
 	"golang.org/x/sys/windows"
 )
 
-func getOSRoot(t *testing.T) string {
+func getOSRoot() (string, error) {
-	t.Helper()
-
 	sysDir, err := windows.GetSystemDirectory()
-	require.NoError(t, err)
+	if err != nil {
-	return filepath.VolumeName(sysDir) + `\`
+		return "", err
+	}
+	return filepath.VolumeName(sysDir) + `\`, nil
 }