Added FileSystem field to kio.LocalPackageWriter

kyaml/kio/pkgio_writer.go

@@ -4,12 +4,14 @@
 package kio
 
 import (
+	"bytes"
 	"fmt"
 	"os"
 	"path/filepath"
 	"strings"
 
 	"sigs.k8s.io/kustomize/kyaml/errors"
+	"sigs.k8s.io/kustomize/kyaml/filesys"
 	"sigs.k8s.io/kustomize/kyaml/kio/kioutil"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
 )
@@ -26,6 +28,9 @@ type LocalPackageWriter struct {
 
 	// ClearAnnotations will clear annotations before writing the resources
 	ClearAnnotations []string `yaml:"clearAnnotations,omitempty"`
+
+	// FileSystem can be used to mock the disk file system.
+	FileSystem filesys.FileSystemOrOnDisk
 }
 
 var _ Writer = LocalPackageWriter{}
@@ -36,9 +41,10 @@ func (r LocalPackageWriter) Write(nodes []*yaml.RNode) error {
 		return err
 	}
 
-	if s, err := os.Stat(r.PackagePath); err != nil {
+	if !r.FileSystem.Exists(r.PackagePath) {
-		return err
+		return errors.WrapPrefixf(os.ErrNotExist, "could not write to %q", r.PackagePath)
-	} else if !s.IsDir() {
+	}
+	if !r.FileSystem.IsDir(r.PackagePath) {
 		// if the user specified input isn't a directory, the package is the directory of the
 		// target
 		r.PackagePath = filepath.Dir(r.PackagePath)
@@ -65,45 +71,36 @@ func (r LocalPackageWriter) Write(nodes []*yaml.RNode) error {
 	// validate outputs before writing any
 	for path := range outputFiles {
 		outputPath := filepath.Join(r.PackagePath, path)
-		if st, err := os.Stat(outputPath); !os.IsNotExist(err) {
+		if r.FileSystem.IsDir(outputPath) {
-			if err != nil {
-				return errors.Wrap(err)
-			}
-			if st.IsDir() {
 			return fmt.Errorf("config.kubernetes.io/path cannot be a directory: %s", path)
 		}
-		}
 
-		err = os.MkdirAll(filepath.Dir(outputPath), 0700)
+		err = r.FileSystem.MkdirAll(filepath.Dir(outputPath))
 		if err != nil {
 			return errors.Wrap(err)
 		}
 	}
 
 	// write files
+	buf := bytes.NewBuffer(nil)
 	for path := range outputFiles {
 		outputPath := filepath.Join(r.PackagePath, path)
-		err = os.MkdirAll(filepath.Dir(filepath.Join(r.PackagePath, path)), 0700)
+		err = r.FileSystem.MkdirAll(filepath.Dir(filepath.Join(r.PackagePath, path)))
 		if err != nil {
 			return errors.Wrap(err)
 		}
 
-		f, err := os.OpenFile(outputPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, os.FileMode(0600))
+		buf.Reset()
-		if err != nil {
-			return errors.Wrap(err)
-		}
-		if err := func() error {
-			defer f.Close()
 		w := ByteWriter{
-				Writer:                f,
+			Writer:                buf,
 			KeepReaderAnnotations: r.KeepReaderAnnotations,
 			ClearAnnotations:      r.ClearAnnotations,
 		}
 		if err = w.Write(outputFiles[path]); err != nil {
 			return errors.Wrap(err)
 		}
-			return nil
+
-		}(); err != nil {
+		if err := r.FileSystem.WriteFile(outputPath, buf.Bytes()); err != nil {
 			return errors.Wrap(err)
 		}
 	}