Add support for Chmod on billy.Filesystem

fs.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"io"
 	"io/fs"
-	"time"
 )
 
 var (
@@ -132,24 +131,12 @@ type Symlink interface {
 	Readlink(link string) (string, error)
 }
 
-// Change abstract the FileInfo change related operations in a storage-agnostic
+// Chmod abstract the FileInfo change related operations in a storage-agnostic
 // interface as an extension to the Basic interface
-type Change interface {
+type Chmod interface {
 	// Chmod changes the mode of the named file to mode. If the file is a
 	// symbolic link, it changes the mode of the link's target.
 	Chmod(name string, mode fs.FileMode) error
-	// Lchown changes the numeric uid and gid of the named file. If the file is
-	// a symbolic link, it changes the uid and gid of the link itself.
-	Lchown(name string, uid, gid int) error
-	// Chown changes the numeric uid and gid of the named file. If the file is a
-	// symbolic link, it changes the uid and gid of the link's target.
-	Chown(name string, uid, gid int) error
-	// Chtimes changes the access and modification times of the named file,
-	// similar to the Unix utime() or utimes() functions.
-	//
-	// The underlying filesystem may truncate or round the values to a less
-	// precise time unit.
-	Chtimes(name string, atime time.Time, mtime time.Time) error
 }
 
 // Chroot abstract the chroot related operations in a storage-agnostic interface

helper/chroot/chroot.go

@@ -201,6 +201,15 @@ func (fs *ChrootHelper) Readlink(link string) (string, error) {
 	return string(os.PathSeparator) + target, nil
 }
 
+func (fs *ChrootHelper) Chmod(path string, mode fs.FileMode) error {
+	fullpath, err := fs.underlyingPath(path)
+	if err != nil {
+		return err
+	}
+
+	return fs.underlying.(billy.Chmod).Chmod(fullpath, mode)
+}
+
 func (fs *ChrootHelper) Chroot(path string) (billy.Filesystem, error) {
 	fullpath, err := fs.underlyingPath(path)
 	if err != nil {

memfs/memory.go

@@ -177,6 +177,10 @@ func (fs *Memory) Remove(filename string) error {
 	return fs.s.Remove(filename)
 }
 
+func (fs *Memory) Chmod(path string, mode gofs.FileMode) error {
+	return fs.s.Chmod(path, mode)
+}
+
 // Falls back to Go's filepath.Join, which works differently depending on the
 // OS where the code is being executed.
 func (fs *Memory) Join(elem ...string) string {

memfs/storage.go

@@ -222,6 +222,18 @@ func (s *storage) Remove(path string) error {
 	return nil
 }
 
+func (s *storage) Chmod(path string, mode fs.FileMode) error {
+	path = clean(path)
+
+	f, has := s.Get(path)
+	if !has {
+		return os.ErrNotExist
+	}
+
+	f.mode = mode
+	return nil
+}
+
 func clean(path string) string {
 	return filepath.Clean(filepath.FromSlash(path))
 }

osfs/os_bound.go

@@ -226,6 +226,14 @@ func (fs *BoundOS) Readlink(link string) (string, error) {
 	return os.Readlink(link)
 }
 
+func (fs *BoundOS) Chmod(path string, mode fs.FileMode) error {
+	abspath, err := fs.abs(path)
+	if err != nil {
+		return err
+	}
+	return os.Chmod(abspath, mode)
+}
+
 // Chroot returns a new BoundOS filesystem, with the base dir set to the
 // result of joining the provided path with the underlying base dir.
 func (fs *BoundOS) Chroot(path string) (billy.Filesystem, error) {

osfs/os_chroot.go

@@ -80,6 +80,10 @@ func (fs *ChrootOS) Remove(filename string) error {
 	return os.Remove(filename)
 }
 
+func (fs *ChrootOS) Chmod(path string, mode fs.FileMode) error {
+	return os.Chmod(path, mode)
+}
+
 func (fs *ChrootOS) TempFile(dir, prefix string) (billy.File, error) {
 	if err := fs.createDir(dir + string(os.PathSeparator)); err != nil {
 		return nil, err