A release

README.md

@@ -1,2 +1,39 @@
-# iofs
-Writable io/fs implentations
+# fs2
+
+[![PkgGoDev](https://pkg.go.dev/badge/github.com/jarxorg/fs2)](https://pkg.go.dev/github.com/jarxorg/fs2)
+[![Report Card](https://goreportcard.com/badge/github.com/jarxorg/fs2)](https://goreportcard.com/report/github.com/jarxorg/fs2)
+
+Package fs2 provides writable [io/fs](https://pkg.go.dev/io/fs).FS interfaces.
+
+```go
+// WriterFile is a file that provides an implementation fs.File and io.Writer.
+type WriterFile interface {
+	fs.File
+	io.Writer
+}
+
+// WriteFileFS is the interface implemented by a filesystem that provides an
+// optimized implementation of MkdirAll, CreateFile, WriteFile.
+type WriteFileFS interface {
+	fs.FS
+	MkdirAll(dir string, mode fs.FileMode) error
+	CreateFile(name string, mode fs.FileMode) (WriterFile, error)
+	WriteFile(name string, p []byte, mode fs.FileMode) (n int, err error)
+}
+
+// RemoveFileFS is the interface implemented by a filesystem that provides an
+// implementation of RemoveFile.
+type RemoveFileFS interface {
+	fs.FS
+	RemoveFile(name string) error
+	RemoveAll(name string) error
+}
+```
+
+This is one of the solutions to an [issue](https://github.com/golang/go/issues/45757) of github.com/golango/go.
+
+The following packages are an implementation of fs2.
+
+- [osfs](https://pkg.go.dev/badge/github.com/jarxorg/fs2/osfs)
+- [memfs](https://pkg.go.dev/badge/github.com/jarxorg/fs2/memfs)
+- [s3fs](https://pkg.go.dev/badge/github.com/jarxorg/s3fs)

fs.go

@@ -0,0 +1,105 @@
+package fs2
+
+import (
+	"errors"
+	"io"
+	"io/fs"
+)
+
+var (
+	// ErrNotImplemented "not implemented"
+	ErrNotImplemented = errors.New("not implemented")
+)
+
+// WriterFile is a file that provides an implementation fs.File and io.Writer.
+type WriterFile interface {
+	fs.File
+	io.Writer
+}
+
+// WriteFileFS is the interface implemented by a filesystem that provides an
+// optimized implementation of MkdirAll, CreateFile, WriteFile.
+type WriteFileFS interface {
+	fs.FS
+	MkdirAll(dir string, mode fs.FileMode) error
+	CreateFile(name string, mode fs.FileMode) (WriterFile, error)
+	WriteFile(name string, p []byte, mode fs.FileMode) (n int, err error)
+}
+
+// MkdirAll creates the named directory. If the filesystem implements
+// WriteFileFS calls fsys.MkdirAll otherwise returns a PathError.
+func MkdirAll(fsys fs.FS, dir string, mode fs.FileMode) error {
+	if fsys, ok := fsys.(WriteFileFS); ok {
+		return fsys.MkdirAll(dir, mode)
+	}
+	return &fs.PathError{Op: "MkdirAll", Path: dir, Err: ErrNotImplemented}
+}
+
+// CreateFile creates the named file. If the filesystem implements
+// WriteFileFS calls fsys.CreateFile otherwise returns a PathError.
+func CreateFile(fsys fs.FS, name string, mode fs.FileMode) (WriterFile, error) {
+	if fsys, ok := fsys.(WriteFileFS); ok {
+		return fsys.CreateFile(name, mode)
+	}
+	return nil, &fs.PathError{Op: "CreateFile", Path: name, Err: ErrNotImplemented}
+}
+
+// WriteFile writes the specified bytes to the named file. If the filesystem implements
+// WriteFileFS calls fsys.WriteFile otherwise returns a PathError.
+func WriteFile(fsys fs.FS, name string, p []byte, mode fs.FileMode) (n int, err error) {
+	if fsys, ok := fsys.(WriteFileFS); ok {
+		return fsys.WriteFile(name, p, mode)
+	}
+	return 0, &fs.PathError{Op: "WriteFile", Path: name, Err: ErrNotImplemented}
+}
+
+// RemoveFileFS is the interface implemented by a filesystem that provides an
+// implementation of RemoveFile.
+type RemoveFileFS interface {
+	fs.FS
+	RemoveFile(name string) error
+	RemoveAll(name string) error
+}
+
+// RemoveFile removes the specified named file. If the filesystem implements
+// RemoveFileFS calls fsys.RemoveFile otherwise return a PathError.
+func RemoveFile(fsys fs.FS, name string) error {
+	if fsys, ok := fsys.(RemoveFileFS); ok {
+		return fsys.RemoveFile(name)
+	}
+	return &fs.PathError{Op: "RemoveFile", Path: name, Err: ErrNotImplemented}
+}
+
+// RemoveAll removes path and any children it contains. If the filesystem
+// implements RemoveFileFS calls fsys.RemoveAll otherwise return a PathError.
+func RemoveAll(fsys fs.FS, path string) error {
+	if fsys, ok := fsys.(RemoveFileFS); ok {
+		return fsys.RemoveAll(path)
+	}
+	return &fs.PathError{Op: "RemoveAll", Path: path, Err: ErrNotImplemented}
+}
+
+// CopyFS walks the specified root directory on src and copies directories and
+// files to dest filesystem.
+func CopyFS(dest, src fs.FS, root string) error {
+	return fs.WalkDir(src, root, func(path string, d fs.DirEntry, err error) error {
+		if err != nil || d == nil {
+			return err
+		}
+		if d.IsDir() {
+			return MkdirAll(dest, path, d.Type())
+		}
+		srcFile, err := src.Open(path)
+		if err != nil {
+			return err
+		}
+		destFile, err := CreateFile(dest, path, d.Type())
+		if err != nil {
+			return err
+		}
+		defer destFile.Close()
+
+		_, err = io.Copy(destFile, srcFile)
+		return err
+	})
+}