feat: Porting io/fs package

examples/gno.land/r/demo/boards/z_4_filetest.gno

@@ -374,7 +374,7 @@ func main() {
 //                     "Escaped": true,
 //                     "ObjectID": "336074805fc853987abe6f7fe3ad97a6a6f3077a:2"
 //                 },
-//                 "Index": "188",
+//                 "Index": "191",
 //                 "TV": null
 //             }
 //         }
@@ -541,7 +541,7 @@ func main() {
 //             },
 //             "V": {
 //                 "@type": "/gno.RefValue",
-//                 "Hash": "8164abed5231309c88497013f7da72a1b5d427b0",
+//                 "Hash": "40c644a23c5104a1d6695e17aeac3939dcfecf70",
 //                 "ObjectID": "f6dbf411da22e67d74cd7ddba6a76cd7e14a4822:115"
 //             }
 //         },
@@ -847,7 +847,7 @@ func main() {
 //             },
 //             "V": {
 //                 "@type": "/gno.RefValue",
-//                 "Hash": "5b4b593f1d4b37cb99166247ea28174f91087fdd",
+//                 "Hash": "8dbf25500e2f04e50584894e606ad0788fe6920d",
 //                 "ObjectID": "f6dbf411da22e67d74cd7ddba6a76cd7e14a4822:82"
 //             }
 //         },
@@ -865,7 +865,7 @@ func main() {
 //             },
 //             "V": {
 //                 "@type": "/gno.RefValue",
-//                 "Hash": "7e9fd9bb5e90a06c7751585cd80f23aedddde25b",
+//                 "Hash": "64d61e4f065f6d0760e37b76fbd832db903b68ec",
 //                 "ObjectID": "f6dbf411da22e67d74cd7ddba6a76cd7e14a4822:83"
 //             }
 //         },

gnovm/stdlibs/internal/oserror/errors.gno

@@ -0,0 +1,11 @@
+package oserror
+
+import "errors"
+
+var (
+	ErrInvalid    = errors.New("invalid argument")
+	ErrPermission = errors.New("permission denied")
+	ErrExist      = errors.New("file already exists")
+	ErrNotExist   = errors.New("file does not exist")
+	ErrClosed     = errors.New("file closed")
+)

gnovm/stdlibs/io/fs/format.gno

@@ -0,0 +1,76 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fs
+
+import (
+	"time"
+)
+
+// FormatFileInfo returns a formatted version of info for human readability.
+// Implementations of [FileInfo] can call this from a String method.
+// The output for a file named "hello.go", 100 bytes, mode 0o644, created
+// January 1, 1970 at noon is
+//
+//	-rw-r--r-- 100 1970-01-01 12:00:00 hello.go
+func FormatFileInfo(info FileInfo) string {
+	name := info.Name()
+	b := make([]byte, 0, 40+len(name))
+	b = append(b, info.Mode().String()...)
+	b = append(b, ' ')
+
+	size := info.Size()
+	var usize uint64
+	if size >= 0 {
+		usize = uint64(size)
+	} else {
+		b = append(b, '-')
+		usize = uint64(-size)
+	}
+	var buf [20]byte
+	i := len(buf) - 1
+	for usize >= 10 {
+		q := usize / 10
+		buf[i] = byte('0' + usize - q*10)
+		i--
+		usize = q
+	}
+	buf[i] = byte('0' + usize)
+	b = append(b, buf[i:]...)
+	b = append(b, ' ')
+
+	b = append(b, info.ModTime().Format(time.DateTime)...)
+	b = append(b, ' ')
+
+	b = append(b, name...)
+	if info.IsDir() {
+		b = append(b, '/')
+	}
+
+	return string(b)
+}
+
+// FormatDirEntry returns a formatted version of dir for human readability.
+// Implementations of [DirEntry] can call this from a String method.
+// The outputs for a directory named subdir and a file named hello.go are:
+//
+//	d subdir/
+//	- hello.go
+func FormatDirEntry(dir DirEntry) string {
+	name := dir.Name()
+	b := make([]byte, 0, 5+len(name))
+
+	// The Type method does not return any permission bits,
+	// so strip them from the string.
+	mode := dir.Type().String()
+	mode = mode[:len(mode)-9]
+
+	b = append(b, mode...)
+	b = append(b, ' ')
+	b = append(b, name...)
+	if dir.IsDir() {
+		b = append(b, '/')
+	}
+	return string(b)
+}

gnovm/stdlibs/io/fs/format_test.gno

@@ -0,0 +1,122 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fs_test
+
+import (
+	"io/fs"
+	"testing"
+	"time"
+)
+
+// formatTest implements FileInfo to test FormatFileInfo,
+// and implements DirEntry to test FormatDirEntry.
+type formatTest struct {
+	name    string
+	size    int64
+	mode    fs.FileMode
+	modTime time.Time
+	isDir   bool
+}
+
+func (fs *formatTest) Name() string {
+	return fs.name
+}
+
+func (fs *formatTest) Size() int64 {
+	return fs.size
+}
+
+func (fs *formatTest) Mode() fs.FileMode {
+	return fs.mode
+}
+
+func (fs *formatTest) ModTime() time.Time {
+	return fs.modTime
+}
+
+func (fs *formatTest) IsDir() bool {
+	return fs.isDir
+}
+
+func (fs *formatTest) Sys() interface{} {
+	return nil
+}
+
+func (fs *formatTest) Type() fs.FileMode {
+	return fs.mode.Type()
+}
+
+func (fs *formatTest) Info() (fs.FileInfo, error) {
+	return fs, nil
+}
+
+var formatTests = []struct {
+	input        formatTest
+	wantFileInfo string
+	wantDirEntry string
+}{
+	{
+		formatTest{
+			name:    "hello.go",
+			size:    100,
+			mode:    0o644,
+			modTime: time.Date(1970, time.January, 1, 12, 0, 0, 0, time.UTC),
+			isDir:   false,
+		},
+		"-rw-r--r-- 100 1970-01-01 12:00:00 hello.go",
+		"- hello.go",
+	},
+	{
+		formatTest{
+			name:    "home/gopher",
+			size:    0,
+			mode:    fs.ModeDir | 0o755,
+			modTime: time.Date(1970, time.January, 1, 12, 0, 0, 0, time.UTC),
+			isDir:   true,
+		},
+		"drwxr-xr-x 0 1970-01-01 12:00:00 home/gopher/",
+		"d home/gopher/",
+	},
+	{
+		formatTest{
+			name:    "big",
+			size:    0x7fffffffffffffff,
+			mode:    fs.ModeIrregular | 0o644,
+			modTime: time.Date(1970, time.January, 1, 12, 0, 0, 0, time.UTC),
+			isDir:   false,
+		},
+		"?rw-r--r-- 9223372036854775807 1970-01-01 12:00:00 big",
+		"? big",
+	},
+	{
+		formatTest{
+			name:    "small",
+			size:    -0x8000000000000000,
+			mode:    fs.ModeSocket | fs.ModeSetuid | 0o644,
+			modTime: time.Date(1970, time.January, 1, 12, 0, 0, 0, time.UTC),
+			isDir:   false,
+		},
+		"Surw-r--r-- -9223372036854775808 1970-01-01 12:00:00 small",
+		"S small",
+	},
+}
+
+func TestFormatFileInfo(t *testing.T) {
+	for i, test := range formatTests {
+		got := fs.FormatFileInfo(&test.input)
+		if got != test.wantFileInfo {
+			t.Errorf("%d: FormatFileInfo(%#v) = %q, want %q", i, test.input, got, test.wantFileInfo)
+		}
+	}
+}
+
+func TestFormatDirEntry(t *testing.T) {
+	for i, test := range formatTests {
+		got := fs.FormatDirEntry(&test.input)
+		if got != test.wantDirEntry {
+			t.Errorf("%d: FormatDirEntry(%#v) = %q, want %q", i, test.input, got, test.wantDirEntry)
+		}
+	}
+}