1 files changed, 187 insertions, 0 deletions
diff --git a/src/os/error_test.go b/src/os/error_test.go
new file mode 100644
index 0000000..6264ccc
--- /dev/null
+++ b/src/os/error_test.go
@@ -0,0 +1,187 @@
+// Copyright 2012 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 os_test
+
+import (
+	"errors"
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestErrIsExist(t *testing.T) {
+	f, err := os.CreateTemp("", "_Go_ErrIsExist")
+	if err != nil {
+		t.Fatalf("open ErrIsExist tempfile: %s", err)
+		return
+	}
+	defer os.Remove(f.Name())
+	defer f.Close()
+	f2, err := os.OpenFile(f.Name(), os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600)
+	if err == nil {
+		f2.Close()
+		t.Fatal("Open should have failed")
+		return
+	}
+	if s := checkErrorPredicate("os.IsExist", os.IsExist, err, fs.ErrExist); s != "" {
+		t.Fatal(s)
+		return
+	}
+}
+
+func testErrNotExist(name string) string {
+	f, err := os.Open(name)
+	if err == nil {
+		f.Close()
+		return "Open should have failed"
+	}
+	if s := checkErrorPredicate("os.IsNotExist", os.IsNotExist, err, fs.ErrNotExist); s != "" {
+		return s
+	}
+
+	err = os.Chdir(name)
+	if err == nil {
+		return "Chdir should have failed"
+	}
+	if s := checkErrorPredicate("os.IsNotExist", os.IsNotExist, err, fs.ErrNotExist); s != "" {
+		return s
+	}
+	return ""
+}
+
+func TestErrIsNotExist(t *testing.T) {
+	tmpDir, err := os.MkdirTemp("", "_Go_ErrIsNotExist")
+	if err != nil {
+		t.Fatalf("create ErrIsNotExist tempdir: %s", err)
+		return
+	}
+	defer os.RemoveAll(tmpDir)
+
+	name := filepath.Join(tmpDir, "NotExists")
+	if s := testErrNotExist(name); s != "" {
+		t.Fatal(s)
+		return
+	}
+
+	name = filepath.Join(name, "NotExists2")
+	if s := testErrNotExist(name); s != "" {
+		t.Fatal(s)
+		return
+	}
+}
+
+func checkErrorPredicate(predName string, pred func(error) bool, err, target error) string {
+	if !pred(err) {
+		return fmt.Sprintf("%s does not work as expected for %#v", predName, err)
+	}
+	if !errors.Is(err, target) {
+		return fmt.Sprintf("errors.Is(%#v, %#v) = false, want true", err, target)
+	}
+	return ""
+}
+
+type isExistTest struct {
+	err   error
+	is    bool
+	isnot bool
+}
+
+var isExistTests = []isExistTest{
+	{&fs.PathError{Err: fs.ErrInvalid}, false, false},
+	{&fs.PathError{Err: fs.ErrPermission}, false, false},
+	{&fs.PathError{Err: fs.ErrExist}, true, false},
+	{&fs.PathError{Err: fs.ErrNotExist}, false, true},
+	{&fs.PathError{Err: fs.ErrClosed}, false, false},
+	{&os.LinkError{Err: fs.ErrInvalid}, false, false},
+	{&os.LinkError{Err: fs.ErrPermission}, false, false},
+	{&os.LinkError{Err: fs.ErrExist}, true, false},
+	{&os.LinkError{Err: fs.ErrNotExist}, false, true},
+	{&os.LinkError{Err: fs.ErrClosed}, false, false},
+	{&os.SyscallError{Err: fs.ErrNotExist}, false, true},
+	{&os.SyscallError{Err: fs.ErrExist}, true, false},
+	{nil, false, false},
+}
+
+func TestIsExist(t *testing.T) {
+	for _, tt := range isExistTests {
+		if is := os.IsExist(tt.err); is != tt.is {
+			t.Errorf("os.IsExist(%T %v) = %v, want %v", tt.err, tt.err, is, tt.is)
+		}
+		if is := errors.Is(tt.err, fs.ErrExist); is != tt.is {
+			t.Errorf("errors.Is(%T %v, fs.ErrExist) = %v, want %v", tt.err, tt.err, is, tt.is)
+		}
+		if isnot := os.IsNotExist(tt.err); isnot != tt.isnot {
+			t.Errorf("os.IsNotExist(%T %v) = %v, want %v", tt.err, tt.err, isnot, tt.isnot)
+		}
+		if isnot := errors.Is(tt.err, fs.ErrNotExist); isnot != tt.isnot {
+			t.Errorf("errors.Is(%T %v, fs.ErrNotExist) = %v, want %v", tt.err, tt.err, isnot, tt.isnot)
+		}
+	}
+}
+
+type isPermissionTest struct {
+	err  error
+	want bool
+}
+
+var isPermissionTests = []isPermissionTest{
+	{nil, false},
+	{&fs.PathError{Err: fs.ErrPermission}, true},
+	{&os.SyscallError{Err: fs.ErrPermission}, true},
+}
+
+func TestIsPermission(t *testing.T) {
+	for _, tt := range isPermissionTests {
+		if got := os.IsPermission(tt.err); got != tt.want {
+			t.Errorf("os.IsPermission(%#v) = %v; want %v", tt.err, got, tt.want)
+		}
+		if got := errors.Is(tt.err, fs.ErrPermission); got != tt.want {
+			t.Errorf("errors.Is(%#v, fs.ErrPermission) = %v; want %v", tt.err, got, tt.want)
+		}
+	}
+}
+
+func TestErrPathNUL(t *testing.T) {
+	f, err := os.CreateTemp("", "_Go_ErrPathNUL\x00")
+	if err == nil {
+		f.Close()
+		t.Fatal("TempFile should have failed")
+	}
+	f, err = os.CreateTemp("", "_Go_ErrPathNUL")
+	if err != nil {
+		t.Fatalf("open ErrPathNUL tempfile: %s", err)
+	}
+	defer os.Remove(f.Name())
+	defer f.Close()
+	f2, err := os.OpenFile(f.Name(), os.O_RDWR, 0600)
+	if err != nil {
+		t.Fatalf("open ErrPathNUL: %s", err)
+	}
+	f2.Close()
+	f2, err = os.OpenFile(f.Name()+"\x00", os.O_RDWR, 0600)
+	if err == nil {
+		f2.Close()
+		t.Fatal("Open should have failed")
+	}
+}
+
+func TestPathErrorUnwrap(t *testing.T) {
+	pe := &fs.PathError{Err: fs.ErrInvalid}
+	if !errors.Is(pe, fs.ErrInvalid) {
+		t.Error("errors.Is failed, wanted success")
+	}
+}
+
+type myErrorIs struct{ error }
+
+func (e myErrorIs) Is(target error) bool { return target == e.error }
+
+func TestErrorIsMethods(t *testing.T) {
+	if os.IsPermission(myErrorIs{fs.ErrPermission}) {
+		t.Error("os.IsPermission(err) = true when err.Is(fs.ErrPermission), wanted false")
+	}
+}