os: ReadDir on regular file returns non nil slice on Windows #75157
Description
Go version
go version go1.25.0 windows/amd64
Output of go env in your module/workspace:
AR=ar
CC=gcc
CGO_CFLAGS=-O2 -g
CGO_CPPFLAGS=
CGO_CXXFLAGS=-O2 -g
CGO_ENABLED=1
CGO_FFLAGS=-O2 -g
CGO_LDFLAGS=-O2 -g
CXX=g++
GCCGO=gccgo
GO111MODULE=
GOAMD64=v1
GOARCH=amd64
GOAUTH=netrc
GOBIN=
GOCACHE=C:\Users\runneradmin\AppData\Local\go-build
GOCACHEPROG=
GODEBUG=
GOENV=C:\Users\runneradmin\AppData\Roaming\go\env
GOEXE=.exe
GOEXPERIMENT=
GOFIPS140=off
GOFLAGS=
GOGCCFLAGS=-m64 -mthreads -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=C:\Users\RUNNER~1\AppData\Local\Temp\go-build2877138821=/tmp/go-build -gno-record-gcc-switches
GOHOSTARCH=amd64
GOHOSTOS=windows
GOINSECURE=
GOMOD=D:\a\tracktools\tracktools\go.mod
GOMODCACHE=C:\Users\runneradmin\go\pkg\mod
GONOPROXY=
GONOSUMDB=
GOOS=windows
GOPATH=C:\Users\runneradmin\go
GOPRIVATE=
GOPROXY=https://proxy.golang.org,direct
GOROOT=C:\hostedtoolcache\windows\go\1.25.0\x64
GOSUMDB=sum.golang.org
GOTELEMETRY=local
GOTELEMETRYDIR=C:\Users\runneradmin\AppData\Roaming\go\telemetry
GOTMPDIR=
GOTOOLCHAIN=auto
GOTOOLDIR=C:\hostedtoolcache\windows\go\1.25.0\x64\pkg\tool\windows_amd64
GOVCS=
GOVERSION=go1.25.0
GOWORK=
PKG_CONFIG=pkg-configWhat did you do?
Call os.ReadDir on a file entry, Linux and Mac both return nil, syscall.ENOTDIR but Windows returns []fs.DirEntry{}, syscall.ENOTDIR.
In previous versions of go (v1.22) all platforms returned []fs.DirEntry{}, syscall.ENOTDIR
package main
import (
"io/fs"
"os"
"syscall"
"testing"
"time"
"github.com/stretchr/testify/require"
)
func Test_ReadDir(t *testing.T) {
tf, err := os.CreateTemp(t.TempDir(), "os-test")
require.NoError(t, err)
name := tf.Name()
require.NoError(t, tf.Close())
dirs, err := os.ReadDir(name)
require.ErrorIs(t, err, syscall.ENOTDIR)
var expectedDirs []fs.DirEntry
require.Equal(t, expectedDirs, dirs)
}Result is:
osfs_test.go:23:
Error Trace: osfs_test.go:23
Error: Not equal:
expected: []fs.DirEntry(nil)
actual : []fs.DirEntry{}
Diff:
--- Expected
+++ Actual
@@ -1,2 +1,3 @@
-([]fs.DirEntry) <nil>
+([]fs.DirEntry) {
+}
Test: Test_ReadDir
What did you see happen?
Windows returned []fs.DirEntry{}, syscall.ENOTDIR
What did you expect to see?
Consistent behaviour between all operating systems, Linux and Mac both return nil, syscall.ENOTDIR but Windows returns []fs.DirEntry{}, syscall.ENOTDIR.