Add simple test for fs.TempFile on windows

internal/fs/file_windows_test.go

@@ -0,0 +1,35 @@
+package fs_test
+
+import (
+	"errors"
+	"os"
+	"testing"
+
+	"github.com/restic/restic/internal/fs"
+	rtest "github.com/restic/restic/internal/test"
+)
+
+func TestTempFile(t *testing.T) {
+	// create two temp files at the same time to check that the
+	// collision avoidance works
+	f, err := fs.TempFile("", "test")
+	fn := f.Name()
+	rtest.OK(t, err)
+	f2, err := fs.TempFile("", "test")
+	fn2 := f2.Name()
+	rtest.OK(t, err)
+	rtest.Assert(t, fn != fn2, "filenames don't differ %s", fn)
+
+	_, err = os.Stat(fn)
+	rtest.OK(t, err)
+	_, err = os.Stat(fn2)
+	rtest.OK(t, err)
+
+	rtest.OK(t, f.Close())
+	rtest.OK(t, f2.Close())
+
+	_, err = os.Stat(fn)
+	rtest.Assert(t, errors.Is(err, os.ErrNotExist), "err %s", err)
+	_, err = os.Stat(fn2)
+	rtest.Assert(t, errors.Is(err, os.ErrNotExist), "err %s", err)
+}