//go:build linux || darwin || windows

package fileops

import (
	"os"
	"path/filepath"
	"testing"
)

func TestRenameDirectoryNoReplacePreservesExistingDestination(t *testing.T) {
	root := t.TempDir()
	src := filepath.Join(root, "source")
	dst := filepath.Join(root, "destination")
	mustWriteFile(t, filepath.Join(src, "value.txt"), []byte("source"), 0o644)
	mustWriteFile(t, filepath.Join(dst, "value.txt"), []byte("existing"), 0o644)

	if err := renameDirectoryNoReplace(src, dst); err == nil {
		t.Fatal("renameDirectoryNoReplace() error = nil, want existing destination failure")
	}
	assertFileBytes(t, filepath.Join(src, "value.txt"), []byte("source"))
	assertFileBytes(t, filepath.Join(dst, "value.txt"), []byte("existing"))
	if info, err := os.Stat(src); err != nil || !info.IsDir() {
		t.Fatalf("source directory was not preserved: info=%v err=%v", info, err)
	}
}