package wal

import (
	"os"
	"strings"
	"testing"
)

func TestDirFsyncSuccess(t *testing.T) {
	dir := t.TempDir()
	if err := dirFsync(dir); err != nil {
		t.Errorf("dirFsync on valid dir: %v", err)
	}
}

func TestDirFsyncNonExistentDir(t *testing.T) {
	err := dirFsync("/nonexistent/path/that/should/not/exist")
	if err == nil {
		t.Fatal("expected error on non-existent dir")
	}
	if !strings.Contains(err.Error(), "open dir") {
		t.Errorf("error should mention 'open dir', got: %v", err)
	}
}

func TestDirFsyncNotADirectory(t *testing.T) {
	dir := t.TempDir()
	filePath := dir + "/notadir"
	if err := os.WriteFile(filePath, []byte("x"), 0o644); err != nil {
		t.Fatalf("WriteFile: %v", err)
	}
	err := dirFsync(filePath)
	if err == nil {
		t.Fatal("expected error when fsyncing a file as dir")
	}
	if !strings.Contains(err.Error(), "not a directory") {
		t.Errorf("error should mention 'not a directory', got: %v", err)
	}
}