Has a Badger Lock file?

Users Badger
3

Golang code:

package main

import (
	"fmt"
	"github.com/dgraph-io/badger"
	"log"
	"time"
)

func main () {
	//Badger -----------
	opts := badger.DefaultOptions
	opts.Dir = "badger"
	opts.ValueDir = "badger"
	db, err := badger.Open(opts)
	if err != nil {
		log.Fatal(err)
	}
	defer db.Close()

	err = db.Update(func(txn *badger.Txn) error {
		err := txn.Set([]byte("name"), []byte("John"))
		return err
	})
	var str string
	err = db.View(func(txn *badger.Txn) error {
		item, err := txn.Get([]byte("name"))
		if err != nil {
			return err
		}
		val, err := item.ValueCopy(nil)
		if err != nil {
			return err
		}
		str = string(val)
		return nil
	})
	fmt.Println(str)
	time.Sleep(20*time.Second)

	fmt.Println("OK")
}

I add time.Sleep to code.
If I interrupt the execution of the program, I get lost data and an error accessing the database.
Value log truncate required to run DB. This might result in data loss.