import { games } from '../lib/games.js' const ids = Object.keys(games) Object.keys(games).forEach((key) => { if (games[key].extra && games[key].extra.old_id) { const idOld = games[key].extra.old_id ids.push(idOld) } }) function hasDuplicates(obj) { const uniqueSet = new Set() for (const item of obj) { if (uniqueSet.has(item)) { console.log('Duplicate:', item) return true } uniqueSet.add(item) } return false } if (hasDuplicates(ids)) { console.log('Duplicates found.') } else { console.log('No duplicates found.') }