Put a semicolon there - Qiita

'use strict'; let range = { from: 1, to: 5, [Symbol.asyncIterator]() { return { current: this.from, last: this.to, async next() { await new Promise(resolve => setTimeout(resolve, 1000)); if (this.current <= this.last) return { done: false, value: this.current++ }; else return { done: true }; } }; } }; // here (async () => { for await (const value of range) console.log(value); })(); here のセミコロンを忘れる