Дополняем Stack Trace ошибок в асинхронном коде
function main() { const startTime = performance.now(); const timeout = parseInt(timeoutEl.value); setTimeout(function onTime() { Promise.resolve('wrong_json').then(data => { return JSON.parse(data); }).finally(() => { testResultEl.innerText = ` ${performance.now() - startTime} ms`; }); }, isNaN(timeout) ? 0 : timeout); }