PerformanceObserver在Firefox中抛出错误,在Chrome中工作
我正在实施PerformanceObserver以跟踪“第一次绘制”和“第一次内容绘制”PerformanceObserver在Firefox中抛出错误,在Chrome中工作,performance,pagespeed,observers,mutation-observers,Performance,Pagespeed,Observers,Mutation Observers,我正在实施PerformanceObserver以跟踪“第一次绘制”和“第一次内容绘制” const observer = new PerformanceObserver((list) => { for (const entry of list.getEntries()) { if (typeof(Storage) !== 'undefined') { if (entry.name === 'first-paint') { localStorage
const observer = new PerformanceObserver((list) => {
for (const entry of list.getEntries()) {
if (typeof(Storage) !== 'undefined') {
if (entry.name === 'first-paint') {
localStorage.setItem(rumMetrics.RUM_METRICS_FIRST_PAINT, entry.startTime);
}
else if (entry.name === 'first-contentful-paint') {
localStorage.setItem(rumMetrics.RUM_METRICS_FIRST_CONTENTFUL_PAINT, entry.startTime);
}
}
else {
console.log('local storage is not supported here. RUM metrics won\'t be recorded.');
}
}
});
observer.observe({ entryTypes: ['paint'] });
这在Chrome中非常有效,但在Firefox中会抛出一个错误
TypeError: The expression cannot be converted to return the specified type. (line: observer.observe({ entryTypes: ['paint'] });)
更新日期:2018年4月20日 Mozilla已经确认了这个bug,并且它每晚都会影响FF61 原始答案 确认即使在开发人员版本中,这也是一个bug 下面是同样的错误
听起来像是要报道的事情