@musi 确实又绕过了。。又升级了下，再看看呢

```
```
function isNative(api) {
if (XMLHttpRequest.hasOwnProperty('toString')) return false;
if (typeof XMLHttpRequest != 'function') return false;
if (typeof XMLHttpRequest.valueOf != 'function' ||
XMLHttpRequest.valueOf().toString() != 'function XMLHttpRequest() { [native code] }') {
return false;
}
return /native code/.test(api.toString()) && typeof api !== 'undefined'
}

console.error(isNative(XMLHttpRequest))
```
```