动态创建 script 方式加载JS脚本

<script>
(function (url) {
    var scrs = document.getElementsByTagName('script');
    var last = scrs[scrs.length - 1];
    var scr = document.createElement('script');
    scr.src = url;
    scr.async = true;
    last.parentNode.insertBefore(scr, last);
})('test.js');
</script>

不应该被block的文字