t6.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script type="text/javascript">
// select the target node
var target = document

delete HTMLElement.prototype.onclick
 
// create an observer instance
var observer = new MutationObserver(function(mutations) {
    mutations.forEach(function(mutation) {
        console.log(mutation);

        if(mutation.addedNodes.length > 0){
         if(mutation.addedNodes[0].hasAttribute && mutation.addedNodes[0].hasAttribute('onerror')){
            //mutation.addedNodes[0].removeAttribute('onerror')
            }

            //console.log(mutation.addedNodes[0])
        }
    });
});
 
// configuration of the observer:
var config = { attributes: true, childList: true, characterData: true, subtree:true }
 
// pass in the target node, as well as the observer options
observer.observe(target, config);

    function test (e) {
        "use strict"
         console.log(e.callee)
         alert('1')
     } 

    </script>

</head>
<body onload='console.log("testddd")'>
	<div id="hello" name='hello2'>
        <button id="test" onclick='alert("1")'>click</button>
    </div>
    <img src="xx" onerror='test(arguments)' />
    
<div id="cla" style="\63&#9\06f&#10\0006c&#12\00006F&#13\R:\000072 Ed;color\0\bla:yellow\0\bla;col\0\00 \&#xA0or:blue;">XXX</div>

<IMG SRC="\63&#9j&#X41vascript:alert('test2')">

    <script class="test">
        
      console.log(document.currentScript)
      var c = document.currentScript

      var fun;
      (function(){
        console.log('inside module', document.currentScript)
        
        fun = function(e){

        console.log('inside fun', document.currentScript, e)
        }
      

      })()

        var cd = document.currentScript;

      window.onload=()=>{ fun(cd)}

      var el =document.getElementById('hello')
 
      Object.defineProperty(el, 'test', {writable:false, configurable:false, value: 1})

      var el2 =document.getElementById('hello')


    </script>
</body>
</html>