A Monkey patch is a way for a program to extend or modify supporting system software locally (affecting only the running instance of the program).”
也可以可以理解为基于原生功能（API）的一些自定义拓展？这个概念常在 Python 里面出现，也叫鸭子双关
Checking if a JavaScript native function is monkey patched
Monkey patching is a powerful but dangerous technique because the code you’re overriding is not in your control: future updates to the JavaScript engine may break some assumptions made in your patch and cause serious bugs. Additionally, by monkey patching code you don’t own, you might override some code that has already been monkey patched by another developer, introducing a potential conflict.
对于 JS 来说，Monkey patch 的问题在于：如果 JS 引擎更新了，可能会带来一些难以预计的 bug，这篇文章说了几种怎么检测是否存在 monkey patch 函数的方法，比如用 toString、iframe、proxy 等等，但都不是很完美，可以根据使用场景来决定用哪种方法