修改从页面加载的脚本

Question

Lets say a website was loading this script:

<script src="https://example.com/scripts/main.js"></script>

Assuming I had access to it, I could modify the script. Though, in this scenario, I don't have access.
Would it be possible to some how "replace" the contents of that script, without changing the URL?

For example, the original script is:

alert("Hello, World!");

But my modified version is:

alert("Hello!");

However, the URL (to the script) would stay the same.

I know this might sound complicated but, hypothetically, is this possible? At least client-side?

Answer 1

You can edit the script (clint only) by using a userscript manager like TamperMonkey .
This is not going to change the loaded script, but you can load your custom script.