How to get through context isolation in Chrome extension (manifest v.3)

Question

Let's say my Chrome extension wants to work with a page containing the following html:

<!DOCTYPE html>
<html> <head> <script>
            var foo = Math.random();

            function bar(e) {
                console.log(e + '_123');
            }
</script> </head>
<body> Baz </body></html>

Inside my extension I want

read generated value of foo
run bar as if it was runned by page native script.

My manifest.json is

{
    "manifest_version": 3,
    "name": "Sample ext",
    "version": "1.0.0",
    "permissions": ["activeTab"],
    "content_scripts": [
      {
        "matches": ["<all_urls>"],
        "js": ["content.js"]
      }
    ]
}

...and content.js is:

window.addEventListener('load', function() {
    console.log(window.foo);
    window.bar('arg');
});

I thought that the script specified in content_scripts is injected into the page as if it were in its code initially.

Obviously, this is not the case: content.js and the page have different window objects:

It seems that content.js (although it has access to DOM) is executed in some kind of sandbox environment.

Is there a way to get past this limitation?

How to get through context isolation in Chrome extension (manifest v.3)

0 Answers0