executeScript function can't access full window/globalThis object

[Marc Lajoie]

Hi, I'm struggling with a devilish issue.

So, I run a function from my popup using `chrome.scripting.executeScript`, invoking it like this:

```
await chrome.scripting.executeScript({
    target: { tabId, allFrames: true },
    func: inPageFunction,

});

```

So far so good. inPageFunction can interact with the current tab, and everything seems to work, so I know my permissions are correct.

Here's where the problem lies:
If inPageFunction tries to access a global variable that is set by site on the window/globalThis object, it comes back undefined.

```
function inPageFunction() {

   console.log(window.theGlobal); // gives undefined

}

```

However, if I open the console on that site, and run `console.log(window.theGlobal)`, I get a result.

The executeScript is invoked by a button in the popup. I'll hit the button, check the console, and see it has outputted "undefined". I'll then immediately run `console.log(window.theGlobal)` and see theGlobal is indeed defined.

Does my content script not have access to the full window/globalThis object? Is it filtered in some way? I can't figure this out. Any help would be appreciated.

(Manifest v3, btw)

Marc

[Oliver Dunk]

Hi Marc,

Extensions have the concept of "isolated worlds". These are separate JavaScript contexts which can access the same DOM. We have some documentation on those here: https://developer.chrome.com/docs/extensions/mv3/content_scripts/#isolated_world

By default, scripting.executeScript executes in the isolated world. But you can specify a world explicitly to override this: https://developer.chrome.com/docs/extensions/reference/scripting/#property-ScriptInjection-world

Hopefully that helps!

Oliver Dunk | DevRel, Chrome Extensions | https://developer.chrome.com/ | London, GB

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[Marc Lajoie]

Thanks, you're a champion. That completely solved it. I don't think I would have ever found that in the docs on my own.

Marc

[Oliver Dunk]

No problem! I'll make a mental note that we might want to improve the docs here.

Oliver Dunk | DevRel, Chrome Extensions | https://developer.chrome.com/ | London, GB