##script:inject(...) takes too long to inject the script

[bakugo]

The ##script:inject(...) directive seems to take 10-50ms to actually inject the specified script after the document starts rendering. This becomes a problem when using scripts like abort-current-inline-script.js because inline scripts placed early enough in the document can bypass it completely by executing early on. It can also lead to cases where a "blocked" script will execute on some page loads but not others.

For example, this rule:

##script:inject(abort-current-inline-script.js, String.fromCharCode)

Should kill this script, but if it loads too fast, it won't happen:

<script>
	window.test = String.fromCharCode;
	console.log("this is not blocked :(");
</script>

Is there any way to remove this delay or is this a browser issue that can't be fixed?

• OS/version: Windows 8.1
• Browser/version: Chrome 63.0.3239.84
• uBlock Origin version: 1.14.20

[uBlock-user]

It can also lead to cases where a "blocked" script will execute on some page loads but not others.

Chrome has a race condition issue, so it's not just that it executes late.

[gorhill]

Browser limitation.

[gorhill]

I've been looking at how to solve this issue since a long time. For example, see #3069.

[uBlock-user]

But that's just for Firefox, what about chrome ?