Improve 'prevent-xhr' — multiple requests

[AdamWr]

In a specific case scriptlet doesn't prevent request.

Steps to reproduce

1. Add this rule:

example.org#%#//scriptlet('prevent-xhr', '/advert')

2. Go to - https://example.org/
3. Run in console

(()=>{
const xhr_should_be_blocked = new XMLHttpRequest();
const xhr_should_not_blocked = new XMLHttpRequest();
xhr_should_be_blocked.open('GET', '/advert', true);
xhr_should_not_blocked.open('GET', '/test', true);
xhr_should_be_blocked.send(null);
xhr_should_not_blocked.send(null);
})();

Request to /advert should be prevented by scriptlet, but it isn't.

Screenshot

As far as I understand, the problem is that initially when open('GET', '/advert', true); is called, shouldPrevent in openWrapper function is set to true (it's fine)

Scriptlets/src/scriptlets/prevent-xhr.js

Line 114 in 202f6d8

shouldPrevent = matchRequestProps(source, propsToMatch, xhrData);

but then open('GET', '/test', true); is fired and shouldPrevent is set to false, so in sendWrapper

Scriptlets/src/scriptlets/prevent-xhr.js

Lines 120 to 123 in 202f6d8

	const sendWrapper = (target, thisArg, args) => {
	if (!shouldPrevent) {
	return Reflect.apply(target, thisArg, args);
	}

shouldPrevent is false and request is not prevented.

If an order will be changed, like this:

Code:

(()=>{
const xhr_should_be_blocked = new XMLHttpRequest();
const xhr_should_not_blocked = new XMLHttpRequest();
xhr_should_not_blocked.open('GET', '/test', true);
xhr_should_be_blocked.open('GET', '/advert', true);
xhr_should_be_blocked.send(null);
xhr_should_not_blocked.send(null);
})();

then both request will be blocked, but only /advert should be blocked.