Fix 'prevent-fetch', 'prevent-xhr' — error on blocked request

[Alex-302]

The main problem - now this scriplet does not help if a request/domain is blocked by DNS filtering.
Affected more than 300 rules.

Steps to reproduce

1. Disable Tracking Protection filter and add yext-pixel.com to user rules.
2. Open https://clinics.vippetcare.com/al/birmingham/1928-montgomery-hwy./db089214-36a7-45a8-8f4e-6a14d7c5f17c
3. Click View Pricing button
   => It does not work, because yext-pixel.com is blocked (in my case - by DNS).
4. Add vippetcare.com#%#//scriptlet('prevent-fetch', 'www.yext-pixel.com')

Actual behavior

Scripltetdoes not intercept fetch request, and the button does not work.

Expected behavior

The rule must work like in 4.1.55, where no request when added that rule, and the button is not broken because of blocking request.

[Alex-302]

Not sure if prevent-xhr has the same problem.

[AdamWr]

If I'm not wrong the problem is in this line:

Scriptlets/src/scriptlets/prevent-fetch.js

Line 148 in e7295bd

const origResponse = await Reflect.apply(target, thisArg, args);

It tries to fetch a content, but request is blocked.

Simple test case:

1. Add these rules:

||example.org^$xmlhttprequest
example.org#%#//scriptlet('prevent-fetch', '/')

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

Code:

new Promise((resolve, reject) => {
  return fetch('/').then(response => {
    if (response.ok) {
        console.log('OK test');
      resolve(response)
    } else {
      reject(new Error('error'))
    }
  }, error => {
    reject(new Error(error.message))
  })
})

There should message in the console OK test, but with latest version of scriptlet it's blocked and there is an error.

[Alex-302]

Another problem:
when all filters are turned off, and added technofino.in#%#//scriptlet('prevent-fetch', 'pagead2.googlesyndication.com'), the site detects ad blocker
https://www.technofino.in/community/threads/how-to-apply-for-hsbc-credit-card-for-non-serviceable-address-pincode.1991/

[AdamWr]

According to my tests, it should be fixed with latest changes.

[Alex-302]

Yes, works fine with dev build.