eliminate-calls-to-url-match.js

function breakOnUrlMatch(str, callback) {
       let nextOpen = XMLHttpRequest.prototype.open;
       XMLHttpRequest.prototype.open = function monkeypatchedOpen(...args) {
               let url = args[1];
               if (url && url.indexOf(str) >= 0) { if (callback()) { return; } }
//               console.log('XHR for ', url);
               return nextOpen(...args);
       }

       let nextFetch = window.fetch;
       window.fetch = function monkeypatchedFetch(...args) {
               let url = args[0];
               if (url && url.indexOf(str) >= 0) { if (callback()) { return; } }
//               console.log('Fetch for ', url);
               return nextFetch(...args);
       }
}

function eliminateCallsToUrlMatch(str) {
  breakOnUrlMatch(str, () => true);
}

eliminateCallsToUrlMatch('/sockjs');