Intercept a HTTP request or response

document.addEventListener("DOMContentLoaded", function () {
  var originalOpen = XMLHttpRequest.prototype.open;
  var originalSend = XMLHttpRequest.prototype.send;

  XMLHttpRequest.prototype.open = function (method, url) {
    console.log("Intercepted HTTP request: " + method + " " + url);
    originalOpen.apply(this, arguments);
  };

  XMLHttpRequest.prototype.send = function () {
    var self = this;

    // Hooking the onreadystatechange event to intercept the response
    this.onreadystatechange = function () {
      if (self.readyState === 4) {
        console.log(
          "Intercepted HTTP response:",
          JSON.parse(self.responseText),
        );
      }
    };

    originalSend.apply(this, arguments);
  };

  // Example: Making a sample XMLHttpRequest
  var xhr = new XMLHttpRequest();
  xhr.open("GET", "https://jsonplaceholder.typicode.com/todos/1", true);
  xhr.send();
});

//Output
("Intercepted HTTP request: GET https://jsonplaceholder.typicode.com/todos/1");
"Intercepted HTTP response:",
  {
    completed: false,
    id: 1,
    title: "delectus aut autem",
    userId: 1,
  };