// 检查未完成的XHR请求
function checkPendingXHR() {
  const pendingXHRs = [];
  const xhrProto = XMLHttpRequest.prototype;
  const originalOpen = xhrProto.open;
  
  xhrProto.open = function() {
    this._url = arguments[1];
    pendingXHRs.push(this);
    originalOpen.apply(this, arguments);
  };
  
  const originalSend = xhrProto.send;
  xhrProto.send = function() {
    this.addEventListener('loadend', () => {
      const index = pendingXHRs.indexOf(this);
      if (index > -1) {
        pendingXHRs.splice(index, 1);
      }
    });
    originalSend.apply(this, arguments);
  };
  
  return {
    getPending: () => pendingXHRs.map(xhr => xhr._url),
    clear: () => { pendingXHRs.length = 0; }
  };
}

const xhrTracker = checkPendingXHR();
// 获取所有待处理XHR
console.log('Pending XHRs:', xhrTracker.getPending());

// 拦截Fetch请求
const originalFetch = window.fetch;
window.fetch = function() {
  console.log('Fetch request:', arguments);
  return originalFetch.apply(this, arguments)
    .then(response => {
      console.log('Fetch response:', response);
      return response;
    });
};

// 取消请求示例
const controller = new AbortController();
const signal = controller.signal;

fetch(url, { signal })
  .then(response => response.json())
  .then(data => console.log(data))
  .catch(err => {
    if (err.name === 'AbortError') {
      console.log('Request aborted');
    }
  });

// 取消请求
controller.abort();