javascript - 什么情况下会触发 axios.interceptors.request.use 错误回调函数？

Question

试过很多情况，还是不知道怎么触发axios.interceptors.request.use错误回调函数

// Add a request interceptor
axios.interceptors.request.use(function (config) {
    // Do something before request is sent
    return config;
  }, function (error) {
    // Do something with request error
    // Under what circumstances will this callback function be triggered?
    return Promise.reject(error);
});

标签： javascriptaxiosxmlhttprequest