封装的fetch

fetch

const defaultUrl = 'https://cnodejs.org/api/v1';
const header = new Headers({
  'Accept': 'application/json',
  'Content-Type': 'application/json'
});
const defaultConfig = {
  method: 'GET',
  headers: header,
  mode: 'cors',
  credentials: "same-origin", // 设置fetch自动地发送本地的Cookie
  cache: 'no-cache',
  redirect: 'follow'
};
let checkStatus = (response) => {
  if (response.ok) {
    return response.json();
  } else {
    let error = new Error(response.statusText)
    error.response = response
    throw error
  }
};


let $fetch = (url, config) => {
  let finalUrl = defaultUrl + url;
  let request = config ? new Request(finalUrl, Object.assign({}, defaultConfig, config)) : finalUrl;
  const fetchDefer = new Promise((resolve, reject) => {
    fetch(request).then(checkStatus).then(data => {
      if (data) {
        resolve(data) //返回成功数据
      } else {
        reject(data) //返回失败数据
      }
    }).catch(error => { //捕获异常
      alert(error.response.status + error.response.statusText)
    })
  });
  return fetchDefer
};


export default $fetch;