Question

我有以下承诺链：

return fetch(request)
  .then(checkStatus)
  .then(response => response.json())
  .then(json => ({ response: json }))
  .catch(error => ({ error }))

checkstatus()检查请求是否成功，如果不成功则返回错误。将捕获并返回此错误。但是，问题是我想将response.statusText和response.json()的结果都添加到错误中。问题在于，当我解析它时，我失去了链中的原始响应，因为我必须返回response.json()，因为它是一个承诺。

这就是checkstatus目前所做的事情：

const checkStatus = response => {
  if (response.ok) return response

  const error = new Error('Response is not ok')

  // this works because the response hasn't been parsed yet
  if (response.statusText) error.message = response.statusText

  // an error response from our api will include errors, but these are
  // not available here since response.json() hasn't been called
  if (response.errors) error.errors = response.errors

  throw error
}

export default checkStatus

如何使用error.message = response.statusText和error.errors = response.json().errors返回错误？

Answer 1

这是我的理解fetch错误处理的帮手， fetchOk ：

let fetchOk = (...args) => fetch(...args)
  .then(res => res.ok ? res : res.json().then(data => {
    throw Object.assign(new Error(data.error_message), {name: res.statusText});
  }));

然后我替换fetch。

＆＃13;

let fetchOk = (...args) => fetch(...args)
  .then(res => res.ok ? res : res.json().then(data => {
    throw Object.assign(new Error(data.error_message), {name: res.statusText});
  }));

fetchOk("https://api.stackexchange.com/2.2/blah")
  .then(response => response.json())
  .catch(e => console.log(e)); // Bad Request: no method found with this name

var console = { log: msg => div.innerHTML += msg + "<br>" };

＆＃13;

<div id="div"></div>

＆＃13;

除非出现错误，否则不会加载数据，直接替换它。

Answer 2

我使用新的async / await语法，因为它以更直观的方式读取：

 async fetchData(request) {
    try {
      const response = await fetch(request)
      const data = await response.json()

      // return the data if the response was ok
      if (response.ok) return { data }

      // otherwise return an error with the error data
      const error = new Error(response.statusText)
      if (data.errors) error.errors = data.errors

      throw error
    } catch (error) {
      return { error }
    }
  }

它可以很容易地处理fetch返回的承诺以及response.json()返回的承诺。

如何在获取错误中包含已解析的响应和原始响应头

2 个答案: