javascript - 在 Ramda 中有条件地 promise

Question

如何将 R.cond 与 promises 一起使用？

像这样的..

const fetchBin = (url) => fetch(`https://httpbin.org${url}`).then((response) => {
    var contentType = response.headers.get("content-type");
    if(contentType && contentType.includes("application/json")) {
      return response.json();
    }
    throw new TypeError("Oops, we haven't got JSON!");
})

const testStatus = (status) => fetchBin(`/status/${status}`);

const isOk = R.propEq('statusCode', 200);
const testCond = R.cond([
    [ R.pipeP(testStatus, isOk), (resp) => console.log('The resp is ', resp) ],
    [ R.T, (code) => console.log('The resp is NOT ok', code) ]
])

testCond(404)
// R.pipeP(testStatus, isOk)(404)

<script src="https://cdnjs.cloudflare.com/ajax/libs/ramda/0.24.1/ramda.min.js"></script>

Answer 1

我认为这就是您所追求的，通过将其与 testStatus 组合在一起，您应该能够获得 response 对象并执行条件分支。

const fetchBin = (url) => fetch(`https://httpbin.org${url}`).then((response) => {
    var contentType = response.headers.get("content-type");
    if(contentType && contentType.includes("application/json")) {
      return response.json();
    }
    throw new TypeError("Oops, we haven't got JSON!");
})

const testStatus = (status) => fetchBin(`/status/${status}`);

const isOk = R.propEq('statusCode', 200);
const testCond = R.pipeP(testStatus, R.cond([
  [isOk, resp => console.log('The resp is OK :' + resp.statusCode)],
  [R.T, resp => console.log('The resp is NOT OK :' + resp.statusCode)]
]));

testCond(404)
// R.pipeP(testStatus, isOk)(404)

<script src="https://cdnjs.cloudflare.com/ajax/libs/ramda/0.24.1/ramda.min.js"></script>