如何从 resolve() 和 reject() 中获取多个值？

Question

我想要 resolve() 到 return {valid_to: cert.valid_to, statusCode, statusMessage} 和 reject() 应该 return {error: -1, statusCode, statusMessage}.

问题

当 statusCode、statusMessage 处于不同的范围时，我该怎么做？

const https = require('https');

(async () => {
  const options = {
    hostname: "github.com",
    port: 443,
    path: '/',
    method: 'GET',
    timeout: 1000
  };

  options.agent = new https.Agent(options);
  let valid_to = await new Promise((resolve, reject) => {
    const req = https.request({
      ...options, checkServerIdentity: function (host, cert) {
        resolve(cert.valid_to);
      }
    }).on('error', error => {
      reject(-2);
    });

    req.on("timeout", chunk => {
      reject(-1);
    });

    req.on('response', response => {
      console.log(response.statusCode);
      console.log(response.statusMessage);
    });

    req.end();
  }).catch(error => {
    console.log(error);
    return -3;
  });

})();

Answer 1

我会做这样的事情。

编辑：您需要在 https.request 对象中指定 res.on('data')。否则，超时将始终发出，因为流中没有 activity。

您可以在 res.on("data") 或 res.on("end") 中解决，这取决于您的用例。

res 是 an IncomingMessage object is created by http.ClientRequest 并分别作为第一个参数传递给 'request' 和 'response' 事件。

req 是 A reference to the original http.ClientRequest.

两个流都可以发出事件，您可以分别处理它们。

还有，当你reject Promise的时候，你实际上是无法从req获取statusCode和StatusMessage的，因为req有错误，.on("response")不会发射。所以，你需要自己定制statusCode和statusMessage。

const https = require("https");

// {valid_to: cert.valid_to, statusCode, statusMessage}
// {error: -1, statusCode, statusMessage}.

(async () => {
    const options = {
        hostname: "githubasdfa.com",
        port: 443,
        path: "/",
        method: "GET",
        timeout: 1000,
    };

    options.agent = new https.Agent(options);
    try {
        const response = await new Promise((resolve, reject) => {
            let valid_to;
            let statusCode;
            let statusMessage;
            const req = https
                .request(
                    {
                        ...options,
                        checkServerIdentity: function (host, cert) {
                            valid_to = cert.valid_to;
                        },
                    },
                    res => {
                        res.on("data", chunk => {
                            resolve({
                                valid_to,
                                statusCode,
                                statusMessage,
                            });
                        });

                        res.on("end", () => {
                            console.log("No more data in response.");
                        });
                    }
                )
                .on("error", err => {
                    console.log(err);
                    reject({
                        error: -2,
                        statusCode: "custom code",
                        statusMessage: "unhandled error",
                    });
                })
                .on("timeout", chunk => {
                    reject({
                        error: -1,
                        statusCode: "custom code",
                        statusMessage: "unhandled error",
                    });
                })
                .on("response", response => {
                    statusCode = response.statusCode;
                    statusMessage = response.statusMessage;
                })
                .end();
        });

        console.log(response);
    } catch (error) {
        console.log(error);
    }
})();

如何从 resolve() 和 reject() 中获取多个值？

How to get multiple values out of resolve() and reject()?

javascript

https

node.js

ecmascript-6