Question

在我的函数“reqHandler”中，我收集表单数据并将其传递给我的http.request。为了链接请求，我声明了一个Promise和.then处理程序。问题是： 1.这写入控制台“Unhandled promise rejection（rejection id：2）：TypeError：无法读取未定义的属性'url'” 2.似乎没有调用.then，因此没有进行API调用。

代码：

"use strict";

const http        = require("http");
const qs          = require("querystring");
const fs          = require("fs");
const PORT        = 3000;

let resObject = {};
let hash = "";

const options = {
  hostname: "netology.tomilomark.ru",
  path: "/api/v1/hash",
  method: "post"
};

const reqHandler = (req, res) => {
  return new Promise((resolve, reject) => {
    if (req.url === "/") {
      switch (req.method.toLowerCase()) {
        case "get":
          // Browse my form with "Name" and "Surname" inputs
          fs.readFile("./logs/form.html", (err, file) => {
            if (err) {
              reject("Promise rejected");
              return
            }
            res.writeHead(200, {'Content-Type': 'text/html','Content-Length':file.length});
            res.write(file);
            res.end();
          });
          break;
        case "post":
          // Collect form data and parse it using querystring
          let body = "";
          req.setEncoding("utf8");
          req.on("data", (data) => {
            body += data;
            if (body.length > 1e6)
              req.connection.destroy();
          });
          req.on("end", () => {
            let post = qs.parse(body);
            console.log(post);
            options.headers = {
              "Content-Type": "application/json",
              "firstname": `${post.firstName}`
            };
            options.body = {
              "lastname": `${post.lastName}`
            };
            // Resolve with "options" object that has headers and body
            resolve(options);
          });
          break;
        default:
          badRequest(res);
      }
    } else {
      notFound(res);
    }
  });
};

reqHandler()
  .then((options) => {
    http.request(options, (res) => {
      let resString = "";
      res.on("data", (data) => {
        resString += data;
      });
      res.on("end", () => {
        console.log(resString);
      });
      res.end();
    });
  })
  .catch(err => {throw err});

let badRequest = (res) => {
  res.statusCode = 400;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Bad Request');
};

let notFound = (res) => {
  res.statusCode = 404;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Not Found');
};

const server = http.createServer();
server.on("error", (err) => console.error(err));
server.on("request", reqHandler);
server.on("listening", () => console.log(`Start HTTP on port ${PORT}`));
server.listen(PORT);

最终，我的承诺错了。然后呢？ 任何帮助将不胜感激！

Answer 1

好的我已经创建了一个测试环境，在这里你有一个源代码的抽象版本。你的错误是将你的承诺包装在一个传递req和res参数的函数中，你必须在你的承诺中调用或拒绝，在几个地方已经忘记了。

此来源已经过测试！

const http = require('http');

const reqHandler = (req, res) => {
  return new Promise((resolve, reject) => {
    if (req.url === "/") {
      switch (req.method.toLowerCase()) {
        case "get":
          console.log('get');
          return resolve('get');
        case "post":
          console.log('post');
          return resolve('post');
        default:
          return resolve('default');
      }
    } else {
      return resolve('some thing else');
    }
  });
};

const myReqHandler = (req, res) => {
    reqHandler(req, res).then(()=> {
        console.log('then reached')
    });
}


const PORT = 8089;
const server = http.createServer();
server.on("error", (err) => console.error(err));
server.on("request", myReqHandler);
server.on("listening", () => console.log(`Start HTTP on port ${PORT}`));
server.listen(PORT);

使用promises链接http请求

1 个答案: