创建用户 ERR_HTTP_HEADERS_SENT 后使用 next.js API 发送电子邮件

Question

我目前正在使用 next.js API 创建用户，但是，我现在想使用 sendgrid 发送电子邮件。

我有这个设置，但是，我得到以下信息

event - compiled successfully in 661 ms (254 modules)
Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
    at new NodeError (internal/errors.js:322:7)
    at ServerResponse.setHeader (_http_outgoing.js:561:11)
    at DevServer.renderError (/Users/ellisbrookes/Documents/Ellis-Developement/node_modules/next/dist/server/next-server.js:1628:17)
    at DevServer.run (/Users/ellisbrookes/Documents/Ellis-Developement/node_modules/next/dist/server/dev/next-dev-server.js:431:35)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (internal/process/task_queues.js:95:5)
    at async DevServer.handleRequest (/Users/ellisbrookes/Documents/Ellis-Developement/node_modules/next/dist/server/next-server.js:305:20) {
  code: 'ERR_HTTP_HEADERS_SENT'
}
error - Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
error - uncaughtException: Error [ERR_STREAM_WRITE_AFTER_END]: write after end

正在创建用户并正在发送电子邮件，但是，我不确定为什么会收到此错误。

这是我在 onSubmit api 调用

方面的明智做法

const res = await fetch('/api/auth/register', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify(data)
})

这是我在 api/auth/register 文件中的内容

import connectDB from '../../../lib/mongodb'
import bcrypt from 'bcrypt'
import User from '../../../models/user'

const mail = require('@sendgrid/mail');

mail.setApiKey(process.env.SENDGRID_API_KEY);

const handler = async (req, res) => {
  // check if user exists in the database already
  const emailExists = await User.findOne({ email: req.body.email })
  if (emailExists) return res.status(400).send("Email already exists")

  // hash password
  const salt = await bcrypt.genSalt(10)
  const hash = await bcrypt.hash(req.body.password, salt)

  var user = new User({
    firstname: req.body.firstname,
    lastname: req.body.lastname,
    username: req.body.username,
    email: req.body.email,
    password: hash
  })

  try {
    user = await user.save();
    res.send({ user: user._id })
  } catch {
    res.status(400).send(err)
  }

  // nodemailer
  const message = `
    First Name: ${req.body.firstname}\r\n
    Last Name: ${req.body.lastname}\r\n
    Username: ${req.body.username}\r\n
    Email: ${req.body.email}
  `;

  const data = {
    to: `${req.body.email}`,
    from: 'Ellis Development <hello@ebrookes.dev>',
    subject: `Welcome ${req.body.firstname} ${req.body.lastname} to Ellis Development`,
    text: message,
    html: message.replace(/\r\n/g, '<br />')
  };

  await mail.send(data);

  res.status(200).json({ status: 'OK' });
}

export default connectDB(handler)

如前所述，正在创建用户并正在发送电子邮件，但不确定为什么我会收到 ERR_HEADERS 错误。

Answer 1

在 try-catch 块中，您发送响应 res.send({ user: user._id }) 而不停止函数。该函数继续执行，您尝试发送另一个响应 res.status(200).json({ status: 'OK' });

我建议将 try-catch 块更改为：

try {
  user = await user.save();
} catch {
  return res.status(400).send(err)
}

如果出现错误（return 语句），这将停止执行，但如果 user.save() 成功完成，将继续执行。最后，它将 return 200 {status: OK} 响应放在最后。

创建用户 ERR_HTTP_HEADERS_SENT 后使用 next.js API 发送电子邮件

Sending emails using next.js API after creating a user ERR_HTTP_HEADERS_SENT

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