使用Nodemailer时如何修复“等待仅在异步函数中有效”错误

Question

我正在尝试按照教程使用 Nodemailer 创建联系我们表单。本教程粘贴了来自 Nodemailer 网站的一些代码，但自该教程录制以来，源代码已更新。

我粘贴了网站上的最新代码，但出现以下控制台错误：

let info = await transporter.sendMail(mailOptions)

语法错误：await 仅在异步函数中有效

下面是我的 app.js 代码：

const express = require("express");
const bodyParser = require("body-parser");
const exphbs = require("express-handlebars");
const path = require("path");
const nodemailer = require("nodemailer");

const app = express();

// View engine setup
app.engine("handlebars", exphbs());
app.set("view engine", "handlebars");

// Static folder
app.use("/public", express.static(path.join(__dirname, "public")));

// Body Parser Middleware
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());

app.get("/", (req, res) => {
  res.render("contact");
});

app.post("/send", (req, res) => {
  const output = `
    <p>You have a new contact request</p>
    <h3>Contact Details</h3>
    <ul>
        <li>Name: ${req.body.name}</li>
        <li>Company: ${req.body.company}</li>
        <li>Email: ${req.body.email}</li>
        <li>Phone: ${req.body.phone}</li>
    </ul>
    <h3>Message</h3>
    <p>${req.body.message}</p>    
    `;
    
    var transporter = nodemailer.createTransport({
        service: 'gmail',
        auth: {
               user: 'youremail@address.com',
               pass: 'yourpassword'
           }
       });

       const mailOptions = {
        from: 'sender@email.com', // sender address
        to: 'to@email.com', // list of receivers
        subject: 'Subject of your email', // Subject line
        html: '<p>Your html here</p>'// plain text body
      };

      let info = await transporter.sendMail(mailOptions)

  console.log("Message sent: %s", info.messageId);
  console.log("Preview URL: %s", nodemailer.getTestMessageUrl(info));
  
});

app.listen(3000, () => console.log("Server started..."));

我粘贴的代码位于此页面上：https : //nodemailer.com/about/

为什么我会收到此错误，我需要进行哪些更改才能使代码按预期工作？

Answer 1

那是因为await仅在async函数内部有效。语法是

async function some() {
  await other
}

改变这一行：

app.post("/send", (req, res) => {

到

注意async这里的关键字 app.post("/send", async (req, res) => {

阅读更多关于 async/await