Node.js中使用Resend库时new运算符报错的解决方法

核心错误原因 #

Resend库的CommonJS导入方式并非默认导出构造函数，你直接require("resend")得到的是包含Resend构造函数的对象，而非构造函数本身，所以无法用new resend()实例化。

修复步骤及代码修改 #

1. 修正工具类sendMail的导入与实例化 #

修改导入语句，解构出Resend构造函数，同时修复函数内未定义的text参数问题：

const { Resend } = require("resend");
const instanceResend = new Resend(process.env.KEY_RESEND);

const sendMail = async (from, to, subject, html, text = "") => {
  try {
    const data = await instanceResend.emails.send({
      from: from,
      to: to,
      subject: subject,
      html: html,
      text: text,
      headers: {
        "X-Entity-Ref-ID": process.env.KEY_RESEND,
      },
      tags: [
        {
          name: "category",
          value: "reset_password",
        },
      ],
    });
    console.log("Email data: ", data);
    return data;
  } catch (error) {
    console.error(error);
    throw error;
  }
};

module.exports = sendMail;

2. 修正控制器中的调用逻辑 #

sendMail是异步函数，无需传入回调，改用try/catch捕获异常：

const sendMail = require("../utils/sendMail");

forgotPassword: async (req, res) => {
  const { email } = req.body;
  try {
    const user = await userModel.findOne({ email });
    if (!email || !user)
      return res
        .status(400)
        .json({ message: "邮箱未找到或无效", success: false });

    await sendMail(
      "from@gmail.com",
      email,
      "重置密码通知",
      "<p>请点击链接完成密码重置</p>",
      "请点击链接完成密码重置"
    );

    return res.status(200).json({
      message: "重置密码邮件已成功发送",
      success: true,
    });

  } catch (error) {
    res.status(400).json({
      message: "发送重置密码邮件失败，请重试",
      error: error.message,
      success: false,
    });
  }
},

额外注意事项 #

• 确保process.env.KEY_RESEND已正确配置你的Resend API密钥
• 发送邮件的from地址需是在Resend控制台验证过的域名或邮箱
• 异步函数内抛出错误而非返回错误，能让上层try/catch更准确捕获异常

内容的提问来源于stack exchange，提问作者Begginer