NextAuth集成nodemailer后sendVerificationRequest不触发无报错

问题描述 #

• 基于NextAuth实现邮箱魔术链接登录：未接入nodemailer、Handlebars自定义邮件模板时，默认邮件发送逻辑运行正常
• 接入二者替换自定义模板后，点击signIn按钮时程序不会进入sendVerificationRequest函数执行，全程无任何报错抛出
• 问题对应的[...nextauth].js配置代码如下：

import NextAuth from "next-auth/next";
import EmailProvider from "next-auth/providers/email";
import nodemailer from 'nodemailer'
import { PrismaAdapter } from "@next-auth/prisma-adapter";
import { PrismaClient } from "@prisma/client";
import Handlebars from 'handlebars'
import { readFileSync } from 'fs'
import path from "path";

const prisma = new PrismaClient()

const transporter = nodemailer.createTransport({
    host: process.env.EMAIL_SERVER_HOST,
    port: process.env.EMAIL_SERVER_PORT,
    auth: {
        user: process.env.EMAIL_SERVER_USER,
        pass: process.env.EMAIL_SERVER_PASSWORD,
    },
    secure: true,
});

const emailsDir = path.resolve(process.cwd(), 'emails');

const sendVerificationRequest = async ({ identifier, url }) => {
    console.log('send verification req entered')
    const emailFile = readFileSync(path.join(emailsDir, 'confirm-email.html'), {
        encoding: 'utf8',
    });
    const emailTemplate = Handlebars.compile(emailFile);
    const result = await transporter.sendMail({
        from: `"✨ FreiDrops" ${process.env.EMAIL_FROM}`,
        to: identifier,
        subject: 'Your sign-in link for FreiDrops',
        html: emailTemplate({
            base_url: process.env.NEXTAUTH_URL,
            signin_url: url,
            email: identifier,
        }),
    });
    const failed = result.rejected.concat(result.pending).filter(Boolean)
    if (failed.length) {
        throw new Error(`Email(s) (${failed.join(", ")}) could not be sent`)
    }
};
export default NextAuth({
    pages: {
        signIn: '/',
        signOut: '/',
        error: '/',
        verifyRequest: '/'
    },
    providers: [
        EmailProvider({
            maxAge: 10 * 60, // Magic links are valid for 10min!!
            sendVerificationRequest,
        })
    ],
    adapter: PrismaAdapter(prisma)
})

配置错误点与修复方案 #

你的配置确实存在3个会直接导致该问题的错误，逐一修复即可：

• EmailProvider必填配置缺失
  未自定义发送函数时，NextAuth内置邮件逻辑会自动读取环境变量里的邮件服务、发件人配置完成初始化；你传入自定义sendVerificationRequest后，Provider不会再自动读取这些环境变量，缺失server和from必填项时会直接静默初始化失败，根本不会触发你写的发送函数。
  修复方式：在EmailProvider配置中补全必填字段：

  EmailProvider({
      maxAge: 10 * 60, // 魔术链接10分钟有效期
      server: {
          host: process.env.EMAIL_SERVER_HOST,
          port: Number(process.env.EMAIL_SERVER_PORT),
          auth: {
              user: process.env.EMAIL_SERVER_USER,
              pass: process.env.EMAIL_SERVER_PASSWORD,
          },
          secure: Number(process.env.EMAIL_SERVER_PORT) === 465, // 465端口走SSL设为true，587等STARTTLS端口设为false
      },
      from: process.env.EMAIL_FROM,
      sendVerificationRequest,
  })
  

• 顶层同步操作错误被静默吞掉
  你把模板目录路径解析、transporter初始化的逻辑都放在了API路由模块的顶层，这部分代码会在NextAuth路由初始化时执行。如果模板文件路径不对、文件不存在，或者nodemailer连接参数不匹配，抛出的同步错误会被Next.js API路由边界捕获后静默吞掉，直接导致整个NextAuth配置加载失败，点击登录不会有任何响应。
  修复方式：将非全局必要的逻辑挪到sendVerificationRequest函数内部执行，同时提前确认emails文件夹会被正确打包到生产构建产物中，避免生产环境找不到文件：

  const sendVerificationRequest = async ({ identifier, url }) => {
      console.log('send verification req entered')
      // 把路径解析、模板读取挪到函数内部
      const emailsDir = path.resolve(process.cwd(), 'emails');
      const emailFile = readFileSync(path.join(emailsDir, 'confirm-email.html'), {
          encoding: 'utf8',
      });
      const emailTemplate = Handlebars.compile(emailFile);
      const result = await transporter.sendMail({
          from: `"✨ FreiDrops" ${process.env.EMAIL_FROM}`,
          to: identifier,
          subject: 'Your sign-in link for FreiDrops',
          html: emailTemplate({
              base_url: process.env.NEXTAUTH_URL,
              signin_url: url,
              email: identifier,
          }),
      });
      const failed = result.rejected.concat(result.pending).filter(Boolean)
      if (failed.length) {
          throw new Error(`Email(s) (${failed.join(", ")}) could not be sent`)
      }
  };
  

• 端口参数类型错误
  从环境变量读取的EMAIL_SERVER_PORT默认是字符串类型，nodemailer要求port字段为数字类型，类型不匹配会导致transporter初始化失败，错误同样会被静默吞掉。修复方式参考上面的代码，读取端口时用Number()做类型转换即可。

修复完成后重启服务，点击登录按钮就能看到你写的入口日志正常打印，后续再调试模板渲染、邮件发送的逻辑即可。

内容的提问来源于stack exchange，提问作者risky last