在vercel上部署后出现错误如何解决？

Question

我使用 vercel 托管了我的作品集网站，当我尝试发送邮件时，我收到此错误

Error: Error: ENOENT: no such file or directory, open 'src/app/emailcount.json'
    at async open (node:internal/fs/promises:636:25)
    at async Object.readFile (node:internal/fs/promises:1246:14)
    at async n6 (/var/task/.next/server/app/api/sendmail/route.js:4:88894)
    at async /var/task/node_modules/next/dist/compiled/next-server/app-route.runtime.prod.js:6:36258
    at async eR.execute (/var/task/node_modules/next/dist/compiled/next-server/app-route.runtime.prod.js:6:26874)
    at async eR.handle (/var/task/node_modules/next/dist/compiled/next-server/app-route.runtime.prod.js:6:37512)
    at async es (/var/task/node_modules/next/dist/compiled/next-server/server.runtime.prod.js:16:25465)
    at async en.responseCache.get.routeKind (/var/task/node_modules/next/dist/compiled/next-server/server.runtime.prod.js:17:1026)
    at async r6.renderToResponseWithComponentsImpl (/var/task/node_modules/next/dist/compiled/next-server/server.runtime.prod.js:17:508)
    at async r6.renderPageComponent (/var/task/node_modules/next/dist/compiled/next-server/server.runtime.prod.js:17:5121) {
  errno: -2,
  code: 'ENOENT',
  syscall: 'open',
  path: 'src/app/emailcount.json'
}

这是我的函数的代码

import EmailTemplate from "@/app/components/EmailTemplate";
import { NextRequest, NextResponse } from "next/server";
import { Resend } from "resend";
import { promises as fs } from "fs";

const resend = new Resend(process.env.RESEND_API_KEY);

export async function POST(req: NextRequest) {
  try {
    const file = await fs.readFile("src/app/emailcount.json",
      "utf8"
    );
    const emailcount = JSON.parse(file);

    const { name, email, phonenumber, emailsub, message }: any = await req.json();
    console.log("name is:", name);

    const test = "portfolio" + emailcount.count;
    console.log(test);

    const data = await resend.emails.send({
      from: `${name} <${test}@resend.dev>`,
      to: "[email protected]",
      subject: emailsub,
      react: EmailTemplate({
        name: name,
        phonenumber: phonenumber,
        email: email,
        emailsub: emailsub,
        message: message,
      }),
    });

    console.log("data is:", data.data?.id);

    // Update the email count after a successful send
    emailcount.count += 1;
    await fs.writeFile( "src/app/emailcount.json",
      JSON.stringify(emailcount, null, 2),
      "utf8"
    );

    return NextResponse.json({
      data,
      message: "Email sent successfully",
      success: true,
      status: 200,
    });
  } catch (error) {
    console.error("Error:", error);
    return NextResponse.json({
      error,
      message: "Failed to send email",
      success: false,
      status: 500,
    });
  }
}

这是文件结构

它在本地环境（localhost）中正常工作，但部署后它不起作用

我尝试过以不同的方式改变路径

“../../countemail.json” “src/app/countemail.json”

Answer 1

vercel 不允许写入 json 文件，所以这就是部署后无法工作的原因