fix: emit handler as ESM for functions v2

Author: orinokai

src/helpers/functions.ts

@@ -11,7 +11,7 @@ import { HANDLER_DIR, HANDLER_NAME, HANDLER_URL, __dirname } from './constants.j
 export const createHandlerFunction = (publishDir: string, config: NetlifyConfig) => {
   emptyDirSync(HANDLER_DIR)
 
-  copySync(`${__dirname}/../templates/handler.cjs`, `${HANDLER_DIR}/${HANDLER_NAME}.js`)
+  copySync(`${__dirname}/../templates/handler.js`, `${HANDLER_DIR}/${HANDLER_NAME}.mjs`)
   copySync(`${__dirname}/../../node_modules/@vercel/node-bridge`, `${HANDLER_DIR}/node_modules/@vercel/node-bridge`)
   copySync(`${publishDir}/standalone/.next`, `${HANDLER_DIR}/.next`)
   copySync(`${publishDir}/standalone/node_modules`, `${HANDLER_DIR}/node_modules`)
@@ -21,7 +21,7 @@ export const createHandlerFunction = (publishDir: string, config: NetlifyConfig)
   config.functions[HANDLER_NAME] ||= {}
   config.functions[HANDLER_NAME].node_bundler = 'none'
   config.functions[HANDLER_NAME].included_files ||= []
-  config.functions[HANDLER_NAME].included_files.push(`${HANDLER_DIR}/${HANDLER_NAME}.js`)
+  config.functions[HANDLER_NAME].included_files.push(`${HANDLER_DIR}/${HANDLER_NAME}.mjs`)
   config.functions[HANDLER_NAME].included_files.push(`${HANDLER_DIR}/.next/**/*`)
   config.functions[HANDLER_NAME].included_files.push(`${HANDLER_DIR}/node_modules/**/*`)
 

src/templates/handler.cts renamed to src/templates/handler.ts

@@ -1,18 +1,23 @@
+import { createRequire } from 'module'
 import { IncomingMessage, ServerResponse } from 'node:http'
+import { fileURLToPath } from 'node:url'
 
 import type { Context } from '@netlify/functions'
-// @ts-ignore
-import { getRequestHandlers } from 'next/dist/server/lib/start-server.js'
 
-// @ts-ignore
-import requiredServerFiles from './.next/required-server-files.json'
+const require = createRequire(import.meta.url)
+const { getRequestHandlers } = require('next/dist/server/lib/start-server.js')
+
+// eslint-disable-next-line import/no-unresolved
+const requiredServerFiles = require('./.next/required-server-files.json')
 
 process.env.__NEXT_PRIVATE_STANDALONE_CONFIG = JSON.stringify(requiredServerFiles.config)
 
+const __dirname = fileURLToPath(new URL('.', import.meta.url))
+
 process.chdir(__dirname)
 
 // eslint-disable-next-line import/no-anonymous-default-export, @typescript-eslint/no-unused-vars
-export default async (request: IncomingMessage, context: Context) => {
+export default async (request: Request, context: Context) => {
   // let Next.js initialize and create the request handler
   const [nextHandler] = await getRequestHandlers({
     port: 3000,