node.js - 语法错误 : Unexpected token export when trying to use @babel/register

Question

当尝试使用 Babel 运行 Node 并使用react时，@babel/register 不起作用

我在 SO 上查看了类似的问题，重新安装了 Node 10.15.1，升级到最新版本 11.9。

下面是package.json中的相关依赖:

"dependencies": {
    "@babel/core": "7.1.6",
    "@babel/polyfill": "^7.2.5",
    "@babel/register": "^7.0.0",
    "@svgr/webpack": "2.4.1",
    "babel-core": "7.0.0-bridge.0",
    "babel-jest": "23.6.0",
    "babel-loader": "8.0.4",
    "babel-plugin-named-asset-import": "0.3.0",
    "babel-preset-react-app": "7.0.0",
    "react": "16.7.0",
    "react-app-polyfill": "0.2.0",
    "react-dev-utils": "7.0.1",
    "react-dom": "16.7.0",
    "resolve": "1.8.1",
    "webpack": "4.19.1",
    "webpack-dev-server": "3.1.14",
    "webpack-manifest-plugin": "2.0.4",
    "workbox-webpack-plugin": "3.6.3"
}

尝试执行本教程中关于使用 React 运行 SSR 的内容。我的 index.js 看起来像这样:

require('@babel/polyfill');
require('@babel/register')({
ignore: [/\/(build|node_modules)\//,    
],
  presets: ['@babel/preset-env','@babel/preset-react'],
  plugins: [
    '@babel/plugin-syntax-dynamic-import',
    'dynamic-import-node',

  ]
});

require('./server');

服务器.js

import express from 'express';
import path from 'path';
import React from 'react';
import { renderToString } from 'react-dom/server';
import App from '../src/App'


const app = express();
const PORT = process.env.PORT || 3000;

const router = express.Router()

const serverRenderer = (req, res, next) => {
  fs.readFile(path.resolve('./build/index.html'), 'utf8', (err, data) => {
    if (err) {
      console.error(err)
      return res.status(500).send('An error occurred')
    }
    return res.send(
      data.replace(
        '<div id="root"></div>',
        `<div id="root">${ReactDOMServer.renderToString(<App />)}</div>`
      )
    )
  })
}
router.use('^/$', serverRenderer)

router.use(
  express.static(path.resolve(__dirname, '..', 'build'), { maxAge: '30d' })
)
// tell the app to use the above rules
app.use(router)


app.listen(PORT, () => {
  console.log(`SSR running on port ${PORT}`)
})

像这样从 CLI 运行时:

npm run build
cross-env NODE_ENV=production node server/index.js

我一直收到这个错误:

/Users/myfolder/workspace/webapp/node_modules/@babel/runtime/helpers/esm/classCallCheck.js:1
(function (exports, require, module, __filename, __dirname) { export default function _classCallCheck(instance, Constructor) {
                                                              ^^^^^^

SyntaxError: Unexpected token export
    at new Script (vm.js:84:7)
    at createScript (vm.js:264:10)
    at Object.runInThisContext (vm.js:312:10)
    at Module._compile (internal/modules/cjs/loader.js:694:28)
    at Module._compile (/Users/myfolder/workspace/webapp/node_modules/pirates/lib/index.js:83:24)
    at Module._extensions..js (internal/modules/cjs/loader.js:745:10)
    at Object.newLoader [as .js] (/Users/myfolder/workspace/webapp/node_modules/pirates/lib/index.js:88:7)
    at Module.load (internal/modules/cjs/loader.js:626:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:566:12)
    at Function.Module._load (internal/modules/cjs/loader.js:558:3)

更新:如果我进入服务器文件夹，我能够成功运行 Node 服务器。我的文件夹结构是:myapp/src/server/index.js

这有效 - 虽然不理想。

cd myapp/src/服务器cross-env NODE_ENV=生产 Node index.js

我没有收到上述错误。我正在使用 webpack 构建应用程序，这让我觉得这与我的 webpack 配置有关。

Answer 1

我能够通过为 babel 添加根目录来解决这个问题。 'root' 是 babel 的配置加载选项，指定当前 babel 项目的概念根文件夹。我的 cwd 是 src。 src/server/index.js 现在看起来像这样。

require('@babel/polyfill');
require('@babel/register')({
ignore: [/\/(build|node_modules)\//], 
root:"./server",   
  presets: ['@babel/preset-env','@babel/preset-react'],
  plugins: [
    '@babel/plugin-syntax-dynamic-import',
    'dynamic-import-node',

  ]
});

require('./server');