错误 \[ERR_UNSUPPORTED_DIR_IMPORT\]：尝试在本地启动 Nodejs 应用程序时导入目录

Question

我在尝试将我的应用程序部署到 Heroku 时陷入了一个循环。由于“无法在 Common JS 中加载 ES6 模块”错误，我的导入语句（例如 import cors from 'cors' ）似乎阻止了应用程序在生产环境中启动。在本地它运行得很好。

但是，当我尝试通过将 "type": "module" 添加到我的 package.json 来解决上述错误时，我收到了一组全新的错误，应用程序将不再在本地运行。我 相信 这个错误是由于我初始化 sequelize 和相关模型的方式造成的，但我不确定。我想解决这个错误，但需要帮助导入新语法……我想。

错误， package.json 和 index.js 包括在下面。

错误文本

[nodemon] starting `babel-node src/index.js`
internal/process/esm_loader.js:74
    internalBinding('errors').triggerUncaughtException(
                              ^

Error [ERR_UNSUPPORTED_DIR_IMPORT]: Directory import '/Users/jeff/Clients/Bummer/Code/Server/src/models' is not supported resolving ES modules imported from /Users/jeff/Clients/Bummer/Code/Server/src/index.js
    at finalizeResolution (internal/modules/esm/resolve.js:272:17)
    at moduleResolve (internal/modules/esm/resolve.js:699:10)
    at Loader.defaultResolve [as _resolve] (internal/modules/esm/resolve.js:810:11)
    at Loader.resolve (internal/modules/esm/loader.js:85:40)
    at Loader.getModuleJob (internal/modules/esm/loader.js:229:28)
    at ModuleWrap.<anonymous> (internal/modules/esm/module_job.js:51:40)
    at link (internal/modules/esm/module_job.js:50:36) {
  code: 'ERR_UNSUPPORTED_DIR_IMPORT',
  url: 'file:///Users/jeff/Clients/Bummer/Code/Server/src/models'
}
[nodemon] app crashed - waiting for file changes before starting...

包.JSON

 {
  "name": "bummer",
  "type": "module",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "node src/index.js",
    "dev": "nodemon --exec babel-node src/index.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@babel/core": "^7.9.6",
    "@babel/node": "^7.8.7",
    "@babel/preset-env": "^7.9.6",
    "nodemon": "^2.0.4",
    "sequelize-cli": "^6.2.0"
  },
  "dependencies": {
    "cookie-parser": "^1.4.5",
    "cors": "^2.8.5",
    "dotenv": "^8.2.0",
    "express": "^4.17.1",
    "pg": "^8.2.1",
    "querystring": "^0.2.0",
    "request": "^2.88.2",
    "sequelize": "^6.3.5",
    "sequelize-auto-migrations": "^1.0.3",
    "uuid": "^8.0.0"
  }
}

索引.js

 import cors from 'cors';
import express from 'express';
import models, { sequelize } from './models';
// import routes from './routes';

//Initiaze Express
const app = express();
const routes = require('./routes');

//Helpers for Spotify oAuth
const cookieParser = require('cookie-parser')

// Include Middleware
app.use(express.static(__dirname + '/public'))
   .use(cors())
   .use(cookieParser())
   .use(express.json())
   .use(express.urlencoded({ extended: true }))
   require('dotenv').config()



// Include all Models
app.use((req, res, next) => {
  req.context = {
    models,
  };
  next();
});

// Load Routes from Router Index
app.use('/', routes);

sequelize.sync().then(() => {
  app.listen(process.env.PORT, () => {
    console.log(`Example app listening on port ${process.env.PORT}!`)
  });
});

想法或指示？谢谢！

原文由 brickandbone 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

在 Node.js 中，import 语句只允许在 ES 模块中使用。因此，目录导入在 Node.js 中不起作用。阅读 Node.js 文档。

原文由 Kelum Sampath Edirisinghe 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 2

明确地指向您的主文件（通常是 index.js ）。例如

import ... from './models'          // ❌
import ... from './models/index.js' // ✅

---

替代方式：

使用 --experimental-specifier-resolution=node 标志。例如：

 node --experimental-specifier-resolution=node main.js

请参阅： https ://nodejs.org/api/esm.html#esm_customizing_esm_specifier_resolution_algorithm

原文由 Mir-Ismaili 发布，翻译遵循 CC BY-SA 4.0 许可协议