Babel NodeJS ES6：SyntaxError：意外的令牌导出

Question

我正在尝试使用 babel 来运行我的 NodeJS 程序，其中包括 ES6 语法和来自 Colyseus 库的导出。但是，当我运行命令时：

babel-node server.js

出现以下错误消息：

export class MyRoom extends colyseus.Room {
^^^^^^

SyntaxError: Unexpected token export

下面是我的 package.json 文件：

{
  "name": "app",
  "version": "1.0.0",
  "description": "a description",
  "main": "server.js",
  "scripts": {
    "test": "babel-node server.js",
    "build": "babel-node server.js"
  },
  "author": "henryzhu",
  "license": "ISC",
  "dependencies": {
    "actionhero": "^19.1.2",
    "colyseus": "^0.9.33",
    "easytimer.js": "^2.3.0",
    "express": "^4.16.3",
    "socket.io": "^2.1.0",
    "socketio": "^1.0.0",
    "uniqid": "^5.0.3"
  },
  "devDependencies": {
    "babel-cli": "^6.26.0",
    "babel-preset-env": "^1.7.0",
    "babel-preset-es2015": "^6.24.1"
  }
}

下面是我的 server.js 文件：

var colyseus = require("colyseus");
var http = require("http");
var express = require("express");
var port = process.env.port || 3000;

var app = express();

app.use(express.static("public", { dotfiles: 'allow' }));

var gameServer = new colyseus.Server({
  server: http.createServer(app)
});

export class MyRoom extends colyseus.Room {
    // When room is initialized
    onInit (options) { }

}

gameServer.listen(port);

Answer 1

添加包含以下内容的配置文件 ( .babel.config.js)：

module.exports = {
    presets: [
        '@babel/preset-env'
    ]
};

然后运行：

babel-node --config-file .babel.config.js server.js