babel-node es6"REPL不支持模块"

Question

babel-preset-es2015已安装,并且可以使用es6功能,如下所示let a = 2;.
但无法使用es6模块功能import fs from 'fs'如下:

$ babel-node --presets es2015
> let a = 2;
'use strict'
> a
2
> import fs from 'fs';
SyntaxError: repl: Modules aren't supported in the REPL
import fs from 'fs';  
    at File.buildCodeFrameError (/usr/lib/node_modules/babel-cli/node_modules/babel-core/lib/transformation/file/index.js:407:15)
    at NodePath.buildCodeFrameError (/usr/lib/node_modules/babel-cli/node_modules/babel-traverse/lib/path/index.js:149:26)
    at PluginPass.ModuleDeclaration (/usr/lib/node_modules/babel-cli/lib/_babel-node.js:78:20)
    at newFn (/usr/lib/node_modules/babel-cli/node_modules/babel-traverse/lib/visitors.js:262:19)
    at NodePath._call (/usr/lib/node_modules/babel-cli/node_modules/babel-traverse/lib/path/context.js:63:18)
    at NodePath.call (/usr/lib/node_modules/babel-cli/node_modules/babel-traverse/lib/path/context.js:47:17)
    at NodePath.visit (/usr/lib/node_modules/babel-cli/node_modules/babel-traverse/lib/path/context.js:93:12)
    at TraversalContext.visitQueue (/usr/lib/node_modules/babel-cli/node_modules/babel-traverse/lib/context.js:152:16)
    at TraversalContext.visitMultiple (/usr/lib/node_modules/babel-cli/node_modules/babel-traverse/lib/context.js:110:17)
    at TraversalContext.visit (/usr/lib/node_modules/babel-cli/node_modules/babel-traverse/lib/context.js:182:19)

那有什么不对？
谢谢!

Answer 1

错误消息正是它所说的.您不能在REPL中使用ES6模块语法,它不受支持.您可以创建一个小型适配器,导入为ES6并导出为CommonJS:

# es6-to-common.js
import MyThing from './somewhere';
module.exports = MyThing;

现在在你通常的babel-node提示中:

> MyThing = require('./es6-to-common')