Node.js - SyntaxError: Unexpected token import

问题: I don't understand what is wrong. Node v5.6.0 NPM v3.10.6 The code: function (exports, require, module, __filename, __dirname) { import express from 'express' };...

问题:

I don't understand what is wrong. Node v5.6.0 NPM v3.10.6

The code:

function (exports, require, module, __filename, __dirname) {
    import express from 'express'
};

The error:

SyntaxError: Unexpected token import
    at exports.runInThisContext (vm.js:53:16)
    at Module._compile (module.js:387:25)
    at Object.Module._extensions..js (module.js:422:10)
    at Module.load (module.js:357:32)
    at Function.Module._load (module.js:314:12)
    at Function.Module.runMain (module.js:447:10)
    at startup (node.js:140:18)
    at node.js:1001:3

回答1:

Update: In Node 9, it is enabled behind a flag, and uses the .mjs extension.

node --experimental-modules my-app.mjs

While import is indeed part of ES6, it is unfortunately not yet supported in NodeJS by default, and has only very recently landed support in browsers.

See browser compat table on MDN and this Node issue.

From James M Snell's Update on ES6 Modules in Node.js (February 2017):

Work is in progress but it is going to take some time — We’re currently looking at around a year at least.

Until support shows up natively, you'll have to continue using classic require statements:

const express = require("express");

If you really want to use new ES6/7 features in NodeJS, you can compile it using Babel. Here's an example server.


回答2:

Unfortunately, Node.js doesn't support ES6's import yet.

To accomplish what you're trying to do (import the Express module), this code should suffice

var express = require("express");

Also, be sure you have Express installed by running

$ npm install express

See the Node.js Docs for more information about learning Node.js.


回答3:

Error: SyntaxError: Unexpected token import or SyntaxError: Unexpected token export


Solution: Change all your imports as example

const express 				= require('express');
const webpack				= require('webpack');
const path				= require('path');
const config				= require('../webpack.config.dev');
const open 				= require('open');

And also change your export default = foo; to module.exports = foo;


回答4:

As mentioned in other answers Node JS currently doesn't support ES6 imports

Enable ES6 imports in node js provides a solution to this issue. I have tired this and it worked for me.

Run the command:

    npm install babel-register babel-preset-env --save-dev

Now you need to create a new file(config.js) and add the following code to it.

    require('babel-register')({
        presets: [ 'env' ]
    })
    // Import the rest of our application.
    module.exports = require('./your_server_file.js')

Now you can write import statements without getting any errors.

Hope this helps.

EDIT:

You need to run the new file which you created with above code. In my case it was config.js. So i have to run:

    node config.js

回答5:

if you can use 'babel', try to add build scripts in package.json(--presets=es2015) as below. it make to precompile import code to es2015

"build": "babel server --out-dir build --presets=es2015 && webpack"

回答6:

In case that you still can't use "import" here is how I handled it: Just translate it to a node friendly require. Example:

import { parse } from 'node-html-parser';

Is the same as:

const parse = require('node-html-parser').parse;

回答7:

In my case it was looking after .babelrc file, and it should contain something like this:

{
  "presets": ["es2015-node5", "stage-3"],
  "plugins": []
}
  • 发表于 2019-03-18 05:55
  • 阅读 ( 1187 )
  • 分类:sof

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