Error using ES7 async/await with node, webpack and babel-loader

问题:

I'm trying to use javascript ES7 syntax on the server using node.js with webpack and babel-loader (es2015 + stage-0 presets). I've gotten it to work with babel-node but when I run webpack I get the following error at the async keyword (9:22 is after the async keyword):

ERROR in ./src/server.js Module parse failed: C:\dev\node-async-sample\src\server.js  Unexpected token (9:22) You may need an appropriate loader to handle this file type.  SyntaxError: Unexpected token (9:22) 

I've put the code on github at https://github.com/qubitron/node-async-sample, any ideas on how to get this to work?

Here is the relevant snippet from src/server.js:

import express from 'express'; import http from 'request-promise';  let server = express();  server.get('/', async function(request, response) {     let result = await http('http://www.google.com');     response.send(result); }); 

.babelrc:

{   "presets": [     "es2015",     "node5",     "stage-0"   ],   "plugins": [     "transform-runtime"   ] } 

and webpack.config.js:

module.exports = {   entry: [     'babel-polyfill',     './src/server.js'   ],   output: {     path: __dirname + '/dist',     filename: 'server_bundle.js'   },   resolve: {       extensions: ['', '.js', '.jsx']   },   module: {     loaders: [       {         test: /\.jsx?$/,         include: __dirname + '/src',         loader: 'babel-loader'       }     ]   } }; 

I saw a similar issue here but it has a different error message and was fixed in babel:master: ES7 async await functions with babel-loader not working

回答1:

Your src path was incorrect. You should never (like never :)) join pathes using string concatenation there is path.join for that.

{    test: /\.jsx?$/,    include: path.join(__dirname, 'src'),    loader: 'babel-loader' } 

BTW, this will fix parsing issue but you still gonna need to handle .json file loading by adding corresponding extension to resolve section and using json-loader

{ test: /\.json$/, loader: 'json-loader' } 

Also you'll need to handle missing modules warning. For example fs and net.

So I do recommend you to use babel-cli to precompile server code.

babel src --out-dir dist 

文章来源: Error using ES7 async/await with node, webpack and babel-loader