Webpack抛出JSX语法错误

Question

When I attempted to use webpack to compile my react jsx code, I received the following error:

ERROR in ./client/index.js
Module parse failed: C:\Users\Gum-Joe\Documents\Projects\bedel/client\index.js Unexpected token (6:11)
You may need an appropriate loader to handle this file type.
SyntaxError: Unexpected token (6:11)
    at Parser.pp.raise (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:920:13)
    at Parser.pp.unexpected (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:1483:8)
    at Parser.pp.parseExprAtom (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:330:12)
    at Parser.pp.parseExprSubscripts (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:225:19)
    at Parser.pp.parseMaybeUnary (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:204:17)
    at Parser.pp.parseExprOps (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:151:19)
    at Parser.pp.parseMaybeConditional (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:133:19)
    at Parser.pp.parseMaybeAssign (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:110:19)
    at Parser.pp.parseExpression (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:86:19)
    at Parser.pp.parseReturnStatement (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:1854:26)
    at Parser.pp.parseStatement (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:1719:19)
    at Parser.pp.parseBlock (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:1991:21)
    at Parser.pp.parseFunctionBody (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:607:22)
    at Parser.pp.parseMethod (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:576:8)
    at Parser.pp.parseClassMethod (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:2137:23)
    at Parser.pp.parseClass (C:\Users\Gum-Joe\Documents\Projects\bedel\node_modules\acorn\dist\acorn.js:2122:10)
 @ ./client/index.js 1:0-20

.babelrc:

{
  "presets": ["es2015", "react"]
}

webpack.config.js:

// Webpack config
const path = require('path');
const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');
module.exports = {

  // Use client as our root
  context: __dirname + "/client",
  // Entry file
  entry: "./index.js",
  // Resolve
  resolve: {
    extensions: ['', '.js', '.jsx']
  },
  // Output to /build
  output: {
        path: path.join(__dirname, "build", "js"),
        filename: "bundle.js"
    },
  loaders: [
    { test: /\.jsx$/, exclude: /node_modules/, loader: "babel-loader" }
  ],
  // Plugins
  plugins: [
    // HTML
    new HtmlWebpackPlugin({
      title: 'Bedel',
      filename: path.join(__dirname, 'views', 'index.ejs'),
      template: path.join(__dirname, 'client', 'templates', 'index.ejs')
    })
  ]
};

index.js:

import React from 'react';
import ReactDOM from 'react-dom';

class App extends React.Component {
  render () {
    return <p> Hello React</p>;
  }
}

ReactDOM.render(<App/>, document.getElementById('app'));

I have installed all the babel presets required, as well as babel-core . I have looked at the following answers already:

• babel-loader jsx SyntaxError: Unexpected token
• React, babel, webpack not parsing jsx code

Edit: After commenting out my jsx syntax, the outputting bundle.js does not appear to have been transformed by babel (ie I can see ES6 code in it)

Edit: Sorry for the inconvenience, but app.jsx was a solution that I tried that involved putting the logic that should be in index.js into a separate file.

Edit: Here is a list of the solutions I tried that did not work:

• Copy .babelrc to client/.babelrc
• Change test to test for .js instead of .js
• Separate app logic into separate file ( app.js )
• Put presets to use in webpack config

Also, I have pushed my code to my GitHub repo ( https://github.com/Gum-Joe/bedel ). Feel free to have a look at it.

Answer 1

You configured the loader to only pass .jsx files through Babel:

test: /\.jsx$/

However, your file has the extension .js . Either rename the file or update the test expression to /\\.jsx?$/ .

In addition to updating the test , you need to rename .babel.rc to .babelrc (no . before rc ). Otherwise Babel thinks that there is no configuration file and won't load any presets.

Answer 2

The loaders property must exist within the module property. Webpack Loaders

module.exports = {
  // ...

  // Output to /build
  output: {
    path: path.join(__dirname, "build", "js"),
    filename: "bundle.js"
  },

  module: {
    loaders: [
      { test: /\.jsx$/, exclude: /node_modules/, loader: "babel-loader" }
    ]
  },

  //...
};

Answer 3

You need to use react-preset with babel, like here:

loaders: [{
  test: /\.(js|jsx)$/,
  loader: 'babel',
  query: {
    presets: [
      'es2015',
      'react'
    ]
  }
}]

Answer 4

I'm having this issue as well, and if you're using Windows and Node 6.x, the only workaround I've found for now seems to be to use Node 4 LTS or 5 instead. Without knowing the root cause, the problem seems to stem from some combination of using JSX, Webpack, Babel, Acorn JS, Node 6, and Windows.

https://github.com/coryhouse/pluralsight-redux-starter/issues/2 https://github.com/danmartinez101/babel-preset-react-hmre/issues/32

Answer 5

Can you try wrapping the entire

element in brackets "()"?

return (<p>...</p>)