webpack不与babel-loader和react捆绑

Question

我遵循了一个相对较旧的RGR教程(2014年)。我不得不使用React，Webpack和Babel的更新版本，所以有一些不同之处。到目前为止，一切都正常，除了我试图将JSX编译到webpack中时，它给了我一个构建错误。

ERROR in ./public/js/app.js
Module build failed: SyntaxError: Unexpected token (7:15)

5 | class Hello extends React.Component {
6 |     render() {
7 |         return <h3>Hello Webpack!</h3>;
  |                ^
8 |     }
9 | }

10

下面是我的React文件：

import React, {Component} from 'react';
import ReactDOM from 'react-dom';


class Hello extends React.Component {
  render() {
    return <h3>Hello Webpack!</h3>;
  }
}


ReactDOM.render(<Hello />, document.getElementById('react'));

这是我的webpack.config.js文件

module.exports = {
entry: "./public/js/app.js",
output: {
    path: __dirname + "/public",
    filename: "bundle.js"
},
module: {
    loaders: [
        {test: /\.js$/, 
            loader: 'babel-loader' }
    ]
}
}

另外，下面是我的package.json文件

{
  "name": "rgrjs",
  "version": "1.0.0",
  "description": "a collection of educational resources about React, GraphQL, and Relay",
  "main": "index.js",
  "scripts": {
    "start": "node server.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": {
    "type": "git",
    "url": "git+https://github.com/krisxcrash/rgr-stack.git"
  },
  "author": "kristine martin",
  "license": "ISC",
  "bugs": {
    "url": "https://github.com/krisxcrash/rgr-stack/issues"
  },
  "homepage": "https://github.com/krisxcrash/rgr-stack#readme",
  "dependencies": {
    "babel-loader": "^7.1.2",
    "create-react-class": "^15.6.2",
    "express": "^4.16.2",
    "react": "^16.2.0",
    "react-dom": "^16.2.0"
  },
  "devDependencies": {
    "babel-cli": "^6.26.0",
    "babel-preset-env": "^1.6.1"
  }
}

有没有人能告诉我，为什么在返回后没有读取<h3>，导致webpack试图捆绑的时候出错？

Answer 1

你遗漏了一些预设：

首先执行npm安装：

npm install  babel-core babel-preset-es2015 babel-preset-react --save-dev

还要在您的根项目目录中创建一个.babelrc，并包含以下内容：

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

同样，在您的webpack配置的加载器部分中，为jsx包含以下内容：

{ test: /\.jsx?$/, exclude: /node_modules/, use: ['babel-loader'] }