编译反应与webpack语法错误

Question

我对使用babel loader和eslint的webpack有点新意，我正在尝试编译一个非常基本的应用程序，我得到这个奇怪的语法错误，我无法弄清楚

这是我的index.js，我得到了编译错误

const store = configureStore()

render(
  <Router>
    <Root store={ store } />
  </Router>,
  document.getElementById('console_root')
)

这是我得到的错误：

ERROR in ./src/index.js
Module build failed: SyntaxError: Unexpected token (19:2)

  17 |
  18 | render(
> 19 |   <Router>
     |   ^
  20 |     <Root store={ store } />
  21 |   </Router>,
  22 |   document.getElementById('console_root')

npm ERR! code ELIFECYCLE
npm ERR! errno 2

这是我的webpack.config.js文件

var webpack = require('webpack')
var path = require('path')

module.exports = {
  entry: {
    main: path.resolve(__dirname, 'src', 'index.js')
  },
  resolve: {
    extensions: ['*', '.js', '.jsx']
  },
  output: {
    path: path.resolve(__dirname, '..'),
    publicPath: '/',
    filename: 'bundle.js'
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        use: ['babel-loader', 'eslint-loader']
      },
      {
        test: /\.scss$/,
        use: ['style-loader', 'css-loader', 'sass-loader']
      }
    ]
  },
  plugins: [
    new webpack.optimize.UglifyJsPlugin({
      compress: {
        warnings: false
      }
    }),
    new webpack.DefinePlugin({
      'process.env': {
        NODE_ENV: '"production"'
      }
    })
  ]
}

这些是我的依赖：

    "dependencies": {
    "material-ui": "^1.0.0-beta.26",
    "material-ui-icons": "^1.0.0-beta.17",
    "prop-types": "^15.6.0",
    "react": "^16.2.0",
    "react-dom": "^16.2.0",
    "react-redux": "^5.0.6",
    "react-router-dom": "^4.2.2",
    "redux": "^3.7.2"
  },
  "devDependencies": {
    "babel-core": "^6.26.0",
    "babel-eslint": "^8.1.2",
    "babel-loader": "^7.1.2",
    "css-loader": "^0.28.7",
    "eslint": "^4.14.0",
    "eslint-loader": "^1.9.0",
    "eslint-plugin-react": "^7.5.1",
    "react-scripts": "^1.0.17",
    "sass-loader": "^6.0.6",
    "style-loader": "^0.19.1",
    "webpack": "^3.10.0"
  }

任何想法我做错了什么？

Answer 1

好像你错过了将react预设添加到webpack.config.js文件或.babelrc。

首先你应该安装它：npm i babel-preset-react --save-dev然后将react预设添加到你的webpack配置，如下所示

  module: {
  rules: [
    {
      test: /\.js$/,
      exclude: /node_modules/,
      use: {
        loader: 'babel-loader',
        options: {
          presets: ['react']
        }
      }
    }
  ]
}

或者创建一个名为.babelrc的新文件并将其添加到那里

// .babelrc
{
  "presets": ["react"]
}

它应该适合你。

Answer 2

我想你需要创建一个包含内容的.babelrc文件

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

这将告诉babel将es6转换为es5，并告诉他们有一个反应项目，它将相应地处理。对于这些，你需要两个包来完成这项工作

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

Check this blog for more info