webpack 不与 babel-loader 捆绑并做出反应

Question

我正在关注一个相对较旧的 RGR 教程（从 2014 年开始）。我必须使用 React、Webpack 和 Babel 的更新版本，因此存在一些差异。到目前为止一切正常，除了当我试图将 JSX 编译成 webpack 时，它给我一个构建错误。

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' }
    ]
}
}

此外，这是我的 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"
  }
}

谁能告诉我为什么它在 return 之后不读取 <h3> 并在 webpack 尝试捆绑时导致错误？

Answer 1

您缺少一些预设：

首先执行 npm 安装：

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

同时在你的根项目目录中创建一个 .babelrc，并包含这个：

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

同样在 webpack 配置的加载器部分，为 jsx 包含这个：

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

webpack 不与 babel-loader 捆绑并做出反应

webpack not bundling with babel-loader and react

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