Webpack 4.x搭建react开发环境的方法步骤

"dependencies": {
  "babel-core": "^6.26.3",
  "babel-loader": "^7.1.5",
  "babel-preset-env": "^1.7.0",
  "react": "^16.4.2",
  "react-dom": "^16.4.2",
  "webpack": "^4.16.5"
  ...
}

var path = require('path');
var node_modules = path.resolve(__dirname, 'node_modules');
var deps = [ 
 ];

//以上代码可以忽略，没有必要不要添加noParse，因为依赖代码中可能会有环境的判断，而浏览器中是拿不到process变量的，会报错！
var config = {
  //这里是打包的入口
 entry: path.resolve(__dirname, './react/app.js'),
 resolve: {
  alias: {
  }
 },
 //打包完成后输出到./build/bundle.js文件中
 output: {
  path: path.resolve(__dirname, './build'),
  filename: 'bundle.js',
 },
 mode: 'development',
 module: {
   //上述的规则，loader就放在这里，这段没什么好说的，从Webpack官方文档上直接拿来用
  rules: [
    {
     test: /\.js$/,
     exclude: /(node_modules|bower_components)/,
     use: {
      loader: 'babel-loader',
      options: {
        //刚刚下载的module之一
       presets: ['babel-preset-env']
      }
     }
    }
   ]
 }
};

//遍历你的自定义要排除的依赖，安装到node_modules里的依赖一般不需要排除掉
deps.forEach(function (dep) {
  var depPath = path.resolve(node_modules, dep);
  config.resolve.alias[dep.split(path.sep)[0]] = depPath;
  config.module.noParse.push(depPath);
 });

module.exports = config;

...
"scripts": {
  ...
  "build-config": "webpack",
  ...
}
...

...
<h1 onClick={this.handleClick.bind(this)} style={{ color: "red" }}>
  {'Hello ' + this.state.text}
</h1>
...

{
  "plugins": ["transform-react-jsx"]
}

> webpack

Hash: e716d360a6a752006c09
Version: webpack 4.16.5
Time: 973ms
Built at: 2018-08-14 15:19:14
  Asset   Size Chunks       Chunk Names
bundle.js 715 KiB  main [emitted] main
Entrypoint main = bundle.js
[./react/app.js] 2.74 KiB {main} [built]
  + 21 hidden modules

var _react = __webpack_require__(/*! react */ "./node_modules/react/index.js");
var _react2 = _interopRequireDefault(_react);
...
_createClass(MyTitle, [{
key: "handleClick",
value: function handleClick() {
  this.setState({
  text: "Clicked"
  });
}
}, {
key: "render",
value: function render() {
  return _react2.default.createElement(
  "h1",
  { onClick: this.handleClick.bind(this), style: { color: "red" } },
  'Hello ' + this.state.text
  );
}
}]);

"devDependencies": {
  ···
  "eslint": "^5.3.0",
  "eslint-plugin-import": "^2.14.0"
  ···
}

{
 "parserOptions": {
   //使用的ecma版本
  "ecmaVersion": 6,
  "sourceType": "module",
  //使用jsx特性
  "ecmaFeatures": {
   "jsx": true
  }
 },
 "rules": {
   //忽略console的警告
  "no-console": "off",
  "semi": ["error", "always"]
 }
}