create-react-app 2.0版本如何启用装饰器语法

create-react-app(简称cra)已经更新之2.0.3版本, babel也更新至7.x版本, JavaScript装饰器语法虽然还不是标准, 但是借助于babel, 也能在项目里愉快的玩耍.

cra2.0时代如何启用装饰器语法呢? 我们依旧采用的是react-app-rewired, 通过劫持webpack cofig对象, 达到修改的目的.

yarn add react-app-rewired

修改package.json

"scripts": {
    "start": "react-app-rewired start",
    "build": "react-app-rewired build",
    "test": "react-app-rewired test"
  }

安装装饰器语法所需的babel插件, 也可以顺带升级babel-core

yarn add @babel/plugin-proposal-decorators metro-react-native-babel-preset -D

在项目根目录下创建.babelrc, config-overrides.js文件

// .babelrc
{
  "presets": ["module:metro-react-native-babel-preset"],
  "plugins": [
    [
      "@babel/plugin-proposal-decorators",
      {
        "legacy": true
      }
    ]
  ]
}

// config-overrides
const { getBabelLoader } = require('react-app-rewired');

const path = require('path');

module.exports = function override(config, env) {
  const babelLoader = getBabelLoader(config.module.rules);
  const pwd = path.resolve();
  babelLoader.include = [path.normalize(`${pwd}/src`)];
  // use babelrc
  babelLoader.options.babelrc = true;
  
  return config;
};

原理就是劫持了config对象, 对其babel规则进行简单的修改.
附上完整的package.json

{
  "name": "my-react-project",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "react": "^16.5.2",
    "react-app-rewired": "^1.6.2",
    "react-dom": "^16.5.2",
    "react-scripts": "2.0.5"
  },
  "scripts": {
    "start": "react-app-rewired start",
    "build": "react-app-rewired build",
    "test": "react-app-rewired test"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": [
    ">0.2%",
    "not dead",
    "not ie <= 11",
    "not op_mini all"
  ],
  "devDependencies": {
    "@babel/plugin-proposal-decorators": "^7.1.2",
    "metro-react-native-babel-preset": "^0.48.1",
    "webpack-bundle-analyzer": "^3.0.3"
  }
}