create-react-app 2.0版本如何啓用裝飾器語法

create-react-app(簡稱cra)已經更新之2.0.3版本, babel也更新至7.x版本, JavaScript裝飾器語法雖然還不是標準, 但是藉助於babel, 也能在項目裏愉快的玩耍.

cra2.0時代如何啓用裝飾器語法呢? 我們依舊採用的是react-app-rewired, 通過劫持webpack cofig對象, 達到修改的目的.

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"
  }

安裝裝飾器語法所需的babel插件, 也可以順帶升級babel-core

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

在項目根目錄下創建.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對象, 對其babel規則進行簡單的修改.
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"
  }
}