详解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"
 }
}