Nodejs學習筆記 安裝 babel

安裝 babel

項目已經創建好。安裝babel相關包

$ npm install --save-dev @babel/core @babel/cli @babel/preset-env @babel/node
$ npm install --save @babel/polyfill

配置babel.config.js

const presets =[
	["@babel/env", {
		targets: {
			ie: "8",
			edge: "17",
			firefox: "60",
			chrome: "67",
			safari: "11.1"
		}	
	}]
];
module.exports = { presets };

創建測試文件.\src\index.js

let str = 'hehe';

let a = [1,2,3], b = [4,5,6];
let arr = [...a, ...b];

let foo = i=> 1+2;

測試 babel

執行：

$ npx babel .\src\index.js -o .\dist\demo.js

查看生成的目標 demo.js
es6語法轉成es5了

"use strict";

var str = 'hehe';

var a = [1, 2, 3],
    b = [4, 5, 6];
var arr = [].concat(a, b);

var foo = function foo(i) {
  return 1 + 2;
};

參考資料

https://babeljs.io
Using Babel =》Language APIs =》Node