安装模块

npm i @babel/core @babel/cli @babel/preset-env corejs -S

test.js

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

class classNew {}
new classNew()

index.js:

import babel from '@babel/core'
import presetEnv from '@babel/preset-env'

import fs from 'node:fs'

const code = fs.readFileSync('./test.js', 'utf-8')
const res = babel.transform(code, {
  presets: [
    [
      presetEnv, 
      {
        useBuiltIns: 'usage', // 引入需要的垫片, entry 手动引入
        corejs: 3 // 转换高级 js 语法糖
      }
    ]
  ]
})

console.log(res.code)

执行命令

转换 react 代码

安装模块

npm i react react-dom @babel/preset-react -S

新建app.jsx

import React from 'react';
import { createRoot } from 'react-dom/client';

const App = ()=> <div>hello world</div>
createRoot(document.getElementById('app')).render(<App />)

修改 index.js

import babel from '@babel/core'
import presetEnv from '@babel/preset-env'

import presetReact from '@babel/preset-react'

import fs from 'node:fs'

const code = fs.readFileSync('./app.jsx', 'utf-8')
const res = babel.transform(code, {
  presets: [
    [
      presetEnv, {
        useBuiltIns: 'usage', // 引入需要的垫片, entry 手动引入
        corejs: 3 // 转换高级 js 语法糖
      }
    ], 
    presetReact
  ]
})

console.log(res.code)