babel核心

const babel = require('@babel/core');
const code = "class glass {get name() { return '水杯' }}";
const options = {
    presets: ['@babel/preset-env'],
}
// 直接转换
const result1 = babel.transform(code, options);
 
// 异步转换
babel.transformAsync(code, options).then(res => console.log(res));
console.log(result);
 
// 加载文件同步转换
const content = babel.transformFileSync('./babel-file.js');
console.log(content);
 
// 生成AST语法树
const parsedAst = babel.parse(code, { parserOpts: { allowReturnOutsideFunction: true } });
console.log(parsedAst);
 
// 通过语法树转换
const result3 = babel.transformFromAst(parsedAst, code, options);
console.log(result3);
 
// 生成config
const config = babel.loadPartialConfig(options); // 提前生成config
const result = babel.transform(code, config.options);
console.log(result);

babel/core的作用
= 
babel/parser(词法分析+语法分析 = AST) 
+ 
babel/traverse (AST 经过plugin转化) 
+ 
babel/generator (AST 生成code字符串)

const babel = require('@babel/core');
const code = "class glass {get name() { return '水杯' }}";
const options = {
    presets: ['@babel/preset-env'],
}
 
const parsedAst = babel.parse(code);
console.log(parsedAst);
 
import { parse } from '@babel/parser';
const ast = parse(code);
console.log(ast);

import { parse } from '@babel/parser';
import generate from '@babel/generator';
const ast = parse(code);
const output = generate(ast, {minified: true}, code);
console.log(output);