babel核心

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1const babel = require('@babel/core');
2const code = "class glass {get name() { return '水杯' }}";
3const options = {
4    presets: ['@babel/preset-env'],
5}
6// 直接转换
7const result1 = babel.transform(code, options);
8
9// 异步转换
10babel.transformAsync(code, options).then(res => console.log(res));
11console.log(result);
12
13// 加载文件同步转换
14const content = babel.transformFileSync('./babel-file.js');
15console.log(content);
16
17// 生成AST语法树
18const parsedAst = babel.parse(code, { parserOpts: { allowReturnOutsideFunction: true } });
19console.log(parsedAst);
20
21// 通过语法树转换
22const result3 = babel.transformFromAst(parsedAst, code, options);
23console.log(result3);
24
25// 生成config
26const config = babel.loadPartialConfig(options); // 提前生成config
27const result = babel.transform(code, config.options);
28console.log(result);

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1babel/core的作用
2= 
3babel/parser(词法分析+语法分析 = AST) 
4+ 
5babel/traverse (AST 经过plugin转化) 
6+ 
7babel/generator (AST 生成code字符串)

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1const babel = require('@babel/core');
2const code = "class glass {get name() { return '水杯' }}";
3const options = {
4    presets: ['@babel/preset-env'],
5}
6
7const parsedAst = babel.parse(code);
8console.log(parsedAst);
9
10import { parse } from '@babel/parser';
11const ast = parse(code);
12console.log(ast);

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1import { parse } from '@babel/parser';
2import generate from '@babel/generator';
3const ast = parse(code);
4const output = generate(ast, {minified: true}, code);
5console.log(output);