I lost the code format when I used '@Babel/parse'

[csywweb]

code like this:

// demo.javascript
function Demo() {
       console.log('Demo')
}

// ast code
import * as parser from '@babel/parser';
import * as generator from '@babel/generator';
import * as traverse from '@babel/traverse';
import * as fs from 'fs';
import * as path from 'path';

function complie(code) {
    const ast = parser.parse(code);
    const visitor = {}
    traverse.default(ast, visitor);
    // 3 代码生成
    return generator.default(ast);
}
const demo = path.resolve(__dirname, `./demo.js`)
const code = fs.readFileSync(demo, { encoding: 'utf8' });
const result = complie(code);
fs.writeFileSync('./output.js', result.code);

output:

function Demo() {
    console.log('Demo')
}

two spaces are missing in front of 'console';
Why did I lose the format with Babel ？ Maybe there are parameters to set

Thank you for your help

[JLHwung]

Babel does not preserve whitespaces after transform. If you are meant to preserve whitespaces, you can try https://github.com/benjamn/recast.