import * as acorn from 'acorn';
import * as astring from 'astring';
const code = `\
class A {
name;
}
`;
const ast = acorn.parse(code, { ecmaVersion: 2022 });
ast.body[0].body.body[0].comments = [{ type: 'Block', value: '* @type {string} ' }];
const formattedCode = astring.generate(ast, { comments: true })
console.log(formattedCode);

class A {
  /** @type {string} */
  name;
}

class A {
  /** @type {string}*/
  name;
}