// user-helper.js /** * @param {import('./user').User} user */ exports.checkAge = user => { return user.age >= 18 }
// user.js const checkAge = require('./user-helper') /** * @typedef {Object} User * @property {string} name * @property {number} age */ /** * @param {User} user */ const createUser = (user) => { if (checkAge(user)) { db.save(user) } }