Private ES6 methods

apple.js

const transformName = Symbol('private:transformName');

class Apple {
  constructor () {
    console.log('i am created')
  }

  [transformName] (name) {
    return name.split('').reverse().join('');
  }

  fallOn (person) {
    console.log(`Fell on ${this[transformName](person)}`)
  }
}

module.exports = Apple

consumer.js

const Apple = require('./apple');

// this outputs "i am created"
const apple = new Apple();

// this outputs "Fell on Newton"
apple.fallOn('notweN')

// this will be a runtime error
apple[Symbol('private:transformName')]()