proper tail call with trampoline in javascript

trampoline.js

var trampoline = fn => (n) => {
  // make sure we call trampoline function only once

  var result = fn(n);

  while (typeof result === 'function') {
    result = result();
  }

  return result;
}

// The recursive function should be a proper tail call, and return recursive call wrapped with a function
var counter = c => {
  if (c === 200000) return; // base case

  if (c % 5000 === 0) console.log(c);

  return () => counter(c + 1);
}

var counterT = trampoline(counter);

counterT(0);