Create Y-combinator function

[Johnius]

This function might have a good fit here to see if testee knows how to implement recursion without having it natively in a language. Yes, it's more theoretical question.

Correct answer is

{
  yCombinator: function (fn) {
    return function (n) {
      return fn(n, fn)
    }
  }
}

[Johnius]

  150:14  error  Do not nest ternary expressions           no-nested-ternary
  150:14  error  Ternary operator used                     no-ternary
  150:26  error  Gratuitous parentheses around expression  no-extra-parens
  150:27  error  Ternary operator used                     no-ternary

Ok...