First stab at Fibonacci

fibonacci.js

const fibonacci = (limit, list=[1, 1]) => {
  const currentIndex = list.length - 1
  const newNumber = list[currentIndex - 1] + list[currentIndex]
  if( newNumber >= limit) {
    return list
  } else {
    return fibonacci(limit, list.concat([newNumber]), currentIndex + 1)
  }
}

console.log(fibonacci(100))