FibBuzz in Ruby

fibbuzz.rb

def fibbuzz(to)
  fib = [0, 1]
  fib << fib[-1] + fib[-2] while fib.last < to
  result = []

  1.upto(to) do |x|
    output = x
    output = 'Fib'      if fib.include?(x)
    output = 'Buzz'     if x % 5 == 0
    output = 'FibBuzz'  if fib.include?(x) && x % 5 == 0
    result << output
  end
  result
end