describe Integer, "#fibonacci?" do
  # A000045
  @seq = [0,1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,
          1597,2584,4181,6765,10946,17711,28657,46368,75025,
          121393,196418,317811,514229,832040,1346269,
          2178309,3524578,5702887,9227465,14930352,24157817,
          39088169].uniq.to_seq

  @seq.each do |n|
    it "returns true for Fibonacci number #{n}" do
      n.should be_fibonacci
    end
  end

  @seq.invert.sample(10).each do |n|
    it "returns false for non-Fibonacci number #{n}" do
      n.should_not be_fibonacci
    end
  end
end