require_relative "ruby-review-2.rb"


def random_fibonacci
   [0,1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,1597,2584,4181,6765,10946].sample
end

describe "is_fibonacci?" do
   it "returns true when a integer is one number of the Fibonacci sequence" do
      expect(is_fibonacci?(random_fibonacci)).to be true
   end
   it "returns true with a large Fibonacci number" do
      expect(is_fibonacci?(8670007398507948658051921)).to be true
   end
   it "returns false when it's not in the Fibonacci seqence" do
      expect(is_fibonacci?(random_fibonacci+100)).to be false
   end
   it "returns false on large non-Fibonacci numbers" do
      expect(is_fibonacci?(927372692193078999171)).to be false
   end
end