PrimeFactors Kata Second iteration

prime_factors_2_spec.rb

class PrimeFactors
  def self.generate(number)
    if number == 1
      []
    elsif number <= 3
      [number]
    else
      result = []
      Array((2..number / 2)).each do |i|
        while(number % i).zero? do
          number = number / i
          result << i
        end
      end
      result
    end
  end
end

describe PrimeFactors do
  it "returns no prime factors of 1" do
    PrimeFactors.generate(1).should be == []
  end

  it "returns the factor 2 for 2" do
    PrimeFactors.generate(2).should be == [2]
  end
  
  it "returns the factor 3 for 3" do
     PrimeFactors.generate(3).should be == [3]
  end

  it "returns the factors 2,2 for 4" do
    PrimeFactors.generate(4).should be == [2,2]
  end

  it "returns the factors 2,3 for 6" do
    PrimeFactors.generate(6).should be == [2,3]
  end

  it "returns the factors 2,2,2 for 8" do
    PrimeFactors.generate(8).should be  == [2,2,2]
  end

  it "returns the factors 2,2,3,5,7 for 420" do
    PrimeFactors.generate(420).should be == [2,2,3,5,7]
  end
end

Forked, refactored and proven wrong ;)