name : prime_division_spec.rb require_relative '../../../spec_helper' ruby_version_is ''...'2.5' do require 'mathn' describe "Integer#prime_division" do it "performs a prime factorization of a positive integer" do 100.prime_division.should == [[2, 2], [5, 2]] end # Proper handling of negative integers has been added to MRI trunk # in revision 24091. Prior to that, all versions of MRI returned nonsense. it "performs a prime factorization of a negative integer" do -26.prime_division.should == [[-1, 1], [2, 1], [13, 1]] end it "raises a ZeroDivisionError when is called on zero" do -> { 0.prime_division }.should raise_error(ZeroDivisionError) end end end