require_relative '../../../spec_helper' ruby_version_is ""..."3.1" do require 'prime' describe "Integer#prime_division" do it "returns an array of a prime factor and a corresponding exponent" do (2*3*5*7*11*13*17).prime_division.should == [[2,1], [3,1], [5,1], [7,1], [11,1], [13,1], [17,1]] end it "returns an empty array for 1" do 1.prime_division.should == [] end it "returns an empty array for -1" do -1.prime_division.should == [[-1, 1]] end it "raises ZeroDivisionError for 0" do -> { 0.prime_division }.should raise_error(ZeroDivisionError) end end end