1 files changed, 21 insertions, 0 deletions
diff --git a/spec/ruby/library/mathn/integer/prime_division_spec.rb b/spec/ruby/library/mathn/integer/prime_division_spec.rb
new file mode 100644
index 0000000000..63a5c39733
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+++ b/spec/ruby/library/mathn/integer/prime_division_spec.rb
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+require File.expand_path('../../../../spec_helper', __FILE__)
+
+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
+      lambda { 0.prime_division }.should raise_error(ZeroDivisionError)
+    end
+  end
+end