1 files changed, 25 insertions, 0 deletions
diff --git a/spec/ruby/library/prime/prime_division_spec.rb b/spec/ruby/library/prime/prime_division_spec.rb
new file mode 100644
index 0000000000..cc39969a56
--- /dev/null
+++ b/spec/ruby/library/prime/prime_division_spec.rb
@@ -0,0 +1,25 @@
+require_relative '../../spec_helper'
+require 'prime'
+
+describe "Prime.prime_division" do
+  it "returns an array of a prime factor and a corresponding exponent" do
+    Prime.prime_division(2*3*5*7*11*13*17).should ==
+      [[2,1], [3,1], [5,1], [7,1], [11,1], [13,1], [17,1]]
+  end
+
+  it "returns an empty array for 1" do
+    Prime.prime_division(1).should == []
+  end
+
+  it "returns [[-1, 1]] for -1" do
+    Prime.prime_division(-1).should == [[-1, 1]]
+  end
+
+  it "includes [[-1, 1]] in the divisors of a negative number" do
+    Prime.prime_division(-10).should.include?([-1, 1])
+  end
+
+  it "raises ZeroDivisionError for 0" do
+    -> { Prime.prime_division(0) }.should.raise(ZeroDivisionError)
+  end
+end