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diff --git a/spec/rubyspec/core/array/repeated_permutation_spec.rb b/spec/rubyspec/core/array/repeated_permutation_spec.rb
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+++ b/spec/rubyspec/core/array/repeated_permutation_spec.rb
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+require File.expand_path('../../../spec_helper', __FILE__)
+
+
+describe "Array#repeated_permutation" do
+
+  before :each do
+    @numbers = [10, 11, 12]
+    @permutations = [[10, 10], [10, 11], [10, 12], [11, 10], [11, 11], [11, 12], [12, 10], [12, 11], [12, 12]]
+  end
+
+  it "returns an Enumerator of all repeated permutations of given length when called without a block" do
+    enum = @numbers.repeated_permutation(2)
+    enum.should be_an_instance_of(Enumerator)
+    enum.to_a.sort.should == @permutations
+  end
+
+  it "yields all repeated_permutations to the block then returns self when called with block but no arguments" do
+    yielded = []
+    @numbers.repeated_permutation(2) {|n| yielded << n}.should equal(@numbers)
+    yielded.sort.should == @permutations
+  end
+
+  it "yields the empty repeated_permutation ([[]]) when the given length is 0" do
+    @numbers.repeated_permutation(0).to_a.should == [[]]
+    [].repeated_permutation(0).to_a.should == [[]]
+  end
+
+  it "does not yield when called on an empty Array with a nonzero argument" do
+    [].repeated_permutation(10).to_a.should == []
+  end
+
+  it "handles duplicate elements correctly" do
+    @numbers[-1] = 10
+    @numbers.repeated_permutation(2).sort.should ==
+      [[10, 10], [10, 10], [10, 10], [10, 10], [10, 11], [10, 11], [11, 10], [11, 10], [11, 11]]
+  end
+
+  it "truncates Float arguments" do
+    @numbers.repeated_permutation(3.7).to_a.sort.should ==
+      @numbers.repeated_permutation(3).to_a.sort
+  end
+
+  it "returns an Enumerator which works as expected even when the array was modified" do
+    @numbers.shift
+    enum = @numbers.repeated_permutation(2)
+    @numbers.unshift 10
+    enum.to_a.sort.should == @permutations
+  end
+
+  it "allows permutations larger than the number of elements" do
+    [1,2].repeated_permutation(3).sort.should ==
+      [[1, 1, 1], [1, 1, 2], [1, 2, 1],
+       [1, 2, 2], [2, 1, 1], [2, 1, 2],
+       [2, 2, 1], [2, 2, 2]]
+  end
+
+  it "generates from a defensive copy, ignoring mutations" do
+    accum = []
+    ary = [1,2]
+    ary.repeated_permutation(3) do |x|
+      accum << x
+      ary[0] = 5
+    end
+
+    accum.sort.should ==
+      [[1, 1, 1], [1, 1, 2], [1, 2, 1],
+       [1, 2, 2], [2, 1, 1], [2, 1, 2],
+       [2, 2, 1], [2, 2, 2]]
+  end
+
+  describe "when no block is given" do
+    describe "returned Enumerator" do
+      describe "size" do
+        it "returns 0 when combination_size is < 0" do
+          @numbers.repeated_permutation(-1).size.should == 0
+          [].repeated_permutation(-1).size.should == 0
+        end
+
+        it "returns array size ** combination_size" do
+          @numbers.repeated_permutation(4).size.should == 81
+          @numbers.repeated_permutation(3).size.should == 27
+          @numbers.repeated_permutation(2).size.should == 9
+          @numbers.repeated_permutation(1).size.should == 3
+          @numbers.repeated_permutation(0).size.should == 1
+          [].repeated_permutation(4).size.should == 0
+          [].repeated_permutation(3).size.should == 0
+          [].repeated_permutation(2).size.should == 0
+          [].repeated_permutation(1).size.should == 0
+          [].repeated_permutation(0).size.should == 1
+        end
+      end
+    end
+  end
+end