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diff --git a/spec/ruby/core/array/rotate_spec.rb b/spec/ruby/core/array/rotate_spec.rb
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+++ b/spec/ruby/core/array/rotate_spec.rb
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+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+describe "Array#rotate" do
+  describe "when passed no argument" do
+    it "returns a copy of the array with the first element moved at the end" do
+      [1, 2, 3, 4, 5].rotate.should == [2, 3, 4, 5, 1]
+    end
+  end
+
+  describe "with an argument n" do
+    it "returns a copy of the array with the first (n % size) elements moved at the end" do
+      a = [1, 2, 3, 4, 5]
+      a.rotate(  2).should == [3, 4, 5, 1, 2]
+      a.rotate( -1).should == [5, 1, 2, 3, 4]
+      a.rotate(-21).should == [5, 1, 2, 3, 4]
+      a.rotate( 13).should == [4, 5, 1, 2, 3]
+      a.rotate(  0).should == a
+    end
+
+    it "coerces the argument using to_int" do
+      [1, 2, 3].rotate(2.6).should == [3, 1, 2]
+
+      obj = mock('integer_like')
+      obj.should_receive(:to_int).and_return(2)
+      [1, 2, 3].rotate(obj).should == [3, 1, 2]
+    end
+
+    it "raises a TypeError if not passed an integer-like argument" do
+      lambda {
+        [1, 2].rotate(nil)
+      }.should raise_error(TypeError)
+      lambda {
+        [1, 2].rotate("4")
+      }.should raise_error(TypeError)
+    end
+  end
+
+  it "returns a copy of the array when its length is one or zero" do
+    [1].rotate.should == [1]
+    [1].rotate(2).should == [1]
+    [1].rotate(-42).should == [1]
+    [ ].rotate.should == []
+    [ ].rotate(2).should == []
+    [ ].rotate(-42).should == []
+  end
+
+  it "does not mutate the receiver" do
+    lambda {
+      [].freeze.rotate
+      [2].freeze.rotate(2)
+      [1,2,3].freeze.rotate(-3)
+    }.should_not raise_error
+  end
+
+  it "does not return self" do
+    a = [1, 2, 3]
+    a.rotate.should_not equal(a)
+    a = []
+    a.rotate(0).should_not equal(a)
+  end
+
+  it "does not return subclass instance for Array subclasses" do
+    ArraySpecs::MyArray[1, 2, 3].rotate.should be_an_instance_of(Array)
+  end
+end
+
+describe "Array#rotate!" do
+  describe "when passed no argument" do
+    it "moves the first element to the end and returns self" do
+      a = [1, 2, 3, 4, 5]
+      a.rotate!.should equal(a)
+      a.should == [2, 3, 4, 5, 1]
+    end
+  end
+
+  describe "with an argument n" do
+    it "moves the first (n % size) elements at the end and returns self" do
+      a = [1, 2, 3, 4, 5]
+      a.rotate!(2).should equal(a)
+      a.should == [3, 4, 5, 1, 2]
+      a.rotate!(-12).should equal(a)
+      a.should == [1, 2, 3, 4, 5]
+      a.rotate!(13).should equal(a)
+      a.should == [4, 5, 1, 2, 3]
+    end
+
+    it "coerces the argument using to_int" do
+      [1, 2, 3].rotate!(2.6).should == [3, 1, 2]
+
+      obj = mock('integer_like')
+      obj.should_receive(:to_int).and_return(2)
+      [1, 2, 3].rotate!(obj).should == [3, 1, 2]
+    end
+
+    it "raises a TypeError if not passed an integer-like argument" do
+      lambda {
+        [1, 2].rotate!(nil)
+      }.should raise_error(TypeError)
+      lambda {
+        [1, 2].rotate!("4")
+      }.should raise_error(TypeError)
+    end
+  end
+
+  it "does nothing and returns self when the length is zero or one" do
+    a = [1]
+    a.rotate!.should equal(a)
+    a.should == [1]
+    a.rotate!(2).should equal(a)
+    a.should == [1]
+    a.rotate!(-21).should equal(a)
+    a.should == [1]
+
+    a = []
+    a.rotate!.should equal(a)
+    a.should == []
+    a.rotate!(2).should equal(a)
+    a.should == []
+    a.rotate!(-21).should equal(a)
+    a.should == []
+  end
+
+  it "raises a RuntimeError on a frozen array" do
+    lambda { [1, 2, 3].freeze.rotate!(0) }.should raise_error(RuntimeError)
+    lambda { [1].freeze.rotate!(42) }.should raise_error(RuntimeError)
+    lambda { [].freeze.rotate! }.should raise_error(RuntimeError)
+  end
+end