1 files changed, 124 insertions, 0 deletions
diff --git a/spec/ruby/core/array/pop_spec.rb b/spec/ruby/core/array/pop_spec.rb
new file mode 100644
index 0000000000..2a19408660
--- /dev/null
+++ b/spec/ruby/core/array/pop_spec.rb
@@ -0,0 +1,124 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Array#pop" do
+  it "removes and returns the last element of the array" do
+    a = ["a", 1, nil, true]
+
+    a.pop.should == true
+    a.should == ["a", 1, nil]
+
+    a.pop.should == nil
+    a.should == ["a", 1]
+
+    a.pop.should == 1
+    a.should == ["a"]
+
+    a.pop.should == "a"
+    a.should == []
+  end
+
+  it "returns nil if there are no more elements" do
+    [].pop.should == nil
+  end
+
+  it "properly handles recursive arrays" do
+    empty = ArraySpecs.empty_recursive_array
+    empty.pop.should == []
+
+    array = ArraySpecs.recursive_array
+    array.pop.should == [1, 'two', 3.0, array, array, array, array]
+  end
+
+  it "raises a FrozenError on a frozen array" do
+    -> { ArraySpecs.frozen_array.pop }.should raise_error(FrozenError)
+  end
+
+  it "raises a FrozenError on an empty frozen array" do
+    -> { ArraySpecs.empty_frozen_array.pop }.should raise_error(FrozenError)
+  end
+
+  describe "passed a number n as an argument" do
+    it "removes and returns an array with the last n elements of the array" do
+      a = [1, 2, 3, 4, 5, 6]
+
+      a.pop(0).should == []
+      a.should == [1, 2, 3, 4, 5, 6]
+
+      a.pop(1).should == [6]
+      a.should == [1, 2, 3, 4, 5]
+
+      a.pop(2).should == [4, 5]
+      a.should == [1, 2, 3]
+
+      a.pop(3).should == [1, 2, 3]
+      a.should == []
+    end
+
+    it "returns an array with the last n elements even if shift was invoked" do
+      a = [1, 2, 3, 4]
+      a.shift
+      a.pop(3).should == [2, 3, 4]
+    end
+
+    it "returns a new empty array if there are no more elements" do
+      a = []
+      popped1 = a.pop(1)
+      popped1.should == []
+      a.should == []
+
+      popped2 = a.pop(2)
+      popped2.should == []
+      a.should == []
+
+      popped1.should_not equal(popped2)
+    end
+
+    it "returns whole elements if n exceeds size of the array" do
+      a = [1, 2, 3, 4, 5]
+      a.pop(6).should == [1, 2, 3, 4, 5]
+      a.should == []
+    end
+
+    it "does not return self even when it returns whole elements" do
+      a = [1, 2, 3, 4, 5]
+      a.pop(5).should_not equal(a)
+
+      a = [1, 2, 3, 4, 5]
+      a.pop(6).should_not equal(a)
+    end
+
+    it "raises an ArgumentError if n is negative" do
+      ->{ [1, 2, 3].pop(-1) }.should raise_error(ArgumentError)
+    end
+
+    it "tries to convert n to an Integer using #to_int" do
+      a = [1, 2, 3, 4]
+      a.pop(2.3).should == [3, 4]
+
+      obj = mock('to_int')
+      obj.should_receive(:to_int).and_return(2)
+      a.should == [1, 2]
+      a.pop(obj).should == [1, 2]
+      a.should == []
+    end
+
+    it "raises a TypeError when the passed n cannot be coerced to Integer" do
+      ->{ [1, 2].pop("cat") }.should raise_error(TypeError)
+      ->{ [1, 2].pop(nil) }.should raise_error(TypeError)
+    end
+
+    it "raises an ArgumentError if more arguments are passed" do
+      ->{ [1, 2].pop(1, 2) }.should raise_error(ArgumentError)
+    end
+
+    it "does not return subclass instances with Array subclass" do
+      ArraySpecs::MyArray[1, 2, 3].pop(2).should be_an_instance_of(Array)
+    end
+
+    it "raises a FrozenError on a frozen array" do
+      -> { ArraySpecs.frozen_array.pop(2) }.should raise_error(FrozenError)
+      -> { ArraySpecs.frozen_array.pop(0) }.should raise_error(FrozenError)
+    end
+  end
+end