1 files changed, 134 insertions, 0 deletions
diff --git a/spec/rubyspec/core/array/shift_spec.rb b/spec/rubyspec/core/array/shift_spec.rb
new file mode 100644
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+++ b/spec/rubyspec/core/array/shift_spec.rb
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+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+describe "Array#shift" do
+  it "removes and returns the first element" do
+    a = [5, 1, 1, 5, 4]
+    a.shift.should == 5
+    a.should == [1, 1, 5, 4]
+    a.shift.should == 1
+    a.should == [1, 5, 4]
+    a.shift.should == 1
+    a.should == [5, 4]
+    a.shift.should == 5
+    a.should == [4]
+    a.shift.should == 4
+    a.should == []
+  end
+
+  it "returns nil when the array is empty" do
+    [].shift.should == nil
+  end
+
+  it "properly handles recursive arrays" do
+    empty = ArraySpecs.empty_recursive_array
+    empty.shift.should == []
+    empty.should == []
+
+    array = ArraySpecs.recursive_array
+    array.shift.should == 1
+    array[0..2].should == ['two', 3.0, array]
+  end
+
+  it "raises a RuntimeError on a frozen array" do
+    lambda { ArraySpecs.frozen_array.shift }.should raise_error(RuntimeError)
+  end
+  it "raises a RuntimeError on an empty frozen array" do
+    lambda { ArraySpecs.empty_frozen_array.shift }.should raise_error(RuntimeError)
+  end
+
+  describe "passed a number n as an argument" do
+    it "removes and returns an array with the first n element of the array" do
+      a = [1, 2, 3, 4, 5, 6]
+
+      a.shift(0).should == []
+      a.should == [1, 2, 3, 4, 5, 6]
+
+      a.shift(1).should == [1]
+      a.should == [2, 3, 4, 5, 6]
+
+      a.shift(2).should == [2, 3]
+      a.should == [4, 5, 6]
+
+      a.shift(3).should == [4, 5, 6]
+      a.should == []
+    end
+
+    it "does not corrupt the array when shift without arguments is followed by shift with an argument" do
+      a = [1, 2, 3, 4, 5]
+
+      a.shift.should == 1
+      a.shift(3).should == [2, 3, 4]
+      a.should == [5]
+    end
+
+    it "returns a new empty array if there are no more elements" do
+      a = []
+      popped1 = a.shift(1)
+      popped1.should == []
+      a.should == []
+
+      popped2 = a.shift(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.shift(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.shift(5).should_not equal(a)
+
+      a = [1, 2, 3, 4, 5]
+      a.shift(6).should_not equal(a)
+    end
+
+    it "raises an ArgumentError if n is negative" do
+      lambda{ [1, 2, 3].shift(-1) }.should raise_error(ArgumentError)
+    end
+
+    it "tries to convert n to an Integer using #to_int" do
+      a = [1, 2, 3, 4]
+      a.shift(2.3).should == [1, 2]
+
+      obj = mock('to_int')
+      obj.should_receive(:to_int).and_return(2)
+      a.should == [3, 4]
+      a.shift(obj).should == [3, 4]
+      a.should == []
+    end
+
+    it "raises a TypeError when the passed n can be coerced to Integer" do
+      lambda{ [1, 2].shift("cat") }.should raise_error(TypeError)
+      lambda{ [1, 2].shift(nil) }.should raise_error(TypeError)
+    end
+
+    it "raises an ArgumentError if more arguments are passed" do
+      lambda{ [1, 2].shift(1, 2) }.should raise_error(ArgumentError)
+    end
+
+    it "does not return subclass instances with Array subclass" do
+      ArraySpecs::MyArray[1, 2, 3].shift(2).should be_an_instance_of(Array)
+    end
+
+    it "returns an untainted array even if the array is tainted" do
+      ary = [1, 2].taint
+      ary.shift(2).tainted?.should be_false
+      ary.shift(0).tainted?.should be_false
+    end
+
+    it "keeps taint status" do
+      a = [1, 2].taint
+      a.shift(2)
+      a.tainted?.should be_true
+      a.shift(2)
+      a.tainted?.should be_true
+    end
+  end
+end