1 files changed, 50 insertions, 0 deletions
diff --git a/spec/ruby/core/array/unshift_spec.rb b/spec/ruby/core/array/unshift_spec.rb
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+++ b/spec/ruby/core/array/unshift_spec.rb
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+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+describe "Array#unshift" do
+  it "prepends object to the original array" do
+    a = [1, 2, 3]
+    a.unshift("a").should equal(a)
+    a.should == ['a', 1, 2, 3]
+    a.unshift().should equal(a)
+    a.should == ['a', 1, 2, 3]
+    a.unshift(5, 4, 3)
+    a.should == [5, 4, 3, 'a', 1, 2, 3]
+
+    # shift all but one element
+    a = [1, 2]
+    a.shift
+    a.unshift(3, 4)
+    a.should == [3, 4, 2]
+
+    # now shift all elements
+    a.shift
+    a.shift
+    a.shift
+    a.unshift(3, 4)
+    a.should == [3, 4]
+  end
+
+  it "quietly ignores unshifting nothing" do
+    [].unshift().should == []
+    [].unshift(*[]).should == []
+  end
+
+  it "properly handles recursive arrays" do
+    empty = ArraySpecs.empty_recursive_array
+    empty.unshift(:new).should == [:new, empty]
+
+    array = ArraySpecs.recursive_array
+    array.unshift(:new)
+    array[0..5].should == [:new, 1, 'two', 3.0, array, array]
+  end
+
+  it "raises a RuntimeError on a frozen array when the array is modified" do
+    lambda { ArraySpecs.frozen_array.unshift(1) }.should raise_error(RuntimeError)
+  end
+
+  # see [ruby-core:23666]
+  it "raises a RuntimeError on a frozen array when the array would not be modified" do
+    lambda { ArraySpecs.frozen_array.unshift    }.should raise_error(RuntimeError)
+  end
+end