1 files changed, 77 insertions, 0 deletions
diff --git a/spec/ruby/core/enumerable/chunk_spec.rb b/spec/ruby/core/enumerable/chunk_spec.rb
new file mode 100644
index 0000000000..7c9b31c991
--- /dev/null
+++ b/spec/ruby/core/enumerable/chunk_spec.rb
@@ -0,0 +1,77 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Enumerable#chunk" do
+  before do
+    ScratchPad.record []
+  end
+
+  it "returns an Enumerator if called without a block" do
+    chunk = EnumerableSpecs::Numerous.new(1, 2, 3, 1, 2).chunk
+    chunk.should.instance_of?(Enumerator)
+    result = chunk.with_index {|elt, i| elt - i }.to_a
+    result.should == [[1, [1, 2, 3]], [-2, [1, 2]]]
+  end
+
+  it "returns an Enumerator if given a block" do
+    EnumerableSpecs::Numerous.new.chunk {}.should.instance_of?(Enumerator)
+  end
+
+  it "yields the current element and the current chunk to the block" do
+    e = EnumerableSpecs::Numerous.new(1, 2, 3)
+    e.chunk { |x| ScratchPad << x }.to_a
+    ScratchPad.recorded.should == [1, 2, 3]
+  end
+
+  it "returns elements of the Enumerable in an Array of Arrays, [v, ary], where 'ary' contains the consecutive elements for which the block returned the value 'v'" do
+    e = EnumerableSpecs::Numerous.new(1, 2, 3, 2, 3, 2, 1)
+    result = e.chunk { |x| x < 3 && 1 || 0 }.to_a
+    result.should == [[1, [1, 2]], [0, [3]], [1, [2]], [0, [3]], [1, [2, 1]]]
+  end
+
+  it "returns a partitioned Array of values" do
+    e = EnumerableSpecs::Numerous.new(1,2,3)
+    e.chunk { |x| x > 2 }.map(&:last).should == [[1, 2], [3]]
+  end
+
+  it "returns elements for which the block returns :_alone in separate Arrays" do
+    e = EnumerableSpecs::Numerous.new(1, 2, 3, 2, 1)
+    result = e.chunk { |x| x < 2 && :_alone }.to_a
+    result.should == [[:_alone, [1]], [false, [2, 3, 2]], [:_alone, [1]]]
+  end
+
+  it "yields Arrays as a single argument to a rest argument" do
+    e = EnumerableSpecs::Numerous.new([1, 2])
+    result = e.chunk { |*x| x.should == [[1,2]] }.to_a
+  end
+
+  it "does not return elements for which the block returns :_separator" do
+    e = EnumerableSpecs::Numerous.new(1, 2, 3, 3, 2, 1)
+    result = e.chunk { |x| x == 2 ? :_separator : 1 }.to_a
+    result.should == [[1, [1]], [1, [3, 3]], [1, [1]]]
+  end
+
+  it "does not return elements for which the block returns nil" do
+    e = EnumerableSpecs::Numerous.new(1, 2, 3, 2, 1)
+    result = e.chunk { |x| x == 2 ? nil : 1 }.to_a
+    result.should == [[1, [1]], [1, [3]], [1, [1]]]
+  end
+
+  it "raises a RuntimeError if the block returns a Symbol starting with an underscore other than :_alone or :_separator" do
+    e = EnumerableSpecs::Numerous.new(1, 2, 3, 2, 1)
+    -> { e.chunk { |x| :_arbitrary }.to_a }.should.raise(RuntimeError)
+  end
+
+  it "does not accept arguments" do
+    e = EnumerableSpecs::Numerous.new(1, 2, 3)
+    -> {
+      e.chunk(1) {}
+    }.should.raise(ArgumentError)
+  end
+
+  it 'returned Enumerator size returns nil' do
+    e = EnumerableSpecs::NumerousWithSize.new(1, 2, 3, 2, 1)
+    enum = e.chunk { |x| true }
+    enum.size.should == nil
+  end
+end