Add specs for Enumerable value packing rule (0->nil, 1->value, N->Array)

core/enumerable/shared/value_packing.rb

@@ -0,0 +1,25 @@
+describe :enumerable_value_packing, shared: true do
+  # @take must be set to a Proc that returns the take-result whose #each
+  # yields packed values (e.g. -> e { e.take(1) } or -> e { e.lazy.take(1) }).
+
+  it "yields a single nil for a zero-argument source yield" do
+    e = Enumerator.new { |y| y.yield }
+    args = nil
+    @take.call(e).each { |*a| args = a }
+    args.should == [nil]
+  end
+
+  it "yields the value for a single-argument source yield" do
+    e = Enumerator.new { |y| y.yield :v }
+    args = nil
+    @take.call(e).each { |*a| args = a }
+    args.should == [:v]
+  end
+
+  it "yields a packed Array for a multi-argument source yield" do
+    e = Enumerator.new { |y| y.yield 1, 2 }
+    args = nil
+    @take.call(e).each { |*a| args = a }
+    args.should == [[1, 2]]
+  end
+end

core/enumerable/take_spec.rb

@@ -1,6 +1,7 @@
 require_relative '../../spec_helper'
 require_relative 'fixtures/classes'
 require_relative 'shared/take'
+require_relative 'shared/value_packing'
 
 describe "Enumerable#take" do
   it "requires an argument" do
@@ -10,4 +11,11 @@
   describe "when passed an argument" do
     it_behaves_like :enumerable_take, :take
   end
+
+  describe "value packing of source yields" do
+    before :each do
+      @take = -> e { e.take(1) }
+    end
+    it_behaves_like :enumerable_value_packing, nil
+  end
 end

core/enumerator/lazy/take_spec.rb

@@ -2,8 +2,16 @@
 
 require_relative '../../../spec_helper'
 require_relative 'fixtures/classes'
+require_relative '../../enumerable/shared/value_packing'
 
 describe "Enumerator::Lazy#take" do
+  describe "value packing of source yields (matches Enumerable#take)" do
+    before :each do
+      @take = -> e { e.lazy.take(1) }
+    end
+    it_behaves_like :enumerable_value_packing, nil
+  end
+
   before :each do
     @yieldsmixed = EnumeratorLazySpecs::YieldsMixed.new.to_enum.lazy
     @eventsmixed = EnumeratorLazySpecs::EventsMixed.new.to_enum.lazy