1 files changed, 70 insertions, 1 deletions
diff --git a/spec/ruby/core/enumerable/shared/collect.rb b/spec/ruby/core/enumerable/shared/collect.rb
index 05e94777c7..4696d32454 100644
--- a/spec/ruby/core/enumerable/shared/collect.rb
+++ b/spec/ruby/core/enumerable/shared/collect.rb
@@ -30,9 +30,78 @@ describe :enumerable_collect, shared: true do
 
   it "returns an enumerator when no block given" do
     enum = EnumerableSpecs::Numerous.new.send(@method)
-    enum.should be_an_instance_of(Enumerator)
+    enum.should.instance_of?(Enumerator)
     enum.each { |i| -i }.should == [-2, -5, -3, -6, -1, -4]
   end
 
+  it "reports the same arity as the given block" do
+    entries = [0, 1, 3, 4, 5, 6]
+    numerous = EnumerableSpecs::Numerous.new(*entries)
+
+    def numerous.each(&block)
+      ScratchPad << block.arity
+      super
+    end
+
+    numerous.send(@method) { |a, b| a % 2 }.should == [0, 1, 1, 0, 1, 0]
+    ScratchPad.recorded.should == [2]
+    ScratchPad.clear
+    ScratchPad.record []
+    numerous.send(@method) { |i| i }.should == entries
+    ScratchPad.recorded.should == [1]
+  end
+
+  it "yields an Array of 2 elements for a Hash when block arity is 1" do
+    c = Class.new do
+      def register(a)
+        ScratchPad << a
+      end
+    end
+    m = c.new.method(:register)
+
+    ScratchPad.record []
+    { 1 => 'a', 2 => 'b' }.map(&m)
+    ScratchPad.recorded.should == [[1, 'a'], [2, 'b']]
+  end
+
+  it "yields 2 arguments for a Hash when block arity is 2" do
+    c = Class.new do
+      def register(a, b)
+        ScratchPad << [a, b]
+      end
+    end
+    m = c.new.method(:register)
+
+    ScratchPad.record []
+    { 1 => 'a', 2 => 'b' }.map(&m)
+    ScratchPad.recorded.should == [[1, 'a'], [2, 'b']]
+  end
+
+  it "raises an error for a Hash when an arity enforcing block of arity >2 is passed in" do
+    c = Class.new do
+      def register(a, b, c)
+      end
+    end
+    m = c.new.method(:register)
+
+    -> do
+      { 1 => 'a', 2 => 'b' }.map(&m)
+    end.should.raise(ArgumentError)
+  end
+
+  it "calls the each method on sub-classes" do
+    c = Class.new(Hash) do
+      def each
+        ScratchPad << 'in each'
+        super
+      end
+    end
+    h = c.new
+    h[1] = 'a'
+    ScratchPad.record []
+    h.send(@method) { |k,v| v }
+    ScratchPad.recorded.should == ['in each']
+  end
+
   it_should_behave_like :enumerable_enumeratorized_with_origin_size
 end