Allows ordering strategy objects to be registered.

lib/rspec/core/ordering.rb

@@ -151,17 +151,17 @@ def order_groups_and_examples(ordering=nil, &block)
           order_examples(ordering, &block)
         end
 
-        def register_group_ordering(name, &block)
-          @group_ordering_registry.register(name, Custom.new(block))
+        def register_group_ordering(name, strategy = Custom.new(Proc.new { |list| yield list }))
+          @group_ordering_registry.register(name, strategy)
         end
 
-        def register_example_ordering(name, &block)
-          @example_ordering_registry.register(name, Custom.new(block))
+        def register_example_ordering(name, strategy = Custom.new(Proc.new { |list| yield list }))
+          @example_ordering_registry.register(name, strategy)
         end
 
-        def register_group_and_example_ordering(name, &block)
-          register_group_ordering(name, &block)
-          register_example_ordering(name, &block)
+        def register_group_and_example_ordering(name, strategy = Custom.new(Proc.new { |list| yield list }))
+          register_group_ordering(name, strategy)
+          register_example_ordering(name, strategy)
         end
       end
     end

spec/rspec/core/configuration_spec.rb

@@ -1434,21 +1434,40 @@ def use_seed_on(registry)
     end
 
     describe "#register_group_and_example_ordering" do
-      before { config.register_group_and_example_ordering(:reverse, &:reverse) }
+      def register_reverse_ordering
+        config.register_group_and_example_ordering(:reverse, &:reverse)
+      end
 
       it 'stores the ordering for group use' do
+        register_reverse_ordering
+
         list = [1, 2, 3]
         strategy = config.group_ordering_registry.fetch(:reverse)
         expect(strategy).to be_a(Ordering::Custom)
         expect(strategy.order(list)).to eq([3, 2, 1])
       end
 
       it 'stores the ordering for example use' do
+        register_reverse_ordering
+
         list = [1, 2, 3]
         strategy = config.example_ordering_registry.fetch(:reverse)
         expect(strategy).to be_a(Ordering::Custom)
         expect(strategy.order(list)).to eq([3, 2, 1])
       end
+
+      it 'can register an ordering object' do
+        strategy = Object.new
+        def strategy.order(list)
+          list.reverse
+        end
+
+        config.register_group_and_example_ordering(:reverse, strategy)
+        list = [1, 2, 3]
+        fetched = config.example_ordering_registry.fetch(:reverse)
+        expect(fetched).to be(strategy)
+        expect(fetched.order(list)).to eq([3, 2, 1])
+      end
     end
 
     describe "#order_examples" do