Add #has_strategy? to ordering

Author: JonRowe

lib/rspec/core/ordering.rb

@@ -99,6 +99,10 @@ def fetch(name, &fallback)
           @strategies.fetch(name, &fallback)
         end
 
+        def has_strategy?(name)
+          @strategies.key?(name)
+        end
+
         def register(sym, strategy)
           @strategies[sym] = strategy
         end

spec/rspec/core/ordering_spec.rb

@@ -144,6 +144,15 @@ def order_with(seed)
             end
           end
         end
+
+        describe "#has_strategy?(name)" do
+          it "returns true if the strategy was registered" do
+            expect {
+              registry.register(:reverse, Custom.new(proc { |list| list.reverse }))
+            }.to change { registry.has_strategy?(:reverse) }.from(false).to(true)
+          end
+        end
+
       end
     end
   end