Merge pull request #358 from rspec/revisited_bugfix_for_doubles_in_ar…

…rays

Ensure null objects behave correctly with to_a and to_ary

features/method_stubs/to_ary.feature

@@ -17,10 +17,6 @@ Feature: double handling to_ary
       """ruby
       describe "#to_ary" do
         shared_examples "to_ary" do
-          it "raises a NoMethodError" do
-            expect { obj.to_ary }.to raise_error(NoMethodError)
-          end
-
           it "can be overridden with a stub" do
             obj.stub(:to_ary) { :non_nil_value }
             obj.to_ary.should be(:non_nil_value)
@@ -35,11 +31,19 @@ Feature: double handling to_ary
         context "sent to a double as_null_object" do
           let(:obj) { double('obj').as_null_object }
           include_examples "to_ary"
+
+          it "returns nil" do
+            expect( obj.to_ary ).to eq nil
+          end
         end
 
         context "sent to a double without as_null_object" do
           let(:obj) { double('obj') }
           include_examples "to_ary"
+
+          it "raises a NoMethodError" do
+            expect { obj.to_ary }.to raise_error(NoMethodError)
+          end
         end
       end
      """

lib/rspec/mocks/test_double.rb

@@ -57,7 +57,7 @@ def to_s
 
       # @private
       def respond_to?(message, incl_private=false)
-        __mock_proxy.null_object? && message != :to_ary ? true : super
+        __mock_proxy.null_object? ? true : super
       end
 
       # @private
@@ -79,13 +79,19 @@ def __initialize_as_test_double(name=nil, stubs_and_options={})
       end
 
       def method_missing(message, *args, &block)
-        raise NoMethodError if message == :to_ary || message == :to_a
-        return 0 if message == :to_int && __mock_proxy.null_object?
+        if __mock_proxy.null_object?
+          case message
+          when :to_int        then return 0
+          when :to_a, :to_ary then return nil
+          end
+        end
         __mock_proxy.record_message_received(message, *args, &block)
 
         begin
           __mock_proxy.null_object? ? self : super
         rescue NameError
+          # Required wrapping doubles in an Array on Ruby 1.9.2
+          raise NoMethodError if [:to_a, :to_ary].include? message
           __mock_proxy.raise_unexpected_message_error(message, *args)
         end
       end

spec/rspec/mocks/mock_spec.rb

@@ -217,6 +217,22 @@ def @double.method_with_default_argument(arg={}); end
         expect( Array(@double) ).to eq([@double])
       end
 
+      it "is wrappable in an array when a null object" do
+        expect( Array(@double.as_null_object) ).to eq [@double]
+      end
+
+      it "responds to to_ary as a null object" do
+        expect(@double.as_null_object.to_ary).to eq nil
+      end
+
+      it "responds to to_a as a null object" do
+        if RUBY_VERSION.to_f > 1.8
+          expect(@double.as_null_object.to_a).to eq nil
+        else
+          expect(@double.as_null_object.to_a).to eq [@double]
+        end
+      end
+
       it "passes proc to expectation block without an argument" do
         @double.should_receive(:foo) { |&block| expect(block.call).to eq(:bar) }
         @double.foo { :bar }

spec/rspec/mocks/to_ary_spec.rb

@@ -2,16 +2,6 @@
 
 describe "a double receiving to_ary" do
   shared_examples "to_ary" do
-    it "returns nil" do
-      expect do
-        expect(obj.to_ary).to be_nil
-      end.to raise_error(NoMethodError)
-    end
-
-    it "doesn't respond" do
-      expect(obj).not_to respond_to(:to_ary)
-    end
-
     it "can be overridden with a stub" do
       obj.stub(:to_ary) { :non_nil_value }
       expect(obj.to_ary).to be(:non_nil_value)
@@ -31,10 +21,34 @@
   context "double as_null_object" do
     let(:obj) { double('obj').as_null_object }
     include_examples "to_ary"
+
+    it "does respond to to_ary" do
+      expect(obj).to respond_to(:to_ary)
+    end
+
+    it "does respond to to_a" do
+      expect(obj).to respond_to(:to_a)
+    end
+
+    it "returns nil" do
+      expect(obj.to_ary).to eq nil
+    end
   end
 
   context "double without as_null_object" do
     let(:obj) { double('obj') }
     include_examples "to_ary"
+
+    it "doesn't respond to to_ary" do
+      expect(obj).not_to respond_to(:to_ary)
+    end
+
+    it "doesn't respond to to_a", :if => ( RUBY_VERSION.to_f > 1.8 ) do
+      expect(obj).not_to respond_to(:to_a)
+    end
+
+    it "raises " do
+      expect { obj.to_ary }.to raise_error(NoMethodError)
+    end
   end
 end