Supports Rails 4.1 inversible associations

lib/rspec/rails/mocks.rb

@@ -29,6 +29,19 @@ def respond_to?(message, include_private=false)
         end
       end
 
+      # Starting with Rails 4.1, ActiveRecord associations are inversible
+      # by default. This class represents an association from the mocked
+      # model's perspective.
+      #
+      # @private
+      class Association
+        attr_accessor :target, :inversed
+
+        def initialize(association_name)
+          @association_name = association_name
+        end
+      end
+
       module ActiveRecordInstanceMethods
         # Stubs `persisted?` to return `false` and `id` to return `nil`.
         def destroy
@@ -45,6 +58,15 @@ def [](key)
         def new_record?
           !persisted?
         end
+
+        # Returns an object representing an association from the mocked
+        # model's perspective. For use by Rails internally only.
+        def association(association_name)
+          unless defined?(@associations)
+            @associations = Hash.new { |h, k| h[k] = Association.new(k) }
+          end
+          @associations[association_name]
+        end
       end
 
       # Creates a test double representing `string_or_model_class` with common

spec/rspec/rails/mocks/mock_model_spec.rb

@@ -54,6 +54,29 @@
     end
   end
 
+  describe "association" do
+    it "constructs a mock association object" do
+      model = mock_model(MockableModel)
+      expect(model.association(:association_name)).to be
+    end
+
+    it "returns a different association object for each association name" do
+      model = mock_model(MockableModel)
+      posts = model.association(:posts)
+      authors = model.association(:authors)
+
+      expect(posts).not_to equal(authors)
+    end
+
+    it "returns the same association model each time for the same association name" do
+      model = mock_model(MockableModel)
+      posts1 = model.association(:posts)
+      posts2 = model.association(:posts)
+
+      expect(posts1).to equal(posts2)
+    end
+  end
+
   describe "errors" do
     context "default" do
       it "is empty" do