Better fix for let definitions eagerly included

lib/rspec/core/example_group.rb

@@ -237,6 +237,13 @@ def self.subclass(parent, args, &example_group_block)
         subclass = Class.new(parent)
         subclass.set_it_up(*args)
         subclass.module_eval(&example_group_block) if example_group_block
+
+        # The LetDefinitions module must be included _after_ other modules
+        # to ensure that it takes precendence when there are name collisions.
+        # Thus, we delay including it until after the example group block
+        # has been eval'd.
+        MemoizedHelpers.define_helpers_on(subclass)
+
         subclass
       end
 

lib/rspec/core/memoized_helpers.rb

@@ -45,8 +45,12 @@ module MemoizedHelpers
       #
       # @see #should
       def subject
-        raise NotImplementedError, 'This definition is here for documentation purposes only'
-          ' - it is overriden anyway below when this module gets included.'
+        __memoized.fetch(:subject) do
+          __memoized[:subject] = begin
+            described = described_class || self.class.description
+            Class === described ? described.new : described
+          end
+        end
       end
 
       # When `should` is called with no explicit receiver, the call is
@@ -148,12 +152,6 @@ def preserve_accessed_lets
 
       def self.included(mod)
         mod.extend(ClassMethods)
-
-        # This logic defines an implicit subject
-        mod.subject do
-          described = described_class || self.class.description
-          Class === described ? described.new : described
-        end
       end
 
       module ClassMethods
@@ -190,12 +188,16 @@ module ClassMethods
         #     end
         #   end
         def let(name, &block)
-          MemoizedHelpers.define_memoized_method(
-            self,
-            name,
-            MemoizedHelpers.memoized_method_name_for(name, 'let'),
-            &block
-          )
+          # We have to pass the block directly to `define_method` to
+          # allow it to use method constructs like `super` and `return`.
+          raise "#let or #subject called without a block" if block.nil?
+          MemoizedHelpers.module_for(self).send(:define_method, name, &block)
+
+          # Apply the memoization. The method has been defined in an ancestor
+          # module so we can use `super` here to get the value.
+          define_method(name) do
+            __memoized.fetch(name) { |k| __memoized[k] = super(&nil) }
+          end
         end
 
         # Just like `let`, except the block is invoked by an implicit `before`
@@ -287,11 +289,10 @@ def let!(name, &block)
         # @see MemoizedHelpers#should
         def subject(name=nil, &block)
           if name
-            subject_method_name = MemoizedHelpers.memoized_method_name_for(name, "subject")
-            MemoizedHelpers.define_memoized_method(self, name, subject_method_name, &block)
+            let(name, &block)
             alias_method :subject, name
 
-            self::NamedSubjectPreventSuper.__send__(:define_method, subject_method_name) do
+            self::NamedSubjectPreventSuper.send(:define_method, name) do
               raise NotImplementedError, "`super` in named subjects is not supported"
             end
           else
@@ -468,30 +469,14 @@ def self.module_for(example_group)
             }
           end
 
-          example_group.__send__(:include, mod)
           example_group.const_set(:LetDefinitions, mod)
           mod
         end
       end
 
       # @api private
-      def self.memoized_method_name_for(name, let_or_subject)
-        "__rspec_#{let_or_subject}_definition_#{name}"
-      end
-
-      # @api private
-      def self.define_memoized_method(example_group, name, memoized_method_name, &block)
-        # We have to pass the block directly to `define_method` to
-        # allow it to use method constructs like `super` and `return`.
-        raise "#let or #subject called without a block" if block.nil?
-
-        MemoizedHelpers.module_for(example_group).__send__(:define_method, memoized_method_name, &block)
-
-        # Apply the memoization. The method has been defined in an ancestor
-        # module so we can use `super` here to get the value.
-        example_group.__send__(:define_method, name) do
-          __memoized.fetch(name) { |k| __memoized[k] = send(memoized_method_name, &nil) }
-        end
+      def self.define_helpers_on(example_group)
+        example_group.send(:include, module_for(example_group))
       end
 
       if Module.method(:const_defined?).arity == 1 # for 1.8

lib/rspec/core/shared_context.rb

@@ -17,31 +17,34 @@ module Core
     #       # ...
     #     end
     module SharedContext
-      include Hooks
-      include MemoizedHelpers::ClassMethods
-
       def included(group)
-        [:before, :after].each do |type|
-          [:all, :each].each do |scope|
-            group.hooks[type][scope].concat hooks[type][scope]
-          end
-        end
-        _nested_group_declarations.each do |name, block, *args|
-          group.describe name, *args, &block
+        __shared_context_recordings.each do |recording|
+          recording.playback_onto(group)
         end
       end
 
-      def describe(name, *args, &block)
-        _nested_group_declarations << [name, block, *args]
+      def __shared_context_recordings
+        @__shared_context_recordings ||= []
       end
 
-      alias_method :context, :describe
-
-      private
+      Recording = Struct.new(:method_name, :args, :block) do
+        def playback_onto(group)
+          group.__send__(method_name, *args, &block)
+        end
+      end
 
-      def _nested_group_declarations
-        @_nested_group_declarations ||= []
+      def self.record(*methods)
+        methods.each do |meth|
+          class_eval <<-EOS, __FILE__, __LINE__ + 1
+            def #{meth}(*args, &block)
+              __shared_context_recordings << Recording.new(:#{meth}, args, block)
+            end
+          EOS
+        end
       end
+
+      record :describe, :context, *Hooks.instance_methods(false),
+             *MemoizedHelpers::ClassMethods.instance_methods(false)
     end
   end