Fix a bug where class extentions were conflicting with ActiveSupport

lib/couchrest/support/class.rb

@@ -25,7 +25,19 @@
 # example, an array without those additions being shared with either their
 # parent, siblings, or children, which is unlike the regular class-level
 # attributes that are shared across the entire hierarchy.
-class Class
+module CouchRest
+  module ClassExtension
+    def self.included(base)
+      if CouchRest::ClassExtension::InstanceMethods.instance_methods.all? {|m| base.respond_to?(m)}
+        # do nothing
+      elsif CouchRest::ClassExtension::InstanceMethods.instance_methods.any? {|m| base.respond_to?(m)}
+        raise RuntimeError, "Conflicting extentions to Class, work it out"
+      else
+        base.send(:include, CouchRest::ClassExtension::InstanceMethods)
+      end
+    end
+    
+    module InstanceMethods
       # Defines class-level and instance-level attribute reader.
       #
       # @param *syms<Array> Array of attributes to define reader for.
@@ -173,3 +185,7 @@ RUBY
         class_inheritable_writer(*syms)
       end
     end
+  end
+end
+
+Class.send(:include, CouchRest::ClassExtension)

spec/couchrest/support/class_spec.rb

@@ -0,0 +1,59 @@
+require File.join(File.dirname(__FILE__), '..', '..', 'spec_helper')
+require File.join(File.dirname(__FILE__), '..', '..', '..', 'lib', 'couchrest', 'support', 'class')
+
+describe CouchRest::ClassExtension do
+  
+  before :all do
+    class FullyDefinedClassExtensions
+      def self.respond_to?(method)
+        if CouchRest::ClassExtension::InstanceMethods.instance_methods.include?(method)
+          true
+        else
+          super
+        end
+      end
+    end
+    
+    class PartDefinedClassExtensions
+      def self.respond_to?(method)
+        methods = CouchRest::ClassExtension::InstanceMethods.instance_methods
+        methods.delete('cattr_reader')
+        
+        if methods.include?(method)
+          false
+        else
+          super
+        end
+      end
+    end
+    
+    class NoClassExtensions
+      def self.respond_to?(method)
+        if CouchRest::ClassExtension::InstanceMethods.instance_methods.include?(method)
+          false
+        else
+          super
+        end
+      end
+    end
+
+
+  end
+  
+  it "should not include InstanceMethods if the class extensions are already defined" do
+    FullyDefinedClassExtensions.send(:include, CouchRest::ClassExtension)
+    FullyDefinedClassExtensions.ancestors.should_not include(CouchRest::ClassExtension::InstanceMethods)
+  end
+  
+  it "should raise RuntimeError if the class extensions are only partially defined" do
+    lambda {
+      PartDefinedClassExtensions.send(:include, CouchRest::ClassExtension)
+    }.should raise_error(RuntimeError)
+  end
+  
+  it "should include class extensions if they are not already defined" do
+    NoClassExtensions.send(:include, CouchRest::ClassExtension)
+    NoClassExtensions.ancestors.should include(CouchRest::ClassExtension::InstanceMethods)
+  end
+  
+end