can? should only go to db if there are mongoid criteria in the conditions.

Easier to just do a simple comparison on the object in memory
than to search the database.  Also this allows method calls
and other attributes that might not be found in the database.

cancan.gemspec

@@ -10,7 +10,7 @@ Gem::Specification.new do |s|
   s.files        = Dir["{lib,spec}/**/*", "[A-Z]*", "init.rb"] - ["Gemfile.lock"]
   s.require_path = "lib"
 
-  s.add_development_dependency 'rspec', '~> 2.0.0.beta.22'
+  s.add_development_dependency 'rspec', '~> 2.1.0'
   s.add_development_dependency 'rails', '~> 3.0.0'
   s.add_development_dependency 'rr', '~> 0.10.11' # 1.0.0 has respond_to? issues: http://github.com/btakita/rr/issues/issue/43
   s.add_development_dependency 'supermodel', '~> 0.1.4'
@@ -18,7 +18,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'mongoid', '~> 2.0.0.beta.19'
   s.add_development_dependency 'bson_ext', '~> 1.1'
   
-  s.add_development_dependency 'ruby-debug'
+  # s.add_development_dependency 'ruby-debug'
   
   s.rubyforge_project = s.name
   s.required_rubygems_version = ">= 1.3.4"

lib/cancan/mongoid_additions.rb

@@ -36,37 +36,28 @@ module CanCan
   end
 
   # customize to handle Mongoid queries in ability definitions conditions
+  # Mongoid Criteria are simpler to check than normal conditions hashes  
+  # When no conditions are given, true should be returned.
+  # The default CanCan behavior relies on the fact that conditions.all? will return true when conditions is empty
+  # The way ruby handles all? for empty hashes can be unexpected:
+  #   {}.all?{|a| a == 5} 
+  #   => true
+  #   {}.all?{|a| a != 5} 
+  #   => true
   class CanDefinition
-    def matches_conditions_hash?(subject, conditions = @conditions)          
-      if subject.class.include?(Mongoid::Document)        # Mongoid Criteria are simpler to check than normal conditions hashes
-        if conditions.empty?  # When no conditions are given, true should be returned.
-                              # The default CanCan behavior relies on the fact that conditions.all? will return true when conditions is empty
-                              # The way ruby handles all? for empty hashes can be unexpected:
-                              #   {}.all?{|a| a == 5} 
-                              #   => true
-                              #   {}.all?{|a| a != 5} 
-                              #   => true
+    def matches_conditions_hash_with_mongoid_subject?(subject, conditions = @conditions)          
+      if subject.class.include?(Mongoid::Document) && conditions.any?{|k,v| !k.kind_of?(Symbol)}      
+        if conditions.empty?  
           true
         else
           subject.class.where(conditions).include?(subject)  # just use Mongoid's where function
         end
       else 
-        conditions.all? do |name, value|
-          attribute = subject.send(name)
-          if value.kind_of?(Hash)
-            if attribute.kind_of? Array
-              attribute.any? { |element| matches_conditions_hash? element, value }
-            else
-              matches_conditions_hash? attribute, value
-            end
-          elsif value.kind_of?(Array) || value.kind_of?(Range)
-            value.include? attribute
-          else
-            attribute == value
-          end
-        end
+        matches_conditions_hash_without_mongoid_subject? subject, conditions
       end
     end
+    alias_method :matches_conditions_hash_without_mongoid_subject?, :matches_conditions_hash?
+    alias_method :matches_conditions_hash?, :matches_conditions_hash_with_mongoid_subject?
   end
 
 
@@ -114,4 +105,4 @@ if defined? Mongoid
       end
     end
   end  
-end
\ No newline at end of file
+end

spec/cancan/mongoid_additions_spec.rb

@@ -49,6 +49,12 @@ describe CanCan::MongoidAdditions do
       collection.name !~ /system/
     end.each(&:drop)    
   end
+  
+  it "should compare properties on mongoid documents with the " do
+    model = @model_class.new
+    @ability.can :read, @model_class, :id => model.id
+    @ability.should be_able_to :read, model
+  end
 
   it "should return [] when no ability is defined so no records are found" do
     @model_class.create :title  => 'Sir'
@@ -88,6 +94,22 @@ describe CanCan::MongoidAdditions do
       @ability.can?(:read, obj2).should == false
     end
     
+    describe "activates only when there are Criteria in the hash" do
+      it "Calls where on the model class when there are criteria" do
+        obj = @model_class.create :title  => 'Bird'
+        @conditions = {:title.nin => ["Fork", "Spoon"]}
+        @model_class.should_receive(:where).with(@conditions) {[obj]}
+        @ability.can :read, @model_class, @conditions
+        @ability.can?(:read, obj)
+      end
+      it "Calls the base version if there are no mongoid criteria" do
+        obj = @model_class.new :title  => 'Bird'
+        @conditions = {:id => obj.id}
+        @ability.can :read, @model_class, @conditions
+        @ability.should be_able_to(:read, obj)
+      end
+    end
+    
     it "should handle :field.nin" do
       obj = @model_class.create :title  => 'Sir'
       @ability.can :read, @model_class, :title.nin => ["Lord", "Madam"]
@@ -141,4 +163,4 @@ describe CanCan::MongoidAdditions do
       @model_class.accessible_by(@ability)
     }.should raise_error(CanCan::Error)
   end
-end
\ No newline at end of file
+end

spec/spec_helper.rb

@@ -5,9 +5,11 @@ require 'supermodel' # shouldn't Bundler do this already?
 require 'active_support/all'
 require 'matchers'
 require 'cancan/matchers'
+require 'mongoid'
+require 'active_support'
 
 RSpec.configure do |config|
-  config.mock_with :rr
+  config.mock_with :rspec
   config.before(:each) do
     Project.delete_all
     Category.delete_all