Implement count limit/offset support for has_many associations

[#348 state:resolved]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

2 files changed, 16 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/associations/has_many_association.rb b/activerecord/lib/active_record/associations/has_many_association.rb
index ce62127505..1535995410 100644
--- a/activerecord/lib/active_record/associations/has_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_association.rb
@@ -14,7 +14,16 @@ module ActiveRecord
             @finder_sql + " AND (#{sanitize_sql(options[:conditions])})"
           options[:include] ||= @reflection.options[:include]
 
-          @reflection.klass.count(column_name, options)
+          value = @reflection.klass.count(column_name, options)
+
+          limit  = @reflection.options[:limit]
+          offset = @reflection.options[:offset]
+
+          if limit || offset
+            [ [value - offset.to_i, 0].max, limit.to_i ].min
+          else
+            value
+          end
         end
       end
 
diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index da3c8fb28e..17fd88ce65 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -48,6 +48,12 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_equal 2, Firm.find(:first).plain_clients.count(:name)
   end
 
+  def test_counting_with_association_limit
+    firm = companies(:first_firm)
+    assert_equal firm.limited_clients.length, firm.limited_clients.size
+    assert_equal firm.limited_clients.length, firm.limited_clients.count
+  end
+
   def test_finding
     assert_equal 2, Firm.find(:first).clients.length
   end