2 files changed, 8 insertions, 9 deletions
diff --git a/activerecord/lib/active_record/associations/association_collection.rb b/activerecord/lib/active_record/associations/association_collection.rb
index 1c3a6b56f3..f4e34657a5 100644
--- a/activerecord/lib/active_record/associations/association_collection.rb
+++ b/activerecord/lib/active_record/associations/association_collection.rb
@@ -418,15 +418,10 @@ module ActiveRecord
         end
 
         def method_missing(method, *args)
-          case method.to_s
-          when 'find_or_create'
-            return find(:first, :conditions => args.first) || create(args.first)
-          when /^find_or_create_by_(.*)$/
-            rest = $1
-            return  send("find_by_#{rest}", *args) ||
-                    method_missing("create_by_#{rest}", *args)
-          when /^create_by_(.*)$/
-            return create Hash[$1.split('_and_').zip(args)]
+          match = DynamicFinderMatch.match(method)
+          if match && match.creator?
+            attributes = match.attribute_names
+            return send(:"find_by_#{attributes.join('and')}", *args) || create(Hash[attributes.zip(args)])
           end
 
           if @target.respond_to?(method) || (!@reflection.klass.respond_to?(method) && Class.respond_to?(method))
diff --git a/activerecord/lib/active_record/dynamic_finder_match.rb b/activerecord/lib/active_record/dynamic_finder_match.rb
index b39b291352..dfb8a3ba60 100644
--- a/activerecord/lib/active_record/dynamic_finder_match.rb
+++ b/activerecord/lib/active_record/dynamic_finder_match.rb
@@ -42,6 +42,10 @@ module ActiveRecord
       @finder == :first && !@instantiator.nil?
     end
 
+    def creator?
+      @finder == :first && @instantiator == :create
+    end
+
     def bang?
       @bang
     end