1 files changed, 21 insertions, 4 deletions
diff --git a/activerecord/lib/active_record/associations/builder/association.rb b/activerecord/lib/active_record/associations/builder/association.rb
index 3911d1b520..947d61ee7b 100644
--- a/activerecord/lib/active_record/associations/builder/association.rb
+++ b/activerecord/lib/active_record/associations/builder/association.rb
@@ -26,10 +26,17 @@ module ActiveRecord::Associations::Builder
     attr_reader :name, :scope, :options
 
     def self.build(model, name, scope, options, &block)
+      if model.dangerous_attribute_method?(name)
+        raise ArgumentError, "You tried to define an association named #{name} on the model #{model.name}, but " \
+                             "this will conflict with a method #{name} already defined by Active Record. " \
+                             "Please choose a different association name."
+      end
+
       builder = create_builder model, name, scope, options, &block
       reflection = builder.build(model)
       define_accessors model, reflection
       define_callbacks model, reflection
+      define_validations model, reflection
       builder.define_extensions model
       reflection
     end
@@ -79,7 +86,11 @@ module ActiveRecord::Associations::Builder
     end
 
     def self.define_callbacks(model, reflection)
-      add_before_destroy_callbacks(model, reflection) if reflection.options[:dependent]
+      if dependent = reflection.options[:dependent]
+        check_dependent_options(dependent)
+        add_destroy_callbacks(model, reflection)
+      end
+
       Association.extensions.each do |extension|
         extension.build model, reflection
       end
@@ -114,17 +125,23 @@ module ActiveRecord::Associations::Builder
       CODE
     end
 
+    def self.define_validations(model, reflection)
+      # noop
+    end
+
     def self.valid_dependent_options
       raise NotImplementedError
     end
 
     private
 
-    def self.add_before_destroy_callbacks(model, reflection)
-      unless valid_dependent_options.include? reflection.options[:dependent]
-        raise ArgumentError, "The :dependent option must be one of #{valid_dependent_options}, but is :#{reflection.options[:dependent]}"
+    def self.check_dependent_options(dependent)
+      unless valid_dependent_options.include? dependent
+        raise ArgumentError, "The :dependent option must be one of #{valid_dependent_options}, but is :#{dependent}"
       end
+    end
 
+    def self.add_destroy_callbacks(model, reflection)
       name = reflection.name
       model.before_destroy lambda { |o| o.association(name).handle_dependency }
     end