Add content_type and size errors to base attribute

This propagates attachment size and content_type validations to the main
attachment attribute, to make them behave the same as presence
validations. This allows paperclip to play more nicely with simple_form
and other form abstraction gems.

This commit includes a behaviorial change. If you emit all errors on a
model instance you will see some failed validations twice: once for the
base attachment attribute and again for the failed presence,
content_type or size attachment attributes.

lib/paperclip/validators/attachment_content_type_validator.rb

@@ -7,29 +7,31 @@ module Paperclip
       end
 
       def validate_each(record, attribute, value)
+        base_attribute = attribute.to_sym
         attribute = "#{attribute}_content_type".to_sym
         value = record.send :read_attribute_for_validation, attribute
 
         return if (value.nil? && options[:allow_nil]) || (value.blank? && options[:allow_blank])
 
-        validate_whitelist(record, attribute, value)
-        validate_blacklist(record, attribute, value)
+        validate_whitelist(record, base_attribute, attribute, value)
+        validate_blacklist(record, base_attribute, attribute, value)
       end
 
-      def validate_whitelist(record, attribute, value)
+      def validate_whitelist(record, base_attribute, attribute, value)
         if allowed_types.present? && allowed_types.none? { |type| type === value }
-          mark_invalid record, attribute, allowed_types
+          mark_invalid record, base_attribute, attribute, allowed_types
         end
       end
 
-      def validate_blacklist(record, attribute, value)
+      def validate_blacklist(record, base_attribute, attribute, value)
         if forbidden_types.present? && forbidden_types.any? { |type| type === value }
-          mark_invalid record, attribute, forbidden_types
+          mark_invalid record, base_attribute, attribute, forbidden_types
         end
       end
 
-      def mark_invalid(record, attribute, types)
+      def mark_invalid(record, base_attribute, attribute, types)
         record.errors.add attribute, :invalid, options.merge(:types => types.join(', '))
+        record.errors.add base_attribute, :invalid, options.merge(:types => types.join(', '))
       end
 
       def allowed_types

lib/paperclip/validators/attachment_size_validator.rb

@@ -11,6 +11,7 @@ module Paperclip
       end
 
       def validate_each(record, attr_name, value)
+        base_attr_name = attr_name
         attr_name = "#{attr_name}_file_size".to_sym
         value = record.send(:read_attribute_for_validation, attr_name)
 
@@ -21,7 +22,8 @@ module Paperclip
 
             unless value.send(CHECKS[option], option_value)
               error_message_key = options[:in] ? :in_between : option
-              record.errors.add(attr_name, error_message_key, filtered_options(value).merge(
+              [ attr_name, base_attr_name ].each do |error_attr_name|
+                record.errors.add(error_attr_name, error_message_key, filtered_options(value).merge(
                   :min => min_value_in_human_size(record),
                   :max => max_value_in_human_size(record),
                   :count => human_size(option_value)
@@ -30,6 +32,7 @@ module Paperclip
             end
           end
         end
+      end
 
       def check_validity!
         unless (AVAILABLE_CHECKS + [:in]).any? { |argument| options.has_key?(argument) }

test/validators/attachment_content_type_validator_test.rb

@@ -50,6 +50,32 @@ class AttachmentContentTypeValidatorTest < Test::Unit::TestCase
     end
   end
 
+  context "with a failing validation" do
+    setup do
+      build_validator :content_type => "image/png", :allow_nil => false
+      @dummy.stubs(:avatar_content_type => nil)
+      @validator.validate(@dummy)
+    end
+
+    should "add error to the base object" do
+      assert @dummy.errors[:avatar].present?,
+        "Error not added to base attribute"
+    end
+  end
+
+  context "with a successful validation" do
+    setup do
+      build_validator :content_type => "image/png", :allow_nil => false
+      @dummy.stubs(:avatar_content_type => "image/png")
+      @validator.validate(@dummy)
+    end
+
+    should "not add error to the base object" do
+      assert @dummy.errors[:avatar].blank?,
+        "Error was added to base attribute"
+    end
+  end
+
   context "with :allow_blank option" do
     context "as true" do
       setup do

test/validators/attachment_size_validator_test.rb

@@ -20,6 +20,11 @@ class AttachmentSizeValidatorTest < Test::Unit::TestCase
         assert @dummy.errors[:avatar_file_size].blank?,
           "Expect an error message on :avatar_file_size, got none."
       end
+
+      should "not add error to the base dummy object" do
+        assert @dummy.errors[:avatar].blank?,
+          "Error added to base attribute"
+      end
     end
   end
 
@@ -35,6 +40,11 @@ class AttachmentSizeValidatorTest < Test::Unit::TestCase
           "Unexpected error message on :avatar_file_size"
       end
 
+      should "add error to the base dummy object" do
+        assert @dummy.errors[:avatar].present?,
+          "Error not added to base attribute"
+      end
+
       if options[:message]
         should "return a correct error message" do
           assert_includes @dummy.errors[:avatar_file_size], options[:message]