Raise unless content type or name validation

It is now a requirement for attachments to do one of three things:
  1. Have a content_type validation (e.g. "image/*")
  2. Have a filename validation (e.g. *.png, *.gif)
  3. Explicitly *not* have one of those validations

The intent is to make the default more secure, and you have to
explicitly reject the security of a validation in order to not have one.

features/step_definitions/attachment_steps.rb

@@ -11,8 +11,10 @@ World(AttachmentHelpers)
 
 When /^I modify my attachment definition to:$/ do |definition|
   content = in_current_dir { File.read("app/models/user.rb") }
+  name = content[/has_attached_file :\w+/][/:\w+/]
   content.gsub!(/has_attached_file.+end/m, <<-FILE)
       #{definition}
+      do_not_validate_attachment_file_type #{name}
     end
   FILE
 

features/step_definitions/rails_steps.rb

@@ -69,6 +69,7 @@ def attach_attachment(name, definition = nil)
     snippet += ", \n"
     snippet += definition
   end
+  snippet += "\ndo_not_validate_attachment_file_type :#{name}\n"
   in_current_dir do
     transform_file("app/models/user.rb") do |content|
       content.sub(/end\Z/, "#{snippet}\nend")

lib/paperclip/attachment.rb

@@ -392,11 +392,8 @@ module Paperclip
     end
 
     def ensure_required_validations!
-      if ! active_validator_classes.include?(Paperclip::Validators::AttachmentContentTypeValidator)
-        ActiveSupport::Deprecation.warn(
-          "You must define a content_type validator to ensure you only accept files of the correct type. Failure to do so will raise an error in Paperclip versions >= 4.0"
-        )
-        # raise Paperclip::Errors::NoContentTypeValidator.new('you must define a content type validation')
+      if (active_validator_classes & Paperclip::REQUIRED_VALIDATORS).empty?
+        raise Paperclip::Errors::MissingRequiredValidatorError
       end
     end
 

lib/paperclip/errors.rb

@@ -13,9 +13,10 @@ module Paperclip
     class CommandNotFoundError < Paperclip::Error
     end
 
-    # Thrown when no content_type validation exists
-    # class NoContentTypeValidator < Paperclip::Error
-    # end
+    # Attachments require a content_type or file_name validator,
+    # or to have explicitly opted out of them.
+    class MissingRequiredValidatorError < Paperclip::Error
+    end
 
     # Will be thrown when ImageMagic cannot determine the uploaded file's
     # metadata, usually this would mean the file is not an image.

lib/paperclip/validators.rb

 require 'active_model'
 require 'active_support/concern'
 require 'paperclip/validators/attachment_content_type_validator'
+require 'paperclip/validators/attachment_file_name_validator'
 require 'paperclip/validators/attachment_presence_validator'
 require 'paperclip/validators/attachment_size_validator'
 require 'paperclip/validators/media_type_spoof_detection_validator'
+require 'paperclip/validators/attachment_file_type_ignorance_validator'
 
 module Paperclip
   module Validators
@@ -14,6 +16,8 @@ module Paperclip
       include HelperMethods
     end
 
+    ::Paperclip::REQUIRED_VALIDATORS = [AttachmentFileNameValidator, AttachmentContentTypeValidator, AttachmentFileTypeIgnoranceValidator]
+
     module ClassMethods
       # This method is a shortcut to validator classes that is in
       # "Attachment...Validator" format. It is almost the same thing as the
@@ -40,7 +44,7 @@ module Paperclip
               local_options = attributes + [validator_options]
               conditional_options = options.slice(:if, :unless)
               local_options.last.merge!(conditional_options)
-              send(:"validates_attachment_#{validator_kind}", *local_options)
+              send(Paperclip::Validators.const_get(constant.to_s).helper_method_name, *local_options)
             end
           end
         end

lib/paperclip/validators/attachment_content_type_validator.rb

@@ -6,6 +6,10 @@ module Paperclip
         super
       end
 
+      def self.helper_method_name
+        :validates_attachment_content_type
+      end
+
       def validate_each(record, attribute, value)
         base_attribute = attribute.to_sym
         attribute = "#{attribute}_content_type".to_sym

lib/paperclip/validators/attachment_file_name_validator.rb

+module Paperclip
+  module Validators
+    class AttachmentFileNameValidator < ActiveModel::EachValidator
+      def initialize(options)
+        options[:allow_nil] = true unless options.has_key?(:allow_nil)
+        super
+      end
+
+      def self.helper_method_name
+        :validates_attachment_file_name
+      end
+
+      def validate_each(record, attribute, value)
+        base_attribute = attribute.to_sym
+        attribute = "#{attribute}_file_name".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)
+
+        if record.errors.include? attribute
+          record.errors[attribute].each do |error|
+            record.errors.add base_attribute, error
+          end
+        end
+      end
+
+      def validate_whitelist(record, attribute, value)
+        if allowed.present? && allowed.none? { |type| type === value }
+          mark_invalid record, attribute, allowed
+        end
+      end
+
+      def validate_blacklist(record, attribute, value)
+        if forbidden.present? && forbidden.any? { |type| type === value }
+          mark_invalid record, attribute, forbidden
+        end
+      end
+
+      def mark_invalid(record, attribute, patterns)
+        record.errors.add attribute, :invalid, options.merge(:names => patterns.join(', '))
+      end
+
+      def allowed
+        [options[:matches]].flatten.compact
+      end
+
+      def forbidden
+        [options[:not]].flatten.compact
+      end
+
+      def check_validity!
+        unless options.has_key?(:matches) || options.has_key?(:not)
+          raise ArgumentError, "You must pass in either :matches or :not to the validator"
+        end
+      end
+    end
+
+    module HelperMethods
+      # Places ActiveModel validations on the name of the file
+      # assigned. The possible options are:
+      # * +matches+: Allowed filename patterns as Regexps. Can be a single one
+      #   or an array.
+      # * +not+: Forbidden file name patterns, specified the same was as +matches+.
+      # * +message+: The message to display when the uploaded file has an invalid
+      #   name.
+      # * +if+: A lambda or name of an instance method. Validation will only
+      #   be run is this lambda or method returns true.
+      # * +unless+: Same as +if+ but validates if lambda or method returns false.
+      def validates_attachment_file_name(*attr_names)
+        options = _merge_attributes(attr_names)
+        validates_with AttachmentFileNameValidator, options.dup
+        validate_before_processing AttachmentFileNameValidator, options.dup
+      end
+    end
+  end
+end
+

lib/paperclip/validators/attachment_file_type_ignorance_validator.rb

+require 'active_model/validations/presence'
+
+module Paperclip
+  module Validators
+    class AttachmentFileTypeIgnoranceValidator < ActiveModel::EachValidator
+      def validate_each(record, attribute, value)
+        # This doesn't do anything. It's just to mark that you don't care about
+        # the file_names or content_types of your incoming attachments.
+      end
+
+      def self.helper_method_name
+        :do_not_validate_attachment_file_type
+      end
+    end
+
+    module HelperMethods
+      # Places ActiveModel validations on the presence of a file.
+      # Options:
+      # * +if+: A lambda or name of an instance method. Validation will only
+      #   be run if this lambda or method returns true.
+      # * +unless+: Same as +if+ but validates if lambda or method returns false.
+      def do_not_validate_attachment_file_type(*attr_names)
+        options = _merge_attributes(attr_names)
+        validates_with AttachmentFileTypeIgnoranceValidator, options.dup
+      end
+    end
+  end
+end
+

lib/paperclip/validators/attachment_presence_validator.rb

@@ -8,6 +8,10 @@ module Paperclip
           record.errors.add(attribute, :blank, options)
         end
       end
+
+      def self.helper_method_name
+        :validates_attachment_presence
+      end
     end
 
     module HelperMethods

lib/paperclip/validators/attachment_size_validator.rb

@@ -10,6 +10,10 @@ module Paperclip
         super
       end
 
+      def self.helper_method_name
+        :validates_attachment_size
+      end
+
       def validate_each(record, attr_name, value)
         base_attr_name = attr_name
         attr_name = "#{attr_name}_file_size".to_sym

test/attachment_definitions_test.rb

@@ -5,6 +5,7 @@ class AttachmentDefinitionsTest < Test::Unit::TestCase
     reset_class "Dummy"
     Dummy.has_attached_file :avatar, {:path => "abc"}
     Dummy.has_attached_file :other_attachment, {:url => "123"}
+    Dummy.do_not_validate_attachment_file_type :avatar
     expected = {:avatar => {:path => "abc"}, :other_attachment => {:url => "123"}}
 
     assert_equal expected, Dummy.attachment_definitions

test/helper.rb

@@ -126,6 +126,7 @@ end
 def rebuild_class options = {}
   reset_class("Dummy").tap do |klass|
     klass.has_attached_file :avatar, options
+    klass.do_not_validate_attachment_file_type :avatar
     Paperclip.reset_duplicate_clash_check!
   end
 end
@@ -133,6 +134,7 @@ end
 def rebuild_meta_class_of obj, options = {}
   (class << obj; self; end).tap do |metaklass|
     metaklass.has_attached_file :avatar, options
+    metaklass.do_not_validate_attachment_file_type :avatar
     Paperclip.reset_duplicate_clash_check!
   end
 end
@@ -170,21 +172,21 @@ end
 
 def should_accept_dummy_class
   should "accept the class" do
-    assert_accepts @matcher, @dummy_class
+    assert_accepts @matcher, Dummy
   end
 
   should "accept an instance of that class" do
-    assert_accepts @matcher, @dummy_class.new
+    assert_accepts @matcher, Dummy.new
   end
 end
 
 def should_reject_dummy_class
   should "reject the class" do
-    assert_rejects @matcher, @dummy_class
+    assert_rejects @matcher, Dummy
   end
 
   should "reject an instance of that class" do
-    assert_rejects @matcher, @dummy_class.new
+    assert_rejects @matcher, Dummy.new
   end
 end
 

test/io_adapters/http_url_proxy_adapter_test.rb

@@ -85,7 +85,6 @@ class HttpUrlProxyAdapterTest < Test::Unit::TestCase
       begin
         @subject.close
       rescue Exception
-        binding.pry
         true
       end
     end

test/matchers/have_attached_file_matcher_test.rb

@@ -3,7 +3,7 @@ require './test/helper'
 class HaveAttachedFileMatcherTest < Test::Unit::TestCase
   context "have_attached_file" do
     setup do
-      @dummy_class = reset_class "Dummy"
+      reset_class "Dummy"
       reset_table "dummies"
       @matcher     = self.class.have_attached_file(:avatar)
     end
@@ -15,7 +15,8 @@ class HaveAttachedFileMatcherTest < Test::Unit::TestCase
     context "given a class with an attachment" do
       setup do
         modify_table("dummies"){|d| d.string :avatar_file_name }
-        @dummy_class.has_attached_file :avatar
+        Dummy.has_attached_file :avatar
+        Dummy.do_not_validate_attachment_file_type :avatar
       end
 
       should_accept_dummy_class

test/matchers/validate_attachment_content_type_matcher_test.rb

@@ -8,8 +8,9 @@ class ValidateAttachmentContentTypeMatcherTest < Test::Unit::TestCase
         d.string :avatar_file_name
         d.string :avatar_content_type
       end
-      @dummy_class = reset_class "Dummy"
-      @dummy_class.has_attached_file :avatar
+      reset_class "Dummy"
+      Dummy.do_not_validate_attachment_file_type :avatar
+      Dummy.has_attached_file :avatar
       @matcher     = self.class.validate_attachment_content_type(:avatar).
                        allowing(%w(image/png image/jpeg)).
                        rejecting(%w(audio/mp3 application/octet-stream))
@@ -21,7 +22,7 @@ class ValidateAttachmentContentTypeMatcherTest < Test::Unit::TestCase
 
     context "given a class with a validation that doesn't match" do
       setup do
-        @dummy_class.validates_attachment_content_type :avatar, :content_type => %r{audio/.*}
+        Dummy.validates_attachment_content_type :avatar, :content_type => %r{audio/.*}
       end
 
       should_reject_dummy_class
@@ -29,7 +30,7 @@ class ValidateAttachmentContentTypeMatcherTest < Test::Unit::TestCase
 
     context "given a class with a matching validation" do
       setup do
-        @dummy_class.validates_attachment_content_type :avatar, :content_type => %r{image/.*}
+        Dummy.validates_attachment_content_type :avatar, :content_type => %r{image/.*}
       end
 
       should_accept_dummy_class
@@ -37,8 +38,8 @@ class ValidateAttachmentContentTypeMatcherTest < Test::Unit::TestCase
 
     context "given a class with other validations but matching types" do
       setup do
-        @dummy_class.validates_presence_of :title
-        @dummy_class.validates_attachment_content_type :avatar, :content_type => %r{image/.*}
+        Dummy.validates_presence_of :title
+        Dummy.validates_attachment_content_type :avatar, :content_type => %r{image/.*}
       end
 
       should_accept_dummy_class
@@ -46,7 +47,7 @@ class ValidateAttachmentContentTypeMatcherTest < Test::Unit::TestCase
 
     context "given a class that matches and a matcher that only specifies 'allowing'" do
       setup do
-        @dummy_class.validates_attachment_content_type :avatar, :content_type => %r{image/.*}
+        Dummy.validates_attachment_content_type :avatar, :content_type => %r{image/.*}
         @matcher     = self.class.validate_attachment_content_type(:avatar).
           allowing(%w(image/png image/jpeg))
       end
@@ -56,7 +57,7 @@ class ValidateAttachmentContentTypeMatcherTest < Test::Unit::TestCase
 
     context "given a class that does not match and a matcher that only specifies 'allowing'" do
       setup do
-        @dummy_class.validates_attachment_content_type :avatar, :content_type => %r{audio/.*}
+        Dummy.validates_attachment_content_type :avatar, :content_type => %r{audio/.*}
         @matcher     = self.class.validate_attachment_content_type(:avatar).
           allowing(%w(image/png image/jpeg))
       end
@@ -66,7 +67,7 @@ class ValidateAttachmentContentTypeMatcherTest < Test::Unit::TestCase
 
     context "given a class that matches and a matcher that only specifies 'rejecting'" do
       setup do
-        @dummy_class.validates_attachment_content_type :avatar, :content_type => %r{image/.*}
+        Dummy.validates_attachment_content_type :avatar, :content_type => %r{image/.*}
         @matcher     = self.class.validate_attachment_content_type(:avatar).
           rejecting(%w(audio/mp3 application/octet-stream))
       end
@@ -76,7 +77,7 @@ class ValidateAttachmentContentTypeMatcherTest < Test::Unit::TestCase
 
     context "given a class that does not match and a matcher that only specifies 'rejecting'" do
       setup do
-        @dummy_class.validates_attachment_content_type :avatar, :content_type => %r{audio/.*}
+        Dummy.validates_attachment_content_type :avatar, :content_type => %r{audio/.*}
         @matcher     = self.class.validate_attachment_content_type(:avatar).
           rejecting(%w(audio/mp3 application/octet-stream))
       end
@@ -86,14 +87,14 @@ class ValidateAttachmentContentTypeMatcherTest < Test::Unit::TestCase
 
     context "using an :if to control the validation" do
       setup do
-        @dummy_class.class_eval do
+        Dummy.class_eval do
           validates_attachment_content_type :avatar, :content_type => %r{image/*} , :if => :go
           attr_accessor :go
         end
         @matcher = self.class.validate_attachment_content_type(:avatar).
                         allowing(%w(image/png image/jpeg)).
                         rejecting(%w(audio/mp3 application/octet-stream))
-        @dummy = @dummy_class.new
+        @dummy = Dummy.new
       end
 
       should "run the validation if the control is true" do

test/matchers/validate_attachment_presence_matcher_test.rb

@@ -6,8 +6,9 @@ class ValidateAttachmentPresenceMatcherTest < Test::Unit::TestCase
       reset_table("dummies") do |d|
         d.string :avatar_file_name
       end
-      @dummy_class = reset_class "Dummy"
-      @dummy_class.has_attached_file :avatar
+      reset_class "Dummy"
+      Dummy.has_attached_file :avatar
+      Dummy.do_not_validate_attachment_file_type :avatar
       @matcher     = self.class.validate_attachment_presence(:avatar)
     end
 
@@ -17,7 +18,7 @@ class ValidateAttachmentPresenceMatcherTest < Test::Unit::TestCase
 
     context "given a class with a matching validation" do
       setup do
-        @dummy_class.validates_attachment_presence :avatar
+        Dummy.validates_attachment_presence :avatar
       end
 
       should_accept_dummy_class
@@ -30,12 +31,12 @@ class ValidateAttachmentPresenceMatcherTest < Test::Unit::TestCase
           d.string :avatar_content_type
         end
 
-        @dummy_class.class_eval do
+        Dummy.class_eval do
           validates_attachment_presence :avatar
           validates_attachment_content_type :avatar, :content_type => 'image/gif'
         end
 
-        @dummy = @dummy_class.new
+        @dummy = Dummy.new
         @matcher = self.class.validate_attachment_presence(:avatar)
       end
 
@@ -47,11 +48,11 @@ class ValidateAttachmentPresenceMatcherTest < Test::Unit::TestCase
 
     context "using an :if to control the validation" do
       setup do
-        @dummy_class.class_eval do
+        Dummy.class_eval do
           validates_attachment_presence :avatar, :if => :go
           attr_accessor :go
         end
-        @dummy = @dummy_class.new
+        @dummy = Dummy.new
         @dummy.avatar = nil
       end
 

test/matchers/validate_attachment_size_matcher_test.rb

@@ -7,8 +7,9 @@ class ValidateAttachmentSizeMatcherTest < Test::Unit::TestCase
         d.string :avatar_file_name
         d.integer :avatar_file_size
       end
-      @dummy_class = reset_class "Dummy"
-      @dummy_class.has_attached_file :avatar
+      reset_class "Dummy"
+      Dummy.do_not_validate_attachment_file_type :avatar
+      Dummy.has_attached_file :avatar
     end
 
     context "of limited size" do
@@ -19,17 +20,17 @@ class ValidateAttachmentSizeMatcherTest < Test::Unit::TestCase
       end
 
       context "given a class with a validation that's too high" do
-        setup { @dummy_class.validates_attachment_size :avatar, :in => 256..2048 }
+        setup { Dummy.validates_attachment_size :avatar, :in => 256..2048 }
         should_reject_dummy_class
       end
 
       context "given a class with a validation that's too low" do
-        setup { @dummy_class.validates_attachment_size :avatar, :in => 0..1024 }
+        setup { Dummy.validates_attachment_size :avatar, :in => 0..1024 }
         should_reject_dummy_class
       end
 
       context "given a class with a validation that matches" do
-        setup { @dummy_class.validates_attachment_size :avatar, :in => 256..1024 }
+        setup { Dummy.validates_attachment_size :avatar, :in => 256..1024 }
         should_accept_dummy_class
       end
     end
@@ -38,23 +39,23 @@ class ValidateAttachmentSizeMatcherTest < Test::Unit::TestCase
       setup{ @matcher = self.class.validate_attachment_size(:avatar) }
 
       context "given a class with an upper limit" do
-        setup { @dummy_class.validates_attachment_size :avatar, :less_than => 1 }
+        setup { Dummy.validates_attachment_size :avatar, :less_than => 1 }
         should_accept_dummy_class
       end
 
       context "given a class with a lower limit" do
-        setup { @dummy_class.validates_attachment_size :avatar, :greater_than => 1 }
+        setup { Dummy.validates_attachment_size :avatar, :greater_than => 1 }
         should_accept_dummy_class
       end
     end
 
     context "using an :if to control the validation" do
       setup do
-        @dummy_class.class_eval do
+        Dummy.class_eval do
           validates_attachment_size :avatar, :greater_than => 1024, :if => :go
           attr_accessor :go
         end
-        @dummy = @dummy_class.new
+        @dummy = Dummy.new
         @matcher = self.class.validate_attachment_size(:avatar).greater_than(1024)
       end
 
@@ -71,9 +72,9 @@ class ValidateAttachmentSizeMatcherTest < Test::Unit::TestCase
 
     context "post processing" do
       setup do
-        @dummy_class.validates_attachment_size :avatar, :greater_than => 1024
+        Dummy.validates_attachment_size :avatar, :greater_than => 1024
 
-        @dummy = @dummy_class.new
+        @dummy = Dummy.new
         @matcher = self.class.validate_attachment_size(:avatar).greater_than(1024)
       end
 

test/validators/attachment_file_name_validator_test.rb

+require './test/helper'
+
+class AttachmentFileNameValidatorTest < Test::Unit::TestCase
+  def setup
+    rebuild_model
+    @dummy = Dummy.new
+    super
+  end
+
+  def build_validator(options)
+    @validator = Paperclip::Validators::AttachmentFileNameValidator.new(options.merge(
+      :attributes => :avatar
+    ))
+  end
+
+  context "with a failing validation" do
+    setup do
+      build_validator :matches => /.*\.png$/, :allow_nil => false
+      @dummy.stubs(:avatar_file_name => "data.txt")
+      @validator.validate(@dummy)
+    end
+
+    should "add error to the base object" do
+      assert @dummy.errors[:avatar].present?,
+        "Error not added to base attribute"
+    end
+
+    should "add error to base object as a string" do
+      assert_kind_of String, @dummy.errors[:avatar].first,
+        "Error added to base attribute as something other than a String"
+    end
+  end
+
+  should "not add error to the base object with a successful validation" do
+    build_validator :matches => /.*\.png$/, :allow_nil => false
+    @dummy.stubs(:avatar_file_name => "image.png")
+    @validator.validate(@dummy)
+
+    assert @dummy.errors[:avatar].blank?, "Error was added to base attribute"
+  end
+
+  context "whitelist format" do
+    context "with an allowed type" do
+      context "as a single regexp" do
+        setup do
+          build_validator :matches => /.*\.jpg$/
+          @dummy.stubs(:avatar_file_name => "image.jpg")
+          @validator.validate(@dummy)
+        end
+
+        should "not set an error message" do
+          assert @dummy.errors[:avatar_file_name].blank?
+        end
+      end
+
+      context "as a list" do
+        setup do
+          build_validator :matches => [/.*\.png$/, /.*\.jpe?g$/]
+          @dummy.stubs(:avatar_file_name => "image.jpg")
+          @validator.validate(@dummy)
+        end
+
+        should "not set an error message" do
+          assert @dummy.errors[:avatar_file_name].blank?
+        end
+      end
+    end
+
+    context "with a disallowed type" do
+      should "set a correct default error message" do
+        build_validator :matches => /^text\/.*/
+        @dummy.stubs(:avatar_file_name => "image.jpg")
+        @validator.validate(@dummy)
+
+        assert @dummy.errors[:avatar_file_name].present?
+        assert_includes @dummy.errors[:avatar_file_name], "is invalid"
+      end
+
+      should "set a correct custom error message" do
+        build_validator :matches => /.*\.png$/, :message => "should be a PNG image"
+        @dummy.stubs(:avatar_file_name => "image.jpg")
+        @validator.validate(@dummy)
+
+        assert_includes @dummy.errors[:avatar_file_name], "should be a PNG image"
+      end
+    end
+  end
+
+  context "blacklist format" do
+    context "with an allowed type" do
+      context "as a single regexp" do
+        setup do
+          build_validator :not => /^text\/.*/
+          @dummy.stubs(:avatar_file_name => "image.jpg")
+          @validator.validate(@dummy)
+        end
+
+        should "not set an error message" do
+          assert @dummy.errors[:avatar_file_name].blank?
+        end
+      end
+
+      context "as a list" do
+        setup do
+          build_validator :not => [/.*\.png$/, /.*\.jpe?g$/]
+          @dummy.stubs(:avatar_file_name => "image.gif")
+          @validator.validate(@dummy)
+        end
+
+        should "not set an error message" do
+          assert @dummy.errors[:avatar_file_name].blank?
+        end
+      end
+    end
+
+    context "with a disallowed type" do
+      should "set a correct default error message" do
+        build_validator :not => /data.*/
+        @dummy.stubs(:avatar_file_name => "data.txt")
+        @validator.validate(@dummy)
+
+        assert @dummy.errors[:avatar_file_name].present?
+        assert_includes @dummy.errors[:avatar_file_name], "is invalid"
+      end
+
+      should "set a correct custom error message" do
+        build_validator :not => /.*\.png$/, :message => "should not be a PNG image"
+        @dummy.stubs(:avatar_file_name => "image.png")
+        @validator.validate(@dummy)
+
+        assert_includes @dummy.errors[:avatar_file_name], "should not be a PNG image"
+      end
+    end
+  end
+
+  context "using the helper" do
+    setup do
+      Dummy.validates_attachment_file_name :avatar, :matches => /.*\.jpg$/
+    end
+
+    should "add the validator to the class" do
+      assert Dummy.validators_on(:avatar).any?{ |validator| validator.kind == :attachment_file_name }
+    end
+  end
+
+  context "given options" do
+    should "raise argument error if no required argument was given" do
+      assert_raises(ArgumentError) do
+        build_validator :message => "Some message"
+      end
+    end
+
+    should "not raise argument error if :matches was given" do
+      build_validator :matches => /.*\.jpg$/
+    end
+
+    should "not raise argument error if :not was given" do
+      build_validator :not => /.*\.jpg$/
+    end
+  end
+end
+

test/validators_test.rb

@@ -61,40 +61,41 @@ class ValidatorsTest < Test::Unit::TestCase
     end
   end
 
-  context 'when no content_type validation exists' do
+  context 'with no other validations on the Dummy#avatar attachment' do
     setup do
-      ActiveSupport::Deprecation.silenced = false
+      reset_class("Dummy")
+      Dummy.has_attached_file :avatar
+      Paperclip.reset_duplicate_clash_check!
     end
 
-    should 'emit a deprecation warning' do
-      assert_deprecated do
+    should 'raise an error when no content_type validation exists' do
+      assert_raises(Paperclip::Errors::MissingRequiredValidatorError) do
         Dummy.new(:avatar => File.new(fixture_file("12k.png")))
       end
     end
 
-    # should 'raise an error' do
-    #   assert_raises(Paperclip::Errors::NoContentTypeValidator) do 
-    #     Dummy.new(:avatar => File.new(fixture_file("12k.png")))
-    #   end
-    # end
-  end
-
-  context 'when a content_type validation exists' do
-    setup do
+    should 'not raise an error when a content_type validation exists' do
       Dummy.validates_attachment :avatar, :content_type => { :content_type => "image/jpeg" }
-      ActiveSupport::Deprecation.silenced = false
+
+      assert_nothing_raised(Paperclip::Errors::MissingRequiredValidatorError) do 
+        Dummy.new(:avatar => File.new(fixture_file("12k.png")))
+      end
     end
 
-    should 'not emit a deprecation warning' do
-      assert_not_deprecated do
+    should 'not raise an error when a file_name validation exists' do
+      Dummy.validates_attachment :avatar, :file_name => { :matches => /png$/ }
+
+      assert_nothing_raised(Paperclip::Errors::MissingRequiredValidatorError) do 
         Dummy.new(:avatar => File.new(fixture_file("12k.png")))
       end
     end
 
-    # should 'not raise an error' do
-    #   assert_nothing_raised(Paperclip::Errors::NoContentTypeValidator) do 
-    #     Dummy.new(:avatar => File.new(fixture_file("12k.png")))
-    #   end
-    # end
+    should 'not raise an error when a the validation has been explicitly rejected' do
+      Dummy.validates_attachment :avatar, :file_type_ignorance => true
+
+      assert_nothing_raised(Paperclip::Errors::MissingRequiredValidatorError) do
+        Dummy.new(:avatar => File.new(fixture_file("12k.png")))
+      end
+    end
   end
 end