Support ActiveModel 4.0, which unfortunately does not send :class an …

…an option to the validator’s constructor.

.gitignore

@@ -3,7 +3,7 @@
 .bundle
 .config
 .yardoc
-Gemfile.lock
+Gemfile*.lock
 InstalledFiles
 _yardoc
 coverage

.travis.yml

@@ -5,5 +5,9 @@ rvm:
 - 2.0.0
 - 2.1.3
 
+gemfile:
+- Gemfile.activerecord40
+- Gemfile.activerecord41
+
 before_script:
 - mysql -e 'create database database_validations;'

Gemfile.activerecord40

@@ -0,0 +1,4 @@
+source 'https://rubygems.org'
+gemspec
+
+gem 'activerecord', '~> 4.0.0'

Gemfile.activerecord41

@@ -0,0 +1,4 @@
+source 'https://rubygems.org'
+gemspec
+
+gem 'activerecord', '~> 4.1.0'

activerecord-databasevalidations.gemspec

@@ -18,10 +18,10 @@ Gem::Specification.new do |spec|
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ["lib"]
 
-  spec.add_runtime_dependency "activerecord", "~> 4"
+  spec.add_runtime_dependency "activerecord", "~> 4.0"
 
   spec.add_development_dependency "bundler", "~> 1.5"
   spec.add_development_dependency "rake"
-  spec.add_development_dependency "minitest", "~> 5"
+  spec.add_development_dependency "minitest"
   spec.add_development_dependency "mysql2"
 end

lib/active_record/validations/database_constraints.rb

@@ -21,12 +21,11 @@ class DatabaseConstraintsValidator < ActiveModel::EachValidator
         longblob:   { validator: ActiveModel::Validations::BytesizeValidator, default_maximum: 2 ** 32 - 1 },
       }
 
-      attr_reader :klass, :constraints
+      attr_reader :constraints
 
       VALID_CONSTRAINTS = Set[:size, :basic_multilingual_plane, :not_null]
 
       def initialize(options = {})
-        @klass = options[:class]
         @constraints = Set.new(Array.wrap(options[:in]) + Array.wrap(options[:with]))
         @constraint_validators = {}
         super
@@ -39,14 +38,14 @@ def check_validity!
         raise ArgumentError, "#{invalid_constraints.map(&:inspect).join(',')} is not a valid constraint." unless invalid_constraints.empty?
       end
 
-      def not_null_validator(column)
+      def not_null_validator(klass, column)
         return unless constraints.include?(:not_null)
         return if column.null
 
         ActiveModel::Validations::NotNullValidator.new(attributes: [column.name.to_sym], class: klass)
       end
 
-      def size_validator(column)
+      def size_validator(klass, column)
         return unless constraints.include?(:size)
         return unless column.text? || column.binary?
 
@@ -61,26 +60,26 @@ def size_validator(column)
         end
       end
 
-      def basic_multilingual_plane_validator(column)
+      def basic_multilingual_plane_validator(klass, column)
         return unless constraints.include?(:basic_multilingual_plane)
         return unless column.text? && column.collation =~ /\Autf8(?:mb3)?_/
         ActiveModel::Validations::BasicMultilingualPlaneValidator.new(attributes: [column.name.to_sym], class: klass)
       end
 
-      def attribute_validators(attribute)
+      def attribute_validators(klass, attribute)
         @constraint_validators[attribute] ||= begin
           column = klass.columns_hash[attribute.to_s] or raise ArgumentError.new("Model #{self.class.name} does not have column #{column_name}!")
 
           [
-            not_null_validator(column),
-            size_validator(column),
-            basic_multilingual_plane_validator(column),
+            not_null_validator(klass, column),
+            size_validator(klass, column),
+            basic_multilingual_plane_validator(klass, column),
           ].compact
         end
       end
 
       def validate_each(record, attribute, value)
-        attribute_validators(attribute).each do |validator|
+        attribute_validators(record.class, attribute).each do |validator|
           validator.validate_each(record, attribute, value)
         end
       end

test/database_constraints_validator_test.rb

@@ -49,22 +49,22 @@ def test_validators_are_defined
 
   def test_not_null_field_defines_not_null_validator_if_requested
     validator = Foo._validators[:checked].first
-    subvalidators = validator.attribute_validators(:checked)
+    subvalidators = validator.attribute_validators(Foo, :checked)
     assert_equal 1, subvalidators.length
     assert_kind_of ActiveModel::Validations::NotNullValidator, subvalidators.first
   end
 
   def test_string_field_defines_length_validator_by_default
     validator = Foo._validators[:string].first
-    subvalidators = validator.attribute_validators(:string)
+    subvalidators = validator.attribute_validators(Foo, :string)
     assert_equal 1, subvalidators.length
     assert_kind_of ActiveModel::Validations::LengthValidator, subvalidators.first
     assert_equal 40, subvalidators.first.options[:maximum]
   end
 
   def test_blob_field_defines_bytesize_validator
     validator = Foo._validators[:blob].first
-    subvalidators = validator.attribute_validators(:blob)
+    subvalidators = validator.attribute_validators(Foo, :blob)
     assert_equal 1, subvalidators.length
     assert_kind_of ActiveModel::Validations::BytesizeValidator, subvalidators.first
     assert_equal 65535, subvalidators.first.options[:maximum]
@@ -73,7 +73,7 @@ def test_blob_field_defines_bytesize_validator
 
   def test_not_null_text_field_defines_requested_bytesize_validator_and_unicode_validator
     validator = Foo._validators[:not_null_text].first
-    subvalidators = validator.attribute_validators(:not_null_text)
+    subvalidators = validator.attribute_validators(Foo, :not_null_text)
     assert_equal 2, subvalidators.length
 
     assert_kind_of ActiveModel::Validations::BytesizeValidator, subvalidators.first
@@ -90,7 +90,7 @@ def test_not_null_columns_with_a_default_value
 
   def test_should_not_create_a_validor_for_a_utf8mb4_field
     assert Bar.new(mb4_string: '💩').valid?
-    Bar._validators[:mb4_string].first.attribute_validators(:mb4_string).empty?
+    Bar._validators[:mb4_string].first.attribute_validators(Bar, :mb4_string).empty?
   end
 
   def test_error_messages

test/test_helper.rb

@@ -9,6 +9,8 @@
 
 require "active_record/database_validations"
 
+Minitest::Test = MiniTest::Unit::TestCase unless defined?(MiniTest::Test)
+
 database_yml = YAML.load_file(File.expand_path('../database.yml', __FILE__))
 ActiveRecord::Base.establish_connection(database_yml['test'])
 I18n.enforce_available_locales = false