AM::Validation#validates: ability to pass custom exception to `:strict` option

activemodel/CHANGELOG.md

@@ -1,5 +1,7 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   `AM::Validation#validates` ability to pass custom exception to `:strict` option *Bogdan Gusiev*
+
 *   Changed `AM::Serializers::JSON.include_root_in_json' default value to false.
     Now, AM Serializers and AR objects have the same default behaviour. Fixes #6578.
 

activemodel/lib/active_model/errors.rb

@@ -283,15 +283,19 @@ module ActiveModel
     #
     # If the <tt>:strict</tt> option is set to true will raise
     # ActiveModel::StrictValidationFailed instead of adding the error.
+    # <tt>:strict</tt> option can also be set to any other exception.
     #
     #   person.errors.add(:name, nil, strict: true)
     #   # => ActiveModel::StrictValidationFailed: name is invalid
+    #   person.errors.add(:name, nil, strict: NameIsInvalid)
+    #   # => NameIsInvalid: name is invalid
     #
     #   person.errors.messages # => {}
     def add(attribute, message = nil, options = {})
       message = normalize_message(attribute, message, options)
-      if options[:strict]
-        raise ActiveModel::StrictValidationFailed, full_message(attribute, message)
+      if exception = options[:strict]
+        exception = ActiveModel::StrictValidationFailed if exception == true
+        raise exception, full_message(attribute, message)
       end
 
       self[attribute] << message

activemodel/lib/active_model/validations/validates.rb

@@ -84,12 +84,15 @@ module ActiveModel
       #   or <tt>unless: Proc.new { |user| user.signup_step <= 2 }</tt>). The
       #   method, proc or string should return or evaluate to a +true+ or
       #   +false+ value.
-      # * <tt>:strict</tt> - Specifies whether validation should be strict.
-      #   See <tt>ActiveModel::Validation#validates!</tt> for more information.
+      # * <tt>:strict</tt> - if the <tt>:strict</tt> option is set to true
+      #   will raise ActiveModel::StrictValidationFailed instead of adding the error.
+      #   <tt>:strict</tt> option can also be set to any other exception.
       #
       # Example:
       #
       #   validates :password, presence: true, confirmation: true, if: :password_required?
+      #   validates :token, uniqueness: true, strict: TokenGenerationException
+      #
       #
       # Finally, the options +:if+, +:unless+, +:on+, +:allow_blank+, +:allow_nil+
       # and +:strict+ can be given to one specific validator, as a hash:

activemodel/test/cases/validations_test.rb

@@ -11,6 +11,8 @@ require 'active_support/xml_mini'
 
 class ValidationsTest < ActiveModel::TestCase
 
+  class CustomStrictValidationException < StandardError; end
+
   def setup
     Topic._validators.clear
   end
@@ -323,6 +325,13 @@ class ValidationsTest < ActiveModel::TestCase
     end
   end
 
+  def test_strict_validation_custom_exception
+    Topic.validates_presence_of :title, :strict => CustomStrictValidationException
+    assert_raises CustomStrictValidationException do
+      Topic.new.valid?
+    end
+  end
+
   def test_validates_with_bang
     Topic.validates! :title,  :presence => true
     assert_raises ActiveModel::StrictValidationFailed do

guides/source/active_record_validations_callbacks.textile

@@ -532,6 +532,16 @@ end
 Person.new.valid?  => ActiveModel::StrictValidationFailed: Name can't be blank
 </ruby>
 
+There is also an ability to pass custom exception to +:strict+ option
+
+<ruby>
+class Person < ActiveRecord::Base
+  validates :token, :presence => true, :uniqueness => true, :strict => TokenGenerationException
+end
+
+Person.new.valid?  => TokenGenerationException: Token can't be blank
+</ruby>
+
 h3. Conditional Validation
 
 Sometimes it will make sense to validate an object just when a given predicate is satisfied. You can do that by using the +:if+ and +:unless+ options, which can take a symbol, a string, a +Proc+ or an +Array+. You may use the +:if+ option when you want to specify when the validation *should* happen. If you want to specify when the validation *should not* happen, then you may use the +:unless+ option.