2 files changed, 24 insertions, 0 deletions
diff --git a/activemodel/test/cases/validations/numericality_validation_test.rb b/activemodel/test/cases/validations/numericality_validation_test.rb
index 01b78ae72e..ca3c3bc40d 100644
--- a/activemodel/test/cases/validations/numericality_validation_test.rb
+++ b/activemodel/test/cases/validations/numericality_validation_test.rb
@@ -262,6 +262,16 @@ class NumericalityValidationTest < ActiveModel::TestCase
     Person.clear_validators!
   end
 
+  def test_validates_numericality_using_value_before_type_cast_if_possible
+    Topic.validates_numericality_of :price
+
+    topic = Topic.new(price: 50)
+
+    assert_equal "$50.00", topic.price
+    assert_equal 50, topic.price_before_type_cast
+    assert_predicate topic, :valid?
+  end
+
   def test_validates_numericality_with_exponent_number
     base = 10_000_000_000_000_000
     Topic.validates_numericality_of :approved, less_than_or_equal_to: base
diff --git a/activemodel/test/models/topic.rb b/activemodel/test/models/topic.rb
index b0af00ee45..db3284f833 100644
--- a/activemodel/test/models/topic.rb
+++ b/activemodel/test/models/topic.rb
@@ -3,6 +3,11 @@
 class Topic
   include ActiveModel::Validations
   include ActiveModel::Validations::Callbacks
+  include ActiveModel::AttributeMethods
+  include ActiveSupport::NumberHelper
+
+  attribute_method_suffix "_before_type_cast"
+  define_attribute_method :price
 
   def self._validates_default_keys
     super | [ :message ]
@@ -10,6 +15,7 @@ class Topic
 
   attr_accessor :title, :author_name, :content, :approved, :created_at
   attr_accessor :after_validation_performed
+  attr_writer :price
 
   after_validation :perform_after_validation
 
@@ -38,4 +44,12 @@ class Topic
   def my_validation_with_arg(attr)
     errors.add attr, "is missing" unless send(attr)
   end
+
+  def price
+    number_to_currency @price
+  end
+
+  def attribute_before_type_cast(attr)
+    instance_variable_get(:"@#{attr}")
+  end
 end