Merge pull request #32852 from gmcgibbon/fix_numericality_float_equality

Fix numericality equality validation on floats

activemodel/CHANGELOG.md

@@ -1,3 +1,8 @@
+*   Fix numericality equality validation of `BigDecimal` and `Float`
+    by casting to `BigDecimal` on both ends of the validation.
+
+    *Gannon McGibbon*
+
 *   Add `#slice!` method to `ActiveModel::Errors`.
 
     *Daniel López Prat*

activemodel/lib/active_model/validations/numericality.rb

@@ -9,6 +9,9 @@ class NumericalityValidator < EachValidator # :nodoc:
 
       RESERVED_OPTIONS = CHECKS.keys + [:only_integer]
 
+      INTEGER_REGEX = /\A[+-]?\d+\z/
+      DECIMAL_REGEX = /\A[+-]?\d+\.?\d*(e|e[+-])?\d+\z/
+
       def check_validity!
         keys = CHECKS.keys - [:odd, :even]
         options.slice(*keys).each do |option, value|
@@ -49,11 +52,7 @@ def validate_each(record, attr_name, value)
           return
         end
 
-        if raw_value.is_a?(Numeric)
-          value = raw_value
-        else
-          value = parse_raw_value_as_a_number(raw_value)
-        end
+        value = parse_as_number(raw_value)
 
         options.slice(*CHECKS.keys).each do |option, option_value|
           case option
@@ -69,6 +68,8 @@ def validate_each(record, attr_name, value)
               option_value = record.send(option_value)
             end
 
+            option_value = parse_as_number(option_value)
+
             unless value.send(CHECKS[option], option_value)
               record.errors.add(attr_name, option, filtered_options(value).merge!(count: option_value))
             end
@@ -79,18 +80,29 @@ def validate_each(record, attr_name, value)
     private
 
       def is_number?(raw_value)
-        !parse_raw_value_as_a_number(raw_value).nil?
+        !parse_as_number(raw_value).nil?
       rescue ArgumentError, TypeError
         false
       end
 
-      def parse_raw_value_as_a_number(raw_value)
-        return raw_value.to_i if is_integer?(raw_value)
-        Kernel.Float(raw_value) unless is_hexadecimal_literal?(raw_value)
+      def parse_as_number(raw_value)
+        if raw_value.is_a?(Float)
+          raw_value.to_d
+        elsif raw_value.is_a?(Numeric)
+          raw_value
+        elsif is_integer?(raw_value)
+          raw_value.to_i
+        elsif is_decimal?(raw_value) && !is_hexadecimal_literal?(raw_value)
+          BigDecimal(raw_value)
+        end
       end
 
       def is_integer?(raw_value)
-        /\A[+-]?\d+\z/ === raw_value.to_s
+        INTEGER_REGEX === raw_value.to_s
+      end
+
+      def is_decimal?(raw_value)
+        DECIMAL_REGEX === raw_value.to_s
       end
 
       def is_hexadecimal_literal?(raw_value)

activemodel/test/cases/validations/numericality_validation_test.rb

@@ -289,6 +289,13 @@ def test_validates_numericality_with_invalid_args
     assert_raise(ArgumentError) { Topic.validates_numericality_of :approved, equal_to: "foo" }
   end
 
+  def test_validates_numericality_equality_for_float_and_big_decimal
+    Topic.validates_numericality_of :approved, equal_to: BigDecimal("65.6")
+
+    invalid!([Float("65.5"), BigDecimal("65.7")], "must be equal to 65.6")
+    valid!([Float("65.6"), BigDecimal("65.6")])
+  end
+
   private
 
     def invalid!(values, error = nil)