Merge pull request rails#47352 from basecamp/ar-freeze-cached

Fix querying of serialized Class attributes

Fix: rails#47352

Author: byroot

activemodel/lib/active_model/attribute.rb

@@ -115,13 +115,17 @@ def has_been_read?
     def ==(other)
       self.class == other.class &&
         name == other.name &&
-        value_before_type_cast == other.value_before_type_cast &&
+        identifier_value == other.identifier_value &&
         type == other.type
     end
     alias eql? ==
 
     def hash
-      [self.class, name, value_before_type_cast, type].hash
+      [self.class, name, identifier_value, type].hash
+    end
+
+    def identifier_value
+      value_before_type_cast
     end
 
     def init_with(coder)

activemodel/lib/active_model/type/helpers/mutable.rb

@@ -4,10 +4,6 @@ module ActiveModel
   module Type
     module Helpers # :nodoc: all
       module Mutable
-        def immutable_value(value)
-          value.deep_dup.freeze
-        end
-
         def cast(value)
           deserialize(serialize(value))
         end

activerecord/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Fix error when querying serialized Class attributes.
+
+    *Jorge Manrubia*
+
 *   Add support for `Array#intersect?` to `ActiveRecord::Relation`.
 
     `Array#intersect?` is only available on Ruby 3.1 or later.

activerecord/lib/active_record/relation/predicate_builder.rb

@@ -66,7 +66,7 @@ def build(attribute, value, operator = nil)
 
     def build_bind_attribute(column_name, value)
       type = table.type(column_name)
-      Relation::QueryAttribute.new(column_name, type.immutable_value(value), type)
+      Relation::QueryAttribute.new(column_name, value, type)
     end
 
     def resolve_arel_attribute(table_name, column_name, &block)

activerecord/lib/active_record/relation/query_attribute.rb

@@ -36,10 +36,24 @@ def unboundable?
         @_unboundable
       end
 
+      def identifier_value
+        if unboundable?
+          super
+        else
+          # Override to define equality based on frozen casted values to prevent caching
+          # issues with mutable database query values.
+          value_for_database
+        end
+      end
+
       private
         def infinity?(value)
           value.respond_to?(:infinite?) && value.infinite?
         end
+
+        def _value_for_database
+          super.deep_dup.freeze
+        end
     end
   end
 end

activerecord/test/cases/serialized_attribute_test.rb

@@ -9,6 +9,11 @@
 class SerializedAttributeTest < ActiveRecord::TestCase
   def setup
     ActiveRecord.use_yaml_unsafe_load = true
+    @yaml_column_permitted_classes_default = ActiveRecord.yaml_column_permitted_classes
+  end
+
+  def teardown
+    ActiveRecord.yaml_column_permitted_classes = @yaml_column_permitted_classes_default
   end
 
   fixtures :topics, :posts
@@ -23,6 +28,10 @@ class ImportantTopic < Topic
     serialize :important, type: Hash
   end
 
+  class ClassifiedTopic < Topic
+    serialize :important, type: Class
+  end
+
   teardown do
     Topic.serialize("content")
   end
@@ -166,6 +175,14 @@ def test_serialized_string_attribute
     assert_equal(myobj, topic.content)
   end
 
+  def test_serialized_class_attribute
+    ActiveRecord.yaml_column_permitted_classes += [Class]
+
+    topic = ClassifiedTopic.create(important: Symbol).reload
+    assert_equal(Symbol, topic.important)
+    assert_not_empty ClassifiedTopic.where(important: Symbol)
+  end
+
   def test_nil_serialized_attribute_without_class_constraint
     topic = Topic.new
     assert_nil topic.content
@@ -551,6 +568,7 @@ def test_serialized_attribute_works_under_concurrent_initial_access
 
 class SerializedAttributeTestWithYamlSafeLoad < SerializedAttributeTest
   def setup
+    super
     ActiveRecord.use_yaml_unsafe_load = false
   end