Merge pull request #220 from jrochkind/fix_nested_model_validation

Keep nested model validation working in Rails post 7.1 (undefined method `custom_validation_context?')

CHANGELOG.md

@@ -8,7 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
-*
+* Keep nested model validation working in Rails post-7.1, by no longer trying to re-use ActiveRecord::Validations::AssociatedValidator, instead supplying our own custom code. https://github.com/jrochkind/attr_json/pull/220
 
 *
 

lib/attr_json/model.rb

@@ -8,6 +8,7 @@
 
 require 'attr_json/type/model'
 require 'attr_json/model/cocoon_compat'
+require 'attr_json/model/nested_model_validator'
 
 require 'attr_json/serialization_coder_from_type'
 
@@ -207,8 +208,8 @@ def attribute_types
       # @option options [String,Symbol] :store_key (nil) Serialize to JSON using
       #   given store_key, rather than name as would be usual.
       #
-      # @option options [Boolean] :validate (true) Create an ActiveRecord::Validations::AssociatedValidator so
-      #   validation errors on the attributes post up to self.
+      # @option options [Boolean] :validate (true) Mak validation errors on the attributes post up
+      #   to self, using something similar to an ActiveRecord::Validations::AssociatedValidator
       def attr_json(name, type, **options)
         options.assert_valid_keys(*(AttributeDefinition::VALID_OPTIONS - [:container_attribute] + [:validate]))
 
@@ -220,9 +221,8 @@ def attr_json(name, type, **options)
 
         # By default, automatically validate nested models
         if type.kind_of?(AttrJson::Type::Model) && options[:validate] != false
-          # Yes. we're passing an ActiveRecord::Validations validator, but
-          # it works fine for ActiveModel. If this changes in the future, tests will catch.
-          self.validates_with ActiveRecord::Validations::AssociatedValidator, attributes: [name.to_sym]
+          # Post validations up with something based on ActiveRecord::Validations::AssociatedValidator
+          self.validates_with ::AttrJson::Model::NestedModelValidator, attributes: [name.to_sym]
         end
 
         _attr_jsons_module.module_eval do

lib/attr_json/model/nested_model_validator.rb

@@ -0,0 +1,27 @@
+module AttrJson
+  module Model
+    # Used to validate an attribute in an AttrJson::Model whose values are other models, when
+    # you want validation errors on the nested models to post up.
+    #
+    # This is based on ActiveRecord's own ActiveRecord::Validations::AssociatedValidator, and actually forked
+    # from it at https://github.com/rails/rails/blob/e37adfed4eff3b43350ec87222a922e9c72d9c1b/activerecord/lib/active_record/validations/associated.rb
+    #
+    # We used to simply use an ActiveRecord::Validations::AssociatedValidator, but as of https://github.com/jrochkind/attr_json/pull/220 (e1e798142d)
+    # it got ActiveRecord-specific functionality that no longer worked with our use case.
+    #
+    # No problem, the implementation is simple, we can provide it here, based on the last version that did work.
+    class NestedModelValidator < ActiveModel::EachValidator
+      def validate_each(record, attribute, value)
+        if Array(value).reject { |r| valid_object?(r) }.any?
+          record.errors.add(attribute, :invalid, **options.merge(value: value))
+        end
+      end
+
+      private
+        def valid_object?(record)
+          #(record.respond_to?(:marked_for_destruction?) && record.marked_for_destruction?) || record.valid?
+          record.valid?
+        end
+    end
+  end
+end