Add support for Rails 8.1

Author: n-rodriguez

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Setup Ruby
         uses: ruby/setup-ruby@v1
@@ -57,6 +57,7 @@ jobs:
           - '3.2'
           - 'head'
         rails:
+          - activerecord_8.1
           - activerecord_8.0
           - activerecord_7.2
 
@@ -65,7 +66,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Setup Ruby
         uses: ruby/setup-ruby@v1

Appraisals

@@ -7,3 +7,7 @@ end
 appraise 'activerecord_8.0' do
   gem 'activerecord', '~> 8.0.0'
 end
+
+appraise 'activerecord_8.1' do
+  gem 'activerecord', '~> 8.1.0'
+end

gemfiles/activerecord_8.1.gemfile

@@ -0,0 +1,16 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "appraisal", git: "https://github.com/thoughtbot/appraisal.git"
+gem "pg"
+gem "rake"
+gem "rspec"
+gem "simplecov"
+gem "guard-rspec", require: false
+gem "rubocop", require: false
+gem "rubocop-rake", require: false
+gem "rubocop-rspec", require: false
+gem "activerecord", "~> 8.1.0"
+
+gemspec path: "../"

lib/store_base_sti_class_for_8_1.rb

@@ -0,0 +1,172 @@
+if ActiveRecord::VERSION::STRING =~ /\A8\.1/
+  module StoreBaseSTIClass
+
+    module Inheritance
+      module ClassMethodsPatch
+
+        # See: https://github.com/rails/rails/blob/v8.1.0/activerecord/lib/active_record/inheritance.rb#L211
+        def polymorphic_name
+          ActiveRecord::Base.store_base_sti_class ? base_class.name : name
+        end
+      end
+    end
+
+    module Associations
+      module Preloader
+        module ThroughAssociationPatch
+          private
+
+          # See: https://github.com/rails/rails/blob/v8.1.0/activerecord/lib/active_record/associations/preloader/through_association.rb#L104
+          def through_scope
+            scope = through_reflection.klass.unscoped
+            options = reflection.options
+
+            return scope if options[:disable_joins]
+
+            values = reflection_scope.values
+            if annotations = values[:annotate]
+              scope.annotate!(*annotations)
+            end
+
+            if options[:source_type]
+              # BEGIN PATCH
+              # original:
+              # scope.where! reflection.foreign_type => options[:source_type]
+
+              adjusted_foreign_type =
+                if ActiveRecord::Base.store_base_sti_class
+                  options[:source_type]
+                else
+                  ([options[:source_type].constantize] + options[:source_type].constantize.descendants).map(&:to_s)
+                end
+
+              scope.where! reflection.foreign_type => adjusted_foreign_type
+              # END PATCH
+
+            elsif !reflection_scope.where_clause.empty?
+              scope.where_clause = reflection_scope.where_clause
+
+              if includes = values[:includes]
+                scope.includes!(source_reflection.name => includes)
+              else
+                scope.includes!(source_reflection.name)
+              end
+
+              if values[:references] && !values[:references].empty?
+                scope.references_values |= values[:references]
+              else
+                scope.references!(source_reflection.table_name)
+              end
+
+              if joins = values[:joins]
+                scope.joins!(source_reflection.name => joins)
+              end
+
+              if left_outer_joins = values[:left_outer_joins]
+                scope.left_outer_joins!(source_reflection.name => left_outer_joins)
+              end
+
+              if scope.eager_loading? && order_values = values[:order]
+                scope = scope.order(order_values)
+              end
+            end
+
+            cascade_strict_loading(scope)
+          end
+        end
+      end
+
+      module AssociationScopePatch
+        private
+
+        # See: https://github.com/rails/rails/blob/v8.1.0/activerecord/lib/active_record/associations/association_scope.rb#L81
+        def next_chain_scope(scope, reflection, next_reflection)
+          primary_key = Array(reflection.join_primary_key)
+          foreign_key = Array(reflection.join_foreign_key)
+
+          table = reflection.aliased_table
+          foreign_table = next_reflection.aliased_table
+
+          primary_key_foreign_key_pairs = primary_key.zip(foreign_key)
+          constraints = primary_key_foreign_key_pairs.map do |join_primary_key, foreign_key|
+            table[join_primary_key].eq(foreign_table[foreign_key])
+          end.inject(&:and)
+
+          if reflection.type
+            # BEGIN PATCH
+            # original:
+            # value = transform_value(next_reflection.klass.polymorphic_name)
+            # scope = apply_scope(scope, table, reflection.type, value)
+
+            if ActiveRecord::Base.store_base_sti_class
+              value = transform_value(next_reflection.klass.polymorphic_name)
+            else
+              klass = next_reflection.klass
+              value = ([klass] + klass.descendants).map(&:name)
+            end
+            scope = apply_scope(scope, table, reflection.type, value)
+            # END PATCH
+          end
+
+          scope.joins!(join(foreign_table, constraints))
+        end
+      end
+
+      module HasManyThroughAssociationPatch
+        private
+
+        # See: https://github.com/rails/rails/blob/v8.1.0/activerecord/lib/active_record/associations/has_many_through_association.rb#L56
+        def build_through_record(record)
+          @through_records[record] ||= begin
+            ensure_mutable
+
+            attributes = through_scope_attributes
+            attributes[source_reflection.name] = record
+
+            through_association.build(attributes).tap do |new_record|
+              if ActiveRecord::Base.store_base_sti_class
+                new_record.send("#{source_reflection.foreign_type}=", options[:source_type]) if options[:source_type]
+              end
+            end
+          end
+        end
+      end
+    end
+
+    module Reflection
+      module PolymorphicReflectionPatch
+        private
+
+        # See: https://github.com/rails/rails/blob/v8.1.0/activerecord/lib/active_record/reflection.rb#L1286
+        def source_type_scope
+          type = @previous_reflection.foreign_type
+          source_type = @previous_reflection.options[:source_type]
+
+          # START PATCH
+          adjusted_source_type =
+            if ActiveRecord::Base.store_base_sti_class
+              source_type
+            else
+              ([source_type.constantize] + source_type.constantize.descendants).map(&:to_s)
+            end
+          # END PATCH
+
+          lambda { |object| where(type => adjusted_source_type) }
+        end
+      end
+    end
+  end
+
+  ActiveRecord::Inheritance::ClassMethods.prepend(StoreBaseSTIClass::Inheritance::ClassMethodsPatch)
+  ActiveRecord::Associations::Preloader::ThroughAssociation.prepend(StoreBaseSTIClass::Associations::Preloader::ThroughAssociationPatch)
+  ActiveRecord::Associations::AssociationScope.prepend(StoreBaseSTIClass::Associations::AssociationScopePatch)
+  ActiveRecord::Associations::HasManyThroughAssociation.prepend(StoreBaseSTIClass::Associations::HasManyThroughAssociationPatch)
+  ActiveRecord::Reflection::PolymorphicReflection.prepend(StoreBaseSTIClass::Reflection::PolymorphicReflectionPatch)
+
+  module ActiveRecord
+    class Base
+      class_attribute :store_base_sti_class
+      self.store_base_sti_class = true
+    end
+  end
+end

store_base_sti_class.gemspec

@@ -26,5 +26,5 @@ Gem::Specification.new do |s|
 
   s.files = Dir['README.md', 'LICENSE', 'lib/**/*.rb']
 
-  s.add_dependency('activerecord', ['>= 7.0', '< 8.1'])
+  s.add_dependency('activerecord', ['>= 7.0', '< 8.2'])
 end