[WIP] Support Rails 7.0

.github/workflows/ci.yaml

@@ -15,6 +15,9 @@ jobs:
         - '2.7'
         - '3.0'
         - '3.1'
+        rails-version:
+        - '6.1'
+        - '7.0'
     services:
       postgres:
         image: postgres:13
@@ -39,6 +42,7 @@ jobs:
       PGPORT: 5432
       PGUSER: postgres
       PGPASSWORD: password
+      TEST_RAILS_VERSION: ${{ matrix.rails-version }}
       # for the mysql cli (mysql, mysqladmin)
       MYSQL_HOST: 127.0.0.1
       MYSQL_PWD: password
@@ -64,7 +68,7 @@ jobs:
           DB: mysql2
         run: bundle exec rake
       - name: Report code coverage
-        if: ${{ github.ref == 'refs/heads/master' && matrix.ruby-version == '3.1' }}
+        if: ${{ github.ref == 'refs/heads/master' && matrix.ruby-version == '3.1' && matrix.rails-version == '6.1' }}
         continue-on-error: true
         uses: paambaati/codeclimate-action@v8
         env:

Gemfile

@@ -2,7 +2,15 @@
 
 source "https://rubygems.org"
 
-gem "activerecord", "~> 6.1.7"
+minimum_version =
+  case ENV['TEST_RAILS_VERSION']
+  when "7.0"
+    "~>7.0.8"
+  else
+    "~>6.1.4"
+  end
+
+gem "activerecord", minimum_version
 gem "mysql2"
 gem "pg"
 gem "sqlite3", "< 2"

activerecord-virtual_attributes.gemspec

@@ -26,7 +26,7 @@ Gem::Specification.new do |spec|
 
   spec.require_paths = ["lib"]
 
-  spec.add_runtime_dependency "activerecord", "~> 6.1.0"
+  spec.add_runtime_dependency "activerecord", ">=6.1.7.6"
 
   spec.add_development_dependency "byebug"
   spec.add_development_dependency "database_cleaner-active_record", "~> 2.1"

lib/active_record/virtual_attributes/virtual_fields.rb

@@ -178,34 +178,46 @@ def grouped_records(orig_association, records, polymorphic_parent)
         end
         # rubocop:enable Style/BlockDelimiters, Lint/AmbiguousBlockAssociation, Style/MethodCallWithArgsParentheses
       })
+      class Branch
+        prepend(Module.new {
+          def grouped_records
+            # binding.pry
+            h = {}
+            polymorphic_parent = !root? && parent.polymorphic?
+            source_records.each do |record|
+              # each class can resolve virtual_{attributes,includes} differently
+              @association = record.class.replace_virtual_fields(self.association)
+
+              # 1 line optimization for single element array:
+              @association = association.first if association.kind_of?(Array)# && association.size == 1
+
+              # !!!!
+              @association = association.keys.first if association.kind_of?(Hash)
+
+              case association
+              when Symbol, String
+                reflection = record.class._reflect_on_association(association)
+                next if polymorphic_parent && !reflection || !record.association(association).klass
+              when nil
+                next
+              else # need parent (preloaders_for_{hash,one}) to handle this Array/Hash
+                reflection = association
+              end
+              (h[reflection] ||= []) << record
+            end
+            h
+          end
+        })
+      end if ActiveRecord.version >= Gem::Version.new(7.0)
     end
   end
 
   class Relation
-    def without_virtual_includes
-      filtered_includes = includes_values && klass.replace_virtual_fields(includes_values)
-      if filtered_includes != includes_values
-        spawn.tap { |other| other.includes_values = filtered_includes }
-      else
-        self
-      end
-    end
-
     include(Module.new {
-      # From ActiveRecord::FinderMethods
-      def apply_join_dependency(*args, **kargs, &block)
-        real = without_virtual_includes
-        if real.equal?(self)
-          super
-        else
-          real.apply_join_dependency(*args, **kargs, &block)
-        end
-      end
-
       # From ActiveRecord::QueryMethods (rails 5.2 - 6.1)
       def build_select(arel)
         if select_values.any?
-          cols = arel_columns(select_values.uniq).map do |col|
+          cols = arel_columns(select_values).map do |col|
             # if it is a virtual attribute, then add aliases to those columns
             if col.kind_of?(Arel::Nodes::Grouping) && col.name
               col.as(connection.quote_column_name(col.name))
@@ -221,7 +233,7 @@ def build_select(arel)
 
       # from ActiveRecord::QueryMethods (rails 5.2 - 6.0)
       # TODO: remove from rails 7.0
-      def arel_column(field, &block)
+      def arel_column(field)
         if virtual_attribute?(field) && (arel = table[field])
           arel
         else
@@ -233,16 +245,6 @@ def construct_join_dependency(associations, join_type) # :nodoc:
         associations = klass.replace_virtual_fields(associations)
         super
       end
-
-      # From ActiveRecord::Calculations
-      # introduces virtual includes support for calculate (we mostly use COUNT(*))
-      def calculate(operation, attribute_name)
-        # allow calculate to work with includes and a virtual attribute
-        real = without_virtual_includes
-        return super if real.equal?(self)
-
-        real.calculate(operation, attribute_name)
-      end
     })
   end
 end

spec/spec_helper.rb

@@ -41,3 +41,7 @@
     end
   end
 end
+
+require "active_record"
+puts
+puts "\e[93mUsing ActiveRecord #{ActiveRecord.version}\e[0m"

spec/virtual_includes_spec.rb

@@ -240,9 +240,7 @@
       expect(books.last.author).to be_nil # the book just created does not have an author
 
       # the second time preloading throws an error
-      preloader = ActiveRecord::Associations::Preloader.new
-      preloader.preload(books, :author => :books)
-
+      preloaded(books, :author => :books)
       expect(books.size).to be(4)
     end
   end
@@ -342,11 +340,13 @@
     end
 
     it "preloads virtual_reflection(:uses => :books => :bookmarks) (nothing virtual)" do
+      skip "ActiveRecord Preloader doesn't preload collection associations in rails 7+. See: https://www.github.com/rails/rails/pull/42654" if ActiveRecord.version >= Gem::Version.new(7.0)
       bookmarked_book = Author.first.books.first
       expect(Author.includes(:book_with_most_bookmarks)).to preload_values(:book_with_most_bookmarks, bookmarked_book)
     end
 
     it "preloads virtual_reflection(:uses => :books => :bookmarks, :uses => :books) (multiple overlapping relations)" do
+      skip "ActiveRecord Preloader doesn't preload collection associations in rails 7+. See: https://www.github.com/rails/rails/pull/42654" if ActiveRecord.version >= Gem::Version.new(7.0)
       bookmarked_book = Author.first.books.first
       expect(Author.includes(:book_with_most_bookmarks, :books)).to preload_values(:book_with_most_bookmarks, bookmarked_book)
     end
@@ -404,6 +404,7 @@
     end
 
     it "preloads virtual_reflection(:uses => :books => :bookmarks) (nothing virtual)" do
+      skip "ActiveRecord Preloader doesn't preload collection associations in rails 7+. See: https://www.github.com/rails/rails/pull/42654" if ActiveRecord.version >= Gem::Version.new(7.0)
       bookmarked_book = Author.first.books.first
       expect(preloaded(Author.all.to_a, :book_with_most_bookmarks)).to preload_values(:book_with_most_bookmarks, bookmarked_book)
     end
@@ -540,8 +541,13 @@
   end
 
   def preloaded(records, associations, preload_scope = nil)
-    preloader = ActiveRecord::Associations::Preloader.new
-    preloader.preload(records, associations, preload_scope)
+    if ActiveRecord::Associations::Preloader.instance_methods.include?(:preload)
+      preloader = ActiveRecord::Associations::Preloader.new
+      preloader.preload(records, associations, preload_scope)
+    else
+      # Rails 7+ interface, see rails commit: e3b9779cb701c63012bc1af007c71dc5a888d35a
+      ActiveRecord::Associations::Preloader.new(records: records, associations: associations, scope: preload_scope).call
+    end
     records
   end
 end