[WIP] Allow rails 7 gems in gemspec

.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@v5
         env:

Gemfile

@@ -2,7 +2,15 @@
 
 source "https://rubygems.org"
 
-gem "activerecord", "~> 6.1.4"
+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"

activerecord-virtual_attributes.gemspec

@@ -25,7 +25,7 @@ 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

@@ -178,6 +178,34 @@ 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
+
+              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
 
@@ -189,7 +217,7 @@ def without_virtual_includes
       else
         self
       end
-    end
+    end if ActiveRecord.version < Gem::Version.new(6.1)
 
     include(Module.new {
       # From ActiveRecord::FinderMethods
@@ -200,12 +228,12 @@ def apply_join_dependency(*args, **kargs, &block)
         else
           real.apply_join_dependency(*args, **kargs, &block)
         end
-      end
+      end if ActiveRecord.version < Gem::Version.new(6.1)
 
       # 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))
@@ -242,7 +270,7 @@ def calculate(operation, attribute_name)
         return super if real.equal?(self)
 
         real.calculate(operation, attribute_name)
-      end
+      end if ActiveRecord.version < Gem::Version.new(6.1)
     })
   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
@@ -540,8 +538,13 @@
   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