config.active_record_tenanted.connection_class

is a config option that takes a class name (default
"ApplicationRecord") that this gem will integrate into Rails test
setup and Record classes (to share a connection pool with that
connection class and create/use tables in that class's database). Or
set to `nil` to turn off integrations.

Also introduce config.active_record_tenanted.tenant_rails_records
which defaults to `true` but can be set to `false` to leave Record
classes in an untenanted primary database.

Also added an `after_initialize` block into the railtie to apply the
connection class configs.

Author: flavorjones

GUIDE.md

@@ -48,6 +48,7 @@ Documentation outline:
 - demonstrate how to configure an app for subdomain tenants
   - app.config.hosts
   - example TenantSelector proc
+- explain Tenanted options "connection_class" and "tenanted_rails_records"
 
 TODO:
 
@@ -117,22 +118,17 @@ TODO:
   - [ ] install a variation on the default database.yml with primary tenanted and non-primary "global" untenanted
   - initializer
     - [ ] install `TenantSelector` and configure it with a proc
-    - [ ] commented line like `Tenant = ActiveRecord::Tenanted::Tenant`
+    - [ ] commented line like `self.connection_class = "ApplicationRecord"`
+    - [ ] commented line like `self.tenanted_rails_records = true`
 
 - pruning connections and connection pools
   - [ ] look into whether the proposed Reaper changes will allow us to set appropriate connection min/max/timeouts
     - and if not, figure out how to prune unused/timed-out connections
   - [ ] we should also look into how to cap the number of connection pools, and prune them
 
 - autoloading and configuration hooks
-  - [ ] create a zeitwerk loader
-  - [ ] install some load hooks (where?)
-
-- design thinking re: global singleton (I think I've decided to not have one in this iteration)
-  - should there be a global singleton `Tenant`? I'm not sure we need it or the limitations of a global.
-  - if we do, though, then `.tenanted` should set `Tenant.base_class=`
-  - and we need to add checks that `.tenanted` is called only ONCE in the application
-  - `.tenanted_class` returns nil or the abstract base class. do we need this? let's wait and see.
+  - [x] create a zeitwerk loader
+  - [x] install a load hook
 
 - test coverage
   - [x] need more complete coverage on `Tenant.ensure_schema_migrations`
@@ -142,8 +138,9 @@ TODO:
 
 Documentation outline:
 
-- introduce the `Tenant` module
+- introduce the `ActiveRecord::Tenanted::Tenant` module
   - demonstrate how to create a tenant, destroy a tenant, etc.
+  - explain `.while_tenanted` and `current_tenant`
 - troubleshooting: what errors you might see in your app and how to deal with it
   - specifically when running untenanted
 
@@ -159,8 +156,8 @@ Documentation outline:
 TODO:
 
 - testing
-  - [ ] set up test helper to default to a tenanted named "test-tenant"
-  - [ ] set up test helpers to deal with parallelized tests, too (e.g. "test-tenant-19")
+  - [x] set up test helper to default to a tenanted named "test-tenant"
+  - [x] set up test helpers to deal with parallelized tests, too (e.g. "test-tenant-19")
   - [ ] allow the creation of tenants within transactional tests if we can?
     - either by cleaning up properly (hard)
     - or by providing a test helper that does `ensure ... Tenant.destroy`

lib/active_record/tenanted.rb

@@ -17,3 +17,5 @@ class NoTenantError < Error; end
 end
 
 loader.eager_load
+
+ActiveSupport.run_load_hooks :active_record_tenanted, ActiveRecord::Tenanted

lib/active_record/tenanted/railtie.rb

@@ -3,6 +3,27 @@
 module ActiveRecord
   module Tenanted
     class Railtie < ::Rails::Railtie
+      config.active_record_tenanted = ActiveSupport::OrderedOptions.new
+
+      # Set this in an initializer if you're tenanting a connection class other than
+      # ApplicationRecord. This value controls how Rails integrates with your tenanted application.
+      #
+      # By default, Rails will configure the test database, test fixtures to use
+      # "ApplicationRecord", but this can be set to `nil` to turn off the integrations entirely,
+      # including Rails records (see `tenanted_rails_records` below).
+      config.active_record_tenanted.connection_class = "ApplicationRecord"
+
+      # Set this to false in an initializer if you don't want Rails records to share a connection
+      # pool with the tenanted connection class.
+      #
+      # By default, this gem will configure ActionMailbox::Record, ActiveStorage::Record, and
+      # ActionText::Record to create/use tables in the database associated with the
+      # `connection_class`, and will share a connection pool with that class.
+      #
+      # This should only be turned off if your primary database configuration is not tenanted, and
+      # that is where you want Rails to create the tables for these records.
+      config.active_record_tenanted.tenanted_rails_records = true
+
       config.before_configuration do
         ActiveSupport.on_load(:active_record) do
           ActiveRecord::DatabaseConfigurations.register_db_config_handler do |env_name, name, _, config|
@@ -12,13 +33,13 @@ class Railtie < ::Rails::Railtie
         end
       end
 
-      initializer "active_record_tenanted.base_records" do
+      initializer "active_record_tenanted.active_record_base" do
         ActiveSupport.on_load(:active_record) do
           prepend ActiveRecord::Tenanted::Base
         end
       end
 
-      initializer "active_record-tenanted.monkey_patches.active_record" do
+      initializer "active_record-tenanted.monkey_patches" do
         ActiveSupport.on_load(:active_record) do
           # require "rails/generators/active_record/migration.rb"
           # ActiveRecord::Generators::Migration.prepend(ActiveRecord::Tenanted::Patches::Migration)
@@ -29,6 +50,40 @@ class Railtie < ::Rails::Railtie
           include(ActiveRecord::Tenanted::Patches::TestFixtures)
         end
       end
+
+      config.after_initialize do
+        ActiveSupport.on_load(:action_mailbox_record) do
+          if Rails.application.config.active_record_tenanted.connection_class.present? &&
+             Rails.application.config.active_record_tenanted.tenanted_rails_records
+            subtenant_of Rails.application.config.active_record_tenanted.connection_class
+          end
+        end
+
+        ActiveSupport.on_load(:active_storage_record) do
+          if Rails.application.config.active_record_tenanted.connection_class.present? &&
+             Rails.application.config.active_record_tenanted.tenanted_rails_records
+            subtenant_of Rails.application.config.active_record_tenanted.connection_class
+          end
+        end
+
+        ActiveSupport.on_load(:action_text_record) do
+          if Rails.application.config.active_record_tenanted.connection_class.present? &&
+             Rails.application.config.active_record_tenanted.tenanted_rails_records
+            subtenant_of Rails.application.config.active_record_tenanted.connection_class
+          end
+        end
+
+        ActiveSupport.on_load(:active_support_test_case) do
+          if Rails.application.config.active_record_tenanted.connection_class.present?
+            klass = Rails.application.config.active_record_tenanted.connection_class.constantize
+
+            klass.current_tenant = "#{Rails.env}-tenant" if Rails.env.test?
+            parallelize_setup do |worker|
+              klass.current_tenant = "#{Rails.env}-tenant-#{worker}"
+            end
+          end
+        end
+      end
     end
   end
 end

test/dummy/config/environment.rb

@@ -1,5 +1,10 @@
 # Load the Rails application.
 require_relative "application"
 
+# turn off the Rails integrations
+ActiveSupport.on_load(:active_record_tenanted) do
+  Rails.application.config.active_record_tenanted.connection_class = nil
+end
+
 # Initialize the Rails application.
 Rails.application.initialize!