Add GoodJob.configure_active_record as alternative to `GoodJob.acti…

…ve_record_parent_class` (#1004)

README.md

@@ -318,7 +318,17 @@ config.good_job.execution_mode = :external
 
 Good Job’s general behavior can also be configured via attributes directly on the `GoodJob` module:
 
-- **`GoodJob.active_record_parent_class`** (string) The ActiveRecord parent class inherited by GoodJob's ActiveRecord model `GoodJob::Job` (defaults to `"ActiveRecord::Base"`). Configure this when using [multiple databases with ActiveRecord](https://guides.rubyonrails.org/active_record_multiple_databases.html) or when other custom configuration is necessary for the ActiveRecord model to connect to the Postgres database. _The value must be a String to avoid premature initialization of ActiveRecord._
+- **`GoodJob.configure_active_record { ... }`** Inject Active Record configuration into GoodJob's base model, for example, when using [multiple databases with ActiveRecord](https://guides.rubyonrails.org/active_record_multiple_databases.html) or when other custom configuration is necessary for the ActiveRecord model to connect to the Postgres database. Example:
+
+    ```ruby
+    # config/initializers/good_job.rb
+    GoodJob.configure_active_record do
+      connects_to database: :special_database
+      self.table_name_prefix = "special_application_"
+    end
+    ```
+
+- **`GoodJob.active_record_parent_class`** (string) Alternatively, modify the ActiveRecord parent class inherited by GoodJob's Active Record model `GoodJob::Job` (defaults to `"ActiveRecord::Base"`). Configure this _The value must be a String to avoid premature initialization of ActiveRecord._
 
 You’ll generally want to configure these in `config/initializers/good_job.rb`, like so:
 

app/models/good_job/active_record_parent_class.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+module GoodJob
+  ActiveRecordParentClass = if GoodJob.active_record_parent_class
+                              Object.const_get(GoodJob.active_record_parent_class)
+                            else
+                              ActiveRecord::Base
+                            end
+end

app/models/good_job/base_record.rb

@@ -1,13 +1,11 @@
 # frozen_string_literal: true
 
 module GoodJob
-  ACTIVE_RECORD_PARENT_CLASS = Object.const_get(GoodJob.active_record_parent_class)
-
   # Base ActiveRecord class that all GoodJob models inherit from.
   # Parent class can be configured with +GoodJob.active_record_parent_class+.
   # @!parse
   #   class BaseRecord < ActiveRecord::Base; end
-  class BaseRecord < ACTIVE_RECORD_PARENT_CLASS
+  class BaseRecord < ActiveRecordParentClass
     self.abstract_class = true
 
     def self.migration_pending_warning!
@@ -29,5 +27,7 @@ def self.migrated?
       migration_pending_warning!
       false
     end
+
+    ActiveSupport.run_load_hooks(:good_job_base_record, self)
   end
 end

lib/good_job.rb

@@ -47,7 +47,7 @@ module GoodJob
   #   @return [ActiveRecord::Base]
   #   @example Change the base class:
   #     GoodJob.active_record_parent_class = "CustomApplicationRecord"
-  mattr_accessor :active_record_parent_class, default: "ActiveRecord::Base"
+  mattr_accessor :active_record_parent_class, default: nil
 
   # @!attribute [rw] logger
   #   @!scope class
@@ -106,6 +106,19 @@ def self._on_thread_error(exception)
     on_thread_error.call(exception) if on_thread_error.respond_to?(:call)
   end
 
+  # Custom Active Record configuration that is class_eval'ed into +GoodJob::BaseRecord+
+  # @param block Custom Active Record configuration
+  # @retyrn [void]
+  #
+  # @example
+  #   GoodJob.configure_active_record do
+  #     connects_to database: :special_database
+  #   end
+  def self.configure_active_record(&block)
+    self._active_record_configuration = block
+  end
+  mattr_accessor :_active_record_configuration, default: nil
+
   # Stop executing jobs.
   # GoodJob does its work in pools of background threads.
   # When forking processes you should shut down these background threads before forking, and restart them after forking.

lib/good_job/engine.rb

@@ -40,6 +40,14 @@ class Engine < ::Rails::Engine
       end
     end
 
+    initializer 'good_job.active_record' do
+      config.to_prepare do
+        ActiveSupport.on_load :good_job_base_record, run_once: true do
+          GoodJob::BaseRecord.class_eval(&GoodJob._active_record_configuration) if GoodJob._active_record_configuration
+        end
+      end
+    end
+
     initializer "good_job.start_async" do
       # This hooks into the hookable places during Rails boot, which is unfortunately not Rails.application.initialized?
       # If an Adapter is initialized during boot, we want to want to start async executors once the framework dependencies have loaded.