Writing configs_from and tests for application configuration.

Author: wangjohn

activerecord/lib/active_record/application_configuration.rb

@@ -3,6 +3,13 @@ module ApplicationConfiguration
     extend ActiveSupport::Concern
 
     module ClassMethods
+      def configs_from(mod)
+        app_record = self
+        define_singleton_method(:application_record) { |klass = nil| app_record }
+
+        mod.define_singleton_method(:application_record) { |klass = nil| app_record }
+      end
+
       def application_record(klass = nil)
         return base_app_record unless klass
 

activerecord/test/cases/application_configuration_test.rb

@@ -0,0 +1,54 @@
+require 'cases/helper'
+
+module SomeNamespace
+  class ApplicationRecord < ::ApplicationRecord
+    configs_from(SomeNamespace)
+  end
+
+  class SomeModel < ApplicationRecord
+  end
+end
+
+class AnotherModel < ApplicationRecord
+end
+
+class ApplicationConfigurationTest < ActiveRecord::TestCase
+  def test_base_application_record
+    assert_equal ApplicationRecord, ActiveRecord::Base.application_record
+  end
+
+  def test_application_record_method_on_namespace
+    assert_equal SomeNamespace::ApplicationRecord, SomeNamespace::ApplicationRecord.application_record
+    assert_equal ApplicationRecord, ApplicationRecord.application_record
+    assert_nothing_raised do
+      assert_equal SomeNamespace::ApplicationRecord, SomeNamespace::ApplicationRecord.application_record('some_object')
+      assert_equal ApplicationRecord, ApplicationRecord.application_record('some_object')
+    end
+  end
+
+  def test_application_record_method_on_model
+    assert_equal SomeNamespace::ApplicationRecord, SomeNamespace::SomeModel.application_record
+    assert_equal ApplicationRecord, AnotherModel.application_record
+
+    assert_nothing_raised do
+      assert_equal SomeNamespace::ApplicationRecord, SomeNamespace::SomeModel.application_record('another_object')
+      assert_equal ApplicationRecord, AnotherModel.application_record('another_object')
+    end
+  end
+
+  def test_application_record_method_on_module
+    assert_equal SomeNamespace::ApplicationRecord, SomeNamespace.application_record
+    assert_nothing_raised do
+      assert_equal SomeNamespace::ApplicationRecord, SomeNamespace.application_record('one_more_object')
+    end
+  end
+
+  def test_arguments_passed_into_application_record_on_ar_base
+    assert_equal SomeNamespace::ApplicationRecord, ActiveRecord::Base.application_record(SomeNamespace)
+    assert_equal SomeNamespace::ApplicationRecord, ActiveRecord::Base.application_record(SomeNamespace::SomeModel)
+    assert_equal SomeNamespace::ApplicationRecord, ActiveRecord::Base.application_record(SomeNamespace::ApplicationRecord)
+
+    assert_equal ApplicationRecord, ActiveRecord::Base.application_record(AnotherModel)
+    assert_equal ApplicationRecord, ActiveRecord::Base.application_record(ApplicationRecord)
+  end
+end