Improve tests found by assert_nil

test/action_controller/serialization_scope_name_test.rb

@@ -33,7 +33,8 @@ module SerializationScopeTesting
     end
   end
   class PostTestController < ActionController::Base
-    attr_accessor :current_user
+    attr_writer :current_user
+
     def render_post_by_non_admin
       self.current_user = User.new(id: 3, name: 'Pete', admin: false)
       render json: new_post, serializer: serializer, adapter: :json
@@ -44,6 +45,10 @@ module SerializationScopeTesting
       render json: new_post, serializer: serializer, adapter: :json
     end
 
+    def current_user
+      defined?(@current_user) ? @current_user : :current_user_not_set
+    end
+
     private
 
     def new_post
@@ -75,10 +80,8 @@ module SerializationScopeTesting
     end
 
     def test_default_serialization_scope_object
-      expected = @controller.current_user
-      actual = @controller.serialization_scope
-      assert_nil expected
-      assert_nil actual
+      assert_equal :current_user_not_set, @controller.current_user
+      assert_equal :current_user_not_set, @controller.serialization_scope
     end
 
     def test_default_scope_non_admin
@@ -128,7 +131,7 @@ module SerializationScopeTesting
     end
 
     def test_defined_serialization_scope_object
-      assert_equal @controller.view_context.class, @controller.serialization_scope.class
+      assert_equal @controller.view_context.controller, @controller.serialization_scope.controller
     end
 
     def test_serialization_scope_non_admin

test/active_model_serializers/railtie_test_isolated.rb

@@ -4,11 +4,13 @@ require 'support/isolated_unit'
 class RailtieTest < ActiveSupport::TestCase
   include ActiveSupport::Testing::Isolation
 
-  class WithRails < RailtieTest
+  class WithRailsRequiredFirst < RailtieTest
     setup do
       require 'rails'
       require 'active_model_serializers'
-      make_basic_app
+      make_basic_app do |app|
+        app.config.action_controller.perform_caching = true
+      end
     end
 
     test 'mixes ActionController::Serialization into ActionController::Base' do
@@ -32,17 +34,17 @@ class RailtieTest < ActiveSupport::TestCase
 
     test 'it is configured for caching' do
       assert_equal ActionController::Base.cache_store, ActiveModelSerializers.config.cache_store
-      expected = Rails.configuration.action_controller.perform_caching
-      actual = ActiveModelSerializers.config.perform_caching
-      assert_nil expected
-      assert_nil actual
+      assert_equal true, Rails.configuration.action_controller.perform_caching
+      assert_equal true, ActiveModelSerializers.config.perform_caching
     end
   end
 
-  class WithoutRails < RailtieTest
+  class WithoutRailsRequiredFirst < RailtieTest
     setup do
       require 'active_model_serializers'
-      make_basic_app
+      make_basic_app do |app|
+        app.config.action_controller.perform_caching = true
+      end
     end
 
     test 'does not mix ActionController::Serialization into ActionController::Base' do
@@ -59,8 +61,8 @@ class RailtieTest < ActiveSupport::TestCase
     test 'it is not configured for caching' do
       refute_nil ActionController::Base.cache_store
       assert_nil ActiveModelSerializers.config.cache_store
-      refute Rails.configuration.action_controller.perform_caching
-      refute ActiveModelSerializers.config.perform_caching
+      assert_equal true, Rails.configuration.action_controller.perform_caching
+      assert_nil ActiveModelSerializers.config.perform_caching
     end
   end
 end