Add test case for class level strict_loading_mode

Author: kamipo

activerecord/lib/active_record/core.rb

@@ -140,7 +140,7 @@ def self.configurations
       mattr_accessor :action_on_strict_loading_violation, instance_accessor: false, default: :raise
 
       class_attribute :strict_loading_by_default, instance_accessor: false, default: false
-      class_attribute :strict_loading_mode, instance_accessor: true, default: []
+      class_attribute :strict_loading_mode, instance_accessor: true, default: :all
 
       mattr_accessor :writing_role, instance_accessor: false, default: :writing
 

activerecord/test/cases/strict_loading_test.rb

@@ -38,7 +38,7 @@ def test_strict_loading_n_plus_one_only_mode
     developer = Developer.first
     ship = Ship.first
     ShipPart.create!(name: "Stern", ship: ship)
-    firm = Firm.create!("name" => "NASA")
+    firm = Firm.create!(name: "NASA")
     project = Project.create!(name: "Apollo", firm: firm)
 
     ship.update_column(:developer_id, developer.id)
@@ -73,6 +73,51 @@ def test_strict_loading_n_plus_one_only_mode
     end
   end
 
+  def test_strict_loading_n_plus_one_only_mode_by_default
+    with_strict_loading_by_default(Developer) do
+      previous_strict_loading_mode = Developer.strict_loading_mode
+      Developer.strict_loading_mode = :n_plus_one_only
+
+      developer = Developer.first
+      ship = Ship.first
+      ShipPart.create!(name: "Stern", ship: ship)
+      firm = Firm.create!(name: "NASA")
+      project = Project.create!(name: "Apollo", firm: firm)
+
+      ship.update_column(:developer_id, developer.id)
+      developer.projects << project
+      developer.reload
+
+      assert_predicate developer, :strict_loading?
+
+      # Does not raise when loading a has_many association (:projects)
+      assert_nothing_raised do
+        developer.projects.to_a
+      end
+
+      # strict_loading is enabled for has_many associations
+      assert developer.projects.all?(&:strict_loading?)
+      assert_raises ActiveRecord::StrictLoadingViolationError do
+        developer.projects.last.firm
+      end
+
+      # Does not raise when a belongs_to association (:ship) loads its
+      # has_many association (:parts)
+      assert_nothing_raised do
+        developer.ship.parts.to_a
+      end
+
+      # strict_loading is enabled for has_many through a belongs_to
+      assert_not developer.ship.strict_loading?
+      assert developer.ship.parts.all?(&:strict_loading?)
+      assert_raises ActiveRecord::StrictLoadingViolationError do
+        developer.ship.parts.first.trinkets.to_a
+      end
+    ensure
+      Developer.strict_loading_mode = previous_strict_loading_mode
+    end
+  end
+
   def test_strict_loading
     Developer.all.each { |d| assert_not d.strict_loading? }
     Developer.strict_loading.each { |d| assert d.strict_loading? }