From a0097cd70181465564f07b223ed069e6f6d23cd9 Mon Sep 17 00:00:00 2001
From: Ryuta Kamizono <kamipo@gmail.com>
Date: Sun, 28 Mar 2021 10:48:56 +0900
Subject: [PATCH] Add test case for class level `strict_loading_mode`

---
 activerecord/lib/active_record/core.rb        |  2 +-
 .../test/cases/strict_loading_test.rb         | 47 ++++++++++++++++++-
 2 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index 1731a51691..cf7ffbe1f0 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -140,7 +140,7 @@ module ActiveRecord
       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
 
diff --git a/activerecord/test/cases/strict_loading_test.rb b/activerecord/test/cases/strict_loading_test.rb
index 7f5253ce14..3ea04ae1d3 100644
--- a/activerecord/test/cases/strict_loading_test.rb
+++ b/activerecord/test/cases/strict_loading_test.rb
@@ -38,7 +38,7 @@ class StrictLoadingTest < ActiveRecord::TestCase
     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 @@ class StrictLoadingTest < ActiveRecord::TestCase
     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? }