Don't auto-preload AGAIN during nested renders

Signed-off-by: Jordan Hollinger <[email protected]>

lib/blueprinter-activerecord/preloader.rb

@@ -36,8 +36,8 @@ def initialize(auto: false, use: :preload, &auto_proc)
     # intelligently handles them. There are several unit tests which confirm this behavior.
     #
     def pre_render(object, blueprint, view, options)
-      case object
-      when ActiveRecord::Relation
+      case object.class.name
+      when "ActiveRecord::Relation"
         if object.preload_blueprint_method || auto || auto_proc&.call(object, blueprint, view, options) == true
           object.before_preload_blueprint = extract_preloads object
           blueprint_preloads = self.class.preloads(blueprint, view, object.model)

test/nested_render_test.rb

@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class NestedRenderTest < Minitest::Test
+  def setup
+    DatabaseCleaner.start
+    customer1 = Customer.create!(name: "ACME")
+    customer2 = Customer.create!(name: "FOO")
+    project1 = Project.create!(customer_id: customer1.id, name: "Project A")
+    project2 = Project.create!(customer_id: customer2.id, name: "Project B")
+    category = Category.create!(name: "Foo")
+    ref_plan = RefurbPlan.create!(name: "Plan A")
+    battery1 = LiIonBattery.create!(num_ions: 100, num_other: 100, refurb_plan_id: ref_plan.id)
+    battery2 = LeadAcidBattery.create!(num_lead: 100, num_acid: 100)
+    Widget.create!(customer_id: customer1.id, project_id: project1.id, category_id: category.id, name: "Widget A", battery1: battery1, battery2: battery2)
+    Widget.create!(customer_id: customer1.id, project_id: project1.id, category_id: category.id, name: "Widget B", battery1: battery1)
+    Widget.create!(customer_id: customer2.id, project_id: project2.id, category_id: category.id, name: "Widget C", battery1: battery1)
+    Blueprinter.configure do |config|
+      config.extensions << BlueprinterActiveRecord::Preloader.new(auto: true)
+    end
+    @queries = []
+    @sub = ActiveSupport::Notifications.subscribe 'sql.active_record' do |_name, _started, _finished, _uid, data|
+      @queries << data.fetch(:sql)
+    end
+  end
+
+  def teardown
+    DatabaseCleaner.clean
+    Blueprinter.configure do |config|
+      config.extensions = []
+    end
+    ActiveSupport::Notifications.unsubscribe @sub
+    @queries.clear
+  end
+
+  def test_queries_with_auto
+    ProjectBlueprint.render(Project.all.strict_loading, view: :extended_plus_with_widgets)
+    assert_equal [
+      'SELECT "projects".* FROM "projects"',
+      'SELECT "customers".* FROM "customers" WHERE "customers"."id" IN (?, ?)',
+      'SELECT "widgets".* FROM "widgets" WHERE "widgets"."project_id" IN (?, ?)',
+    ], @queries
+  end
+
+  def test_queries_with_auto_and_nested_render
+    blueprint = Class.new(ProjectBlueprint) do
+      view :widgets_field do
+        field :widgets do |project, options|
+          WidgetBlueprint.render_as_hash(project.widgets, view: :default)
+        end
+      end
+    end
+
+    blueprint.render(Project.all.preload(:widgets).strict_loading, view: :widgets_field)
+    assert_equal [
+      'SELECT "projects".* FROM "projects"',
+      'SELECT "widgets".* FROM "widgets" WHERE "widgets"."project_id" IN (?, ?)',
+    ], @queries
+  end
+end