Add flexible with_adjustable_action trait to Promotion factory

core/lib/spree/testing_support/factories/promotion_factory.rb

@@ -22,23 +22,40 @@
     end
 
     trait :with_action do
-      after(:create) do |promotion, _evaluator|
-        promotion.actions << Spree::Promotion::Actions::CreateAdjustment.new
+      transient do
+        promotion_action_class { Spree::Promotion::Actions::CreateAdjustment }
+      end
+
+      after(:create) do |promotion, evaluator|
+        promotion.actions << evaluator.promotion_action_class.new
       end
     end
 
-    trait :with_line_item_adjustment do
+    trait :with_adjustable_action do
       transient do
-        adjustment_rate { 10 }
+        preferred_amount { 10 }
+        calculator_class { Spree::Calculator::FlatRate }
+        promotion_action_class { Spree::Promotion::Actions::CreateItemAdjustments }
       end
 
       after(:create) do |promotion, evaluator|
-        calculator = Spree::Calculator::FlatRate.new
-        calculator.preferred_amount = evaluator.adjustment_rate
-        Spree::Promotion::Actions::CreateItemAdjustments.create!(calculator: calculator, promotion: promotion)
+        calculator = evaluator.calculator_class.new
+        calculator.preferred_amount = evaluator.preferred_amount
+        evaluator.promotion_action_class.create!(calculator: calculator, promotion: promotion)
       end
     end
 
+    factory :promotion_with_action_adjustment, traits: [:with_adjustable_action]
+
+    trait :with_line_item_adjustment do
+      transient do
+        adjustment_rate { 10 }
+      end
+
+      with_adjustable_action
+      preferred_amount { adjustment_rate }
+    end
+
     factory :promotion_with_item_adjustment, traits: [:with_line_item_adjustment]
 
     trait :with_free_shipping do
@@ -52,14 +69,11 @@
         weighted_order_adjustment_amount { 10 }
       end
 
-      after(:create) do |promotion, evaluator|
-        calculator = Spree::Calculator::FlatRate.new
-        calculator.preferred_amount = evaluator.weighted_order_adjustment_amount
-        action = Spree::Promotion::Actions::CreateAdjustment.create!(calculator: calculator)
-        promotion.actions << action
-        promotion.save!
-      end
+      with_adjustable_action
+      preferred_amount { weighted_order_adjustment_amount }
+      promotion_action_class { Spree::Promotion::Actions::CreateAdjustment }
     end
+
     factory :promotion_with_order_adjustment, traits: [:with_order_adjustment]
 
     trait :with_item_total_rule do

core/spec/lib/spree/core/testing_support/factories/promotion_factory_spec.rb

@@ -11,6 +11,12 @@
     it_behaves_like 'a working factory'
   end
 
+  describe 'promotion with action adjustment' do
+    let(:factory) { :promotion_with_action_adjustment }
+
+    it_behaves_like 'a working factory'
+  end
+
   describe 'promotion with item adjustment' do
     let(:factory) { :promotion_with_item_adjustment }