Update transaction fees of completed orders

The adjustments associated to incomplete payments are re-calculated when
a line item is removed from a completed order.

app/controllers/line_items_controller.rb

@@ -31,6 +31,7 @@ class LineItemsController < BaseController
     order.with_lock do
       item.destroy
       order.update_shipping_fees!
+      order.update_payment_fees!
       order.update_distribution_charge!
     end
   end

app/models/spree/order_decorator.rb

@@ -144,14 +144,22 @@ Spree::Order.class_eval do
     line_items(:reload)
     shipments.each do |shipment|
       next if shipment.shipped?
-      adjustment = shipment.adjustment
-      locked = adjustment.locked
-      adjustment.locked = false
-      adjustment.update!
-      adjustment.locked = locked
-      update_totals
-      save
+      update_adjustment! shipment.adjustment
     end
+    update_totals
+    save
+  end
+
+  # After changing line items of a completed order
+  def update_payment_fees!
+    payments(:reload)
+    line_items(:reload)
+    payments.each do |payment|
+      next if payment.completed?
+      update_adjustment! payment.adjustment
+    end
+    update_totals
+    save
   end
 
   def cap_quantity_at_stock!
@@ -333,4 +341,11 @@ Spree::Order.class_eval do
       self.customer = Customer.create(enterprise: distributor, email: email_for_customer, user: user, name: customer_name, bill_address: bill_address.andand.clone, ship_address: ship_address.andand.clone)
     end
   end
+
+  def update_adjustment!(adjustment)
+    locked = adjustment.locked
+    adjustment.locked = false
+    adjustment.update!
+    adjustment.locked = locked
+  end
 end

spec/controllers/line_items_controller_spec.rb

@@ -68,8 +68,8 @@ describe LineItemsController do
 
     # Sanity check fees
     item_num = order.line_items.length
-    expected_fees = item_num * (shipping_fee + payment_fee)
-    expect(order.adjustment_total).to eq expected_fees
+    initial_fees = item_num * (shipping_fee + payment_fee)
+    expect(order.adjustment_total).to eq initial_fees
 
     # Delete the item
     item = order.line_items.first
@@ -80,6 +80,6 @@ describe LineItemsController do
 
     # Check the fees again
     order.reload
-    expect(order.adjustment_total).to eq expected_fees - shipping_fee
+    expect(order.adjustment_total).to eq initial_fees - shipping_fee - payment_fee
   end
 end

spec/factories.rb

@@ -271,7 +271,7 @@ FactoryGirl.define do
       order.create_shipment!
       payment_calculator = build(:calculator_per_item, preferred_amount: evaluator.payment_fee)
       payment_method = create(:payment_method, calculator: payment_calculator)
-      create(:payment, order: order, amount: order.total, payment_method: payment_method, state: 'completed')
+      create(:payment, order: order, amount: order.total, payment_method: payment_method, state: 'checkout')
       order.finalize!
     end
   end

spec/models/spree/order_spec.rb

@@ -674,6 +674,20 @@ describe Spree::Order do
       expect(order.line_items.length).to eq item_num - 1
       expect(order.adjustment_total).to eq expected_fees - shipping_fee
     end
+
+    it "updates transaction fees" do
+      item_num = order.line_items.length
+      initial_fees = item_num * (shipping_fee + payment_fee)
+
+      # Delete the item
+      order.line_items.first.destroy
+      order.update_payment_fees!
+
+      # Check if fees got updated
+      expect(order.adjustments.length).to eq 2
+      expect(order.line_items.length).to eq item_num - 1
+      expect(order.adjustment_total).to eq initial_fees - payment_fee
+    end
   end
 
   describe "retrieving previously ordered items" do