fix: Credit note calculation with trial period

app/services/credit_notes/create_from_termination.rb

@@ -77,7 +77,7 @@ def remaining_duration
         billed_from = if subscription.trial_end_date > to_date
           to_date
         else
-          subscription.trial_end_date
+          subscription.trial_end_date - 1.day
         end
       end
 

spec/scenarios/invoices/invoices_spec.rb

@@ -25,7 +25,7 @@
     let(:plan) { create(:plan, organization:, amount_cents: 3500, pay_in_advance: true, trial_period: 7) }
 
     it 'creates an invoice for the expected period' do
-      travel_to(DateTime.new(2024, 3, 2)) do
+      travel_to(DateTime.new(2024, 3, 4, 21)) do
         create_subscription(
           {
             external_customer_id: customer.external_id,
@@ -37,14 +37,17 @@
 
       subscription = customer.subscriptions.first
       invoice = subscription.invoices.first
-      expect(invoice.total_amount_cents).to eq(2597) # (31 - 1 - 7) * 35 / 31
+      expect(invoice.total_amount_cents).to eq(2371) # (31 - 3 - 7) * 35 / 31
 
-      travel_to(DateTime.new(2024, 3, 3)) do
+      travel_to(DateTime.new(2024, 3, 5, 3)) do
         terminate_subscription(subscription)
       end
 
-      invoice = subscription.invoices.order(created_at: :desc).first
-      expect(invoice.total_amount_cents).to eq(0)
+      term_invoice = subscription.invoices.order(created_at: :desc).first
+      expect(term_invoice.total_amount_cents).to eq(0)
+
+      expect(invoice.reload.credit_notes.count).to eq(1)
+      expect(invoice.credit_notes.first.total_amount_cents).to eq(2371)
 
       travel_to(DateTime.new(2024, 3, 5, 4)) do
         create_subscription(
@@ -57,8 +60,7 @@
 
         subscription = customer.subscriptions.active.first
         invoice = subscription.invoices.first
-        # NOTE: 4 days of trial left
-        expect(invoice.fees_amount_cents).to eq(2597) # (31 - 4 - 4) * 35 / 31
+        expect(invoice.fees_amount_cents).to eq(2371) # (31 - 4 - 6) * 35 / 31
       end
     end
   end

spec/services/credit_notes/create_from_termination_spec.rb

@@ -217,11 +217,11 @@
           credit_note = result.credit_note
           expect(credit_note).to be_available
           expect(credit_note).to be_order_change
-          expect(credit_note.total_amount_cents).to eq(17)
+          expect(credit_note.total_amount_cents).to eq(18) # 15 * 1.2
           expect(credit_note.total_amount_currency).to eq('EUR')
-          expect(credit_note.credit_amount_cents).to eq(17)
+          expect(credit_note.credit_amount_cents).to eq(18)
           expect(credit_note.credit_amount_currency).to eq('EUR')
-          expect(credit_note.balance_amount_cents).to eq(17)
+          expect(credit_note.balance_amount_cents).to eq(18)
           expect(credit_note.balance_amount_currency).to eq('EUR')
 
           expect(credit_note.items.count).to eq(1)