""" Test to verify the rollover loan total amount calculation fix. This test ensures that the rollover_fee is not double-counted in the total_amount. """ from decimal import Decimal from datetime import timedelta from django.utils import timezone from django.contrib.auth import get_user_model from loans.models import LoanProduct, LoanApplication, Loan, RolloverRequest import sys User = get_user_model() def test_rollover_total_amount_fix(): """Test that rollover_fee is not double-counted in total_amount""" print("\n" + "="*70) print("TESTING ROLLOVER TOTAL AMOUNT CALCULATION FIX") print("="*70) # 1. Create test borrower print("\n1. Creating test borrower...") borrower = User.objects.create( username=f'test_rollover_borrower_{timezone.now().timestamp()}', email='test_rollover@example.com', role='borrower', first_name='Test', last_name='Rollover', phone_number='0712345678', id_number='12345678' ) print(f" ✓ Created borrower: {borrower.get_full_name()}") # 2. Create loan product print("\n2. Creating loan product...") loan_product, created = LoanProduct.objects.get_or_create( name='Test Boost', defaults={ 'product_type': 'boost', 'interest_rate': 20.0, # 20% 'processing_fee': 2.0, # 2% 'min_amount': 1000, 'max_amount': 50000, 'min_duration': 30, 'max_duration': 90, 'rollover_fee_percentage': 10.0, # 10% rollover fee } ) print(f" ✓ Using loan product: {loan_product.name}") # 3. Create original loan print("\n3. Creating original loan...") principal = Decimal('10000.00') interest = Decimal('2000.00') # 20% of 10,000 processing_fee = Decimal('200.00') # 2% of 10,000 application = LoanApplication.objects.create( borrower=borrower, loan_product=loan_product, requested_amount=principal, requested_duration=30, purpose='Test loan for rollover', repayment_method='monthly', interest_amount=interest, processing_fee_amount=processing_fee, total_amount=principal + interest + processing_fee, status='approved' ) loan = Loan.objects.create( application=application, borrower=borrower, principal_amount=principal, interest_amount=interest, processing_fee=processing_fee, total_amount=principal + interest + processing_fee, disbursement_date=timezone.now(), due_date=timezone.now() + timedelta(days=30), duration_days=30, status='active' ) original_total = loan.total_amount print(f" ✓ Created loan: {loan.loan_number}") print(f" - Principal: KES {principal:,.2f}") print(f" - Interest: KES {interest:,.2f}") print(f" - Processing Fee: KES {processing_fee:,.2f}") print(f" - Total Amount: KES {original_total:,.2f}") # 4. Create rollover request print("\n4. Creating rollover request...") rollover_fee = Decimal('1000.00') # 10% of 10,000 rollover_request = RolloverRequest.objects.create( loan=loan, borrower=borrower, requested_amount=principal, # Rolling over same amount requested_duration=30, reason='Testing rollover calculation', rollover_fee=rollover_fee, status='pending' ) print(f" ✓ Created rollover request with fee: KES {rollover_fee:,.2f}") # 5. Approve rollover print("\n5. Approving rollover...") admin_user = User.objects.filter(role='admin').first() if not admin_user: admin_user = User.objects.create( username='admin_test', email='admin@test.com', role='admin', first_name='Admin', last_name='User' ) new_loan = rollover_request.approve( approved_by=admin_user, notes='Test rollover approval' ) print(f" ✓ Rollover approved, new loan created: {new_loan.loan_number}") # 6. Verify the calculations print("\n6. VERIFICATION:") print("-" * 70) new_principal = new_loan.principal_amount new_interest = new_loan.interest_amount new_processing_fee = new_loan.processing_fee new_total = new_loan.total_amount print(f" New Loan Components:") print(f" - Principal Amount: KES {new_principal:,.2f}") print(f" - Interest Amount: KES {new_interest:,.2f}") print(f" - Processing Fee: KES {new_processing_fee:,.2f}") print(f" (includes rollover fee of KES {rollover_fee:,.2f})") print(f" - Total Amount: KES {new_total:,.2f}") # Calculate expected values expected_processing_fee = processing_fee + rollover_fee # 200 + 1000 = 1200 expected_total = new_principal + new_interest + new_processing_fee # Note: processing_fee should already include rollover_fee, so we don't add it again expected_total_correct = new_principal + new_interest + expected_processing_fee print(f"\n Expected Calculations:") print(f" - Expected Processing Fee: KES {expected_processing_fee:,.2f}") print(f" (processing_fee {processing_fee} + rollover_fee {rollover_fee})") print(f" - Expected Total: KES {expected_total_correct:,.2f}") print(f" (principal {new_principal} + interest {new_interest} + processing_fee {expected_processing_fee})") # Verify processing fee includes rollover fee print(f"\n Checks:") processing_fee_check = new_processing_fee == expected_processing_fee print(f" ✓ Processing fee includes rollover fee: {processing_fee_check}") if not processing_fee_check: print(f" ERROR: Expected {expected_processing_fee}, got {new_processing_fee}") # Verify total amount is correct (NOT double-counting rollover_fee) total_check = new_total == expected_total_correct print(f" ✓ Total amount is correct (no double-counting): {total_check}") if not total_check: print(f" ERROR: Expected {expected_total_correct}, got {new_total}") print(f" Difference: {new_total - expected_total_correct}") # Additional check: Ensure total_amount equals sum of components component_sum = new_principal + new_interest + new_processing_fee component_check = new_total == component_sum print(f" ✓ Total equals sum of components: {component_check}") if not component_check: print(f" ERROR: Expected {component_sum}, got {new_total}") # Final verdict print("\n" + "="*70) if processing_fee_check and total_check and component_check: print("✓ TEST PASSED: Rollover fee is not double-counted!") print("="*70) return True else: print("✗ TEST FAILED: Rollover calculation is incorrect!") print("="*70) return False # Cleanup new_loan.delete() loan.delete() application.delete() rollover_request.delete() borrower.delete() if __name__ == '__main__': try: result = test_rollover_total_amount_fix() sys.exit(0 if result else 1) except Exception as e: print(f"\n✗ TEST ERROR: {str(e)}") import traceback traceback.print_exc() sys.exit(1)