""" Property-Based Tests for Disbursed Loans Report Filtering (Task 2.3) Feature: comprehensive-reports-and-fixes Tests Properties 1 and 2 from the design document. These tests use hypothesis to verify filtering logic works correctly across all possible inputs. """ import os import sys import django from decimal import Decimal from datetime import datetime, timedelta, date # Setup Django os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'branch_system.settings') django.setup() from django.test import TestCase, RequestFactory from django.contrib.auth import get_user_model from django.utils import timezone from hypothesis import given, strategies as st, settings, assume from hypothesis.extra.django import TestCase as HypothesisTestCase from loans.models import Loan, LoanApplication, LoanProduct from users.models import Branch User = get_user_model() class DisbursedLoansFilteringPropertiesTest(HypothesisTestCase): """ Property-based tests for disbursed loans report filtering logic. **Validates: Requirements 1.2, 1.4, 1.5, 1.6** """ @classmethod def setUpClass(cls): super().setUpClass() # Create test data that will be reused cls.factory = RequestFactory() # Create test user with staff permissions cls.user = User.objects.create_user( username='test_staff', email='staff@test.com', password='testpass123', role='admin', is_staff=True, is_superuser=True ) # Create test branch cls.branch = Branch.objects.create( name='Test Branch', code='TB001', is_active=True ) # Create test loan product cls.loan_product = LoanProduct.objects.create( name='Test Product', product_type='boost', description='Test loan product', min_amount=Decimal('1000.00'), max_amount=Decimal('100000.00'), interest_rate=Decimal('10.00'), processing_fee=Decimal('5.00'), min_duration=7, max_duration=90, available_repayment_methods=['monthly'], is_active=True ) # Create test borrower cls.borrower = User.objects.create_user( username='test_borrower', email='borrower@test.com', password='testpass123', role='borrower', first_name='Test', last_name='Borrower', phone_number='+254700000000', branch=cls.branch ) def tearDown(self): """Clean up test data after each test""" # Delete loans and applications created during tests Loan.objects.filter(borrower=self.borrower).delete() LoanApplication.objects.filter(borrower=self.borrower).delete() def create_test_loan(self, status, disbursement_date): """Helper method to create a test loan with specific status and disbursement date""" # Create loan application application = LoanApplication.objects.create( borrower=self.borrower, loan_product=self.loan_product, requested_amount=Decimal('10000.00'), requested_duration=30, purpose='Test loan', repayment_method='monthly', status='approved' ) # Create loan loan = Loan.objects.create( application=application, borrower=self.borrower, principal_amount=Decimal('10000.00'), interest_amount=Decimal('1000.00'), processing_fee=Decimal('500.00'), total_amount=Decimal('11500.00'), disbursement_date=disbursement_date, due_date=disbursement_date + timedelta(days=30), duration_days=30, status=status, is_deleted=False ) return loan @settings(max_examples=50, deadline=None) @given( status=st.sampled_from(['active', 'paid', 'defaulted', 'rolled_over', 'written_off', 'pending']) ) def test_property_1_disbursed_loans_filter_correctness(self, status): """ **Property 1: Disbursed Loans Filter Correctness** For any set of loans in the database, when the disbursed loans report is filtered by status, the results should only include loans with status in ['active', 'paid', 'defaulted', 'rolled_over', 'written_off']. **Validates: Requirements 1.2** """ # Create a loan with the given status disbursement_date = datetime.now() loan = self.create_test_loan(status, disbursement_date) # Define disbursed statuses disbursed_statuses = ['active', 'paid', 'defaulted', 'rolled_over', 'written_off'] # Query loans using the same logic as the view loans = Loan.objects.filter( status__in=disbursed_statuses, is_deleted=False ) # Property: All returned loans must have status in disbursed_statuses for loan_obj in loans: assert loan_obj.status in disbursed_statuses, \ f"Loan {loan_obj.loan_number} has status '{loan_obj.status}' which is not in disbursed_statuses" # Property: If loan status is in disbursed_statuses, it should be included if status in disbursed_statuses: assert loans.filter(id=loan.id).exists(), \ f"Loan with status '{status}' should be included in disbursed loans" else: # If status is not in disbursed_statuses, it should NOT be included assert not loans.filter(id=loan.id).exists(), \ f"Loan with status '{status}' should NOT be included in disbursed loans" @settings(max_examples=50, deadline=None) @given( days_offset=st.integers(min_value=-30, max_value=30), filter_period=st.sampled_from(['today', 'this_week', 'total']) ) def test_property_2_date_filtering_accuracy(self, days_offset, filter_period): """ **Property 2: Date Filtering Accuracy** For any date range (start_date, end_date) and any set of loans, when filtering by date range, all returned loans should have disbursement_date >= start_date AND disbursement_date <= end_date, and all loans meeting this criteria should be included. **Validates: Requirements 1.4, 1.5, 1.6** """ # Create a loan with disbursement date offset from today today = date.today() disbursement_date = datetime.combine(today + timedelta(days=days_offset), datetime.min.time()) loan = self.create_test_loan('active', disbursement_date) # Apply period filter logic from the view if filter_period == 'today': # Filter loans disbursed today start_date = today end_date = today loans = Loan.objects.filter( status__in=['active', 'paid', 'defaulted', 'rolled_over', 'written_off'], is_deleted=False, disbursement_date__date=today ) elif filter_period == 'this_week': # Filter loans disbursed this week (Monday to Sunday) week_start = today - timedelta(days=today.weekday()) week_end = week_start + timedelta(days=6) start_date = week_start end_date = week_end loans = Loan.objects.filter( status__in=['active', 'paid', 'defaulted', 'rolled_over', 'written_off'], is_deleted=False, disbursement_date__date__gte=week_start, disbursement_date__date__lte=week_end ) else: # 'total' means no date filter start_date = None end_date = None loans = Loan.objects.filter( status__in=['active', 'paid', 'defaulted', 'rolled_over', 'written_off'], is_deleted=False ) # Get the loan's disbursement date as a date object loan_disbursement_date = loan.disbursement_date.date() if hasattr(loan.disbursement_date, 'date') else loan.disbursement_date # Property: All returned loans must have disbursement_date within the filter range for loan_obj in loans: loan_date = loan_obj.disbursement_date.date() if hasattr(loan_obj.disbursement_date, 'date') else loan_obj.disbursement_date if filter_period == 'today': assert loan_date == today, \ f"Loan {loan_obj.loan_number} disbursed on {loan_date} should match today {today}" elif filter_period == 'this_week': assert start_date <= loan_date <= end_date, \ f"Loan {loan_obj.loan_number} disbursed on {loan_date} should be within week range {start_date} to {end_date}" # For 'total', no date constraint # Property: If loan meets the date criteria, it should be included if filter_period == 'today': if loan_disbursement_date == today: assert loans.filter(id=loan.id).exists(), \ f"Loan disbursed today ({loan_disbursement_date}) should be included in 'today' filter" else: assert not loans.filter(id=loan.id).exists(), \ f"Loan disbursed on {loan_disbursement_date} should NOT be included in 'today' filter" elif filter_period == 'this_week': if start_date <= loan_disbursement_date <= end_date: assert loans.filter(id=loan.id).exists(), \ f"Loan disbursed on {loan_disbursement_date} should be included in 'this_week' filter ({start_date} to {end_date})" else: assert not loans.filter(id=loan.id).exists(), \ f"Loan disbursed on {loan_disbursement_date} should NOT be included in 'this_week' filter ({start_date} to {end_date})" elif filter_period == 'total': # All disbursed loans should be included regardless of date assert loans.filter(id=loan.id).exists(), \ f"Loan should be included in 'total' filter regardless of disbursement date" if __name__ == '__main__': import unittest # Run the tests suite = unittest.TestLoader().loadTestsFromTestCase(DisbursedLoansFilteringPropertiesTest) runner = unittest.TextTestRunner(verbosity=2) result = runner.run(suite) # Exit with appropriate code sys.exit(0 if result.wasSuccessful() else 1)