fix financials

tests/app/Libraries/RefundEligibilityServiceTest.php

@@ -0,0 +1,95 @@
+<?php
+
+namespace Tests\App\Libraries;
+
+use App\Libraries\RefundEligibilityService;
+use CodeIgniter\Test\CIUnitTestCase;
+
+class RefundEligibilityServiceHarness extends RefundEligibilityService
+{
+    public function __construct(
+        private int $sourceCreditCents,
+        private int $completedPayoutCents,
+        private int $reservedAmountCents
+    ) {
+    }
+
+    protected function calculateSourceCreditCents(int $parentId, ?int $invoiceId, string $sourceType, int $sourceId): int
+    {
+        return $this->sourceCreditCents;
+    }
+
+    protected function calculateCompletedPayoutCents(string $sourceType, int $sourceId, ?int $excludeRefundId): int
+    {
+        return $this->completedPayoutCents;
+    }
+
+    protected function calculateReservedAmountCents(string $sourceType, int $sourceId, ?int $excludeRefundId): int
+    {
+        return $this->reservedAmountCents;
+    }
+}
+
+class RefundEligibilityServiceTest extends CIUnitTestCase
+{
+    public function testInvoiceOverpaymentAvailableCreditDoesNotDoubleSubtractCompletedPayouts(): void
+    {
+        $service = new RefundEligibilityServiceHarness(10000, 2500, 1500);
+
+        $result = $service->calculateAvailableCredit(10, 20, 'invoice_overpayment', 20);
+
+        $this->assertSame(10000, $result->sourceCreditCents);
+        $this->assertSame(0, $result->completedPayoutCents);
+        $this->assertSame(1500, $result->reservedAmountCents);
+        $this->assertSame(8500, $result->availableAmountCents);
+        $this->assertNotContains('HAS_COMPLETED_PAYOUTS', $result->reasonCodes);
+        $this->assertContains('HAS_APPROVED_RESERVATIONS', $result->reasonCodes);
+    }
+
+    public function testPaymentSourceAvailableCreditSubtractsCompletedPayoutsAndReservations(): void
+    {
+        $service = new RefundEligibilityServiceHarness(10000, 2500, 1500);
+
+        $result = $service->calculateAvailableCredit(10, 20, 'payment_duplicate', 77);
+
+        $this->assertSame(10000, $result->sourceCreditCents);
+        $this->assertSame(2500, $result->completedPayoutCents);
+        $this->assertSame(1500, $result->reservedAmountCents);
+        $this->assertSame(6000, $result->availableAmountCents);
+        $this->assertContains('HAS_COMPLETED_PAYOUTS', $result->reasonCodes);
+        $this->assertContains('HAS_APPROVED_RESERVATIONS', $result->reasonCodes);
+    }
+
+    public function testValidateRejectsAmountAboveAvailableCredit(): void
+    {
+        $service = new RefundEligibilityServiceHarness(10000, 7000, 1000);
+        $result = $service->calculateAvailableCredit(10, 20, 'payment_duplicate', 20);
+
+        $this->expectException(\RuntimeException::class);
+        $this->expectExceptionMessage('Refund amount exceeds available source credit.');
+
+        $service->validateRequestedAmount($result, 2500);
+    }
+
+    public function testValidateRejectsNonPositiveAmount(): void
+    {
+        $service = new RefundEligibilityServiceHarness(10000, 0, 0);
+        $result = $service->calculateAvailableCredit(10, 20, 'invoice_overpayment', 20);
+
+        $this->expectException(\RuntimeException::class);
+        $this->expectExceptionMessage('Refund amount must be greater than zero.');
+
+        $service->validateRequestedAmount($result, 0);
+    }
+
+    public function testZeroAvailableCreditCarriesReasonCodes(): void
+    {
+        $service = new RefundEligibilityServiceHarness(0, 0, 0);
+
+        $result = $service->calculateAvailableCredit(10, 20, 'invoice_overpayment', 20);
+
+        $this->assertSame(0, $result->availableAmountCents);
+        $this->assertContains('NO_SOURCE_CREDIT', $result->reasonCodes);
+        $this->assertContains('NO_AVAILABLE_CREDIT', $result->reasonCodes);
+    }
+}