src/test/java/com/acquirex/approval/service/ApprovalServiceTest.java

@@ -0,0 +1,120 @@
+package com.acquirex.approval.service;
+
+import com.acquirex.approval.domain.ApprovalRequest;
+import com.acquirex.approval.domain.ApprovalRequest.ApprovalStatus;
+import com.acquirex.approval.dto.ApprovalDto.Request;
+import com.acquirex.approval.dto.ApprovalDto.Response;
+import com.acquirex.approval.repository.ApprovalRequestRepository;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.math.BigDecimal;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.*;
+
+@ExtendWith(MockitoExtension.class)
+class ApprovalServiceTest {
+
+    @Mock
+    private ApprovalRequestRepository repository;
+
+    private ApprovalService approvalService;
+
+    @BeforeEach
+    void setUp() {
+        approvalService = new ApprovalService(repository);
+    }
+
+    @Test
+    @DisplayName("Should approve valid request")
+    void processApproval_ValidRequest_ReturnsApproved() {
+        Request dto = new Request("4532123456789012", "MERCHANT001", new BigDecimal("100.00"), "KRW");
+
+        ApprovalRequest savedRequest = new ApprovalRequest(dto.getCardNumber(), dto.getMerchantId(), dto.getAmount(), dto.getCurrency());
+        savedRequest.setId(1L);
+
+        when(repository.save(any(ApprovalRequest.class))).thenReturn(savedRequest);
+
+        Response response = approvalService.processApproval(dto);
+
+        assertNotNull(response);
+        assertEquals(ApprovalStatus.APPROVED, response.getStatus());
+        assertNotNull(response.getApprovalCode());
+        assertTrue(response.getApprovalCode().startsWith("APP-"));
+        verify(repository, times(2)).save(any(ApprovalRequest.class));
+    }
+
+    @Test
+    @DisplayName("Should decline request with invalid amount")
+    void processApproval_InvalidAmount_ReturnsDeclined() {
+        Request dto = new Request("4532123456789012", "MERCHANT001", new BigDecimal("-10.00"), "KRW");
+
+        ApprovalRequest savedRequest = new ApprovalRequest(dto.getCardNumber(), dto.getMerchantId(), dto.getAmount(), dto.getCurrency());
+        savedRequest.setId(1L);
+
+        when(repository.save(any(ApprovalRequest.class))).thenReturn(savedRequest);
+
+        Response response = approvalService.processApproval(dto);
+
+        assertNotNull(response);
+        assertEquals(ApprovalStatus.DECLINED, response.getStatus());
+        assertEquals("Validation failed", response.getMessage());
+    }
+
+    @Test
+    @DisplayName("Should decline request with short card number")
+    void processApproval_ShortCardNumber_ReturnsDeclined() {
+        Request dto = new Request("1234", "MERCHANT001", new BigDecimal("100.00"), "KRW");
+
+        ApprovalRequest savedRequest = new ApprovalRequest(dto.getCardNumber(), dto.getMerchantId(), dto.getAmount(), dto.getCurrency());
+        savedRequest.setId(1L);
+
+        when(repository.save(any(ApprovalRequest.class))).thenReturn(savedRequest);
+
+        Response response = approvalService.processApproval(dto);
+
+        assertNotNull(response);
+        assertEquals(ApprovalStatus.DECLINED, response.getStatus());
+    }
+
+    @Test
+    @DisplayName("Should find approval by ID")
+    void findById_ExistingId_ReturnsRequest() {
+        ApprovalRequest request = new ApprovalRequest("4532123456789012", "MERCHANT001", new BigDecimal("100.00"), "KRW");
+        request.setId(1L);
+        request.setStatus(ApprovalStatus.APPROVED);
+
+        when(repository.findById(1L)).thenReturn(java.util.Optional.of(request));
+
+        ApprovalRequest result = approvalService.findById(1L);
+
+        assertNotNull(result);
+        assertEquals(1L, result.getId());
+        assertEquals(ApprovalStatus.APPROVED, result.getStatus());
+    }
+
+    @Test
+    @DisplayName("Should throw exception for non-existing ID")
+    void findById_NonExistingId_ThrowsException() {
+        when(repository.findById(999L)).thenReturn(java.util.Optional.empty());
+
+        assertThrows(IllegalArgumentException.class, () -> approvalService.findById(999L));
+    }
+
+    @Test
+    @DisplayName("Should count pending approvals")
+    void countPendingApprovals_ReturnsCorrectCount() {
+        when(repository.countByStatus(ApprovalStatus.PENDING)).thenReturn(5L);
+
+        long count = approvalService.countPendingApprovals();
+
+        assertEquals(5L, count);
+        verify(repository).countByStatus(ApprovalStatus.PENDING);
+    }
+}