add :: BuyStockServiceImplTest 테스트 코드 추가

src/test/java/com/juicycool/backend/stock/service/impl/BuyStockServiceImplTest.java

@@ -0,0 +1,108 @@
+package com.juicycool.backend.stock.service.impl;
+
+import com.juicycool.backend.domain.receipt.Receipt;
+import com.juicycool.backend.domain.receipt.repository.ReceiptRepository;
+import com.juicycool.backend.domain.stock.OwnedStocks;
+import com.juicycool.backend.domain.stock.Stock;
+import com.juicycool.backend.domain.stock.exception.InvalidBuyingNumberException;
+import com.juicycool.backend.domain.stock.exception.NotFoundStockException;
+import com.juicycool.backend.domain.stock.exception.PointLowerThanPresentPriceException;
+import com.juicycool.backend.domain.stock.presentation.dto.request.BuyStockRequestDto;
+import com.juicycool.backend.domain.stock.repository.OwnedStocksRepository;
+import com.juicycool.backend.domain.stock.repository.StockRepository;
+import com.juicycool.backend.domain.stock.service.impl.BuyStockServiceImpl;
+import com.juicycool.backend.domain.user.User;
+import com.juicycool.backend.domain.user.util.UserUtil;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.Optional;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.Mockito.*;
+
+class BuyStockServiceImplTest {
+
+    @Mock
+    private StockRepository stockRepository;
+
+    @Mock
+    private OwnedStocksRepository ownedStocksRepository;
+
+    @Mock
+    private UserUtil userUtil;
+
+    @Mock
+    private ReceiptRepository receiptRepository;
+
+    @InjectMocks
+    private BuyStockServiceImpl buyStockService;
+
+    private User mockUser;
+    private Stock mockStock;
+    private BuyStockRequestDto mockDto;
+
+    @BeforeEach
+    void setUp() {
+        MockitoAnnotations.openMocks(this);
+
+        mockUser = User.builder()
+                .points(1000L)
+                .build();
+
+        mockStock = Stock.builder()
+                .code("AAPL")
+                .presentPrice(100L)
+                .build();
+
+        mockDto = new BuyStockRequestDto(5L);
+        when(userUtil.getCurrentUser()).thenReturn(mockUser);
+    }
+
+    @Test
+    @DisplayName("주식 코드로 조회 시, 주식을 찾을 수 없는 경우")
+    void If_you_cant_find_the_stock_when_you_look_it_up_stock_code() {
+        when(stockRepository.findByCode(anyString())).thenReturn(Optional.empty());
+
+        assertThrows(NotFoundStockException.class, () -> buyStockService.execute("AAPL", mockDto));
+    }
+
+    @Test
+    @DisplayName("매수하려는 갯수가 0개 이하인 경우")
+    void If_the_number_of_purchases_to_be_made_is_zero_or_less() {
+        mockDto = new BuyStockRequestDto(0L);
+
+        when(stockRepository.findByCode(anyString())).thenReturn(Optional.of(mockStock));
+
+        assertThrows(InvalidBuyingNumberException.class, () -> buyStockService.execute("AAPL", mockDto));
+    }
+
+    @Test
+    @DisplayName("매수하려는 주식의 총 가격보다 내 포인트가 적은 경우")
+    void If_my_point_is_less_than_the_total_price_of_the_stock() {
+        mockUser = User.builder().points(400L).build();
+        mockStock = Stock.builder().presentPrice(500L).code("AAPL").build();
+
+        when(stockRepository.findByCode(anyString())).thenReturn(Optional.of(mockStock));
+
+        assertThrows(PointLowerThanPresentPriceException.class, () -> buyStockService.execute("AAPL", mockDto));
+    }
+
+
+    @Test
+    @DisplayName("정상적으로 주식이 매수되고 내역에 저장된 경우")
+    void If_the_stock_id_normally_bought_and_stored () {
+        when(stockRepository.findByCode(anyString())).thenReturn(Optional.of(mockStock));
+        when(ownedStocksRepository.findByUserAndStockCode(any(User.class), anyString()))
+                .thenReturn(Optional.empty());
+
+        buyStockService.execute("AAPL", mockDto);
+
+        verify(ownedStocksRepository, times(1)).save(any(OwnedStocks.class));
+        verify(receiptRepository, times(1)).save(any(Receipt.class));
+    }
+}