[Order API TDD] test: StubClass to using Mockito

product-order-service/src/test/java/com/example/productorderservice/product/ProductServiceTest.java

@@ -3,45 +3,32 @@
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mockito;
+import org.mockito.junit.jupiter.MockitoExtension;
 
+@ExtendWith(MockitoExtension.class)
 public class ProductServiceTest {
 
     private ProductService productService;
-    private StubProductPort productPort = new StubProductPort();
+    private ProductPort productPort;
 
     @BeforeEach
     void setUp() {
+        productPort = Mockito.mock(ProductPort.class);
         productService = new ProductService(productPort);
     }
 
     @Test
     void updateProduct() {
         final Long productId = 1L;
-        final String name = "상품 수정";
-        int price = 2000;
-        final DiscountPolicy discountPolicy = DiscountPolicy.NONE;
-        final UpdateProductRequest request = new UpdateProductRequest(name, price, discountPolicy);
+        final UpdateProductRequest request = new UpdateProductRequest("상품 수정", 2000, DiscountPolicy.NONE);
         final Product product = new Product("상품명", 1000, DiscountPolicy.NONE);
-        productPort.getProduct_will_return = product;
+        Mockito.when(productPort.getProduct(productId)).thenReturn(product);
 
         productService.updateProduct(productId, request);
 
         Assertions.assertEquals("상품 수정", product.getName());
         Assertions.assertEquals(2000, product.getPrice());
     }
-
-    private class StubProductPort implements ProductPort {
-
-        public Product getProduct_will_return;
-
-        @Override
-        public void save(final Product product) {
-            throw new UnsupportedOperationException("StubProductPort#save not implemented yet !!");
-        }
-
-        @Override
-        public Product getProduct(final long productId) {
-            return getProduct_will_return;
-        }
-    }
 }