BAEL-5889: Added code for Spy and SpyBean difference implementation

spring-boot-modules/spring-boot-testing-2/src/test/java/com/baeldung/spytest/OrderServiceIntegrationTest.java

@@ -0,0 +1,32 @@
+package com.baeldung.spytest;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.verify;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.SpyBean;
+
+@SpringBootTest
+class OrderServiceIntegrationTest {
+
+    @Autowired
+    OrderRepository orderRepository;
+    @SpyBean
+    NotificationService notificationService;
+    @SpyBean
+    OrderService orderService;
+
+    @Test
+    void givenNotificationServiceIsUsingSpyBean_whenOrderServiceIsCalled_thenNotificationServiceSpyBeanShouldBeInvoked() {
+
+        Order orderInput = new Order(null, "Test", 1.0, "17 St Andrews Croft, Leeds ,LS17 7TP");
+        Order order = orderService.save(orderInput);
+        Assertions.assertNotNull(order);
+        Assertions.assertNotNull(order.getId());
+        verify(notificationService).notify(any(Order.class));
+    }
+
+}

spring-boot-modules/spring-boot-testing-2/src/test/java/com/baeldung/spytest/OrderServiceUnitTest.java

@@ -0,0 +1,39 @@
+package com.baeldung.spytest;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.verify;
+
+import java.util.UUID;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Spy;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+@ExtendWith(SpringExtension.class)
+class OrderServiceUnitTest {
+
+    @Spy
+    OrderRepository orderRepository;
+    @Spy
+    NotificationService notificationService;
+    @InjectMocks
+    OrderService orderService;
+
+    @Test
+    void givenNotificationServiceIsUsingSpy_whenOrderServiceIsCalled_thenNotificationServiceSpyShouldBeInvoked() {
+
+        UUID orderId = UUID.randomUUID();
+        Order orderInput = new Order(orderId, "Test", 1.0, "17 St Andrews Croft, Leeds ,LS17 7TP");
+        doReturn(orderInput).when(orderRepository)
+            .save(any());
+        Order order = orderService.save(orderInput);
+        Assertions.assertNotNull(order);
+        Assertions.assertEquals(orderId, order.getId());
+        verify(notificationService).notify(any(Order.class));
+    }
+
+}