BAEL-9322 What is @MockitoSpyBean in Spring

Author: Saber-k

spring-boot-modules/pom.xml

@@ -94,6 +94,7 @@
         <module>spring-boot-testing-2</module>
         <module>spring-boot-testing-3</module>
         <module>spring-boot-testing-4</module>
+        <module>spring-boot-testing-5</module>
         <module>spring-boot-testing-spock</module>
         <module>spring-boot-vue</module>
         <module>spring-boot-actuator</module>

spring-boot-modules/spring-boot-testing-5/pom.xml

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>com.baeldung.spring-boot-modules</groupId>
+        <artifactId>spring-boot-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>spring-boot-testing-5</artifactId>
+
+    <properties>
+        <java.version>21</java.version>
+        <junit-jupiter.version>5.12.2</junit-jupiter.version>
+        <logback.version>1.5.20</logback.version>
+        <spring-boot.version>3.5.7</spring-boot.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+</project>

spring-boot-modules/spring-boot-testing-5/src/main/java/com/baeldung/mockitospytest/ExternalAlertService.java

@@ -0,0 +1,6 @@
+package com.baeldung.mockitospytest;
+
+public interface ExternalAlertService {
+    public boolean alert(Order order);
+
+}

spring-boot-modules/spring-boot-testing-5/src/main/java/com/baeldung/mockitospytest/NotificationService.java

@@ -0,0 +1,18 @@
+package com.baeldung.mockitospytest;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class NotificationService {
+
+    private ExternalAlertService externalAlertService;
+
+    public void notify(Order order) {
+        System.out.println(order);
+    }
+
+    public boolean raiseAlert(Order order) {
+        return externalAlertService.alert(order);
+    }
+
+}

spring-boot-modules/spring-boot-testing-5/src/main/java/com/baeldung/mockitospytest/Order.java

@@ -0,0 +1,49 @@
+package com.baeldung.mockitospytest;
+
+import java.util.UUID;
+
+public class Order {
+
+    private UUID id;
+
+    private String name;
+
+    private OrderType orderType;
+
+    private double orderQuantity;
+
+    private String address;
+
+    public Order(UUID id, String name, double orderQuantity, String address) {
+        this.id = id;
+        this.name = name;
+        this.orderQuantity = orderQuantity;
+        this.address = address;
+    }
+
+    public enum OrderType {
+        INDIVIDUAL, BULK;
+    }
+
+    public UUID getId() {
+        return id;
+    }
+
+    public void setId(UUID id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public double getOrderQuantity() {
+        return orderQuantity;
+    }
+
+    public String getAddress() {
+        return address;
+    }
+}
+
+

spring-boot-modules/spring-boot-testing-5/src/main/java/com/baeldung/mockitospytest/OrderRepository.java

@@ -0,0 +1,19 @@
+package com.baeldung.mockitospytest;
+
+import org.springframework.stereotype.Component;
+
+import java.util.HashMap;
+import java.util.UUID;
+
+@Component
+public class OrderRepository {
+
+    public static final HashMap<UUID, Order> orders = new HashMap<>();
+
+    public Order save(Order order) {
+        UUID orderId = UUID.randomUUID();
+        order.setId(orderId);
+        orders.put(UUID.randomUUID(), order);
+        return order;
+    }
+}

spring-boot-modules/spring-boot-testing-5/src/main/java/com/baeldung/mockitospytest/OrderService.java

@@ -0,0 +1,25 @@
+package com.baeldung.mockitospytest;
+
+import org.springframework.stereotype.Service;
+
+@Service
+public class OrderService {
+
+    public final OrderRepository orderRepository;
+
+    public final NotificationService notificationService;
+
+    public OrderService(OrderRepository orderRepository, NotificationService notificationService) {
+        this.orderRepository = orderRepository;
+        this.notificationService = notificationService;
+    }
+
+    public Order save(Order order) {
+        order = orderRepository.save(order);
+        notificationService.notify(order);
+        if (!notificationService.raiseAlert(order)) {
+            throw new RuntimeException("Alert not raised");
+        }
+        return order;
+    }
+}

spring-boot-modules/spring-boot-testing-5/src/main/java/com/baeldung/mockitospytest/SpyTestApplication.java

@@ -0,0 +1,13 @@
+package com.baeldung.mockitospytest;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpyTestApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(SpyTestApplication.class, args);
+    }
+
+}

spring-boot-modules/spring-boot-testing-5/src/test/java/com/baeldung/mockitospytest/OrderServiceUnitTest.java

@@ -0,0 +1,30 @@
+package com.baeldung.mockitospytest;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.bean.override.mockito.MockitoSpyBean;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.verify;
+
+@SpringBootTest
+class OrderServiceUnitTest {
+    @MockitoSpyBean
+    NotificationService notificationService;
+    @MockitoSpyBean
+    OrderService orderService;
+
+    @Test
+    void givenNotificationServiceIsUsingSpyBean_whenOrderServiceIsCalled_thenNotificationServiceSpyBeanShouldBeInvoked() {
+        Order orderInput = new Order(null, "Test", 1.0, "17 St Andrews Croft, Leeds ,LS17 7TP");
+        doReturn(true).when(notificationService)
+            .raiseAlert(any(Order.class));
+        Order order = orderService.save(orderInput);
+        Assertions.assertNotNull(order);
+        Assertions.assertNotNull(order.getId());
+        verify(notificationService).notify(any(Order.class));
+    }
+
+}