Merge pull request #16204 from etrandafir93/features/BAEL-7547-testing_spring_events

BAEL-7547: testing spring events article

spring-boot-modules/spring-boot-libraries-3/pom.xml

@@ -17,7 +17,6 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-data-jpa</artifactId>
         </dependency>
-
         <dependency>
             <groupId>org.springframework.kafka</groupId>
             <artifactId>spring-kafka</artifactId>
@@ -28,20 +27,27 @@
             <artifactId>postgresql</artifactId>
             <version>${postgresql.version}</version>
         </dependency>
+
         <dependency>
             <groupId>org.springframework.modulith</groupId>
             <artifactId>spring-modulith-events-api</artifactId>
-            <version>${spring-modulith-events-kafka.version}</version>
+            <version>${spring-modulith.version}</version>
         </dependency>
         <dependency>
             <groupId>org.springframework.modulith</groupId>
             <artifactId>spring-modulith-events-kafka</artifactId>
-            <version>${spring-modulith-events-kafka.version}</version>
+            <version>${spring-modulith.version}</version>
         </dependency>
         <dependency>
             <groupId>org.springframework.modulith</groupId>
             <artifactId>spring-modulith-starter-jpa</artifactId>
-            <version>${spring-modulith-events-kafka.version}</version>
+            <version>${spring-modulith.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.modulith</groupId>
+            <artifactId>spring-modulith-starter-test</artifactId>
+            <version>${spring-modulith.version}</version>
+            <scope>test</scope>
         </dependency>
 
         <dependency>
@@ -54,7 +60,6 @@
             <artifactId>spring-boot-testcontainers</artifactId>
             <scope>test</scope>
         </dependency>
-
         <dependency>
             <groupId>org.testcontainers</groupId>
             <artifactId>kafka</artifactId>
@@ -73,7 +78,6 @@
             <version>${testcontainers.version}</version>
             <scope>test</scope>
         </dependency>
-
         <dependency>
             <groupId>org.testcontainers</groupId>
             <artifactId>postgresql</artifactId>
@@ -87,16 +91,23 @@
             <version>${awaitility.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <version>${h2.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
 
     <properties>
         <java.version>17</java.version>
         <spring-boot.version>3.1.5</spring-boot.version>
-        <spring-modulith-events-kafka.version>1.1.2</spring-modulith-events-kafka.version>
+        <spring-modulith.version>1.1.3</spring-modulith.version>
         <testcontainers.version>1.19.3</testcontainers.version>
         <awaitility.version>4.2.0</awaitility.version>
         <postgresql.version>42.3.1</postgresql.version>
+        <h2.version>2.2.224</h2.version>
     </properties>
 
 </project>

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/springmodulith/application/events/orders/Order.java

@@ -0,0 +1,12 @@
+package com.baeldung.springmodulith.application.events.orders;
+
+import java.time.Instant;
+import java.util.List;
+
+record Order(String id, String customerId, List<String> productIds, Instant timestamp) {
+
+    public Order(String customerId, List<String> productIds) {
+        this(null, customerId, productIds, Instant.now());
+    }
+
+}

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/springmodulith/application/events/orders/OrderCompletedEvent.java

@@ -0,0 +1,6 @@
+package com.baeldung.springmodulith.application.events.orders;
+
+import java.time.Instant;
+
+public record OrderCompletedEvent(String orderId, String customerId, Instant timestamp) {
+}

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/springmodulith/application/events/orders/OrderRepository.java

@@ -0,0 +1,27 @@
+package com.baeldung.springmodulith.application.events.orders;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+import org.springframework.stereotype.Component;
+
+@Component
+class OrderRepository {
+    private final List<Order> orders = new ArrayList<>();
+
+    public Order save(Order order) {
+        order = new Order(UUID.randomUUID()
+            .toString(), order.customerId(), order.productIds(), order.timestamp());
+        orders.add(order);
+        return order;
+    }
+
+    public List<Order> ordersByCustomer(String customerId) {
+        return orders.stream()
+            .filter(it -> it.customerId()
+                .equals(customerId))
+            .toList();
+    }
+
+}

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/springmodulith/application/events/orders/OrderService.java

@@ -0,0 +1,29 @@
+package com.baeldung.springmodulith.application.events.orders;
+
+import java.util.Arrays;
+
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.stereotype.Service;
+
+@Service
+public class OrderService {
+
+    private final OrderRepository repository;
+    private final ApplicationEventPublisher eventPublisher;
+
+    public OrderService(OrderRepository orders, ApplicationEventPublisher eventsPublisher) {
+        this.repository = orders;
+        this.eventPublisher = eventsPublisher;
+    }
+
+    public void placeOrder(String customerId, String... productIds) {
+        Order order = new Order(customerId, Arrays.asList(productIds));
+        // business logic to validate and place the order
+
+        Order savedOrder = repository.save(order);
+
+        OrderCompletedEvent event = new OrderCompletedEvent(savedOrder.id(), savedOrder.customerId(), savedOrder.timestamp());
+        eventPublisher.publishEvent(event);
+    }
+
+}

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/springmodulith/application/events/rewards/LoyalCustomersRepository.java

@@ -0,0 +1,44 @@
+package com.baeldung.springmodulith.application.events.rewards;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class LoyalCustomersRepository {
+
+    private List<LoyalCustomer> customers = new ArrayList<>();
+
+    public Optional<LoyalCustomer> find(String customerId) {
+        return customers.stream()
+            .filter(it -> it.customerId()
+                .equals(customerId))
+            .findFirst();
+    }
+
+    public void awardPoints(String customerId, int points) {
+        var customer = find(customerId).orElseGet(() -> save(new LoyalCustomer(customerId, 0)));
+
+        customers.remove(customer);
+        customers.add(customer.addPoints(points));
+    }
+
+    public LoyalCustomer save(LoyalCustomer customer) {
+        customers.add(customer);
+        return customer;
+    }
+
+    public boolean isLoyalCustomer(String customerId) {
+        return find(customerId).isPresent();
+    }
+
+    public record LoyalCustomer(String customerId, int points) {
+
+        LoyalCustomer addPoints(int points) {
+            return new LoyalCustomer(customerId, this.points() + points);
+        }
+    }
+
+}

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/springmodulith/application/events/rewards/LoyaltyPointsService.java

@@ -0,0 +1,24 @@
+package com.baeldung.springmodulith.application.events.rewards;
+
+import org.springframework.context.event.EventListener;
+import org.springframework.stereotype.Service;
+
+import com.baeldung.springmodulith.application.events.orders.OrderCompletedEvent;
+
+@Service
+public class LoyaltyPointsService {
+
+    public static final int ORDER_COMPLETED_POINTS = 60;
+    private final LoyalCustomersRepository loyalCustomers;
+
+    public LoyaltyPointsService(LoyalCustomersRepository loyalCustomers) {
+        this.loyalCustomers = loyalCustomers;
+    }
+
+    @EventListener
+    public void onOrderCompleted(OrderCompletedEvent event) {
+        // business logic to award points to loyal customers
+        loyalCustomers.awardPoints(event.customerId(), ORDER_COMPLETED_POINTS);
+    }
+
+}

spring-boot-modules/spring-boot-libraries-3/src/test/java/com/baeldung/springmodulith/application/events/EventListenerUnitTest.java

@@ -0,0 +1,36 @@
+package com.baeldung.springmodulith.application.events;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.time.Instant;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.ApplicationEventPublisher;
+
+import com.baeldung.springmodulith.application.events.orders.OrderCompletedEvent;
+import com.baeldung.springmodulith.application.events.rewards.LoyalCustomersRepository;
+
+@SpringBootTest
+class EventListenerUnitTest {
+
+    @Autowired
+    private LoyalCustomersRepository customers;
+
+    @Autowired
+    private ApplicationEventPublisher testEventPublisher;
+
+    @Test
+    void whenPublishingOrderCompletedEvent_thenRewardCustomerWithLoyaltyPoints() {
+        OrderCompletedEvent event = new OrderCompletedEvent("order-1", "customer-1", Instant.now());
+
+        testEventPublisher.publishEvent(event);
+
+        assertThat(customers.find("customer-1"))
+          .isPresent().get()
+          .hasFieldOrPropertyWithValue("customerId", "customer-1")
+          .hasFieldOrPropertyWithValue("points", 60);
+    }
+
+}

spring-boot-modules/spring-boot-libraries-3/src/test/java/com/baeldung/springmodulith/application/events/EventPublisherUnitTest.java

@@ -0,0 +1,37 @@
+package com.baeldung.springmodulith.application.events;
+
+import com.baeldung.springmodulith.application.events.orders.OrderService;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.ComponentScan;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@SpringBootTest
+class EventPublisherUnitTest {
+
+	@Autowired
+	OrderService orderService;
+
+	@Autowired
+	TestEventListener testEventListener;
+
+	@BeforeEach
+	void beforeEach() {
+		testEventListener.reset();
+	}
+
+	@Test
+	void whenPlacingOrder_thenPublishApplicationEvent() {
+		orderService.placeOrder("customer1", "product1", "product2");
+
+		assertThat(testEventListener.getEvents())
+		  .hasSize(1).first()
+		  .hasFieldOrPropertyWithValue("customerId", "customer1")
+		  .hasFieldOrProperty("orderId")
+		  .hasFieldOrProperty("timestamp");
+	}
+
+}

spring-boot-modules/spring-boot-libraries-3/src/test/java/com/baeldung/springmodulith/application/events/SpringModulithScenarioApiUnitTest.java

@@ -0,0 +1,46 @@
+package com.baeldung.springmodulith.application.events;
+
+import com.baeldung.springmodulith.application.events.orders.OrderCompletedEvent;
+import com.baeldung.springmodulith.application.events.orders.OrderService;
+import com.baeldung.springmodulith.application.events.rewards.LoyalCustomersRepository;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.modulith.test.ApplicationModuleTest;
+import org.springframework.modulith.test.ApplicationModuleTest.BootstrapMode;
+import org.springframework.modulith.test.Scenario;
+
+import java.time.Duration;
+import java.time.Instant;
+
+import static java.time.Duration.ofMillis;
+import static org.assertj.core.api.Assertions.assertThat;
+
+@ApplicationModuleTest
+class SpringModulithScenarioApiUnitTest {
+
+	@Autowired
+	OrderService orderService;
+
+	@Autowired
+	LoyalCustomersRepository loyalCustomers;
+
+	@Test
+	void whenPlacingOrder_thenPublishOrderCompletedEvent(Scenario scenario) {
+		scenario.stimulate(() -> orderService.placeOrder("customer-1", "product-1", "product-2"))
+		  .andWaitForEventOfType(OrderCompletedEvent.class)
+		  .toArriveAndVerify(evt -> assertThat(evt)
+			.hasFieldOrPropertyWithValue("customerId", "customer-1")
+			.hasFieldOrProperty("orderId")
+			.hasFieldOrProperty("timestamp"));
+	}
+
+	@Test
+	void whenReceivingPublishOrderCompletedEvent_thenRewardCustomerWithLoyaltyPoints(Scenario scenario) {
+		scenario.publish(new OrderCompletedEvent("order-1", "customer-1", Instant.now()))
+		  .andWaitForStateChange(() -> loyalCustomers.find("customer-1"))
+		  .andVerify(it -> assertThat(it)
+		    .isPresent().get()
+		    .hasFieldOrPropertyWithValue("customerId", "customer-1")
+		    .hasFieldOrPropertyWithValue("points", 60));
+	}
+}

spring-boot-modules/spring-boot-libraries-3/src/test/java/com/baeldung/springmodulith/application/events/TestEventListener.java

@@ -0,0 +1,29 @@
+package com.baeldung.springmodulith.application.events;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.context.event.EventListener;
+import org.springframework.stereotype.Component;
+
+import com.baeldung.springmodulith.application.events.orders.OrderCompletedEvent;
+
+@Component
+class TestEventListener {
+
+    private final List<OrderCompletedEvent> events = new ArrayList<>();
+
+    @EventListener
+    void onEvent(OrderCompletedEvent event) {
+        events.add(event);
+    }
+
+    public List<OrderCompletedEvent> getEvents() {
+        return events;
+    }
+
+    public void reset() {
+        events.clear();
+    }
+}
+