src/test/java/de/dev089/eventproducer/config/RabbitConfigurationTest.java

@@ -0,0 +1,37 @@
+package de.dev089.eventproducer.config;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.amqp.core.Binding;
+import org.springframework.amqp.core.Queue;
+import org.springframework.amqp.core.TopicExchange;
+import org.springframework.amqp.rabbit.connection.ConnectionFactory;
+import org.springframework.amqp.rabbit.core.RabbitTemplate;
+import org.springframework.amqp.support.converter.MessageConverter;
+import org.springframework.test.util.ReflectionTestUtils;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+class RabbitConfigurationTest {
+
+    @Test
+    void beans_areConfiguredFromProperties() {
+        RabbitConfiguration config = new RabbitConfiguration();
+        ReflectionTestUtils.setField(config, "producerExchange", "exchange.x");
+        ReflectionTestUtils.setField(config, "queueName", "queue.q");
+        ReflectionTestUtils.setField(config, "routingKey", "route.r");
+
+        TopicExchange exchange = config.topicExchange();
+        Queue queue = config.producerQueue();
+        Binding binding = config.queueBinding(queue, exchange);
+        MessageConverter converter = config.jacksonConverter();
+        RabbitTemplate template = config.rabbitTemplate(mock(ConnectionFactory.class), converter);
+
+        assertThat(exchange.getName()).isEqualTo("exchange.x");
+        assertThat(exchange.isDurable()).isTrue();
+        assertThat(queue.getName()).isEqualTo("queue.q");
+        assertThat(binding.getRoutingKey()).isEqualTo("route.r");
+        assertThat(template.getExchange()).isEqualTo("exchange.x");
+        assertThat(template.getMessageConverter()).isSameAs(converter);
+    }
+}

src/test/java/de/dev089/eventproducer/producer/HealthRequestProducerTest.java

@@ -0,0 +1,30 @@
+package de.dev089.eventproducer.producer;
+
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+import org.springframework.amqp.rabbit.core.RabbitTemplate;
+
+import static org.mockito.Mockito.verify;
+
+class HealthRequestProducerTest {
+
+    @Test
+    void publish_usesProvidedRoutingKey() {
+        RabbitTemplate rabbitTemplate = Mockito.mock(RabbitTemplate.class);
+        HealthRequestProducer producer = new HealthRequestProducer(rabbitTemplate, "default.route");
+
+        producer.publish("custom.route", "payload");
+
+        verify(rabbitTemplate).convertAndSend("custom.route", "payload");
+    }
+
+    @Test
+    void publishToDefaultQueue_usesDefaultRoutingKey() {
+        RabbitTemplate rabbitTemplate = Mockito.mock(RabbitTemplate.class);
+        HealthRequestProducer producer = new HealthRequestProducer(rabbitTemplate, "default.route");
+
+        producer.publishToDefaultQueue("payload");
+
+        verify(rabbitTemplate).convertAndSend("default.route", "payload");
+    }
+}

src/test/java/de/dev089/eventproducer/web/RequestProducerControllerIT.java

@@ -0,0 +1,49 @@
+package de.dev089.eventproducer.web;
+
+import de.dev089.eventproducer.producer.HealthRequestProducer;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.verify;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@SpringBootTest(properties = {
+        "RABBITMQ_HOST=localhost",
+        "RABBITMQ_PORT=5672",
+        "RABBITMQ_USERNAME=guest",
+        "RABBITMQ_PASSWORD=guest"
+})
+@AutoConfigureMockMvc
+class RequestProducerControllerIT {
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @MockBean
+    private HealthRequestProducer healthRequestProducer;
+
+    @Test
+    void postPopulate_acceptsValidRequest() throws Exception {
+        mockMvc.perform(post("/api/events/populate")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("{\"message\":\"hello\"}"))
+                .andExpect(status().isAccepted());
+
+        verify(healthRequestProducer).publishToDefaultQueue(any());
+    }
+
+    @Test
+    void postPopulate_rejectsInvalidRequest() throws Exception {
+        mockMvc.perform(post("/api/events/populate")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("{\"message\":\"\"}"))
+                .andExpect(status().isBadRequest());
+    }
+}

src/test/java/de/dev089/eventproducer/web/RequestProducerControllerTest.java

@@ -0,0 +1,32 @@
+package de.dev089.eventproducer.web;
+
+import de.dev089.eventproducer.producer.HealthRequestProducer;
+import de.dev089.eventproducer.web.dto.MessageRequest;
+import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mockito;
+
+import java.time.Instant;
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.verify;
+
+class RequestProducerControllerTest {
+
+    @Test
+    void publishMessage_wrapsMessageAndTimestamp() {
+        HealthRequestProducer producer = Mockito.mock(HealthRequestProducer.class);
+        RequestProducerController controller = new RequestProducerController(producer);
+
+        controller.publishMessage(new MessageRequest("hello"));
+
+        ArgumentCaptor<Map<String, Object>> captor = ArgumentCaptor.forClass(Map.class);
+        verify(producer).publishToDefaultQueue(captor.capture());
+
+        Map<String, Object> envelope = captor.getValue();
+        assertThat(envelope.get("message")).isEqualTo("hello");
+        assertThat(envelope.get("sentAt")).isInstanceOf(String.class);
+        assertThat(Instant.parse((String) envelope.get("sentAt"))).isNotNull();
+    }
+}

src/test/java/de/dev089/eventproducer/web/dto/MessageRequestValidationTest.java

@@ -0,0 +1,22 @@
+package de.dev089.eventproducer.web.dto;
+
+import jakarta.validation.ConstraintViolation;
+import jakarta.validation.Validation;
+import jakarta.validation.Validator;
+import org.junit.jupiter.api.Test;
+
+import java.util.Set;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class MessageRequestValidationTest {
+
+    private final Validator validator = Validation.buildDefaultValidatorFactory().getValidator();
+
+    @Test
+    void message_mustNotBeBlank() {
+        Set<ConstraintViolation<MessageRequest>> violations = validator.validate(new MessageRequest(""));
+
+        assertThat(violations).isNotEmpty();
+    }
+}