BAEL-6761 - How to mock AmazonSQS in unit test

aws-modules/aws-miscellaneous/pom.xml

@@ -30,6 +30,18 @@
             <artifactId>gson</artifactId>
             <version>${gson.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>5.12.0</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-junit-jupiter</artifactId>
+            <version>5.12.0</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

aws-modules/aws-miscellaneous/src/main/java/com/baeldung/sqs/SqsAsyncMessagePublisher.java

@@ -0,0 +1,26 @@
+package com.baeldung.sqs;
+
+import software.amazon.awssdk.services.sqs.SqsAsyncClient;
+import software.amazon.awssdk.services.sqs.model.SendMessageRequest;
+import software.amazon.awssdk.services.sqs.model.SendMessageResponse;
+
+import java.util.concurrent.CompletableFuture;
+
+public class SqsAsyncMessagePublisher {
+
+    private final SqsAsyncClient sqsAsyncClient;
+
+    public SqsAsyncMessagePublisher(SqsAsyncClient sqsAsyncClient) {
+        this.sqsAsyncClient = sqsAsyncClient;
+    }
+
+    public CompletableFuture<String> publishMessage(String queueUrl, String messageBody) {
+        SendMessageRequest request = SendMessageRequest.builder()
+                .queueUrl(queueUrl)
+                .messageBody(messageBody)
+                .build();
+
+        return sqsAsyncClient.sendMessage(request)
+                .thenApply(SendMessageResponse::messageId);
+    }
+}

aws-modules/aws-miscellaneous/src/main/java/com/baeldung/sqs/SqsMessagePublisher.java

@@ -0,0 +1,24 @@
+package com.baeldung.sqs;
+
+import software.amazon.awssdk.services.sqs.SqsClient;
+import software.amazon.awssdk.services.sqs.model.SendMessageRequest;
+import software.amazon.awssdk.services.sqs.model.SendMessageResponse;
+
+public class SqsMessagePublisher {
+
+    private final SqsClient sqsClient;
+
+    public SqsMessagePublisher(SqsClient sqsClient) {
+        this.sqsClient = sqsClient;
+    }
+
+    public String publishMessage(String queueUrl, String messageBody) {
+        SendMessageRequest request = SendMessageRequest.builder()
+                .queueUrl(queueUrl)
+                .messageBody(messageBody)
+                .build();
+
+        SendMessageResponse response = sqsClient.sendMessage(request);
+        return response.messageId();
+    }
+}

aws-modules/aws-miscellaneous/src/test/java/com/baeldung/sqs/SqsAsyncMessagePublisherUnitTest.java

@@ -0,0 +1,53 @@
+package com.baeldung.sqs;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import software.amazon.awssdk.services.sqs.SqsAsyncClient;
+import software.amazon.awssdk.services.sqs.model.SendMessageRequest;
+import software.amazon.awssdk.services.sqs.model.SendMessageResponse;
+import java.util.concurrent.CompletableFuture;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class SqsAsyncMessagePublisherUnitTest {
+
+    @Mock
+    private SqsAsyncClient sqsAsyncClient;
+
+    @InjectMocks
+    private SqsAsyncMessagePublisher messagePublisher;
+
+    @Test
+    void whenPublishMessage_thenMessageIsSentAsynchronously() throws Exception {
+        // Arrange
+        String queueUrl = "https://sqs.us-east-1.amazonaws.com/123456789012/MyAsyncQueue";
+        String messageBody = "Hello, Async SQS!";
+        String expectedMessageId = "test-async-message-id-456";
+
+        SendMessageResponse mockResponse = SendMessageResponse.builder()
+                .messageId(expectedMessageId)
+                .build();
+        when(sqsAsyncClient.sendMessage(any(SendMessageRequest.class)))
+                .thenReturn(CompletableFuture.completedFuture(mockResponse));
+
+        // Act
+        String actualMessageId = messagePublisher.publishMessage(queueUrl, messageBody).get();
+
+        // Assert
+        assertThat(actualMessageId).isEqualTo(expectedMessageId);
+
+        ArgumentCaptor<SendMessageRequest> requestCaptor = ArgumentCaptor.forClass(SendMessageRequest.class);
+        verify(sqsAsyncClient).sendMessage(requestCaptor.capture());
+
+        SendMessageRequest capturedRequest = requestCaptor.getValue();
+        assertThat(capturedRequest.queueUrl()).isEqualTo(queueUrl);
+        assertThat(capturedRequest.messageBody()).isEqualTo(messageBody);
+    }
+}

aws-modules/aws-miscellaneous/src/test/java/com/baeldung/sqs/SqsMessagePublisherUnitTest.java

@@ -0,0 +1,52 @@
+package com.baeldung.sqs;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import software.amazon.awssdk.services.sqs.SqsClient;
+import software.amazon.awssdk.services.sqs.model.SendMessageRequest;
+import software.amazon.awssdk.services.sqs.model.SendMessageResponse;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class SqsMessagePublisherUnitTest {
+
+    @Mock
+    private SqsClient sqsClient;
+
+    @InjectMocks
+    private SqsMessagePublisher messagePublisher;
+
+    @Test
+    void whenPublishMessage_thenMessageIsSentWithCorrectParameters() {
+        // Arrange
+        String queueUrl = "https://sqs.us-east-1.amazonaws.com/123456789012/MyQueue";
+        String messageBody = "Hello, SQS!";
+        String expectedMessageId = "test-message-id-123";
+
+        SendMessageResponse mockResponse = SendMessageResponse.builder()
+                .messageId(expectedMessageId)
+                .build();
+        when(sqsClient.sendMessage(any(SendMessageRequest.class))).thenReturn(mockResponse);
+
+        // Act
+        String actualMessageId = messagePublisher.publishMessage(queueUrl, messageBody);
+
+        // Assert
+        assertThat(actualMessageId).isEqualTo(expectedMessageId);
+
+        ArgumentCaptor<SendMessageRequest> requestCaptor = ArgumentCaptor.forClass(SendMessageRequest.class);
+        verify(sqsClient).sendMessage(requestCaptor.capture());
+
+        SendMessageRequest capturedRequest = requestCaptor.getValue();
+        assertThat(capturedRequest.queueUrl()).isEqualTo(queueUrl);
+        assertThat(capturedRequest.messageBody()).isEqualTo(messageBody);
+    }
+}