Migrate to Mockito.mock(T...) where feasible

spring-messaging/src/test/java/org/springframework/messaging/converter/ProtobufMessageConverterTests.java

@@ -18,7 +18,6 @@ package org.springframework.messaging.converter;
 
 import java.util.Map;
 
-import com.google.protobuf.ExtensionRegistry;
 import org.junit.jupiter.api.Test;
 import org.skyscreamer.jsonassert.JSONAssert;
 
@@ -108,7 +107,7 @@ class ProtobufMessageConverterTests {
 	void jsonWithGoogleProtobuf() throws Exception {
 		ProtobufMessageConverter converter = new ProtobufMessageConverter(
 				new ProtobufMessageConverter.ProtobufJavaUtilSupport(null, null),
-				mock(ExtensionRegistry.class));
+				mock());
 
 		//convertTo
 		Message<?> message = converter.toMessage(testMsg, new MessageHeaders(Map.of(CONTENT_TYPE, APPLICATION_JSON)));

spring-messaging/src/test/java/org/springframework/messaging/core/CachingDestinationResolverTests.java

@@ -36,7 +36,7 @@ public class CachingDestinationResolverTests {
 	@Test
 	public void cachedDestination() {
 		@SuppressWarnings("unchecked")
-		DestinationResolver<String> resolver = mock(DestinationResolver.class);
+		DestinationResolver<String> resolver = mock();
 		CachingDestinationResolverProxy<String> resolverProxy = new CachingDestinationResolverProxy<>(resolver);
 
 		given(resolver.resolveDestination("abcd")).willReturn("dcba");

spring-messaging/src/test/java/org/springframework/messaging/core/GenericMessagingTemplateTests.java

@@ -72,7 +72,7 @@ public class GenericMessagingTemplateTests {
 
 	@Test
 	public void sendWithTimeout() {
-		SubscribableChannel channel = mock(SubscribableChannel.class);
+		SubscribableChannel channel = mock();
 		final AtomicReference<Message<?>> sent = new AtomicReference<>();
 		willAnswer(invocation -> {
 			sent.set(invocation.getArgument(0));
@@ -91,7 +91,7 @@ public class GenericMessagingTemplateTests {
 
 	@Test
 	public void sendWithTimeoutMutable() {
-		SubscribableChannel channel = mock(SubscribableChannel.class);
+		SubscribableChannel channel = mock();
 		final AtomicReference<Message<?>> sent = new AtomicReference<>();
 		willAnswer(invocation -> {
 			sent.set(invocation.getArgument(0));
@@ -129,7 +129,7 @@ public class GenericMessagingTemplateTests {
 		this.template.setSendTimeout(30_000L);
 		this.template.setThrowExceptionOnLateReply(true);
 
-		SubscribableChannel channel = mock(SubscribableChannel.class);
+		SubscribableChannel channel = mock();
 		MessageHandler handler = createLateReplier(latch, failure);
 		willAnswer(invocation -> {
 			this.executor.execute(() -> handler.handleMessage(invocation.getArgument(0)));
@@ -155,7 +155,7 @@ public class GenericMessagingTemplateTests {
 		this.template.setReceiveTimeout(10_000);
 		this.template.setThrowExceptionOnLateReply(true);
 
-		SubscribableChannel channel = mock(SubscribableChannel.class);
+		SubscribableChannel channel = mock();
 		MessageHandler handler = createLateReplier(latch, failure);
 		willAnswer(invocation -> {
 			this.executor.execute(() -> handler.handleMessage(invocation.getArgument(0)));
@@ -187,7 +187,7 @@ public class GenericMessagingTemplateTests {
 		this.template.setSendTimeoutHeader("sto");
 		this.template.setReceiveTimeoutHeader("rto");
 
-		SubscribableChannel channel = mock(SubscribableChannel.class);
+		SubscribableChannel channel = mock();
 		MessageHandler handler = createLateReplier(latch, failure);
 		willAnswer(invocation -> {
 			this.executor.execute(() -> handler.handleMessage(invocation.getArgument(0)));

spring-messaging/src/test/java/org/springframework/messaging/handler/annotation/support/MessageMethodArgumentResolverTests.java

@@ -44,20 +44,17 @@ import static org.mockito.Mockito.mock;
  */
 public class MessageMethodArgumentResolverTests {
 
-	private MessageConverter converter;
+	private MessageConverter converter = mock();
 
-	private MessageMethodArgumentResolver resolver;
+	private MessageMethodArgumentResolver resolver = new MessageMethodArgumentResolver(this.converter);
 
 	private Method method;
 
 
 	@BeforeEach
 	public void setup() throws Exception {
-		this.method = MessageMethodArgumentResolverTests.class.getDeclaredMethod("handle",
+		this.method = getClass().getDeclaredMethod("handle",
 				Message.class, Message.class, Message.class, Message.class, ErrorMessage.class, Message.class);
-
-		this.converter = mock(MessageConverter.class);
-		this.resolver = new MessageMethodArgumentResolver(this.converter);
 	}
 
 

spring-messaging/src/test/java/org/springframework/messaging/handler/invocation/InvocableHandlerMethodTests.java

@@ -39,7 +39,7 @@ import static org.mockito.Mockito.mock;
  */
 public class InvocableHandlerMethodTests {
 
-	private final Message<?> message = mock(Message.class);
+	private final Message<?> message = mock();
 
 	private final HandlerMethodArgumentResolverComposite resolvers = new HandlerMethodArgumentResolverComposite();
 

spring-messaging/src/test/java/org/springframework/messaging/handler/invocation/reactive/InvocableHandlerMethodTests.java

@@ -46,7 +46,7 @@ import static org.mockito.Mockito.mock;
  */
 public class InvocableHandlerMethodTests {
 
-	private final Message<?> message = mock(Message.class);
+	private final Message<?> message = mock();
 
 	private final List<HandlerMethodArgumentResolver> resolvers = new ArrayList<>();
 

spring-messaging/src/test/java/org/springframework/messaging/rsocket/DefaultRSocketRequesterBuilderTests.java

@@ -66,7 +66,7 @@ import static org.mockito.Mockito.verify;
  */
 public class DefaultRSocketRequesterBuilderTests {
 
-	private ClientTransport transport;
+	private ClientTransport transport = mock();
 
 	private final MockConnection connection = new MockConnection();
 
@@ -75,7 +75,6 @@ public class DefaultRSocketRequesterBuilderTests {
 
 	@BeforeEach
 	public void setup() {
-		this.transport = mock(ClientTransport.class);
 		given(this.transport.connect()).willReturn(Mono.just(this.connection));
 		given(this.transport.maxFrameLength()).willReturn(16777215);
 	}
@@ -84,7 +83,7 @@ public class DefaultRSocketRequesterBuilderTests {
 	@Test
 	@SuppressWarnings("unchecked")
 	public void rsocketConnectorConfigurer() {
-		Consumer<RSocketStrategies.Builder> strategiesConfigurer = mock(Consumer.class);
+		Consumer<RSocketStrategies.Builder> strategiesConfigurer = mock();
 		RSocketRequester.builder()
 				.rsocketConnector(this.connectorConfigurer)
 				.rsocketStrategies(strategiesConfigurer)

spring-messaging/src/test/java/org/springframework/messaging/rsocket/DefaultRSocketStrategiesTests.java

@@ -110,7 +110,7 @@ class DefaultRSocketStrategiesTests {
 	@Test
 	@SuppressWarnings("unchecked")
 	void applyMetadataExtractors() {
-		Consumer<MetadataExtractorRegistry> consumer = mock(Consumer.class);
+		Consumer<MetadataExtractorRegistry> consumer = mock();
 		RSocketStrategies.builder().metadataExtractorRegistry(consumer).build();
 		verify(consumer, times(1)).accept(any());
 	}

spring-messaging/src/test/java/org/springframework/messaging/simp/SimpAttributesTests.java

@@ -60,7 +60,7 @@ public class SimpAttributesTests {
 
 	@Test
 	public void registerDestructionCallback() {
-		Runnable callback = mock(Runnable.class);
+		Runnable callback = mock();
 		this.simpAttributes.registerDestructionCallback("name1", callback);
 
 		assertThat(this.simpAttributes.getAttribute(
@@ -70,15 +70,15 @@ public class SimpAttributesTests {
 	@Test
 	public void registerDestructionCallbackAfterSessionCompleted() {
 		this.simpAttributes.sessionCompleted();
-		assertThatIllegalStateException().isThrownBy(() ->
-				this.simpAttributes.registerDestructionCallback("name1", mock(Runnable.class)))
-			.withMessageContaining("already completed");
+		assertThatIllegalStateException()
+				.isThrownBy(() -> this.simpAttributes.registerDestructionCallback("name1", mock()))
+				.withMessageContaining("already completed");
 	}
 
 	@Test
 	public void removeDestructionCallback() {
-		Runnable callback1 = mock(Runnable.class);
-		Runnable callback2 = mock(Runnable.class);
+		Runnable callback1 = mock();
+		Runnable callback2 = mock();
 		this.simpAttributes.registerDestructionCallback("name1", callback1);
 		this.simpAttributes.registerDestructionCallback("name2", callback2);
 
@@ -100,8 +100,8 @@ public class SimpAttributesTests {
 
 	@Test
 	public void sessionCompleted() {
-		Runnable callback1 = mock(Runnable.class);
-		Runnable callback2 = mock(Runnable.class);
+		Runnable callback1 = mock();
+		Runnable callback2 = mock();
 		this.simpAttributes.registerDestructionCallback("name1", callback1);
 		this.simpAttributes.registerDestructionCallback("name2", callback2);
 
@@ -113,7 +113,7 @@ public class SimpAttributesTests {
 
 	@Test
 	public void sessionCompletedIsIdempotent() {
-		Runnable callback1 = mock(Runnable.class);
+		Runnable callback1 = mock();
 		this.simpAttributes.registerDestructionCallback("name1", callback1);
 
 		this.simpAttributes.sessionCompleted();

spring-messaging/src/test/java/org/springframework/messaging/simp/SimpMessageHeaderAccessorTests.java

@@ -77,11 +77,11 @@ public class SimpMessageHeaderAccessorTests {
 		SimpMessageHeaderAccessor accessor = SimpMessageHeaderAccessor.create();
 		accessor.setUserChangeCallback(userCallback);
 
-		Principal user1 = mock(Principal.class);
+		Principal user1 = mock();
 		accessor.setUser(user1);
 		assertThat(userCallback.getUser()).isEqualTo(user1);
 
-		Principal user2 = mock(Principal.class);
+		Principal user2 = mock();
 		accessor.setUser(user2);
 		assertThat(userCallback.getUser()).isEqualTo(user2);
 	}

spring-messaging/src/test/java/org/springframework/messaging/simp/SimpSessionScopeTests.java

@@ -21,12 +21,12 @@ import java.util.concurrent.ConcurrentHashMap;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
-import org.mockito.Mockito;
 
 import org.springframework.beans.factory.ObjectFactory;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 
@@ -38,19 +38,16 @@ import static org.mockito.Mockito.verify;
  */
 public class SimpSessionScopeTests {
 
-	private SimpSessionScope scope;
+	private SimpSessionScope scope = new SimpSessionScope();
 
 	@SuppressWarnings("rawtypes")
-	private ObjectFactory objectFactory;
+	private ObjectFactory objectFactory = mock();
 
-	private SimpAttributes simpAttributes;
+	private SimpAttributes simpAttributes = new SimpAttributes("session1", new ConcurrentHashMap<>());
 
 
 	@BeforeEach
 	public void setUp() {
-		this.scope = new SimpSessionScope();
-		this.objectFactory = Mockito.mock(ObjectFactory.class);
-		this.simpAttributes = new SimpAttributes("session1", new ConcurrentHashMap<>());
 		SimpAttributesContextHolder.setAttributes(this.simpAttributes);
 	}
 
@@ -90,7 +87,7 @@ public class SimpSessionScopeTests {
 
 	@Test
 	public void registerDestructionCallback() {
-		Runnable runnable = Mockito.mock(Runnable.class);
+		Runnable runnable = mock();
 		this.scope.registerDestructionCallback("name", runnable);
 
 		this.simpAttributes.sessionCompleted();
@@ -102,5 +99,4 @@ public class SimpSessionScopeTests {
 		assertThat(this.scope.getConversationId()).isEqualTo("session1");
 	}
 
-
 }

spring-messaging/src/test/java/org/springframework/messaging/simp/annotation/support/SendToMethodReturnValueHandlerTests.java

@@ -322,7 +322,7 @@ public class SendToMethodReturnValueHandlerTests {
 	public void testHeadersToSend() throws Exception {
 		Message<?> message = createMessage("sess1", "sub1", "/app", "/dest", null);
 
-		SimpMessageSendingOperations messagingTemplate = mock(SimpMessageSendingOperations.class);
+		SimpMessageSendingOperations messagingTemplate = mock();
 		SendToMethodReturnValueHandler handler = new SendToMethodReturnValueHandler(messagingTemplate, false);
 
 		handler.handleReturnValue(PAYLOAD, this.noAnnotationsReturnType, message);

spring-messaging/src/test/java/org/springframework/messaging/simp/annotation/support/SubscriptionMethodReturnValueHandlerTests.java

@@ -150,7 +150,7 @@ public class SubscriptionMethodReturnValueHandlerTests {
 		String destination = "/dest";
 		Message<?> inputMessage = createInputMessage(sessionId, subscriptionId, destination, null);
 
-		MessageSendingOperations messagingTemplate = mock(MessageSendingOperations.class);
+		MessageSendingOperations messagingTemplate = mock();
 		SubscriptionMethodReturnValueHandler handler = new SubscriptionMethodReturnValueHandler(messagingTemplate);
 
 		handler.handleReturnValue(PAYLOAD, this.subscribeEventReturnType, inputMessage);

spring-messaging/src/test/java/org/springframework/messaging/simp/broker/BrokerMessageHandlerTests.java

@@ -26,8 +26,6 @@ import org.junit.jupiter.api.Test;
 import org.springframework.context.ApplicationEvent;
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.messaging.Message;
-import org.springframework.messaging.MessageChannel;
-import org.springframework.messaging.SubscribableChannel;
 import org.springframework.messaging.simp.SimpMessageHeaderAccessor;
 import org.springframework.messaging.simp.SimpMessageType;
 import org.springframework.messaging.support.GenericMessage;
@@ -165,8 +163,7 @@ public class BrokerMessageHandlerTests {
 
 
 		TestBrokerMessageHandler(String... destinationPrefixes) {
-			super(mock(SubscribableChannel.class), mock(MessageChannel.class),
-					mock(SubscribableChannel.class), Arrays.asList(destinationPrefixes));
+			super(mock(), mock(), mock(), Arrays.asList(destinationPrefixes));
 
 			setApplicationEventPublisher(this);
 		}

spring-messaging/src/test/java/org/springframework/messaging/simp/broker/SimpleBrokerMessageHandlerTests.java

@@ -184,7 +184,7 @@ public class SimpleBrokerMessageHandlerTests {
 	@Test
 	@SuppressWarnings("rawtypes")
 	public void startAndStopWithHeartbeatValue() {
-		ScheduledFuture future = mock(ScheduledFuture.class);
+		ScheduledFuture future = mock();
 		given(this.taskScheduler.scheduleWithFixedDelay(any(Runnable.class), eq(Duration.ofMillis(15000)))).willReturn(future);
 
 		this.messageHandler.setTaskScheduler(this.taskScheduler);

spring-messaging/src/test/java/org/springframework/messaging/simp/config/MessageBrokerConfigurationTests.java

@@ -314,7 +314,7 @@ public class MessageBrokerConfigurationTests {
 
 	@Test
 	public void configureMessageConvertersCustom() {
-		final MessageConverter testConverter = mock(MessageConverter.class);
+		final MessageConverter testConverter = mock();
 		AbstractMessageBrokerConfiguration config = new BaseTestMessageBrokerConfig() {
 			@Override
 			protected boolean configureMessageConverters(List<MessageConverter> messageConverters) {
@@ -331,7 +331,7 @@ public class MessageBrokerConfigurationTests {
 
 	@Test
 	public void configureMessageConvertersCustomAndDefault() {
-		final MessageConverter testConverter = mock(MessageConverter.class);
+		final MessageConverter testConverter = mock();
 
 		AbstractMessageBrokerConfiguration config = new BaseTestMessageBrokerConfig() {
 			@Override
@@ -378,7 +378,7 @@ public class MessageBrokerConfigurationTests {
 
 	@Test
 	public void simpValidatorCustom() {
-		final Validator validator = mock(Validator.class);
+		final Validator validator = mock();
 		AbstractMessageBrokerConfiguration config = new BaseTestMessageBrokerConfig() {
 			@Override
 			public Validator getValidator() {
@@ -654,12 +654,12 @@ public class MessageBrokerConfigurationTests {
 
 		@Override
 		protected void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
-			argumentResolvers.add(mock(HandlerMethodArgumentResolver.class));
+			argumentResolvers.add(mock());
 		}
 
 		@Override
 		protected void addReturnValueHandlers(List<HandlerMethodReturnValueHandler> returnValueHandlers) {
-			returnValueHandlers.add(mock(HandlerMethodReturnValueHandler.class));
+			returnValueHandlers.add(mock());
 		}
 
 		@Override

spring-messaging/src/test/java/org/springframework/messaging/simp/stomp/DefaultStompSessionTests.java

@@ -279,7 +279,7 @@ public class DefaultStompSessionTests {
 	public void handleMessageFrame() {
 		this.session.afterConnected(this.connection);
 
-		StompFrameHandler frameHandler = mock(StompFrameHandler.class);
+		StompFrameHandler frameHandler = mock();
 		String destination = "/topic/foo";
 		Subscription subscription = this.session.subscribe(destination, frameHandler);
 
@@ -307,7 +307,7 @@ public class DefaultStompSessionTests {
 		this.session.afterConnected(this.connection);
 		assertThat(this.session.isConnected()).isTrue();
 
-		StompFrameHandler frameHandler = mock(StompFrameHandler.class);
+		StompFrameHandler frameHandler = mock();
 		String destination = "/topic/foo";
 		Subscription subscription = this.session.subscribe(destination, frameHandler);
 
@@ -377,7 +377,7 @@ public class DefaultStompSessionTests {
 		this.session.afterConnected(this.connection);
 		assertThat(this.session.isConnected()).isTrue();
 
-		this.session.setTaskScheduler(mock(TaskScheduler.class));
+		this.session.setTaskScheduler(mock());
 		this.session.setAutoReceipt(true);
 		this.session.send("/topic/foo", "sample payload");
 
@@ -449,7 +449,7 @@ public class DefaultStompSessionTests {
 		assertThat(this.session.isConnected()).isTrue();
 
 		String destination = "/topic/foo";
-		StompFrameHandler frameHandler = mock(StompFrameHandler.class);
+		StompFrameHandler frameHandler = mock();
 		Subscription subscription = this.session.subscribe(destination, frameHandler);
 
 		Message<byte[]> message = this.messageCaptor.getValue();
@@ -473,7 +473,7 @@ public class DefaultStompSessionTests {
 		StompHeaders stompHeaders = new StompHeaders();
 		stompHeaders.setId(subscriptionId);
 		stompHeaders.setDestination(destination);
-		StompFrameHandler frameHandler = mock(StompFrameHandler.class);
+		StompFrameHandler frameHandler = mock();
 
 		Subscription subscription = this.session.subscribe(stompHeaders, frameHandler);
 		assertThat(subscription.getSubscriptionId()).isEqualTo(subscriptionId);
@@ -494,7 +494,7 @@ public class DefaultStompSessionTests {
 		assertThat(this.session.isConnected()).isTrue();
 
 		String destination = "/topic/foo";
-		StompFrameHandler frameHandler = mock(StompFrameHandler.class);
+		StompFrameHandler frameHandler = mock();
 		Subscription subscription = this.session.subscribe(destination, frameHandler);
 		subscription.unsubscribe();
 
@@ -518,7 +518,7 @@ public class DefaultStompSessionTests {
 		StompHeaders subscribeHeaders = new StompHeaders();
 		subscribeHeaders.setDestination("/topic/foo");
 		subscribeHeaders.set(headerName, headerValue);
-		StompFrameHandler frameHandler = mock(StompFrameHandler.class);
+		StompFrameHandler frameHandler = mock();
 		Subscription subscription = this.session.subscribe(subscribeHeaders, frameHandler);
 
 		StompHeaders unsubscribeHeaders = new StompHeaders();
@@ -572,7 +572,7 @@ public class DefaultStompSessionTests {
 	@Test
 	public void receiptReceived() {
 		this.session.afterConnected(this.connection);
-		this.session.setTaskScheduler(mock(TaskScheduler.class));
+		this.session.setTaskScheduler(mock());
 
 		AtomicReference<Boolean> received = new AtomicReference<>();
 		AtomicReference<StompHeaders> receivedHeaders = new AtomicReference<>();
@@ -580,7 +580,7 @@ public class DefaultStompSessionTests {
 		StompHeaders headers = new StompHeaders();
 		headers.setDestination("/topic/foo");
 		headers.setReceipt("my-receipt");
-		Subscription subscription = this.session.subscribe(headers, mock(StompFrameHandler.class));
+		Subscription subscription = this.session.subscribe(headers, mock());
 		subscription.addReceiptTask(receiptHeaders -> {
 			received.set(true);
 			receivedHeaders.set(receiptHeaders);
@@ -604,7 +604,7 @@ public class DefaultStompSessionTests {
 	@Test
 	public void receiptReceivedBeforeTaskAdded() {
 		this.session.afterConnected(this.connection);
-		this.session.setTaskScheduler(mock(TaskScheduler.class));
+		this.session.setTaskScheduler(mock());
 
 		AtomicReference<Boolean> received = new AtomicReference<>();
 		AtomicReference<StompHeaders> receivedHeaders = new AtomicReference<>();
@@ -612,7 +612,7 @@ public class DefaultStompSessionTests {
 		StompHeaders headers = new StompHeaders();
 		headers.setDestination("/topic/foo");
 		headers.setReceipt("my-receipt");
-		Subscription subscription = this.session.subscribe(headers, mock(StompFrameHandler.class));
+		Subscription subscription = this.session.subscribe(headers, mock());
 
 		StompHeaderAccessor accessor = StompHeaderAccessor.create(StompCommand.RECEIPT);
 		accessor.setReceiptId("my-receipt");
@@ -635,14 +635,14 @@ public class DefaultStompSessionTests {
 	@Test
 	@SuppressWarnings({ "unchecked", "rawtypes" })
 	public void receiptNotReceived() {
-		TaskScheduler taskScheduler = mock(TaskScheduler.class);
+		TaskScheduler taskScheduler = mock();
 
 		this.session.afterConnected(this.connection);
 		this.session.setTaskScheduler(taskScheduler);
 
 		AtomicReference<Boolean> notReceived = new AtomicReference<>();
 
-		ScheduledFuture future = mock(ScheduledFuture.class);
+		ScheduledFuture future = mock();
 		given(taskScheduler.schedule(any(Runnable.class), any(Instant.class))).willReturn(future);
 
 		StompHeaders headers = new StompHeaders();

spring-messaging/src/test/java/org/springframework/messaging/simp/stomp/StompBrokerRelayMessageHandlerTests.java

@@ -39,7 +39,6 @@ import org.springframework.messaging.tcp.ReconnectStrategy;
 import org.springframework.messaging.tcp.TcpConnection;
 import org.springframework.messaging.tcp.TcpConnectionHandler;
 import org.springframework.messaging.tcp.TcpOperations;
-import org.springframework.scheduling.TaskScheduler;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.eq;
@@ -55,18 +54,15 @@ class StompBrokerRelayMessageHandlerTests {
 
 	private StompBrokerRelayMessageHandler brokerRelay;
 
-	private StubMessageChannel outboundChannel;
+	private StubMessageChannel outboundChannel = new StubMessageChannel();
 
-	private StubTcpOperations tcpClient;
+	private StubTcpOperations tcpClient = new StubTcpOperations();
 
-	ArgumentCaptor<Runnable> messageCountTaskCaptor = ArgumentCaptor.forClass(Runnable.class);
+	private ArgumentCaptor<Runnable> messageCountTaskCaptor = ArgumentCaptor.forClass(Runnable.class);
 
 
 	@BeforeEach
 	void setup() {
-
-		this.outboundChannel = new StubMessageChannel();
-
 		this.brokerRelay = new StompBrokerRelayMessageHandler(new StubMessageChannel(),
 				this.outboundChannel, new StubMessageChannel(), Collections.singletonList("/topic")) {
 
@@ -77,16 +73,13 @@ class StompBrokerRelayMessageHandlerTests {
 			}
 		};
 
-		this.tcpClient = new StubTcpOperations();
 		this.brokerRelay.setTcpClient(this.tcpClient);
 
-		this.brokerRelay.setTaskScheduler(mock(TaskScheduler.class));
+		this.brokerRelay.setTaskScheduler(mock());
 	}
 
-
 	@Test
 	void virtualHost() {
-
 		this.brokerRelay.setVirtualHost("ABC");
 
 		this.brokerRelay.start();
@@ -107,7 +100,6 @@ class StompBrokerRelayMessageHandlerTests {
 
 	@Test
 	void loginAndPasscode() {
-
 		this.brokerRelay.setSystemLogin("syslogin");
 		this.brokerRelay.setSystemPasscode("syspasscode");
 		this.brokerRelay.setClientLogin("clientlogin");
@@ -180,7 +172,6 @@ class StompBrokerRelayMessageHandlerTests {
 
 	@Test
 	void messageFromBrokerIsEnriched() {
-
 		this.brokerRelay.start();
 		this.brokerRelay.handleMessage(connectMessage("sess1", "joe"));
 
@@ -200,7 +191,6 @@ class StompBrokerRelayMessageHandlerTests {
 
 	@Test
 	void connectWhenBrokerNotAvailable() {
-
 		this.brokerRelay.start();
 		this.brokerRelay.stopInternal();
 		this.brokerRelay.handleMessage(connectMessage("sess1", "joe"));
@@ -215,7 +205,6 @@ class StompBrokerRelayMessageHandlerTests {
 
 	@Test
 	void sendAfterBrokerUnavailable() {
-
 		this.brokerRelay.start();
 		assertThat(this.brokerRelay.getConnectionCount()).isEqualTo(1);
 
@@ -237,8 +226,7 @@ class StompBrokerRelayMessageHandlerTests {
 	@Test
 	@SuppressWarnings("rawtypes")
 	void systemSubscription() {
-
-		MessageHandler handler = mock(MessageHandler.class);
+		MessageHandler handler = mock();
 		this.brokerRelay.setSystemSubscriptions(Collections.singletonMap("/topic/foo", handler));
 		this.brokerRelay.start();
 
@@ -262,7 +250,6 @@ class StompBrokerRelayMessageHandlerTests {
 
 	@Test
 	void alreadyConnected() {
-
 		this.brokerRelay.start();
 
 		Message<byte[]> connect = connectMessage("sess1", "joe");

spring-messaging/src/test/java/org/springframework/messaging/simp/user/DefaultUserDestinationResolverTests.java

@@ -34,16 +34,15 @@ import static org.mockito.BDDMockito.given;
 import static org.mockito.Mockito.mock;
 
 /**
- * Unit tests for
- * {@link org.springframework.messaging.simp.user.DefaultUserDestinationResolver}.
+ * Unit tests for {@link DefaultUserDestinationResolver}.
  *
  * @author Rossen Stoyanchev
  */
 public class DefaultUserDestinationResolverTests {
 
-	private DefaultUserDestinationResolver resolver;
+	private SimpUserRegistry registry = mock();
 
-	private SimpUserRegistry registry;
+	private DefaultUserDestinationResolver resolver = new DefaultUserDestinationResolver(this.registry);
 
 
 	@BeforeEach
@@ -51,10 +50,7 @@ public class DefaultUserDestinationResolverTests {
 		TestSimpUser simpUser = new TestSimpUser("joe");
 		simpUser.addSessions(new TestSimpSession("123"));
 
-		this.registry = mock(SimpUserRegistry.class);
 		given(this.registry.getUser("joe")).willReturn(simpUser);
-
-		this.resolver = new DefaultUserDestinationResolver(this.registry);
 	}
 
 	@Test

spring-messaging/src/test/java/org/springframework/messaging/simp/user/MultiServerUserRegistryTests.java

@@ -23,7 +23,6 @@ import java.util.Iterator;
 import java.util.Set;
 
 import org.junit.jupiter.api.Test;
-import org.mockito.Mockito;
 
 import org.springframework.messaging.Message;
 import org.springframework.messaging.converter.MappingJackson2MessageConverter;
@@ -40,7 +39,7 @@ import static org.mockito.Mockito.mock;
  */
 class MultiServerUserRegistryTests {
 
-	private final SimpUserRegistry localRegistry = Mockito.mock(SimpUserRegistry.class);
+	private final SimpUserRegistry localRegistry = mock();
 
 	private final MultiServerUserRegistry registry = new MultiServerUserRegistry(this.localRegistry);
 
@@ -49,7 +48,7 @@ class MultiServerUserRegistryTests {
 
 	@Test
 	void getUserFromLocalRegistry() {
-		SimpUser user = Mockito.mock(SimpUser.class);
+		SimpUser user = mock();
 		Set<SimpUser> users = Collections.singleton(user);
 		given(this.localRegistry.getUsers()).willReturn(users);
 		given(this.localRegistry.getUserCount()).willReturn(1);
@@ -66,7 +65,7 @@ class MultiServerUserRegistryTests {
 		TestSimpSession testSession = new TestSimpSession("remote-sess");
 		testSession.addSubscriptions(new TestSimpSubscription("remote-sub", "/remote-dest"));
 		testUser.addSessions(testSession);
-		SimpUserRegistry testRegistry = mock(SimpUserRegistry.class);
+		SimpUserRegistry testRegistry = mock();
 		given(testRegistry.getUsers()).willReturn(Collections.singleton(testUser));
 		Object registryDto = new MultiServerUserRegistry(testRegistry).getLocalRegistryDto();
 		Message<?> message = this.converter.toMessage(registryDto, null);
@@ -105,7 +104,7 @@ class MultiServerUserRegistryTests {
 		user1.addSessions(session1);
 		user2.addSessions(session2);
 		user3.addSessions(session3);
-		SimpUserRegistry userRegistry = mock(SimpUserRegistry.class);
+		SimpUserRegistry userRegistry = mock();
 		given(userRegistry.getUsers()).willReturn(new HashSet<>(Arrays.asList(user1, user2, user3)));
 		Object registryDto = new MultiServerUserRegistry(userRegistry).getLocalRegistryDto();
 		Message<?> message = this.converter.toMessage(registryDto, null);
@@ -135,7 +134,7 @@ class MultiServerUserRegistryTests {
 		TestSimpUser remoteUser = new TestSimpUser("joe");
 		TestSimpSession remoteSession = new TestSimpSession("sess456");
 		remoteUser.addSessions(remoteSession);
-		SimpUserRegistry remoteRegistry = mock(SimpUserRegistry.class);
+		SimpUserRegistry remoteRegistry = mock();
 		given(remoteRegistry.getUsers()).willReturn(Collections.singleton(remoteUser));
 		Object remoteRegistryDto = new MultiServerUserRegistry(remoteRegistry).getLocalRegistryDto();
 		Message<?> message = this.converter.toMessage(remoteRegistryDto, null);
@@ -164,7 +163,7 @@ class MultiServerUserRegistryTests {
 		// Prepare broadcast message from remote server
 		TestSimpUser testUser = new TestSimpUser("joe");
 		testUser.addSessions(new TestSimpSession("remote-sub"));
-		SimpUserRegistry testRegistry = mock(SimpUserRegistry.class);
+		SimpUserRegistry testRegistry = mock();
 		given(testRegistry.getUsers()).willReturn(Collections.singleton(testUser));
 		Object registryDto = new MultiServerUserRegistry(testRegistry).getLocalRegistryDto();
 		Message<?> message = this.converter.toMessage(registryDto, null);

spring-messaging/src/test/java/org/springframework/messaging/simp/user/UserDestinationMessageHandlerTests.java

@@ -46,9 +46,9 @@ class UserDestinationMessageHandlerTests {
 
 	private static final String SESSION_ID = "123";
 
-	private final SimpUserRegistry registry = mock(SimpUserRegistry.class);
+	private final SimpUserRegistry registry = mock();
 
-	private final SubscribableChannel brokerChannel = mock(SubscribableChannel.class);
+	private final SubscribableChannel brokerChannel = mock();
 
 	private final UserDestinationMessageHandler handler = new UserDestinationMessageHandler(new StubMessageChannel(), this.brokerChannel, new DefaultUserDestinationResolver(this.registry));
 

spring-messaging/src/test/java/org/springframework/messaging/simp/user/UserRegistryMessageHandlerTests.java

@@ -24,10 +24,7 @@ import java.util.concurrent.ScheduledFuture;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.ArgumentCaptor;
-import org.mockito.Mock;
-import org.mockito.junit.jupiter.MockitoExtension;
 
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageChannel;
@@ -49,52 +46,43 @@ import static org.mockito.Mockito.verifyNoMoreInteractions;
 
 /**
  * User tests for {@link UserRegistryMessageHandler}.
+ *
  * @author Rossen Stoyanchev
  */
-@ExtendWith(MockitoExtension.class)
-public class UserRegistryMessageHandlerTests {
+class UserRegistryMessageHandlerTests {
+
+	private SimpUserRegistry localRegistry = mock();
+
+	private MessageChannel brokerChannel = mock();
+
+	private TaskScheduler taskScheduler = mock();
+
+	private MultiServerUserRegistry multiServerRegistry = new MultiServerUserRegistry(this.localRegistry);
+
+	private MessageConverter converter = new MappingJackson2MessageConverter();
 
 	private UserRegistryMessageHandler handler;
 
-	private SimpUserRegistry localRegistry;
-
-	private MultiServerUserRegistry multiServerRegistry;
-
-	private MessageConverter converter;
-
-
-	@Mock
-	private MessageChannel brokerChannel;
-
-	@Mock
-	private TaskScheduler taskScheduler;
-
 
 	@BeforeEach
-	public void setUp() throws Exception {
-		this.converter = new MappingJackson2MessageConverter();
-
+	void setUp() throws Exception {
 		SimpMessagingTemplate brokerTemplate = new SimpMessagingTemplate(this.brokerChannel);
 		brokerTemplate.setMessageConverter(this.converter);
 
-		this.localRegistry = mock(SimpUserRegistry.class);
-		this.multiServerRegistry = new MultiServerUserRegistry(this.localRegistry);
-
 		this.handler = new UserRegistryMessageHandler(this.multiServerRegistry, brokerTemplate,
 				"/topic/simp-user-registry", this.taskScheduler);
 	}
 
 	@Test
-	public void brokerAvailableEvent() throws Exception {
+	void brokerAvailableEvent() throws Exception {
 		Runnable runnable = getUserRegistryTask();
 		assertThat(runnable).isNotNull();
 	}
 
 	@Test
 	@SuppressWarnings({ "unchecked", "rawtypes" })
-	public void brokerUnavailableEvent() throws Exception {
-
-		ScheduledFuture future = mock(ScheduledFuture.class);
+	void brokerUnavailableEvent() throws Exception {
+		ScheduledFuture future = mock();
 		given(this.taskScheduler.scheduleWithFixedDelay(any(Runnable.class), any(Duration.class))).willReturn(future);
 
 		BrokerAvailabilityEvent event = new BrokerAvailabilityEvent(true, this);
@@ -108,7 +96,7 @@ public class UserRegistryMessageHandlerTests {
 
 	@Test
 	@SuppressWarnings("rawtypes")
-	public void broadcastRegistry() throws Exception {
+	void broadcastRegistry() throws Exception {
 		given(this.brokerChannel.send(any())).willReturn(true);
 
 		TestSimpUser simpUser1 = new TestSimpUser("joe");
@@ -130,7 +118,7 @@ public class UserRegistryMessageHandlerTests {
 		MessageHeaders headers = message.getHeaders();
 		assertThat(SimpMessageHeaderAccessor.getDestination(headers)).isEqualTo("/topic/simp-user-registry");
 
-		MultiServerUserRegistry remoteRegistry = new MultiServerUserRegistry(mock(SimpUserRegistry.class));
+		MultiServerUserRegistry remoteRegistry = new MultiServerUserRegistry(mock());
 		remoteRegistry.addRemoteRegistryDto(message, this.converter, 20000);
 		assertThat(remoteRegistry.getUserCount()).isEqualTo(2);
 		assertThat(remoteRegistry.getUser("joe")).isNotNull();
@@ -138,8 +126,7 @@ public class UserRegistryMessageHandlerTests {
 	}
 
 	@Test
-	public void handleMessage() throws Exception {
-
+	void handleMessage() throws Exception {
 		TestSimpUser simpUser1 = new TestSimpUser("joe");
 		TestSimpUser simpUser2 = new TestSimpUser("jane");
 
@@ -147,7 +134,7 @@ public class UserRegistryMessageHandlerTests {
 		simpUser2.addSessions(new TestSimpSession("456"));
 
 		HashSet<SimpUser> simpUsers = new HashSet<>(Arrays.asList(simpUser1, simpUser2));
-		SimpUserRegistry remoteUserRegistry = mock(SimpUserRegistry.class);
+		SimpUserRegistry remoteUserRegistry = mock();
 		given(remoteUserRegistry.getUserCount()).willReturn(2);
 		given(remoteUserRegistry.getUsers()).willReturn(simpUsers);
 
@@ -162,8 +149,7 @@ public class UserRegistryMessageHandlerTests {
 	}
 
 	@Test
-	public void handleMessageFromOwnBroadcast() throws Exception {
-
+	void handleMessageFromOwnBroadcast() throws Exception {
 		TestSimpUser simpUser = new TestSimpUser("joe");
 		simpUser.addSessions(new TestSimpSession("123"));
 		given(this.localRegistry.getUserCount()).willReturn(1);

spring-messaging/src/test/java/org/springframework/messaging/support/ChannelInterceptorTests.java

@@ -54,7 +54,7 @@ public class ChannelInterceptorTests {
 
 	@Test
 	public void preSendInterceptorReturningModifiedMessage() {
-		Message<?> expected = mock(Message.class);
+		Message<?> expected = mock();
 		PreSendInterceptor interceptor = new PreSendInterceptor();
 		interceptor.setMessageToReturn(expected);
 		this.channel.addInterceptor(interceptor);

spring-messaging/src/test/java/org/springframework/messaging/support/ExecutorSubscribableChannelTests.java

@@ -83,7 +83,7 @@ public class ExecutorSubscribableChannelTests {
 	@Test
 	public void sendWithExecutor() {
 		BeforeHandleInterceptor interceptor = new BeforeHandleInterceptor();
-		TaskExecutor executor = mock(TaskExecutor.class);
+		TaskExecutor executor = mock();
 		ExecutorSubscribableChannel testChannel = new ExecutorSubscribableChannel(executor);
 		testChannel.addInterceptor(interceptor);
 		testChannel.subscribe(this.handler);
@@ -117,7 +117,7 @@ public class ExecutorSubscribableChannelTests {
 	public void failurePropagates()  {
 		RuntimeException ex = new RuntimeException();
 		willThrow(ex).given(this.handler).handleMessage(this.message);
-		MessageHandler secondHandler = mock(MessageHandler.class);
+		MessageHandler secondHandler = mock();
 		this.channel.subscribe(this.handler);
 		this.channel.subscribe(secondHandler);
 		try {
@@ -139,7 +139,7 @@ public class ExecutorSubscribableChannelTests {
 
 	@Test
 	public void interceptorWithModifiedMessage() {
-		Message<?> expected = mock(Message.class);
+		Message<?> expected = mock();
 		BeforeHandleInterceptor interceptor = new BeforeHandleInterceptor();
 		interceptor.setMessageToReturn(expected);
 		this.channel.addInterceptor(interceptor);