GH-10083: Apply Nullability to test-support module

spring-integration-test-support/src/main/java/org/springframework/integration/test/condition/package-info.java

@@ -0,0 +1,5 @@
+/**
+ * JUnit Jupiter conditions.
+ */
+@org.jspecify.annotations.NullMarked
+package org.springframework.integration.test.condition;

spring-integration-test-support/src/main/java/org/springframework/integration/test/context/TestApplicationContextAware.java

@@ -16,6 +16,8 @@
 
 package org.springframework.integration.test.context;
 
+import java.util.Objects;
+
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeAll;
 
@@ -54,7 +56,7 @@ static void beforeAll() {
 			TEST_INTEGRATION_CONTEXT.refresh();
 		}
 		catch (IllegalStateException ex) {
-			if (!ex.getMessage().contains("just call 'refresh' once")) {
+			if (!Objects.requireNonNull(ex.getMessage()).contains("just call 'refresh' once")) {
 				throw ex;
 			}
 		}

spring-integration-test-support/src/main/java/org/springframework/integration/test/context/package-info.java

@@ -0,0 +1,5 @@
+/**
+ * Test context support classes.
+ */
+@org.jspecify.annotations.NullMarked
+package org.springframework.integration.test.context;

spring-integration-test-support/src/main/java/org/springframework/integration/test/matcher/PayloadAndHeaderMatcher.java

@@ -22,6 +22,7 @@
 
 import org.hamcrest.BaseMatcher;
 import org.hamcrest.Description;
+import org.jspecify.annotations.Nullable;
 
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageHeaders;
@@ -56,13 +57,13 @@ public final class PayloadAndHeaderMatcher<T> extends BaseMatcher<Message<?>> {
 
 	private final Map<String, Object> headers;
 
-	private final String[] ignoreKeys;
+	private final String @Nullable [] ignoreKeys;
 
 	public static <P> PayloadAndHeaderMatcher<P> sameExceptIgnorableHeaders(Message<P> expected, String... ignoreKeys) {
 		return new PayloadAndHeaderMatcher<>(expected, ignoreKeys);
 	}
 
-	private PayloadAndHeaderMatcher(Message<T> expected, String... ignoreKeys) {
+	private PayloadAndHeaderMatcher(Message<T> expected, String @Nullable ... ignoreKeys) {
 		this.ignoreKeys = ignoreKeys != null ? Arrays.copyOf(ignoreKeys, ignoreKeys.length) : null;
 		this.payload = expected.getPayload();
 		this.headers = extractHeadersToAssert(expected);

spring-integration-test-support/src/main/java/org/springframework/integration/test/matcher/package-info.java

@@ -1,4 +1,5 @@
 /**
  * Provides several {@link org.hamcrest.BaseMatcher} implementations.
  */
+@org.jspecify.annotations.NullMarked
 package org.springframework.integration.test.matcher;

spring-integration-test-support/src/main/java/org/springframework/integration/test/predicate/package-info.java

@@ -0,0 +1,5 @@
+/**
+ * AssertJ predicates.
+ */
+@org.jspecify.annotations.NullMarked
+package org.springframework.integration.test.predicate;

spring-integration-test-support/src/main/java/org/springframework/integration/test/support/AbstractRequestResponseScenarioTest.java

@@ -17,6 +17,7 @@
 package org.springframework.integration.test.support;
 
 import java.util.List;
+import java.util.Objects;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -54,14 +55,15 @@
 @DirtiesContext
 public abstract class AbstractRequestResponseScenarioTest {
 
-	private List<RequestResponseScenario> scenarios = null;
+	@SuppressWarnings("NullAway.Init")
+	private List<RequestResponseScenario> scenarios;
 
 	@Autowired
 	private ApplicationContext applicationContext;
 
 	@BeforeEach
 	public void setUp() {
-		scenarios = defineRequestResponseScenarios();
+		this.scenarios = defineRequestResponseScenarios();
 	}
 
 	/**
@@ -79,8 +81,9 @@ public void testRequestResponseScenarios() {
 					MessageChannel.class);
 			MessageChannel outputChannel = applicationContext.getBean(scenario.getOutputChannelName(),
 					MessageChannel.class);
-			if (outputChannel instanceof SubscribableChannel) {
-				((SubscribableChannel) outputChannel).subscribe(scenario.getResponseValidator());
+			AbstractResponseValidator<?> responseValidator = scenario.getResponseValidator();
+			if (outputChannel instanceof SubscribableChannel subscribableChannel) {
+				subscribableChannel.subscribe(responseValidator);
 			}
 
 			assertThat(inputChannel.send(scenario.getMessage()))
@@ -89,14 +92,14 @@ public void testRequestResponseScenarios() {
 			if (outputChannel instanceof PollableChannel) {
 				Message<?> response = ((PollableChannel) outputChannel).receive(10000); // NOSONAR magic number
 				assertThat(response).as(name + ": receive timeout on " + scenario.getOutputChannelName()).isNotNull();
-				scenario.getResponseValidator().handleMessage(response);
+				responseValidator.handleMessage(Objects.requireNonNull(response));
 			}
 
-			assertThat(scenario.getResponseValidator().getLastMessage())
+			assertThat(responseValidator.getLastMessage())
 					.as("message was not handled on " + outputChannel + " for scenario '" + name + "'.").isNotNull();
 
 			if (outputChannel instanceof SubscribableChannel) {
-				((SubscribableChannel) outputChannel).unsubscribe(scenario.getResponseValidator());
+				((SubscribableChannel) outputChannel).unsubscribe(responseValidator);
 			}
 		}
 	}

spring-integration-test-support/src/main/java/org/springframework/integration/test/support/AbstractRequestResponseScenarioTests.java

@@ -17,6 +17,7 @@
 package org.springframework.integration.test.support;
 
 import java.util.List;
+import java.util.Objects;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -56,14 +57,15 @@
 @Deprecated(since = "7.0", forRemoval = true)
 public abstract class AbstractRequestResponseScenarioTests {
 
-	private List<RequestResponseScenario> scenarios = null;
+	@SuppressWarnings("NullAway.Init")
+	private List<RequestResponseScenario> scenarios;
 
 	@Autowired
 	private ApplicationContext applicationContext;
 
 	@Before
 	public void setUp() {
-		scenarios = defineRequestResponseScenarios();
+		this.scenarios = defineRequestResponseScenarios();
 	}
 
 	/**
@@ -91,7 +93,7 @@ public void testRequestResponseScenarios() {
 			if (outputChannel instanceof PollableChannel) {
 				Message<?> response = ((PollableChannel) outputChannel).receive(10000); // NOSONAR magic number
 				assertThat(response).as(name + ": receive timeout on " + scenario.getOutputChannelName()).isNotNull();
-				scenario.getResponseValidator().handleMessage(response);
+				scenario.getResponseValidator().handleMessage(Objects.requireNonNull(response));
 			}
 
 			assertThat(scenario.getResponseValidator().getLastMessage())

spring-integration-test-support/src/main/java/org/springframework/integration/test/support/AbstractResponseValidator.java

@@ -16,18 +16,22 @@
 
 package org.springframework.integration.test.support;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageHandler;
 import org.springframework.messaging.MessagingException;
 
 /**
  * The base class for response validators used for {@link RequestResponseScenario}s
+ *
  * @author David Turanski
+ * @author Artem Bilan
  *
  */
 public abstract class AbstractResponseValidator<T> implements MessageHandler {
 
-	private Message<?> lastMessage;
+	private @Nullable Message<?> lastMessage;
 
 	/**
 	 * handle the message
@@ -39,6 +43,13 @@ public void handleMessage(Message<?> message) throws MessagingException {
 		validateResponse((T) (extractPayload() ? message.getPayload() : message));
 	}
 
+	/**
+	 * @return the lastMessage
+	 */
+	public @Nullable Message<?> getLastMessage() {
+		return this.lastMessage;
+	}
+
 	/**
 	 * Implement this method to validate the response (Message or Payload)
 	 * @param response The response.
@@ -51,11 +62,4 @@ public void handleMessage(Message<?> message) throws MessagingException {
 	 */
 	protected abstract boolean extractPayload();
 
-	/**
-	 * @return the lastMessage
-	 */
-	public Message<?> getLastMessage() {
-		return lastMessage;
-	}
-
 }

spring-integration-test-support/src/main/java/org/springframework/integration/test/support/RequestResponseScenario.java

@@ -16,14 +16,20 @@
 
 package org.springframework.integration.test.support;
 
+import java.util.Objects;
+
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.messaging.Message;
 import org.springframework.messaging.support.GenericMessage;
 import org.springframework.util.Assert;
 
 /**
  * Defines a Spring Integration request response test scenario. All setter methods may
  * be chained.
+ *
  * @author David Turanski
+ * @author Artem Bilan
  *
  */
 public class RequestResponseScenario {
@@ -32,20 +38,21 @@ public class RequestResponseScenario {
 
 	private final String outputChannelName;
 
-	private Object payload;
+	private @Nullable Object payload;
 
-	private Message<?> message;
+	private @Nullable Message<?> message;
 
+	@SuppressWarnings("NullAway.Init")
 	private AbstractResponseValidator<?> responseValidator;
 
-	private String name;
+	private @Nullable String name;
 
-	protected Message<? extends Object> getMessage() {
-		if (message == null) {
-			return new GenericMessage<Object>(this.payload);
+	protected Message<?> getMessage() {
+		if (this.message == null) {
+			return new GenericMessage<>(Objects.requireNonNull(this.payload));
 		}
 		else {
-			return message;
+			return this.message;
 		}
 	}
 
@@ -64,23 +71,23 @@ public RequestResponseScenario(String inputChannelName, String outputChannelName
 	 * @return the input channel name
 	 */
 	public String getInputChannelName() {
-		return inputChannelName;
+		return this.inputChannelName;
 	}
 
 	/**
 	 *
 	 * @return the output channel name
 	 */
 	public String getOutputChannelName() {
-		return outputChannelName;
+		return this.outputChannelName;
 	}
 
 	/**
 	 *
 	 * @return the request message payload
 	 */
-	public Object getPayload() {
-		return payload;
+	public @Nullable Object getPayload() {
+		return this.payload;
 	}
 
 	/**
@@ -97,8 +104,8 @@ public RequestResponseScenario setPayload(Object payload) {
 	 *
 	 * @return the scenario name
 	 */
-	public String getName() {
-		return name;
+	public @Nullable String getName() {
+		return this.name;
 	}
 
 	/**
@@ -117,7 +124,7 @@ public RequestResponseScenario setName(String name) {
 	 * @see AbstractResponseValidator
 	 */
 	public AbstractResponseValidator<?> getResponseValidator() {
-		return responseValidator;
+		return this.responseValidator;
 	}
 
 	/**
@@ -142,7 +149,10 @@ public RequestResponseScenario setMessage(Message<?> message) {
 	}
 
 	protected void init() {
-		Assert.state(message == null || payload == null, "cannot set both message and payload");
+		Assert.state(this.message == null || this.payload == null, "cannot set both message and payload");
+		Assert.state(this.responseValidator != null,
+				"A 'responseValidator' must be provided for the 'SubscribableChannel' scenario.");
+
 	}
 
 }

spring-integration-test-support/src/main/java/org/springframework/integration/test/support/package-info.java

@@ -2,4 +2,5 @@
  * Provides several test support classes including for testing Spring Integration
  * request-response message scenarios.
  */
+@org.jspecify.annotations.NullMarked
 package org.springframework.integration.test.support;

spring-integration-test-support/src/main/java/org/springframework/integration/test/util/OnlyOnceTrigger.java

@@ -21,6 +21,8 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.scheduling.Trigger;
 import org.springframework.scheduling.TriggerContext;
 
@@ -52,7 +54,7 @@ public OnlyOnceTrigger() {
 	}
 
 	@Override
-	public Instant nextExecution(TriggerContext triggerContext) {
+	public @Nullable Instant nextExecution(TriggerContext triggerContext) {
 		if (this.hasRun.getAndSet(true)) {
 			this.latch.countDown();
 			return null;
@@ -61,6 +63,23 @@ public Instant nextExecution(TriggerContext triggerContext) {
 		return this.executionTime;
 	}
 
+	public void reset() {
+		this.latch = new CountDownLatch(1);
+		this.hasRun.set(false);
+	}
+
+	public void await() {
+		try {
+			if (!this.latch.await(10000, TimeUnit.MILLISECONDS)) { // NOSONAR magic number
+				throw new IllegalStateException("test latch.await() did not count down");
+			}
+		}
+		catch (InterruptedException ex) {
+			Thread.currentThread().interrupt();
+			throw new IllegalStateException("test latch.await() interrupted", ex);
+		}
+	}
+
 	@Override
 	public int hashCode() {
 		final int prime = 31;
@@ -84,21 +103,4 @@ public boolean equals(Object obj) {
 		return this.executionTime.equals(other.executionTime);
 	}
 
-	public void reset() {
-		this.latch = new CountDownLatch(1);
-		this.hasRun.set(false);
-	}
-
-	public void await() {
-		try {
-			if (!this.latch.await(10000, TimeUnit.MILLISECONDS)) { // NOSONAR magic number
-				throw new IllegalStateException("test latch.await() did not count down");
-			}
-		}
-		catch (InterruptedException ex) {
-			Thread.currentThread().interrupt();
-			throw new IllegalStateException("test latch.await() interrupted", ex);
-		}
-	}
-
 }