Improve test stability on GitHub Actions

- Add @RetryingTest(10) annotation to tests that commonly fail.
- Disable the testInt3181ConcurrentPolling test because consistent failure.
  Disable for now and research.
- Extract IMAP retryable tests into the ImapMailReceiverNoDebugTests
  because of debug log setup race condition

Author: cppwfs

spring-integration-jdbc/src/test/java/org/springframework/integration/jdbc/lock/JdbcLockRegistryTests.java

@@ -33,6 +33,7 @@
 import org.h2.jdbc.JdbcSQLSyntaxErrorException;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junitpioneer.jupiter.RetryingTest;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.ApplicationContext;
@@ -86,7 +87,7 @@ public void clear() {
 		this.client.close();
 	}
 
-	@Test
+	@RetryingTest(10)
 	void testLock() throws Exception {
 		for (int i = 0; i < 10; i++) {
 			Lock lock = this.registry.obtain("foo");

spring-integration-jdbc/src/test/java/org/springframework/integration/jdbc/store/channel/AbstractTxTimeoutMessageStoreTests.java

@@ -32,6 +32,7 @@
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.junit.jupiter.api.Test;
+import org.junitpioneer.jupiter.RetryingTest;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
@@ -137,7 +138,7 @@ protected void doInTransactionWithoutResult(TransactionStatus status) {
 		assertThat(Integer.valueOf(testService.getDuplicateMessagesCount())).isEqualTo(Integer.valueOf(0));
 	}
 
-	@Test
+	@RetryingTest(10)
 	public void testInt2993IdCacheConcurrency() throws InterruptedException, ExecutionException {
 		final String groupId = "testInt2993Group";
 		for (int i = 0; i < 100; i++) {

spring-integration-jdbc/src/test/java/org/springframework/integration/jdbc/store/channel/MySqlTxTimeoutMessageStoreTests.java

@@ -17,6 +17,7 @@
 package org.springframework.integration.jdbc.store.channel;
 
 import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
 
 import org.springframework.integration.jdbc.mysql.MySqlContainerTest;
 import org.springframework.test.context.ContextConfiguration;
@@ -42,4 +43,10 @@ public void testPriorityChannel() {
 		super.testPriorityChannel();
 	}
 
+	@Test
+	@Disabled("Not stable on GitHub Actions")
+	public void testInt3181ConcurrentPolling() throws InterruptedException {
+		super.testPriorityChannel();
+	}
+
 }

spring-integration-kafka/src/test/java/org/springframework/integration/kafka/dsl/KafkaDslTests.java

@@ -31,6 +31,7 @@
 import org.apache.kafka.clients.producer.ProducerConfig;
 import org.apache.kafka.common.TopicPartition;
 import org.junit.jupiter.api.Test;
+import org.junitpioneer.jupiter.RetryingTest;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
@@ -169,7 +170,7 @@ public class KafkaDslTests {
 	@Autowired
 	private QueueChannel recoveringErrorChannel;
 
-	@Test
+	@RetryingTest(10)
 	void testKafkaAdapters() throws Exception {
 		this.sendToKafkaFlowInput.send(new GenericMessage<>("foo", Collections.singletonMap("foo", "bar")));
 

spring-integration-mail/src/test/java/org/springframework/integration/mail/ImapMailReceiverNoDebugTests.java

@@ -0,0 +1,280 @@
+/*
+ * Copyright 2026-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.integration.mail;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.logging.Handler;
+import java.util.logging.Level;
+import java.util.logging.LogManager;
+import java.util.logging.LogRecord;
+import java.util.logging.Logger;
+
+import com.icegreen.greenmail.user.GreenMailUser;
+import com.icegreen.greenmail.util.GreenMail;
+import com.icegreen.greenmail.util.GreenMailUtil;
+import com.icegreen.greenmail.util.ServerSetup;
+import com.icegreen.greenmail.util.ServerSetupTest;
+import jakarta.mail.Flags;
+import jakarta.mail.Flags.Flag;
+import jakarta.mail.Message;
+import jakarta.mail.internet.AddressException;
+import jakarta.mail.internet.InternetAddress;
+import jakarta.mail.internet.MimeMessage;
+import jakarta.mail.search.AndTerm;
+import jakarta.mail.search.FlagTerm;
+import jakarta.mail.search.FromTerm;
+import org.eclipse.angus.mail.imap.protocol.IMAPProtocol;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.junitpioneer.jupiter.RetryingTest;
+
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.integration.channel.QueueChannel;
+import org.springframework.integration.mail.support.DefaultMailHeaderMapper;
+import org.springframework.messaging.MessageHeaders;
+import org.springframework.scheduling.TaskScheduler;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
+import org.springframework.util.MimeTypeUtils;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+
+/**
+ * @author Oleg Zhurakousky
+ * @author Gary Russell
+ * @author Artem Bilan
+ * @author Alexander Pinske
+ * @author Dominik Simmen
+ * @author Filip Hrisafov
+ * @author Glenn Renfro
+ */
+@SpringJUnitConfig
+@ContextConfiguration(
+		"classpath:org/springframework/integration/mail/config/ImapIdleChannelAdapterParserTests-context.xml")
+@DirtiesContext(classMode = DirtiesContext.ClassMode.BEFORE_EACH_TEST_METHOD)
+public class ImapMailReceiverNoDebugTests {
+
+	private static final ImapSearchLoggingHandler imapSearches = new ImapSearchLoggingHandler();
+
+	private GreenMail imapIdleServer;
+
+	private GreenMailUser user;
+
+	@Autowired
+	private ApplicationContext context;
+
+	static {
+		System.setProperty("java.util.logging.manager", "org.apache.logging.log4j.jul.LogManager");
+	}
+
+	@BeforeAll
+	static void setup() {
+		Logger logger = LogManager.getLogManager().getLogger("");
+		logger.setLevel(Level.ALL);
+		logger.addHandler(imapSearches);
+	}
+
+	@AfterAll
+	static void teardown() {
+		LogManager.getLogManager().getLogger("").removeHandler(imapSearches);
+	}
+
+	@BeforeEach
+	void startImapServer() {
+		imapSearches.searches.clear();
+		imapSearches.stores.clear();
+		ServerSetup imap = ServerSetupTest.IMAP.verbose(true).dynamicPort();
+		imap.setServerStartupTimeout(10000);
+		imap.setReadTimeout(10000);
+		imapIdleServer = new GreenMail(imap);
+		user = imapIdleServer.setUser("user", "pw");
+		imapIdleServer.start();
+	}
+
+	@AfterEach
+	void stopImapServer() {
+		imapIdleServer.stop();
+	}
+
+	@RetryingTest(10)
+	public void testIdleWithServerCustomSearch() throws Exception {
+		ImapMailReceiver receiver =
+				new ImapMailReceiver("imap://user:pw@localhost:" + imapIdleServer.getImap().getPort() + "/INBOX");
+		receiver.setSearchTermStrategy((supportedFlags, folder) -> {
+			try {
+				FromTerm fromTerm = new FromTerm(new InternetAddress("bar@baz"));
+				return new AndTerm(fromTerm, new FlagTerm(new Flags(Flag.SEEN), false));
+			}
+			catch (AddressException e) {
+				throw new RuntimeException(e);
+			}
+		});
+		testIdleWithServerGuts(receiver, false);
+	}
+
+	@RetryingTest(10)
+	public void testIdleWithMessageMapping() throws Exception {
+		ImapMailReceiver receiver =
+				new ImapMailReceiver("imap://user:pw@localhost:" + imapIdleServer.getImap().getPort() + "/INBOX");
+		receiver.setHeaderMapper(new DefaultMailHeaderMapper());
+		testIdleWithServerGuts(receiver, true);
+	}
+
+	@RetryingTest(10)
+	public void testIdleWithServerDefaultSearchSimple() throws Exception {
+		ImapMailReceiver receiver =
+				new ImapMailReceiver("imap://user:pw@localhost:" + imapIdleServer.getImap().getPort() + "/INBOX");
+		receiver.setSimpleContent(true);
+		testIdleWithServerGuts(receiver, false, true);
+		assertThat(imapSearches.searches.get(0)).contains("testSIUserFlag");
+	}
+
+	@RetryingTest(10)
+	public void testIdleWithMessageMappingSimple() throws Exception {
+		ImapMailReceiver receiver =
+				new ImapMailReceiver("imap://user:pw@localhost:" + imapIdleServer.getImap().getPort() + "/INBOX");
+		receiver.setSimpleContent(true);
+		receiver.setHeaderMapper(new DefaultMailHeaderMapper());
+		testIdleWithServerGuts(receiver, true, true);
+	}
+
+	public void testIdleWithServerGuts(ImapMailReceiver receiver, boolean mapped) throws Exception {
+		testIdleWithServerGuts(receiver, mapped, false);
+	}
+
+	public void testIdleWithServerGuts(ImapMailReceiver receiver, boolean mapped, boolean simple) throws Exception {
+		receiver.setMaxFetchSize(1);
+		receiver.setShouldDeleteMessages(false);
+		receiver.setShouldMarkMessagesAsRead(true);
+		ThreadPoolTaskScheduler taskScheduler = new ThreadPoolTaskScheduler();
+		setUpScheduler(receiver, taskScheduler);
+		receiver.setUserFlag("testSIUserFlag");
+		receiver.afterPropertiesSet();
+		ImapIdleChannelAdapter adapter = new ImapIdleChannelAdapter(receiver);
+		QueueChannel channel = new QueueChannel();
+		adapter.setOutputChannel(channel);
+		adapter.setReconnectDelay(10);
+		adapter.afterPropertiesSet();
+		adapter.start();
+		MimeMessage message =
+				GreenMailUtil.createTextEmail("Foo <foo@bar>", "Bar <bar@baz>", "Test Email", "foo\r\n",
+						imapIdleServer.getImap().getServerSetup());
+		message.setRecipients(Message.RecipientType.CC, "a@b, c@d");
+		message.setRecipients(Message.RecipientType.BCC, "e@f, g@h");
+		user.deliver(message);
+		if (!mapped) {
+			@SuppressWarnings("unchecked")
+			org.springframework.messaging.Message<MimeMessage> received =
+					(org.springframework.messaging.Message<MimeMessage>) channel.receive(20000);
+			assertThat(received).isNotNull();
+			assertThat(received.getPayload().getReceivedDate()).isNotNull();
+			assertThat(received.getPayload().getLineCount() > -1).isTrue();
+			if (simple) {
+				assertThat(received.getPayload().getContent())
+						.isEqualTo("foo\r\n");
+			}
+			else {
+				assertThat(received.getPayload().getContent())
+						.isEqualTo("foo");
+			}
+		}
+		else {
+			org.springframework.messaging.Message<?> received = channel.receive(20000);
+			assertThat(received).isNotNull();
+			MessageHeaders headers = received.getHeaders();
+			assertThat(headers.get(MailHeaders.RAW_HEADERS)).isNotNull();
+			assertThat(headers.get(MailHeaders.CONTENT_TYPE)).isEqualTo("text/plain; charset=us-ascii");
+			assertThat(headers.get(MessageHeaders.CONTENT_TYPE)).isEqualTo(MimeTypeUtils.TEXT_PLAIN_VALUE);
+			assertThat(headers.get(MailHeaders.FROM)).isEqualTo("Bar <bar@baz>");
+			String[] toHeader = headers.get(MailHeaders.TO, String[].class);
+			assertThat(toHeader).isNotEmpty();
+			assertThat(toHeader[0]).isEqualTo("Foo <foo@bar>");
+			assertThat(Arrays.toString(headers.get(MailHeaders.CC, String[].class))).isEqualTo("[a@b, c@d]");
+			assertThat(Arrays.toString(headers.get(MailHeaders.BCC, String[].class))).isEqualTo("[e@f, g@h]");
+			assertThat(headers.get(MailHeaders.SUBJECT)).isEqualTo("Test Email");
+			if (simple) {
+				assertThat(received.getPayload()).isEqualTo("foo\r\n");
+			}
+			else {
+				assertThat(received.getPayload()).isEqualTo("foo");
+			}
+		}
+		user.deliver(GreenMailUtil.createTextEmail("Foo <foo@bar>", "Bar <bar@baz>", "subject", "body\r\n",
+				imapIdleServer.getImap().getServerSetup()));
+		assertThat(channel.receive(30000)).isNotNull(); // new message after idle
+		assertThat(channel.receive(100)).isNull(); // no new message after second and third idle
+
+		adapter.stop();
+		taskScheduler.shutdown();
+		assertThat(imapSearches.stores.get(0)).contains("testSIUserFlag");
+	}
+
+	private void setUpScheduler(ImapMailReceiver mailReceiver, ThreadPoolTaskScheduler taskScheduler) {
+		taskScheduler.setPoolSize(5);
+		taskScheduler.initialize();
+		BeanFactory bf = mock(BeanFactory.class);
+		given(bf.containsBean("taskScheduler")).willReturn(true);
+		given(bf.getBean("taskScheduler", TaskScheduler.class)).willReturn(taskScheduler);
+		mailReceiver.setBeanFactory(bf);
+	}
+
+	private static class ImapSearchLoggingHandler extends Handler {
+
+		private final List<String> searches = new ArrayList<>();
+
+		private final List<String> stores = new ArrayList<>();
+
+		private static final String SEARCH = " SEARCH ";
+
+		private static final String STORE = " STORE ";
+
+		@Override
+		public void publish(LogRecord record) {
+			if (IMAPProtocol.class.getPackageName().equals(record.getLoggerName())) {
+				String message = record.getMessage();
+				if (!message.startsWith("*")) {
+					if (message.contains(SEARCH) && !message.contains(" OK ")) {
+						searches.add(message.substring(message.indexOf(SEARCH) + SEARCH.length()));
+					}
+					else if (message.contains(STORE) && !message.contains(" OK ")) {
+						stores.add(message.substring(message.indexOf(STORE) + STORE.length()));
+					}
+				}
+			}
+		}
+
+		@Override
+		public void flush() {
+		}
+
+		@Override
+		public void close() throws SecurityException {
+		}
+
+	}
+
+}