GH-2463 - Apply default transaction timeout if possible.

This applies the default transaction timeout of the platform transaction
manager when the transaction definition is using the default.

Closes #2463

Author: michael-simons

src/main/java/org/springframework/data/neo4j/core/transaction/Neo4jTransactionManager.java

@@ -288,7 +288,7 @@ protected boolean isExistingTransaction(Object transaction) throws TransactionEx
 	protected void doBegin(Object transaction, TransactionDefinition definition) throws TransactionException {
 		Neo4jTransactionObject transactionObject = extractNeo4jTransaction(transaction);
 
-		TransactionConfig transactionConfig = Neo4jTransactionUtils.createTransactionConfigFrom(definition);
+		TransactionConfig transactionConfig = Neo4jTransactionUtils.createTransactionConfigFrom(definition, super.getDefaultTimeout());
 		boolean readOnly = definition.isReadOnly();
 
 		TransactionSynchronizationManager.setCurrentTransactionReadOnly(readOnly);

src/main/java/org/springframework/data/neo4j/core/transaction/Neo4jTransactionUtils.java

@@ -87,9 +87,10 @@ public static SessionConfig sessionConfig(boolean readOnly, Collection<Bookmark>
 	 * {@link TransactionDefinition#PROPAGATION_REQUIRED propagation required} behaviour are supported.
 	 *
 	 * @param definition The transaction definition passed to a Neo4j transaction manager
+	 * @param defaultTxManagerTimeout Default timeout from the tx manager (if available, if not, use something negative)
 	 * @return A Neo4j native transaction configuration
 	 */
-	static TransactionConfig createTransactionConfigFrom(TransactionDefinition definition) {
+	static TransactionConfig createTransactionConfigFrom(TransactionDefinition definition, int defaultTxManagerTimeout) {
 
 		if (definition.getIsolationLevel() != TransactionDefinition.ISOLATION_DEFAULT) {
 			throw new InvalidIsolationLevelException(
@@ -106,6 +107,8 @@ static TransactionConfig createTransactionConfigFrom(TransactionDefinition defin
 		TransactionConfig.Builder builder = TransactionConfig.builder();
 		if (definition.getTimeout() > 0) {
 			builder = builder.withTimeout(Duration.ofSeconds(definition.getTimeout()));
+		} else if (defaultTxManagerTimeout > 0) {
+			builder = builder.withTimeout(Duration.ofSeconds(defaultTxManagerTimeout));
 		}
 
 		return builder.build();

src/main/java/org/springframework/data/neo4j/core/transaction/ReactiveNeo4jTransactionManager.java

@@ -288,7 +288,7 @@ protected Mono<Void> doBegin(TransactionSynchronizationManager transactionSynchr
 		return Mono.defer(() -> {
 			ReactiveNeo4jTransactionObject transactionObject = extractNeo4jTransaction(transaction);
 
-			TransactionConfig transactionConfig = Neo4jTransactionUtils.createTransactionConfigFrom(transactionDefinition);
+			TransactionConfig transactionConfig = Neo4jTransactionUtils.createTransactionConfigFrom(transactionDefinition, -1);
 			boolean readOnly = transactionDefinition.isReadOnly();
 
 			transactionSynchronizationManager.setCurrentTransactionReadOnly(readOnly);

src/test/java/org/springframework/data/neo4j/core/transaction/Neo4jTransactionUtilsTest.java

@@ -17,10 +17,16 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+import java.time.Duration;
+
+import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.CsvSource;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.neo4j.driver.TransactionConfig;
 import org.springframework.data.neo4j.core.DatabaseSelection;
 import org.springframework.data.neo4j.core.UserSelection;
+import org.springframework.transaction.support.DefaultTransactionDefinition;
 import org.springframework.util.StringUtils;
 
 /**
@@ -57,4 +63,33 @@ void formatOngoingTxInAnotherDbErrorMessageShouldWork(String cdb, String rdb, St
 		);
 		assertThat(result).isEqualTo(expected);
 	}
+
+	@ParameterizedTest // GH-2463
+	@ValueSource(ints = {Integer.MIN_VALUE, -1, 0, DefaultTransactionDefinition.TIMEOUT_DEFAULT})
+	void shouldNotApplyNegativeOrZeroTimeOuts(int value) {
+
+		DefaultTransactionDefinition springDef = new DefaultTransactionDefinition();
+		springDef.setTimeout(DefaultTransactionDefinition.TIMEOUT_DEFAULT);
+		TransactionConfig driverConfig = Neo4jTransactionUtils.createTransactionConfigFrom(springDef, value);
+		assertThat(driverConfig.timeout()).isNull();
+	}
+
+	@ParameterizedTest // GH-2463
+	@ValueSource(ints = {Integer.MIN_VALUE, -1, 0})
+	void shouldPreferTxDef(int value) {
+
+		DefaultTransactionDefinition springDef = new DefaultTransactionDefinition();
+		springDef.setTimeout(2);
+		TransactionConfig driverConfig = Neo4jTransactionUtils.createTransactionConfigFrom(springDef, value);
+		assertThat(driverConfig.timeout()).isEqualTo(Duration.ofSeconds(2));
+	}
+
+	@Test // GH-2463
+	void shouldFallbackToTxManagerDefault() {
+
+		DefaultTransactionDefinition springDef = new DefaultTransactionDefinition();
+		springDef.setTimeout(DefaultTransactionDefinition.TIMEOUT_DEFAULT);
+		TransactionConfig driverConfig = Neo4jTransactionUtils.createTransactionConfigFrom(springDef, 3);
+		assertThat(driverConfig.timeout()).isEqualTo(Duration.ofSeconds(3));
+	}
 }