fix: Propagate the readOnly property to the Bolt transaction. (#544)

This update makes sure that the connection's `readOnly` property is used when beginning a new Bolt transaction.

neo4j-jdbc/src/main/java/org/neo4j/jdbc/ConnectionImpl.java

@@ -640,7 +640,7 @@ Neo4jTransaction getTransaction(boolean autoCommitCheck) throws SQLException {
 					&& Neo4jTransaction.State.FAILED.equals(this.transaction.getState()))
 							? this.boltConnection.reset(false) : CompletableFuture.completedStage(null);
 			var transactionType = this.autoCommit ? TransactionType.UNCONSTRAINED : TransactionType.DEFAULT;
-			var beginStage = this.boltConnection.beginTransaction(Collections.emptySet(), AccessMode.WRITE,
+			var beginStage = this.boltConnection.beginTransaction(Collections.emptySet(), getAccessMode(),
 					transactionType, false);
 			this.transaction = new DefaultTransactionImpl(this.boltConnection,
 					exception -> this.fatalException = exception, resetStage.thenCompose(ignored -> beginStage),
@@ -649,6 +649,10 @@ Neo4jTransaction getTransaction(boolean autoCommitCheck) throws SQLException {
 		return this.transaction;
 	}
 
+	private AccessMode getAccessMode() {
+		return this.readOnly ? AccessMode.READ : AccessMode.WRITE;
+	}
+
 	@Override
 	public void flushTranslationCache() {
 		synchronized (this) {

neo4j-jdbc/src/test/java/org/neo4j/jdbc/ConnectionImplTests.java

@@ -301,6 +301,26 @@ void shouldUpdateReadOnly() throws SQLException {
 		assertThat(connection.isReadOnly()).isTrue();
 	}
 
+	@ParameterizedTest
+	@ValueSource(booleans = { true, false })
+	void shouldPassAccessModeToBoltConnection(boolean readOnly) throws SQLException {
+		// given
+		var boltConnection = mock(BoltConnection.class);
+		var accessMode = readOnly ? AccessMode.READ : AccessMode.WRITE;
+		given(boltConnection.beginTransaction(Collections.emptySet(), accessMode, TransactionType.UNCONSTRAINED, false))
+			.willReturn(CompletableFuture.completedStage(null));
+		var connection = makeConnection(boltConnection);
+		connection.setReadOnly(readOnly);
+
+		// when
+		var transaction = connection.getTransaction();
+
+		// then
+		assertThat(transaction).isNotNull();
+		then(boltConnection).should()
+			.beginTransaction(Collections.emptySet(), accessMode, TransactionType.UNCONSTRAINED, false);
+	}
+
 	@Test
 	void shouldThrowOnUpdatingReadOnlyDuringTransaction() throws SQLException {
 		var boltConnection = mock(BoltConnection.class);