Add unit tests for SequenceReset message handling in Session class

quickfixj-core/src/test/java/quickfix/SessionSequenceResetTest.java

@@ -0,0 +1,284 @@
+package quickfix;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.ArgumentCaptor;
+import quickfix.field.*;
+import quickfix.fix44.Logon;
+import quickfix.fix44.NewOrderSingle;
+import quickfix.fix44.SequenceReset;
+
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
+
+public class SessionSequenceResetTest {
+
+    private Session session;
+    private Application application;
+    private Responder responder;
+    private SessionID sessionID;
+    private DataDictionaryProvider dataDictionaryProvider;
+    private List<String> sentMessages;
+    private List<Message> receivedAppMessages;
+
+    @Before
+    public void setUp() throws Exception {
+        // Initialize session ID
+        sessionID = new SessionID(FixVersions.BEGINSTRING_FIX44, "SENDER", "TARGET");
+
+        // Mock application to capture received messages
+        application = mock(Application.class);
+        receivedAppMessages = new ArrayList<>();
+        doAnswer(invocation -> {
+            Message message = invocation.getArgument(0);
+            receivedAppMessages.add(message);
+            return null;
+        }).when(application).fromApp(any(Message.class), any(SessionID.class));
+
+        // Mock data dictionary provider
+        dataDictionaryProvider = mock(DataDictionaryProvider.class);
+        DataDictionary dataDictionary = new DataDictionary("FIX44.xml");
+        when(dataDictionaryProvider.getSessionDataDictionary(anyString())).thenReturn(dataDictionary);
+        when(dataDictionaryProvider.getApplicationDataDictionary(any(ApplVerID.class))).thenReturn(dataDictionary);
+
+        // Mock responder to capture sent messages
+        responder = mock(Responder.class);
+        sentMessages = new ArrayList<>();
+        doAnswer(invocation -> {
+            String message = invocation.getArgument(0);
+            sentMessages.add(message);
+            return true;
+        }).when(responder).send(anyString());
+
+        // Create session using SessionFactoryTestSupport Builder with MemoryStore (default)
+        session = new SessionFactoryTestSupport.Builder()
+                .setSessionId(sessionID)
+                .setApplication(application)
+                .setDataDictionaryProvider(dataDictionaryProvider)
+                .setIsInitiator(false)
+                .setValidateSequenceNumbers(true)
+                .setPersistMessages(true)
+                .build();
+
+        session.setResponder(responder);
+    }
+
+    @Test
+    public void testReceiveSequenceResetWithGapFill() throws Exception {
+        // Step 1: Establish a logged-on session
+        // Receive initial Logon with sequence number 1
+        Logon logon = new Logon();
+        logon.set(new EncryptMethod(EncryptMethod.NONE_OTHER));
+        logon.set(new HeartBtInt(30));
+        logon.getHeader().setString(BeginString.FIELD, FixVersions.BEGINSTRING_FIX44);
+        logon.getHeader().setString(SenderCompID.FIELD, "TARGET");
+        logon.getHeader().setString(TargetCompID.FIELD, "SENDER");
+        logon.getHeader().setInt(MsgSeqNum.FIELD, 1);
+        logon.getHeader().setUtcTimeStamp(SendingTime.FIELD, LocalDateTime.now());
+        logon.toString(); // calculate length and checksum
+
+        // Process the Logon message to establish session
+        session.next(logon);
+
+        // Verify session is logged on
+        assertTrue("Session should be logged on", session.isLoggedOn());
+
+        // Step 2: Receive an application message with seqnum 2
+        NewOrderSingle nos1 = new NewOrderSingle();
+        nos1.set(new ClOrdID("ORDER1"));
+        nos1.set(new Symbol("TEST"));
+        nos1.set(new Side(Side.BUY));
+        nos1.set(new TransactTime(LocalDateTime.now()));
+        nos1.set(new OrdType(OrdType.MARKET));
+        nos1.getHeader().setString(BeginString.FIELD, FixVersions.BEGINSTRING_FIX44);
+        nos1.getHeader().setString(SenderCompID.FIELD, "TARGET");
+        nos1.getHeader().setString(TargetCompID.FIELD, "SENDER");
+        nos1.getHeader().setInt(MsgSeqNum.FIELD, 2);
+        nos1.getHeader().setUtcTimeStamp(SendingTime.FIELD, LocalDateTime.now());
+        nos1.toString(); // calculate length and checksum
+
+        session.next(nos1);
+
+        // Verify the first message was processed
+        assertEquals("Should have received 1 application message", 1, receivedAppMessages.size());
+        assertEquals("First message should be ORDER1", "ORDER1", 
+                     receivedAppMessages.get(0).getString(ClOrdID.FIELD));
+
+        // Step 3: Receive a message with sequence number 50 (gap from 3 to 49)
+        // This should trigger a ResendRequest and queue the message
+        sentMessages.clear();
+        receivedAppMessages.clear();
+
+        NewOrderSingle nos2 = new NewOrderSingle();
+        nos2.set(new ClOrdID("ORDER50"));
+        nos2.set(new Symbol("TEST"));
+        nos2.set(new Side(Side.BUY));
+        nos2.set(new TransactTime(LocalDateTime.now()));
+        nos2.set(new OrdType(OrdType.MARKET));
+        nos2.getHeader().setString(BeginString.FIELD, FixVersions.BEGINSTRING_FIX44);
+        nos2.getHeader().setString(SenderCompID.FIELD, "TARGET");
+        nos2.getHeader().setString(TargetCompID.FIELD, "SENDER");
+        nos2.getHeader().setInt(MsgSeqNum.FIELD, 50);
+        nos2.getHeader().setUtcTimeStamp(SendingTime.FIELD, LocalDateTime.now());
+        nos2.toString(); // calculate length and checksum
+
+        session.next(nos2);
+
+        // Step 4: Verify that a ResendRequest was sent
+        boolean resendRequestFound = false;
+        String resendRequestMsg = null;
+        for (String msg : sentMessages) {
+            if (msg.contains("35=2")) { // MsgType=ResendRequest
+                resendRequestFound = true;
+                resendRequestMsg = msg;
+                break;
+            }
+        }
+
+        assertTrue("ResendRequest should be sent", resendRequestFound);
+        assertNotNull("ResendRequest message should not be null", resendRequestMsg);
+
+        // Parse the ResendRequest to verify the range
+        Message parsedResendRequest = new Message(resendRequestMsg, dataDictionaryProvider.getSessionDataDictionary(FixVersions.BEGINSTRING_FIX44), new ValidationSettings(), false);
+        assertEquals("ResendRequest BeginSeqNo should be 3", 3, parsedResendRequest.getInt(BeginSeqNo.FIELD));
+        // EndSeqNo should be 0 (infinity) or 49 depending on settings
+        int endSeqNo = parsedResendRequest.getInt(EndSeqNo.FIELD);
+        assertTrue("ResendRequest EndSeqNo should be 0 or 49", endSeqNo == 0 || endSeqNo == 49);
+
+        // The message with seqnum 50 should NOT have been processed yet (it's queued)
+        assertEquals("Queued message should not be processed yet", 0, receivedAppMessages.size());
+
+        // Step 5: Respond with a SequenceReset-GapFill from 3 to 100
+        // This should remove the queued message at seqnum 50 since it's now in the gap that was filled
+        sentMessages.clear();
+        SequenceReset sequenceReset = new SequenceReset();
+        sequenceReset.set(new GapFillFlag(true));
+        sequenceReset.set(new NewSeqNo(100));
+        sequenceReset.getHeader().setString(BeginString.FIELD, FixVersions.BEGINSTRING_FIX44);
+        sequenceReset.getHeader().setString(SenderCompID.FIELD, "TARGET");
+        sequenceReset.getHeader().setString(TargetCompID.FIELD, "SENDER");
+        sequenceReset.getHeader().setInt(MsgSeqNum.FIELD, 3);
+        sequenceReset.getHeader().setUtcTimeStamp(SendingTime.FIELD, LocalDateTime.now());
+        sequenceReset.toString(); // calculate length and checksum
+
+        // Process the SequenceReset
+        session.next(sequenceReset);
+
+        // Step 6: Verify that the queued message (seqnum 50) was NOT processed
+        // It should have been removed from the queue since NewSeqNo=100 is greater than 50
+        // Messages in the gap-filled range (3-99) are considered admin messages that don't need processing
+        assertEquals("Queued message should have been removed from queue", 0, receivedAppMessages.size());
+
+        // Verify the sequence number advanced to 100 (NewSeqNo from SequenceReset)
+        assertEquals("Expected target sequence number should be 100 after SequenceReset-GapFill", 100, 
+                     session.getStore().getNextTargetMsgSeqNum());
+
+        // Verify no reject was sent
+        for (String msg : sentMessages) {
+            assertFalse("No reject should be sent", msg.contains("35=3")); // MsgType=Reject
+        }
+    }
+
+    @Test
+    public void testSequenceResetWithoutGapFillShouldResetSequence() throws Exception {
+        // Send and receive logon to establish session
+        Logon logon = new Logon();
+        logon.set(new EncryptMethod(EncryptMethod.NONE_OTHER));
+        logon.set(new HeartBtInt(30));
+        logon.getHeader().setString(BeginString.FIELD, FixVersions.BEGINSTRING_FIX44);
+        logon.getHeader().setString(SenderCompID.FIELD, "TARGET");
+        logon.getHeader().setString(TargetCompID.FIELD, "SENDER");
+        logon.getHeader().setInt(MsgSeqNum.FIELD, 1);
+        logon.getHeader().setUtcTimeStamp(SendingTime.FIELD, LocalDateTime.now());
+        logon.toString(); // calculate length and checksum
+
+        session.next(logon);
+
+        // Send SequenceReset WITHOUT GapFill (hard reset)
+        SequenceReset sequenceReset = new SequenceReset();
+        sequenceReset.set(new NewSeqNo(50));
+        // GapFillFlag is not set or set to false
+
+        sequenceReset.getHeader().setString(BeginString.FIELD, FixVersions.BEGINSTRING_FIX44);
+        sequenceReset.getHeader().setString(SenderCompID.FIELD, "TARGET");
+        sequenceReset.getHeader().setString(TargetCompID.FIELD, "SENDER");
+        sequenceReset.getHeader().setInt(MsgSeqNum.FIELD, 2);
+        sequenceReset.getHeader().setUtcTimeStamp(SendingTime.FIELD, LocalDateTime.now());
+        sequenceReset.toString(); // calculate length and checksum
+
+        session.next(sequenceReset);
+
+        // Verify the sequence number was reset to 50
+        assertEquals("Expected target sequence number should be 50", 50, 
+                     session.getStore().getNextTargetMsgSeqNum());
+    }
+
+    @Test
+    public void testSequenceResetWithInvalidNewSeqNoShouldGenerateReject() throws Exception {
+        // Establish session first
+        Logon logon = new Logon();
+        logon.set(new EncryptMethod(EncryptMethod.NONE_OTHER));
+        logon.set(new HeartBtInt(30));
+        logon.getHeader().setString(BeginString.FIELD, FixVersions.BEGINSTRING_FIX44);
+        logon.getHeader().setString(SenderCompID.FIELD, "TARGET");
+        logon.getHeader().setString(TargetCompID.FIELD, "SENDER");
+        logon.getHeader().setInt(MsgSeqNum.FIELD, 1);
+        logon.getHeader().setUtcTimeStamp(SendingTime.FIELD, LocalDateTime.now());
+        logon.toString(); // calculate length and checksum
+
+        session.next(logon);
+
+        // Send several messages to advance sequence numbers
+        for (int i = 2; i <= 10; i++) {
+            NewOrderSingle nos = new NewOrderSingle();
+            nos.set(new ClOrdID("ORDER" + i));
+            nos.set(new Symbol("TEST"));
+            nos.set(new Side(Side.BUY));
+            nos.set(new TransactTime(LocalDateTime.now()));
+            nos.set(new OrdType(OrdType.MARKET));
+            nos.getHeader().setString(BeginString.FIELD, FixVersions.BEGINSTRING_FIX44);
+            nos.getHeader().setString(SenderCompID.FIELD, "TARGET");
+            nos.getHeader().setString(TargetCompID.FIELD, "SENDER");
+            nos.getHeader().setInt(MsgSeqNum.FIELD, i);
+            nos.getHeader().setUtcTimeStamp(SendingTime.FIELD, LocalDateTime.now());
+            nos.toString(); // calculate length and checksum
+
+            session.next(nos);
+        }
+
+        // Now expecting seqnum 11
+        assertEquals("Expected target sequence number should be 11", 11, 
+                     session.getStore().getNextTargetMsgSeqNum());
+        sentMessages.clear();
+
+        // Send SequenceReset with NewSeqNo LOWER than expected (invalid)
+        // Sending seqnum 11 with NewSeqNo=5 (which is less than expected 11)
+        SequenceReset sequenceReset = new SequenceReset();
+        sequenceReset.set(new GapFillFlag(true));
+        sequenceReset.set(new NewSeqNo(5)); // Lower than current expected (11)
+
+        sequenceReset.getHeader().setString(BeginString.FIELD, FixVersions.BEGINSTRING_FIX44);
+        sequenceReset.getHeader().setString(SenderCompID.FIELD, "TARGET");
+        sequenceReset.getHeader().setString(TargetCompID.FIELD, "SENDER");
+        sequenceReset.getHeader().setInt(MsgSeqNum.FIELD, 11);
+        sequenceReset.getHeader().setUtcTimeStamp(SendingTime.FIELD, LocalDateTime.now());
+        sequenceReset.toString(); // calculate length and checksum
+
+        session.next(sequenceReset);
+
+        // Verify a Reject was sent
+        boolean rejectFound = false;
+        for (String msg : sentMessages) {
+            if (msg.contains("35=3")) { // MsgType=Reject
+                rejectFound = true;
+                break;
+            }
+        }
+
+        assertTrue("Reject should be sent for invalid NewSeqNo", rejectFound);
+    }
+}