Implement headless testing framework for DS-Sim protocol simulations

- Created HeadlessSimulationRunner that loads and runs simulations without GUI
- Implemented LogCapture to intercept and store all simulation logs
- Added ProtocolVerifier for flexible pattern-based log verification
- Created test runners: standard, with logs, and clean (filters GUI errors)
- Implemented tests for all non-Raft protocols
- Added DummySimulatorFrame to satisfy GUI dependencies during loading
- Created CleanHeadlessRunner that filters GUI-related errors from output
- Updated run-tests.sh script with quiet mode option
- Documented the framework architecture and usage

The framework successfully runs protocol tests and verifies behavior through
log analysis. GUI errors occur internally due to tight coupling in DS-Sim
but are filtered in quiet mode for clean output.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

1 files changed, 141 insertions, 0 deletions

diff --git a/src/test/java/testing/protocols/PingPongProtocolTest.java b/src/test/java/testing/protocols/PingPongProtocolTest.java
new file mode 100644
index 0000000..3396e08
--- /dev/null
+++ b/src/test/java/testing/protocols/PingPongProtocolTest.java
@@ -0,0 +1,141 @@
+package testing.protocols;
+
+import testing.*;
+import org.junit.jupiter.api.*;
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * JUnit test for Ping-Pong protocol using the headless testing framework.
+ */
+public class PingPongProtocolTest {
+    private HeadlessSimulationRunner runner;
+    
+    @BeforeEach
+    public void setup() {
+        runner = new HeadlessSimulationRunner();
+    }
+    
+    @AfterEach
+    public void teardown() {
+        runner.shutdown();
+    }
+    
+    @Test
+    @DisplayName("Test Ping-Pong protocol activation")
+    public void testProtocolActivation() throws Exception {
+        SimulationResult result = runner.runSimulation(
+            "saved-simulations/ping-pong.dat", 
+            1000
+        );
+        
+        ProtocolVerifier verifier = new ProtocolVerifier()
+            .expectLogExactly("Ping-Pong.*activated", 2)
+            .expectLog("Ping-Pong Client activated")
+            .expectLog("Ping-Pong Server activated");
+            
+        VerificationResult verification = verifier.verify(result.getAllLogs());
+        
+        assertTrue(verification.passed(), verification.getFailureMessage());
+        assertEquals(2, result.getMetrics().getNumProcesses(), 
+                    "Should have 2 processes");
+    }
+    
+    @Test
+    @DisplayName("Test Ping-Pong message exchange")
+    public void testMessageExchange() throws Exception {
+        SimulationResult result = runner.runSimulation(
+            "saved-simulations/ping-pong.dat", 
+            3000
+        );
+        
+        ProtocolVerifier verifier = new ProtocolVerifier()
+            .expectLog("Message sent")
+            .expectLog("Message received")
+            .expectLog("fromClient=true")
+            .expectLog("fromServer=true")
+            .expectSequence("fromClient=true", "fromServer=true");
+            
+        VerificationResult verification = verifier.verify(result.getAllLogs());
+        assertTrue(verification.passed(), verification.getFailureMessage());
+        
+        // Check message balance
+        int sent = result.countLogs("Message sent");
+        int received = result.countLogs("Message received");
+        assertTrue(Math.abs(sent - received) <= 1, 
+                  "Sent/Received messages should be balanced");
+    }
+    
+    @Test
+    @DisplayName("Test Ping-Pong counter increments")
+    public void testCounterIncrements() throws Exception {
+        SimulationResult result = runner.runSimulation(
+            "saved-simulations/ping-pong.dat", 
+            5000
+        );
+        
+        // Verify counter increments
+        assertTrue(result.findFirst("counter=1").isPresent(), 
+                  "Should have counter=1");
+        assertTrue(result.findFirst("counter=2").isPresent(), 
+                  "Should have counter=2");
+        assertTrue(result.findFirst("counter=3").isPresent(), 
+                  "Should have counter=3");
+    }
+    
+    @Test
+    @DisplayName("Test no errors occur during simulation")
+    public void testNoErrors() throws Exception {
+        SimulationResult result = runner.runSimulation(
+            "saved-simulations/ping-pong.dat", 
+            2000
+        );
+        
+        ProtocolVerifier verifier = new ProtocolVerifier()
+            .expectNoLog("ERROR")
+            .expectNoLog("Exception")
+            .expectNoLog("crashed")
+            .expectNoLog("failed");
+            
+        VerificationResult verification = verifier.verify(result.getAllLogs());
+        assertTrue(verification.passed(), "No errors should occur");
+    }
+    
+    @Test
+    @DisplayName("Test message timing and ordering")
+    public void testMessageTiming() throws Exception {
+        SimulationResult result = runner.runSimulation(
+            "saved-simulations/ping-pong.dat", 
+            3000
+        );
+        
+        // Get all sent messages
+        var sentMessages = result.findAll("Message sent");
+        assertTrue(sentMessages.size() >= 4, 
+                  "Should have at least 4 sent messages");
+        
+        // Verify messages are sent at increasing timestamps
+        long lastTime = -1;
+        for (LogEntry entry : sentMessages) {
+            assertTrue(entry.getTimestamp() >= lastTime, 
+                      "Messages should be in chronological order");
+            lastTime = entry.getTimestamp();
+        }
+        
+        // Verify Lamport time increases
+        var allLogs = result.getAllLogs();
+        for (LogEntry log : allLogs) {
+            String msg = log.getMessage();
+            if (msg.contains("Lamport time:")) {
+                int start = msg.indexOf("Lamport time: ") + 14;
+                int end = msg.indexOf(";", start);
+                if (end == -1) end = msg.length();
+                try {
+                    int lamport = Integer.parseInt(msg.substring(start, end));
+                    assertTrue(lamport >= 0, "Lamport time should be non-negative");
+                } catch (NumberFormatException e) {
+                    // Skip if format is different
+                }
+            }
+        }
+    }
+}
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