fix: address PR #421 review findings from Copilot and Claude Code Review

- Fix misleading "statically-linked" comment in fast-sim/build.gradle.kts (C3)
- Switch buildFastSim task to release binary, matching CI (R1)
- Fix SimulationEvent 2-part message duplication: source="" when only 2 parts (R3)
- Remove obsolete TRAIN_EVENTS backward compat fallback in TextReporter (R4)
- Use cp -rn in Dockerfile.fast-sim for BuildKit cache consistency (R5)
- Make SIGINT_EXIT_CODE internal (R6)
- Fix NativeExampleRegistry error message formatting (R7)
- Remove 2 legacy fallback tests, update affected test assertions

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: bedaHovorka

Dockerfile.fast-sim

@@ -60,7 +60,7 @@ COPY docker-kdisco/ /root/kdisco-prebuild/
 RUN --mount=type=cache,target=/root/.gradle/caches,id=fast-sim-gradle \
     --mount=type=cache,target=/root/.gradle/wrapper,id=fast-sim-wrapper \
     --mount=type=cache,target=/root/.m2/repository,id=fast-sim-m2 \
-    cp -r /root/kdisco-prebuild/. /root/.m2/repository/ && \
+    cp -rn /root/kdisco-prebuild/. /root/.m2/repository/ && \
     ./gradlew dependencies --no-daemon --warning-mode=summary
 
 # Layer 4: Copy source code (changes most frequently)
@@ -76,7 +76,7 @@ ENV GRADLE_OPTS="-Xmx2g"
 RUN --mount=type=cache,target=/root/.gradle/caches,id=fast-sim-gradle \
     --mount=type=cache,target=/root/.gradle/wrapper,id=fast-sim-wrapper \
     --mount=type=cache,target=/root/.m2/repository,id=fast-sim-m2 \
-    cp -r /root/kdisco-prebuild/. /root/.m2/repository/ && \
+    cp -rn /root/kdisco-prebuild/. /root/.m2/repository/ && \
     ./gradlew :fast-sim:linkReleaseExecutableLinuxX64 --no-daemon --warning-mode=summary
 
 # Verify binary was created

build.gradle.kts

@@ -79,7 +79,7 @@ listOf(
     tasks.register(name) { dependsOn(":desktop-ui:$name") }
 }
 
-tasks.register("buildFastSim") { dependsOn(":fast-sim:linkDebugExecutableLinuxX64") }  // debug; flip to Release once #415 lands
+tasks.register("buildFastSim") { dependsOn(":fast-sim:linkReleaseExecutableLinuxX64") }
 tasks.register("runFastSim") { dependsOn(":fast-sim:runDebugExecutableLinuxX64") }
 tasks.register("buildFastSimRelease") { dependsOn(":fast-sim:linkReleaseExecutableLinuxX64") }
 tasks.register("runFastSimRelease") { dependsOn(":fast-sim:runReleaseExecutableLinuxX64") }

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/sim/SimulationEvent.kt

@@ -35,8 +35,7 @@ data class SimulationEvent(
 			val fullMessage = event.newValue?.toString() ?: return null
 			val parts = fullMessage.trim().split(Regex("\\s+"), limit = 3)
 			val simulationTime = parts[0].toDoubleOrNull() ?: return null
-			val source = if (parts.size > 1) parts[1] else ""
-			// When only one non-time token exists (degenerate input), source and message are the same token.
+			val source = if (parts.size > 2) parts[1] else ""
 			val message = if (parts.size > 2) parts[2] else if (parts.size > 1) parts[1] else fullMessage
 			return SimulationEvent(simulationTime, reportType, source, message)
 		}

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/sim/TextReporter.kt

@@ -48,15 +48,6 @@ class TextReporter(
 			if (match != null) {
 				trainNames.add(match.groupValues[1])
 			}
-		} else if (simEvent.eventType == ReportType.TRAIN_EVENTS) {
-			// Backward compatibility for legacy logs that still emit TRAIN_EVENTS with
-			// the word "approved" in the message (pre-TRAIN_APPROVED). This path can be
-			// removed once all emitters migrate to TRAIN_APPROVED.
-			val combined = "${simEvent.source} ${simEvent.message}"
-			val approvedIndex = combined.indexOf("approved")
-			if (approvedIndex > 0) {
-				trainNames.add(combined.substring(0, approvedIndex).trim())
-			}
 		}
 
 		if (simEvent.eventType !in allowedTypes) return

core/src/commonTest/kotlin/cz/vutbr/fit/interlockSim/sim/SimulationEventTest.kt

@@ -78,7 +78,7 @@ class SimulationEventTest {
 		val cce = ContextChangeEvent("TRAIN_EVENTS", null, "5.0 vlak1")
 		val event = SimulationEvent.fromContextChangeEvent(cce)!!
 		assertEquals(5.0, event.simulationTime)
-		assertEquals("vlak1", event.source)
+		assertEquals("", event.source)
 		assertEquals("vlak1", event.message)
 	}
 

core/src/commonTest/kotlin/cz/vutbr/fit/interlockSim/sim/TextReporterTest.kt

@@ -229,29 +229,6 @@ class TextReporterTest {
 		assertTrue(summary.contains("0 trains"), "No train should be counted without regex match: $summary")
 	}
 
-	@Test
-	fun legacyTrainEventsFallbackCountsApprovedTrains() {
-		// Legacy path: TRAIN_EVENTS with "approved" keyword (backward compat)
-		val output = mutableListOf<String>()
-		val reporter = TextReporter(Verbosity.DEFAULT) { output.add(it) }
-		fireEvent(reporter, ReportType.TRAIN_EVENTS, "1.0 vlak1 approved IO1->IO2")
-		reporter.printSummary()
-		val summary = output.last()
-		assertTrue(summary.contains("1 trains"), "Legacy fallback should count 1 train: $summary")
-	}
-
-	@Test
-	fun legacyFallbackIgnoresApprovedAtStartOfCombined() {
-		// approvedIndex must be > 0 (not at position 0) to extract train name
-		val output = mutableListOf<String>()
-		val reporter = TextReporter(Verbosity.DEFAULT) { output.add(it) }
-		// SimulationEvent parsing: "1.0 approved" -> source="approved", message="approved"
-		// combined = "approved approved", approvedIndex=0 -> skipped
-		fireEvent(reporter, ReportType.TRAIN_EVENTS, "1.0 approved something")
-		reporter.printSummary()
-		val summary = output.last()
-		assertTrue(summary.contains("0 trains"), "Should not count when 'approved' is at position 0: $summary")
-	}
 
 	@Test
 	fun summaryWithZeroTrains() {
@@ -298,9 +275,7 @@ class TextReporterTest {
 	fun formatEventWithEmptySource() {
 		val output = mutableListOf<String>()
 		val reporter = TextReporter(Verbosity.DEFAULT) { output.add(it) }
-		// Two-part message: "5.0 msg" -> source="msg", message="msg"
-		// But source is not empty so it goes through else branch
-		// To test empty source, we need a degenerate one-part message that still parses
+		// Three-part message: "5.0 pathSet some-details" -> source="pathSet", message="some-details"
 		fireEvent(reporter, ReportType.PATH_SETTING, "5.0 pathSet some-details")
 		assertTrue(output[0].contains("pathSet"))
 	}
@@ -326,14 +301,14 @@ class TextReporterTest {
 	}
 
 	@Test
-	fun legacyFallbackDoesNotCountNonApprovedTrainEvents() {
+	fun trainEventsDoNotCountTrains() {
 		val output = mutableListOf<String>()
 		val reporter = TextReporter(Verbosity.DEFAULT) { output.add(it) }
 		fireEvent(reporter, ReportType.TRAIN_EVENTS, "1.0 vlak1 stopped at signal")
 		fireEvent(reporter, ReportType.TRAIN_EVENTS, "2.0 vlak1 exiting system")
 		reporter.printSummary()
 		val summary = output.last()
-		assertTrue(summary.contains("0 trains"), "Non-approved events should not count trains: $summary")
+		assertTrue(summary.contains("0 trains"), "TRAIN_EVENTS should not count trains: $summary")
 	}
 
 	// --- Contract tests: verify Train.formatApprovalMessage produces TextReporter-parseable output ---

fast-sim/build.gradle.kts

@@ -2,7 +2,7 @@
  * fast-sim/build.gradle.kts
  *
  * :fast-sim — native linuxX64 simulation CLI
- * Compiles to a statically-linked native binary with no JVM dependency.
+ * Compiles to a native binary with no JVM dependency.
  * Depends on :core (commonMain provides simulation engine, XML parsing, domain model).
  */
 

fast-sim/src/linuxX64Main/kotlin/cz/vutbr/fit/interlockSim/fastsim/Main.kt

@@ -26,7 +26,7 @@ import kotlin.concurrent.AtomicInt
 import kotlin.system.exitProcess
 
 /** Unix convention exit code for processes terminated by SIGINT (128 + 2). */
-const val SIGINT_EXIT_CODE = 130
+internal const val SIGINT_EXIT_CODE = 130
 
 /**
  * Holds the atomic SIGINT flag. Encapsulated in an object because the signal handler

fast-sim/src/linuxX64Main/kotlin/cz/vutbr/fit/interlockSim/fastsim/NativeExampleRegistry.kt

@@ -30,7 +30,7 @@ internal object NativeExampleRegistry {
 	fun create(name: String, endTime: Long, factory: NativeContextFactory): DefaultSimulationContext =
 		when (name) {
 			EXAMPLE_SHUNTING_LOOP -> createShuntingLoop(endTime, factory)
-			else -> throw IllegalArgumentException("Unknown example: '$name'. Available: $AVAILABLE")
+			else -> throw IllegalArgumentException("Unknown example: '$name'. Available: ${AVAILABLE.sorted().joinToString()}")
 		}
 
 	@Suppress("TooGenericExceptionCaught")