Address PR #2 review feedback

ArrivalDepartureGeneratorDefaultImplTest: replace vacuous stub
re-assertions with verify()/verify(never()) interaction checks so the
tests fail if the short-circuit guards are removed.

FrequencyKalmanPredictionGeneratorImplTest: call
getMaxPredictionsTimeSecs() through KalmanPredictionGeneratorImpl
rather than PredictionGeneratorDefaultImpl so a future static
override on any intermediate layer will break the test.

SpatialMatchTest.atStop_layoverStopAlwaysCountsAsAtStop: move the
match to the segment midpoint, outside both beforeStopDistance and
afterStopDistance windows, so isAtStop can only be true via the
layover flag.

Author: aaronbrethorst

transitclock/src/test/java/org/transitclock/core/ArrivalDepartureGeneratorDefaultImplTest.java

@@ -2,6 +2,8 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoInteractions;
 import static org.mockito.Mockito.when;
 
@@ -22,11 +24,8 @@ public void generate_unpredictableVehicleIsANoOp() {
 
 		new ArrivalDepartureGeneratorDefaultImpl().generate(vs);
 
-		// The method returns early; nothing else on the mock should have been
-		// touched. isPredictable() will show in interactions, so we just
-		// re-assert the guard held by checking getMatch() was never consulted.
-		// Using a looser check here since Mockito's strict mode isn't enabled.
-		assertThat(vs.isPredictable()).isFalse();
+		verify(vs).isPredictable();
+		verify(vs, never()).getMatch();
 	}
 
 	@Test
@@ -35,20 +34,25 @@ public void generate_nullMatchIsANoOp() {
 		when(vs.isPredictable()).thenReturn(true);
 		when(vs.getMatch()).thenReturn(null);
 
-		// Should not throw, should not reach any downstream processing.
 		new ArrivalDepartureGeneratorDefaultImpl().generate(vs);
+
+		verify(vs).isPredictable();
+		verify(vs).getMatch();
+		verify(vs, never()).getPreviousMatch();
 	}
 
 	@Test
 	public void generate_doesNotTouchTrivialCollaboratorsWhenUnpredictable() {
 		VehicleState vs = mock(VehicleState.class);
 		when(vs.isPredictable()).thenReturn(false);
-		SpatialMatch match = mock(SpatialMatch.class);
+		TemporalMatch match = mock(TemporalMatch.class);
+		when(vs.getMatch()).thenReturn(match);
 
 		new ArrivalDepartureGeneratorDefaultImpl().generate(vs);
 
-		// Since the method short-circuits, it should never have asked for a
-		// match or a previous match.
+		verify(vs).isPredictable();
+		// Guard short-circuited before ever reading match off the state.
+		verify(vs, never()).getMatch();
 		verifyNoInteractions(match);
 	}
 }

transitclock/src/test/java/org/transitclock/core/SpatialMatchTest.java

@@ -152,8 +152,13 @@ public void atStop_inMiddleOfPathIsNotAtStop() {
 	@Test
 	public void atStop_layoverStopAlwaysCountsAsAtStop() {
 		// Layover flag forces atStop regardless of how far from the stop we are.
+		// Position the match at the midpoint of the segment — outside both
+		// beforeStopDistance (50m from end) and afterStopDistance (50m from
+		// start) — so the only thing that can drive isAtStop to true is the
+		// layover flag itself.
 		Block block = buildSimpleBlock(2, new boolean[] {true, false});
-		SpatialMatch match = matchAt(block, 0, 5.0); // almost at the start
+		VectorWithHeading seg = block.getStopPath(0, 0).getSegmentVector(0);
+		SpatialMatch match = matchAt(block, 0, seg.length() / 2.0);
 
 		assertThat(match.isAtStop()).isTrue();
 		assertThat(match.atEndOfPathStop()).isTrue();

transitclock/src/test/java/org/transitclock/core/predictiongenerator/frequency/traveltime/kalman/FrequencyKalmanPredictionGeneratorImplTest.java

@@ -26,8 +26,11 @@ public void classHierarchy_flowsThroughHistoricalAverageAndLastVehicleToDefault(
 	@Test
 	public void maxPredictionsTimeSecs_usesInheritedDefault() {
 		// Not overridden in any of the intermediate layers, so the 45-min
-		// default from PredictionGeneratorDefaultImpl still applies.
-		assertThat(PredictionGeneratorDefaultImpl.getMaxPredictionsTimeSecs())
+		// default from PredictionGeneratorDefaultImpl still applies. Assert
+		// through the Kalman class so that if a future change adds a static
+		// override on Kalman (or any intermediate layer), this test breaks
+		// instead of silently continuing to read the base-class value.
+		assertThat(KalmanPredictionGeneratorImpl.getMaxPredictionsTimeSecs())
 				.isEqualTo(45 * 60);
 	}
 }