Coverage

Author: triceo

core/src/main/java/ai/timefold/solver/core/impl/bavet/common/ExistsCounterHandle.java

@@ -29,11 +29,11 @@ final class ExistsCounterHandle<LeftTuple_ extends AbstractTuple> {
     }
 
     public void removeByLeft() {
-        rightHandleSet.remove(this);
+        rightHandleSet.remove(this); // The counter will be removed from the left handle set by the caller.
     }
 
     public void removeByRight() {
-        counter.leftHandleSet.remove(this);
+        counter.leftHandleSet.remove(this); // The counter will be removed from the right handle set by the caller.
     }
 
 }

core/src/main/java/ai/timefold/solver/core/impl/bavet/common/index/IndexedSet.java

@@ -1,16 +1,17 @@
 package ai.timefold.solver.core.impl.bavet.common.index;
 
-import ai.timefold.solver.core.impl.util.ElementAwareList;
-import org.jspecify.annotations.NullMarked;
-import org.jspecify.annotations.Nullable;
-
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 import java.util.function.Consumer;
 import java.util.function.Predicate;
 
+import ai.timefold.solver.core.impl.util.ElementAwareList;
+
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
 /**
  * {@link ArrayList}-backed set which allows to {@link #remove(Object)} an element
  * without knowing its position and without an expensive lookup.
@@ -161,10 +162,14 @@ private void forEachNonCompacting(Consumer<T> elementConsumer) {
     }
 
     private void forEachNonCompacting(Consumer<T> elementConsumer, int startingIndex) {
-        for (var i = startingIndex; i <= lastElementPosition; i++) {
+        var oldLastElementPosition = lastElementPosition;
+        for (var i = startingIndex; i <= oldLastElementPosition; i++) {
             var element = elementList.get(i);
             if (element != null) {
                 elementConsumer.accept(element);
+                if (lastElementPosition != oldLastElementPosition) {
+                    throw new IllegalStateException("Impossible state: the IndexedSet was modified while being iterated.");
+                }
             }
         }
     }
@@ -239,11 +244,15 @@ private void forEachCompacting(Consumer<T> elementConsumer) {
     }
 
     private @Nullable T findFirstNonCompacting(Predicate<T> elementPredicate, int startingIndex) {
-        for (var i = startingIndex; i <= lastElementPosition; i++) {
+        var oldLastElementPosition = lastElementPosition;
+        for (var i = startingIndex; i <= oldLastElementPosition; i++) {
             var element = elementList.get(i);
             if (element != null && elementPredicate.test(element)) {
                 return element;
             }
+            if (lastElementPosition != oldLastElementPosition) {
+                throw new IllegalStateException("Impossible state: the IndexedSet was modified while being searched.");
+            }
         }
         return null;
     }