fix(model-datastructure): detect changed children in a node if a child node changes its role

Author: Oleksandr Dzhychko

model-datastructure/src/commonMain/kotlin/org/modelix/model/lazy/CLTree.kt

@@ -450,9 +450,14 @@ class CLTree : ITree, IBulkTree {
                             if (oldElement!!::class != newElement!!::class) {
                                 throw RuntimeException("Unsupported type change of node " + key + "from " + oldElement::class.simpleName + " to " + newElement::class.simpleName)
                             }
-                            if (oldElement.parentId != newElement.parentId || oldElement.roleInParent != newElement.roleInParent) {
+                            if (oldElement.parentId != newElement.parentId) {
                                 visitor.containmentChanged(key)
                             }
+                            if (oldElement.parentId == newElement.parentId && oldElement.roleInParent != newElement.roleInParent) {
+                                visitor.containmentChanged(key)
+                                visitor.childrenChanged(oldElement.parentId, oldElement.roleInParent)
+                                visitor.childrenChanged(newElement.parentId, newElement.roleInParent)
+                            }
                             oldElement.propertyRoles.asSequence()
                                 .plus(newElement.propertyRoles.asSequence())
                                 .distinct()

model-datastructure/src/commonMain/kotlin/org/modelix/model/persistent/CPHamtNode.kt

@@ -23,6 +23,9 @@ import org.modelix.model.persistent.SerializationUtil.intFromHex
 import org.modelix.model.persistent.SerializationUtil.longFromHex
 import kotlin.jvm.JvmStatic
 
+/**
+ * Implementation of a hash array mapped trie.
+ */
 abstract class CPHamtNode : IKVValue {
     override var isWritten: Boolean = false
 

model-datastructure/src/commonTest/kotlin/DiffTest.kt

@@ -70,6 +70,41 @@ class DiffTest {
         }
     }
 
+    @Test
+    fun moveChildOutsideNode() {
+        runTest(
+            setOf(
+                TreeChangeCollector.ChildrenChangedEvent(ITree.ROOT_ID, "children1"),
+                TreeChangeCollector.ChildrenChangedEvent(200, "children1"),
+                TreeChangeCollector.ContainmentChangedEvent(100),
+            ),
+            {
+                it.addNewChild(ITree.ROOT_ID, "children1", -1, 100, null as ConceptReference?)
+                    .addNewChild(ITree.ROOT_ID, "children2", -1, 200, null as ConceptReference?)
+            },
+            {
+                it.moveChild(200, "children1", -1, 100)
+            },
+        )
+    }
+
+    @Test
+    fun moveChildInsideNode() {
+        runTest(
+            setOf(
+                TreeChangeCollector.ChildrenChangedEvent(ITree.ROOT_ID, "children1"),
+                TreeChangeCollector.ChildrenChangedEvent(ITree.ROOT_ID, "children2"),
+                TreeChangeCollector.ContainmentChangedEvent(100),
+            ),
+            {
+                it.addNewChild(ITree.ROOT_ID, "children1", -1, 100, null as ConceptReference?)
+            },
+            {
+                it.moveChild(ITree.ROOT_ID, "children2", -1, 100)
+            },
+        )
+    }
+
     @Test
     fun removeChild() {
         runTest(
@@ -90,7 +125,11 @@ class DiffTest {
         runTest(expectedEvents, { it }, mutator)
     }
 
-    private fun runTest(expectedEvents: Set<TreeChangeCollector.ChangeEvent>, initialMutator: (ITree) -> ITree, mutator: (ITree) -> ITree) {
+    private fun runTest(
+        expectedEvents: Set<TreeChangeCollector.ChangeEvent>,
+        initialMutator: (ITree) -> ITree,
+        mutator: (ITree) -> ITree,
+    ) {
         val tree1 = initialMutator(CLTree.builder(ObjectStoreCache(MapBaseStore())).build())
         val tree2 = mutator(tree1)
         val collector = TreeChangeCollector()