fix: Refactor CTAVLNode copy to postCopy and add testCopyLeafNode

Author: HossamSaberr

src/Containers-AVL-Tree-Tests/CTAVLTreeTest.class.st

@@ -148,6 +148,21 @@ CTAVLTreeTest >> testCopyLargeTree [
 	self assert: copiedTree asArray equals: tree asArray.
 ]
 
+{ #category : 'tests' }
+CTAVLTreeTest >> testCopyLeafNode [
+	| node copiedNode |
+	node := CTAVLNode new contents: 42.
+	
+	copiedNode := node copy.
+	
+	self assert: copiedNode contents equals: 42.
+	self deny: node == copiedNode.
+	
+	self assert: copiedNode height equals: 1.
+	self assert: copiedNode left isNilNode.
+	self assert: copiedNode right isNilNode
+]
+
 { #category : 'tests' }
 CTAVLTreeTest >> testCopySingleNode [
 	| copiedTree |

src/Containers-AVL-Tree/CTAVLNode.class.st

@@ -60,19 +60,6 @@ CTAVLNode >> contents: anObject [
 	contents := anObject
 ]
 
-{ #category : 'copying' }
-CTAVLNode >> copy [
-	| newNode |
-	newNode := self class new.
-	newNode contents: contents.
-	newNode left: left copy.
-	newNode right: right copy.
-
-	newNode instVarNamed: 'height' put: height. 
-
-	^ newNode
-]
-
 { #category : 'enumerating' }
 CTAVLNode >> elementsFrom: min to: max into: aCollection [
 
@@ -186,6 +173,14 @@ CTAVLNode >> left: aNode [
 	aNode ifNotNil: [ aNode parent: self ]
 ]
 
+{ #category : 'copying' }
+CTAVLNode >> postCopy [
+	super postCopy.
+	
+	left isNilNode ifFalse: [ left := left copy ].
+	right isNilNode ifFalse: [ right := right copy ]
+]
+
 { #category : 'enumerating' }
 CTAVLNode >> postOrderDo: aBlock [