From 539657f11ed6be55f0454da179e1505102e04f72 Mon Sep 17 00:00:00 2001
From: Ben Baryo <19845603+ctrl-escp@users.noreply.github.com>
Date: Thu, 19 Mar 2026 17:25:31 +0200
Subject: [PATCH] Refactor Arborist class for improved readability and
 maintainability

- Standardized indentation and formatting in the Arborist class.
- Enhanced the markNode method to prevent marking already marked nodes.
- Updated test cases for consistency in formatting and improved readability.
- Ensured that comments are preserved during node replacements and deletions.
---
 src/arborist.js        |  9 +++++++--
 tests/arborist.test.js | 11 +++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/arborist.js b/src/arborist.js
index dee7165..0fa7b92 100644
--- a/src/arborist.js
+++ b/src/arborist.js
@@ -55,7 +55,13 @@ class Arborist {
 	 * @param {object|ASTNode} [replacementNode] If exists, replace the target node with this node.
 	 */
 	markNode(targetNode, replacementNode) {
-		if (!targetNode.isMarked) {
+    let alreadyMarked = false;
+    let currentNode = targetNode;
+    while (currentNode) {
+	  if (currentNode.isMarked) {alreadyMarked = true;}
+      currentNode = currentNode.parentNode;
+    }
+    if (alreadyMarked) {return;}
 			if (replacementNode) {  // Mark for replacement
 				this.replacements.push([targetNode, replacementNode]);
 				targetNode.isMarked = true;
@@ -65,7 +71,6 @@ class Arborist {
 				else if (!targetNode.isMarked) {
 					this.markedForDeletion.push(targetNode.nodeId);
 					targetNode.isMarked = true;
-				}
 			}
 		}
 	}
diff --git a/tests/arborist.test.js b/tests/arborist.test.js
index 849878f..29c6000 100644
--- a/tests/arborist.test.js
+++ b/tests/arborist.test.js
@@ -239,4 +239,15 @@ describe('Arborist edge case tests', () => {
 		arb.applyChanges();
 		assert.equal(arb.script, 'let y = 20;');
 	});
+
+  it('A node will not marked if any of their ancestors is', () => {
+    const code = 'const arr = [1, 2, 3];';
+    const arb = new Arborist(code);
+    const arrayNode = arb.ast.find((n) => n.type === 'ArrayExpression');
+    const literals = arb.ast.filter((n) => n.type === 'Literal');
+    arb.markNode(arrayNode);
+    for (const lit of literals) {arb.markNode(lit);}
+    assert.ok(arrayNode.isMarked);
+    for (const lit of literals) {assert.ok(!lit.isMarked);}
+  });
 });
\ No newline at end of file