From e533a10b1c26c3d6a03af9cdb95d7f0a3c81da5c Mon Sep 17 00:00:00 2001
From: Wilmer Arambula <terabytesoftw@gmail.com>
Date: Mon, 30 Jun 2025 12:09:47 -0400
Subject: [PATCH 1/3] test: Add method to verify children order in tree
 traversal with disordered `XML` data.

---
 tests/NestedSetsBehaviorTest.php     | 49 ++++++++++++++++++++++++++++
 tests/support/data/test-disorder.xml | 17 ++++++++++
 2 files changed, 66 insertions(+)
 create mode 100644 tests/support/data/test-disorder.xml

diff --git a/tests/NestedSetsBehaviorTest.php b/tests/NestedSetsBehaviorTest.php
index ac6adbd..4ec1699 100644
--- a/tests/NestedSetsBehaviorTest.php
+++ b/tests/NestedSetsBehaviorTest.php
@@ -2271,4 +2271,53 @@ public function testProtectedMoveNodeAsRootRemainsAccessibleToSubclasses(): void
             '\'moveNodeAsRoot\' method should remain protected to allow subclass customization.',
         );
     }
+
+    public function testChildrenMethodRequiresOrderByForCorrectTreeTraversal(): void
+    {
+        $this->createDatabase();
+
+        $command = $this->getDb()->createCommand();
+        $xml = $this->loadFixtureXML('test-disorder.xml');
+
+        $children = $xml->children();
+
+        self::assertNotNull(
+            $children,
+            'XML children should not be \'null\'.',
+        );
+
+        foreach ($children as $element => $treeElement) {
+            if ($element === 'tree') {
+                $command->insert(
+                    'tree',
+                    [
+                        'name' => (string) $treeElement['name'],
+                        'lft' => (int) $treeElement['lft'],
+                        'rgt' => (int) $treeElement['rgt'],
+                        'depth' => (int) $treeElement['depth'],
+                    ],
+                )->execute();
+            }
+        }
+
+        $root = Tree::findOne(1);
+
+        self::assertNotNull(
+            $root,
+            'Root node with ID \'1\' should exist in the database.',
+        );
+
+        $childrenList = $root->children()->all();
+        $expectedOrder = ['Child B', 'Child C', 'Child A'];
+
+        for ($i = 0; $i < 3; $i++) {
+            if (isset($childrenList[$i]) === true) {
+                self::assertEquals(
+                    $expectedOrder[$i],
+                    $childrenList[$i]->getAttribute('name'),
+                    "Child at index {$i} should be {$expectedOrder[$i]} in correct \'lft\' order.",
+                );
+            }
+        }
+    }
 }
diff --git a/tests/support/data/test-disorder.xml b/tests/support/data/test-disorder.xml
new file mode 100644
index 0000000..fc6846f
--- /dev/null
+++ b/tests/support/data/test-disorder.xml
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<dataset>
+    <!-- Root node -->
+    <tree id="1" lft="1" rgt="8" depth="0" name="Root"/>
+
+    <!-- Children with INTENTIONALLY DISORDERED lft values to test ORDER BY dependency -->
+    <!-- Normal logical order would be: Child A(lft=2), Child B(lft=4), Child C(lft=6) -->
+    <!-- But we arrange them with swapped lft values to test if ORDER BY clause works -->
+    <!-- This child should be LAST in tree order (lft=6) but is inserted FIRST in XML -->
+    <tree id="2" lft="6" rgt="7" depth="1" name="Child A"/>
+
+    <!-- This child should be FIRST in tree order (lft=2) but is inserted SECOND in XML -->
+    <tree id="3" lft="2" rgt="3" depth="1" name="Child B"/>
+
+    <!-- This child should be MIDDLE in tree order (lft=4) but is inserted THIRD in XML -->
+    <tree id="4" lft="4" rgt="5" depth="1" name="Child C"/>
+</dataset>

From 4655cb0da30e46fe4e709a1f1d54ee8d26f9d345 Mon Sep 17 00:00:00 2001
From: Wilmer Arambula <terabytesoftw@gmail.com>
Date: Mon, 30 Jun 2025 12:16:50 -0400
Subject: [PATCH 2/3] test: Add assertion to verify the count of children in
 the list after tree traversal.

---
 tests/NestedSetsBehaviorTest.php | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tests/NestedSetsBehaviorTest.php b/tests/NestedSetsBehaviorTest.php
index 4ec1699..d8e7a1f 100644
--- a/tests/NestedSetsBehaviorTest.php
+++ b/tests/NestedSetsBehaviorTest.php
@@ -2310,6 +2310,12 @@ public function testChildrenMethodRequiresOrderByForCorrectTreeTraversal(): void
         $childrenList = $root->children()->all();
         $expectedOrder = ['Child B', 'Child C', 'Child A'];
 
+        self::assertCount(
+            3,
+            $childrenList,
+            'Children list should contain exactly 3 elements.',
+        );
+
         for ($i = 0; $i < 3; $i++) {
             if (isset($childrenList[$i]) === true) {
                 self::assertEquals(

From 0937cb7106ed06d8900b2c3ba151b60465aeb4db Mon Sep 17 00:00:00 2001
From: Wilmer Arambula <terabytesoftw@gmail.com>
Date: Mon, 30 Jun 2025 12:28:05 -0400
Subject: [PATCH 3/3] test: Refactor assertion loop for verifying children
 order in tree traversal.

---
 tests/NestedSetsBehaviorTest.php | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/tests/NestedSetsBehaviorTest.php b/tests/NestedSetsBehaviorTest.php
index d8e7a1f..59bef74 100644
--- a/tests/NestedSetsBehaviorTest.php
+++ b/tests/NestedSetsBehaviorTest.php
@@ -2316,12 +2316,12 @@ public function testChildrenMethodRequiresOrderByForCorrectTreeTraversal(): void
             'Children list should contain exactly 3 elements.',
         );
 
-        for ($i = 0; $i < 3; $i++) {
-            if (isset($childrenList[$i]) === true) {
+        foreach ($childrenList as $index => $child) {
+            if (isset($expectedOrder[$index])) {
                 self::assertEquals(
-                    $expectedOrder[$i],
-                    $childrenList[$i]->getAttribute('name'),
-                    "Child at index {$i} should be {$expectedOrder[$i]} in correct \'lft\' order.",
+                    $expectedOrder[$index],
+                    $child->getAttribute('name'),
+                    "Child at index {$index} should be {$expectedOrder[$index]} in correct \'lft\' order.",
                 );
             }
         }