added a test for a self-referential tree structure using only one table

tests/TreeStructureTestCase.php

+<?php
+class TreeLeaf extends Doctrine_Record
+{
+    public function setTableDefinition()
+    {
+        $this->hasColumn('parent_id', 'integer');
+        $this->hasOne('TreeLeaf as Parent', 'TreeLeaf.parent_id', 'id');
+        $this->hasMany('TreeLeaf as Children', 'TreeLeaf.parent_id');
+    }
+}
+
+class Doctrine_TreeStructure_TestCase extends Doctrine_UnitTestCase
+{
+    public function prepareTables() { } /* we don't need the standard tables here */
+    public function prepareData() { } /* we don't need the standard data here */
+
+    public function testSelfReferentialRelationship() 
+    {
+        $component = new TreeLeaf();
+
+        try {
+            $rel = $component->getTable()->getRelation('Parent');
+            $rel = $component->getTable()->getRelation('Children');
+            $this->pass();
+        } catch(Doctrine_Exception $e) {
+            $this->fail();
+        }
+    }
+
+    public function testTreeLeafRelationships() 
+    {
+        /* structure:
+         *
+         * o1
+         *  -> o2
+         *  -> o3
+         *
+         * o4
+         *
+         * thus it would be expected that o1 has 2 children and o4 is a
+         * leaf with no parents or children.
+         */
+
+        $o1 = new TreeLeaf();
+        $o1->Parent = null;
+        $o1->save();
+
+        $o2 = new TreeLeaf();
+        $o2->Parent = $o1;
+        $o2->save();
+
+        $o3 = new TreeLeaf();
+        $o3->Parent = $o1;
+        $o3->save();
+
+        $o1->refresh();
+
+        $o4 = new TreeLeaf();
+        $o4->save();
+
+        $this->assertFalse(isset($o1->Parent));
+        $this->assertTrue(count($o1->Children) == 2);
+        $this->assertTrue(count($o1->get('Children')) == 2);
+
+        $this->assertTrue(isset($o2->Parent));
+        $this->assertTrue($o2->Parent == $o1);
+
+        $this->assertTrue(count($o4->Children) == 0);
+        $this->assertFalse(isset($o4->Parent));
+    }
+}
+

tests/run.php

@@ -136,6 +136,7 @@ $test->addTestCase(new Doctrine_Collection_TestCase());
 $test->addTestCase(new Doctrine_Relation_TestCase());
 $test->addTestCase(new Doctrine_Relation_Access_TestCase());
 $test->addTestCase(new Doctrine_Relation_ManyToMany_TestCase());
+$test->addTestCase(new Doctrine_TreeStructure_TestCase());
 
 
 // Datatypes