Initial commit: Django project with boxes app

- Set up Django 5.2.9 project structure
- Add boxes app with Box and BoxType models
- Box: alphanumeric ID (max 10 chars) with foreign key to BoxType
- BoxType: name and dimensions (width/height/length in mm)
- Configure admin interface for both models
- Add comprehensive test suite (14 tests)

boxes/tests.py

@@ -0,0 +1,130 @@
+from django.contrib.admin.sites import AdminSite
+from django.db import IntegrityError
+from django.test import TestCase
+
+from .admin import BoxAdmin, BoxTypeAdmin
+from .models import Box, BoxType
+
+
+class BoxTypeModelTests(TestCase):
+    """Tests for the BoxType model."""
+
+    def setUp(self):
+        """Set up test fixtures."""
+        self.box_type = BoxType.objects.create(
+            name='Small Box',
+            width=100,
+            height=50,
+            length=150
+        )
+
+    def test_box_type_str_returns_name(self):
+        """BoxType __str__ should return the name."""
+        self.assertEqual(str(self.box_type), 'Small Box')
+
+    def test_box_type_creation(self):
+        """BoxType should be created with correct attributes."""
+        self.assertEqual(self.box_type.name, 'Small Box')
+        self.assertEqual(self.box_type.width, 100)
+        self.assertEqual(self.box_type.height, 50)
+        self.assertEqual(self.box_type.length, 150)
+
+    def test_box_type_ordering(self):
+        """BoxTypes should be ordered by name."""
+        BoxType.objects.create(name='Alpha Box', width=10, height=10, length=10)
+        BoxType.objects.create(name='Zeta Box', width=20, height=20, length=20)
+        box_types = list(BoxType.objects.values_list('name', flat=True))
+        self.assertEqual(box_types, ['Alpha Box', 'Small Box', 'Zeta Box'])
+
+
+class BoxModelTests(TestCase):
+    """Tests for the Box model."""
+
+    def setUp(self):
+        """Set up test fixtures."""
+        self.box_type = BoxType.objects.create(
+            name='Standard Box',
+            width=200,
+            height=100,
+            length=300
+        )
+        self.box = Box.objects.create(
+            id='BOX001',
+            box_type=self.box_type
+        )
+
+    def test_box_str_returns_id(self):
+        """Box __str__ should return the box ID."""
+        self.assertEqual(str(self.box), 'BOX001')
+
+    def test_box_creation(self):
+        """Box should be created with correct attributes."""
+        self.assertEqual(self.box.id, 'BOX001')
+        self.assertEqual(self.box.box_type, self.box_type)
+
+    def test_box_type_relationship(self):
+        """Box should be accessible from BoxType via related_name."""
+        self.assertIn(self.box, self.box_type.boxes.all())
+
+    def test_box_id_max_length(self):
+        """Box ID should accept up to 10 characters."""
+        box = Box.objects.create(id='ABCD123456', box_type=self.box_type)
+        self.assertEqual(len(box.id), 10)
+
+    def test_box_type_protect_on_delete(self):
+        """Deleting a BoxType with boxes should raise IntegrityError."""
+        with self.assertRaises(IntegrityError):
+            self.box_type.delete()
+
+    def test_box_type_delete_when_no_boxes(self):
+        """Deleting a BoxType without boxes should succeed."""
+        empty_type = BoxType.objects.create(
+            name='Empty Type',
+            width=10,
+            height=10,
+            length=10
+        )
+        empty_type_id = empty_type.id
+        empty_type.delete()
+        self.assertFalse(BoxType.objects.filter(id=empty_type_id).exists())
+
+
+class BoxTypeAdminTests(TestCase):
+    """Tests for the BoxType admin configuration."""
+
+    def setUp(self):
+        """Set up test fixtures."""
+        self.site = AdminSite()
+        self.admin = BoxTypeAdmin(BoxType, self.site)
+
+    def test_list_display(self):
+        """BoxTypeAdmin should display correct fields."""
+        self.assertEqual(
+            self.admin.list_display,
+            ('name', 'width', 'height', 'length')
+        )
+
+    def test_search_fields(self):
+        """BoxTypeAdmin should search by name."""
+        self.assertEqual(self.admin.search_fields, ('name',))
+
+
+class BoxAdminTests(TestCase):
+    """Tests for the Box admin configuration."""
+
+    def setUp(self):
+        """Set up test fixtures."""
+        self.site = AdminSite()
+        self.admin = BoxAdmin(Box, self.site)
+
+    def test_list_display(self):
+        """BoxAdmin should display correct fields."""
+        self.assertEqual(self.admin.list_display, ('id', 'box_type'))
+
+    def test_list_filter(self):
+        """BoxAdmin should filter by box_type."""
+        self.assertEqual(self.admin.list_filter, ('box_type',))
+
+    def test_search_fields(self):
+        """BoxAdmin should search by id."""
+        self.assertEqual(self.admin.search_fields, ('id',))