[layerindex-web,2/5] tests: add StatsView tests

diff --git a/tests/test_stats_view.py b/tests/test_stats_view.py
new file mode 100644
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--- /dev/null
+++ b/tests/test_stats_view.py
@@ -0,0 +1,164 @@ 
+# layerindex-web - tests for StatsView
+#
+# Copyright (C) 2026 Konsulko Group
+#
+# Licensed under the MIT license, see COPYING.MIT for details
+#
+# SPDX-License-Identifier: MIT
+
+# Tests for bug #15391 - Statistics page timeout
+# https://bugzilla.yoctoproject.org/show_bug.cgi?id=15391
+#
+# The fix replaces a single annotated queryset (which generated one huge SQL
+# query with multiple COUNT(DISTINCT ...) JOINs) with per-branch individual
+# COUNT queries that are much cheaper at production data volumes.
+
+import pytest
+from django.test import TestCase
+from django.urls import reverse
+
+from layerindex.models import (Branch, LayerItem, LayerBranch, Recipe,
+                                BBClass, Machine, Distro)
+
+
+@pytest.mark.django_db
+class TestStatsView(TestCase):
+    """Tests for StatsView (bug #15391 - statistics page timeout fix)."""
+
+    def setUp(self):
+        # Create two visible branches with different sort priorities
+        self.branch1 = Branch.objects.create(
+            name='main',
+            bitbake_branch='master',
+            short_description='Main branch',
+            sort_priority=1,
+            hidden=False,
+            updates_enabled=True,
+        )
+        self.branch2 = Branch.objects.create(
+            name='wrynose',
+            bitbake_branch='2.18',
+            short_description='Wrynose branch',
+            sort_priority=2,
+            hidden=False,
+            updates_enabled=False,
+        )
+        # A hidden branch that should never appear in perbranch
+        self.branch_hidden = Branch.objects.create(
+            name='old-hidden',
+            bitbake_branch='1.0',
+            short_description='Old hidden branch',
+            sort_priority=99,
+            hidden=True,
+            updates_enabled=False,
+        )
+
+        # A layer
+        self.layer = LayerItem.objects.create(
+            name='meta-test',
+            status='P',
+            layer_type='A',
+            summary='Test layer',
+            description='A test layer',
+            vcs_url='git://example.com/meta-test.git',
+        )
+
+        # Wire up layerbranches
+        self.lb1 = LayerBranch.objects.create(layer=self.layer, branch=self.branch1)
+        self.lb2 = LayerBranch.objects.create(layer=self.layer, branch=self.branch2)
+
+        # Add objects only to branch1
+        Recipe.objects.create(
+            layerbranch=self.lb1,
+            filename='test_1.0.bb',
+            pn='test',
+            pv='1.0',
+            filepath='recipes-test',
+        )
+        BBClass.objects.create(
+            layerbranch=self.lb1,
+            name='testclass',
+        )
+        Machine.objects.create(
+            layerbranch=self.lb1,
+            name='qemux86',
+            description='QEMU x86 machine',
+        )
+        Distro.objects.create(
+            layerbranch=self.lb1,
+            name='testdistro',
+            description='Test distro',
+        )
+
+    def test_stats_view_returns_200(self):
+        """StatsView should return HTTP 200."""
+        response = self.client.get(reverse('stats'))
+        self.assertEqual(response.status_code, 200)
+
+    def test_perbranch_is_list_of_dicts(self):
+        """perbranch context should be a list of dicts, not a queryset."""
+        response = self.client.get(reverse('stats'))
+        perbranch = response.context['perbranch']
+        self.assertIsInstance(perbranch, list)
+        for item in perbranch:
+            self.assertIsInstance(item, dict)
+
+    def test_perbranch_excludes_hidden_branches(self):
+        """Hidden branches should not appear in perbranch."""
+        response = self.client.get(reverse('stats'))
+        names = [b['name'] for b in response.context['perbranch']]
+        self.assertIn('main', names)
+        self.assertIn('wrynose', names)
+        self.assertNotIn('old-hidden', names)
+
+    def test_perbranch_sorted_by_priority(self):
+        """Branches should be ordered by sort_priority."""
+        response = self.client.get(reverse('stats'))
+        names = [b['name'] for b in response.context['perbranch']]
+        self.assertEqual(names, ['master', 'main', 'wrynose'])
+
+    def test_perbranch_dict_has_required_keys(self):
+        """Each perbranch dict must contain all keys the template expects."""
+        required_keys = {'name', 'updates_enabled', 'layer_count',
+                         'recipe_count', 'class_count', 'machine_count', 'distro_count'}
+        response = self.client.get(reverse('stats'))
+        for item in response.context['perbranch']:
+            self.assertTrue(required_keys.issubset(item.keys()),
+                            f"Missing keys in perbranch item: {required_keys - item.keys()}")
+
+    def test_perbranch_counts_branch1(self):
+        """Per-branch counts for branch1 should reflect the test data."""
+        response = self.client.get(reverse('stats'))
+        branch1_data = next(b for b in response.context['perbranch'] if b['name'] == 'main')
+        self.assertEqual(branch1_data['layer_count'], 1)
+        self.assertEqual(branch1_data['recipe_count'], 1)
+        self.assertEqual(branch1_data['class_count'], 1)
+        self.assertEqual(branch1_data['machine_count'], 1)
+        self.assertEqual(branch1_data['distro_count'], 1)
+    
+    def test_perbranch_counts_branch2_empty(self):
+        """Branch2 has a layerbranch but no recipes/classes/machines/distros."""
+        response = self.client.get(reverse('stats'))
+        branch2_data = next(b for b in response.context['perbranch'] if b['name'] == 'wrynose')
+        self.assertEqual(branch2_data['layer_count'], 1)
+        self.assertEqual(branch2_data['recipe_count'], 0)
+        self.assertEqual(branch2_data['class_count'], 0)
+        self.assertEqual(branch2_data['machine_count'], 0)
+        self.assertEqual(branch2_data['distro_count'], 0)
+
+    def test_perbranch_updates_enabled_field(self):
+        """updates_enabled should be correctly reflected per branch."""
+        response = self.client.get(reverse('stats'))
+        perbranch = response.context['perbranch']
+        b1 = next(b for b in perbranch if b['name'] == 'main')
+        b2 = next(b for b in perbranch if b['name'] == 'wrynose')
+        self.assertTrue(b1['updates_enabled'])
+        self.assertFalse(b2['updates_enabled'])
+
+    def test_overall_context_keys_present(self):
+        """Overall statistics context keys should all be present."""
+        response = self.client.get(reverse('stats'))
+        for key in ('layercount', 'recipe_count_distinct', 'class_count_distinct',
+                    'machine_count_distinct', 'distro_count_distinct'):
+            self.assertIn(key, response.context,
+                          f"Missing context key: {key}")