Fixed #25791 -- Implement autoreload behaviour for cached template loader.

tests/template_tests/test_autoreloader.py

@@ -0,0 +1,92 @@
+from pathlib import Path
+from unittest import mock
+
+from django.template import autoreload
+from django.test import SimpleTestCase, override_settings
+from django.test.utils import require_jinja2
+
+ROOT = Path(__file__).parent.absolute()
+EXTRA_TEMPLATES_DIR = ROOT / "templates_extra"
+
+
+@override_settings(
+    INSTALLED_APPS=['template_tests'],
+    TEMPLATES=[{
+        'BACKEND': 'django.template.backends.dummy.TemplateStrings',
+        'APP_DIRS': True,
+    }, {
+        'BACKEND': 'django.template.backends.django.DjangoTemplates',
+        'DIRS': [EXTRA_TEMPLATES_DIR],
+        'OPTIONS': {
+            'context_processors': [
+                'django.template.context_processors.request',
+            ],
+            'loaders': [
+                'django.template.loaders.filesystem.Loader',
+                'django.template.loaders.app_directories.Loader',
+            ]
+        },
+    }])
+class TemplateReloadTests(SimpleTestCase):
+    @mock.patch('django.template.autoreload.reset_loaders')
+    def test_template_changed(self, mock_reset):
+        template_path = Path(__file__).parent / 'templates' / 'index.html'
+        self.assertTrue(autoreload.template_changed(None, template_path))
+        mock_reset.assert_called_once()
+
+    @mock.patch('django.template.autoreload.reset_loaders')
+    def test_non_template_changed(self, mock_reset):
+        self.assertIsNone(autoreload.template_changed(None, Path(__file__)))
+        mock_reset.assert_not_called()
+
+    def test_watch_for_template_changes(self):
+        mock_reloader = mock.MagicMock()
+        autoreload.watch_for_template_changes(mock_reloader)
+        self.assertSequenceEqual(
+            sorted(mock_reloader.watch_dir.call_args_list),
+            [
+                mock.call(ROOT / 'templates', '**/*'),
+                mock.call(ROOT / 'templates_extra', '**/*')
+            ]
+        )
+
+    def test_get_template_directories(self):
+        self.assertSetEqual(
+            autoreload.get_template_directories(),
+            {
+                ROOT / 'templates_extra',
+                ROOT / 'templates',
+            }
+        )
+
+    @mock.patch('django.template.loaders.base.Loader.reset')
+    def test_reset_all_loaders(self, mock_reset):
+        autoreload.reset_loaders()
+        self.assertEqual(mock_reset.call_count, 2)
+
+
+@require_jinja2
+@override_settings(INSTALLED_APPS=['template_tests'])
+class Jinja2TemplateReloadTests(SimpleTestCase):
+    def test_watch_for_template_changes(self):
+        mock_reloader = mock.MagicMock()
+        autoreload.watch_for_template_changes(mock_reloader)
+        self.assertSequenceEqual(
+            sorted(mock_reloader.watch_dir.call_args_list),
+            [
+                mock.call(ROOT / 'templates', '**/*'),
+            ]
+        )
+
+    def test_get_template_directories(self):
+        self.assertSetEqual(
+            autoreload.get_template_directories(),
+            {
+                ROOT / 'templates',
+            }
+        )
+
+    @mock.patch('django.template.loaders.base.Loader.reset')
+    def test_reset_all_loaders(self, mock_reset):
+        autoreload.reset_loaders()
+        self.assertEqual(mock_reset.call_count, 0)