feat: expand platform APIs, sources, and test coverage

tests/apps/core/test_celery_module.py

@@ -0,0 +1,61 @@
+from __future__ import annotations
+
+import importlib.util
+import os
+import sys
+from pathlib import Path
+from types import SimpleNamespace
+from unittest.mock import MagicMock, patch
+
+from django.test import SimpleTestCase
+
+
+CELERY_MODULE_PATH = (
+    Path(__file__).resolve().parents[3] / "src" / "core" / "celery.py"
+)
+
+
+def _load_module(module_name: str):
+    spec = importlib.util.spec_from_file_location(module_name, CELERY_MODULE_PATH)
+    module = importlib.util.module_from_spec(spec)
+    assert spec.loader is not None
+    spec.loader.exec_module(module)
+    return module
+
+
+class CeleryModuleTest(SimpleTestCase):
+    def test_import_requires_django_settings_module(self):
+        with patch.dict(os.environ, {}, clear=True):
+            with self.assertRaisesMessage(
+                RuntimeError,
+                "DJANGO_SETTINGS_MODULE is not set.",
+            ):
+                _load_module("isolated_core_celery_missing")
+
+    def test_import_runs_startup_checks_for_worker_runtime(self):
+        app_mock = MagicMock()
+        app_mock.conf = SimpleNamespace()
+
+        with patch.dict(os.environ, {"DJANGO_SETTINGS_MODULE": "settings.test"}, clear=True):
+            with patch.object(sys, "argv", ["celery", "-A", "project", "worker"]):
+                with patch("apps.core.startup_checks.run_startup_checks") as checks_mock:
+                    with patch("celery.Celery", return_value=app_mock):
+                        module = _load_module("isolated_core_celery_worker")
+
+        checks_mock.assert_called_once_with(component="celery")
+        app_mock.config_from_object.assert_called_once_with(
+            "django.conf:settings",
+            namespace="CELERY",
+        )
+        app_mock.autodiscover_tasks.assert_called_once_with()
+        self.assertEqual(module.app, app_mock)
+
+    def test_debug_task_prints_request(self):
+        with patch.dict(os.environ, {"DJANGO_SETTINGS_MODULE": "settings.test"}, clear=True):
+            with patch.object(sys, "argv", ["python", "manage.py", "shell"]):
+                module = _load_module("isolated_core_celery_debug")
+
+        with patch("builtins.print") as print_mock:
+            module.debug_task.run()
+
+        print_mock.assert_called_once()