Add additional test cases for process management (#88)

Sending signals on Windows is surprisingly difficult. CTRL-C is handled by `SIGINT`, which is tested on other platforms and should behave the same. Improving test coverage for Windows will be a future task.

Author: RealOrangeOne

.github/workflows/ci.yml

@@ -49,6 +49,8 @@ jobs:
         run: just lint
       - name: Run tests
         run: just test
+      - name: Run fast tests
+        run: just test-fast
 
   test-postgres:
     runs-on: ubuntu-latest

.gitignore

@@ -62,8 +62,8 @@ cover/
 # Django stuff:
 *.log
 local_settings.py
-db.sqlite3
-db.sqlite3-journal
+*.sqlite3
+*.sqlite3-journal
 
 # Flask stuff:
 instance/

CONTRIBUTING.md

@@ -42,3 +42,9 @@ just test-sqlite
 # To run all of the above:
 just test-dbs
 ```
+
+Due to database worker process' tests, tests cannot run using an in-memory database, which means tests run quite slow locally. If you're not modifying the worker, and want you tests run run quicker, run:
+
+```sh
+just test-fast
+```

django_tasks/backends/database/management/commands/db_worker.py

@@ -27,21 +27,28 @@
 
 class Worker:
     def __init__(
-        self, *, queue_names: List[str], interval: float, batch: bool, backend_name: str
+        self,
+        *,
+        queue_names: List[str],
+        interval: float,
+        batch: bool,
+        backend_name: str,
+        startup_delay: bool,
     ):
         self.queue_names = queue_names
         self.process_all_queues = "*" in queue_names
         self.interval = interval
         self.batch = batch
         self.backend_name = backend_name
+        self.startup_delay = startup_delay
 
         self.running = True
         self.running_task = False
 
     def shutdown(self, signum: int, frame: Optional[FrameType]) -> None:
         if not self.running:
             logger.warning(
-                "Received %s - shutting down immediately.", signal.strsignal(signum)
+                "Received %s - terminating current task.", signal.strsignal(signum)
             )
             sys.exit(1)
 
@@ -67,7 +74,7 @@ def start(self) -> None:
 
         logger.info("Starting worker for queues=%s", ",".join(self.queue_names))
 
-        if self.interval:
+        if self.startup_delay and self.interval:
             # Add a random small delay before starting the loop to avoid a thundering herd
             time.sleep(random.random())
 
@@ -87,7 +94,7 @@ def start(self) -> None:
                     except OperationalError as e:
                         # Ignore locked databases and keep trying.
                         # It should unlock eventually.
-                        if "database is locked" in e.args[0]:
+                        if "is locked" in e.args[0]:
                             task_result = None
                         else:
                             raise
@@ -150,10 +157,6 @@ def run_task(self, db_task_result: DBTaskResult) -> None:
                     task_result=task_result,
                 )
 
-            # If the user tried to terminate, let them
-            if isinstance(e, KeyboardInterrupt):
-                raise
-
 
 def valid_backend_name(val: str) -> str:
     try:
@@ -205,6 +208,12 @@ def add_arguments(self, parser: ArgumentParser) -> None:
             dest="backend_name",
             help="The backend to operate on (default: %(default)r)",
         )
+        parser.add_argument(
+            "--no-startup-delay",
+            action="store_false",
+            dest="startup_delay",
+            help="Don't add a small delay at startup.",
+        )
 
     def configure_logging(self, verbosity: int) -> None:
         if verbosity == 0:
@@ -229,6 +238,7 @@ def handle(
         interval: float,
         batch: bool,
         backend_name: str,
+        startup_delay: bool,
         **options: dict,
     ) -> None:
         self.configure_logging(verbosity)
@@ -238,6 +248,7 @@ def handle(
             interval=interval,
             batch=batch,
             backend_name=backend_name,
+            startup_delay=startup_delay,
         )
 
         worker.start()

justfile

@@ -9,6 +9,9 @@ test *ARGS:
     python -m coverage report
     python -m coverage html
 
+test-fast *ARGS:
+    python -m manage test --shuffle --noinput --settings tests.settings_fast {{ ARGS }}
+
 format:
     python -m ruff check django_tasks tests --fix
     python -m ruff format django_tasks tests
@@ -19,7 +22,6 @@ lint:
     python -m mypy django_tasks tests
 
 start-dbs:
-    docker-compose pull
     docker-compose up -d
 
 test-sqlite *ARGS:

pyproject.toml

@@ -65,6 +65,10 @@ postgres = [
 select = ["E", "F", "I", "W", "N", "B", "A", "C4", "T20", "DJ"]
 ignore = ["E501", "DJ008"]
 
+[tool.ruff.lint.per-file-ignores]
+"tests/db_worker_test_settings.py" = ["F403", "F405"]
+"tests/settings_fast.py" = ["F403", "F405"]
+
 [tool.mypy]
 plugins = ["mypy_django_plugin.main"]
 warn_unused_ignores = true

tests/db_worker_test_settings.py

@@ -0,0 +1,9 @@
+from .settings import *
+
+TASKS = {"default": {"BACKEND": "django_tasks.backends.database.DatabaseBackend"}}
+
+# Force the test DB to be used
+if "sqlite" in DATABASES["default"]["ENGINE"]:
+    DATABASES["default"]["NAME"] = DATABASES["default"]["TEST"]["NAME"]
+else:
+    DATABASES["default"]["NAME"] = "test_" + DATABASES["default"]["NAME"]

tests/settings.py

@@ -55,16 +55,18 @@
 
 DATABASES = {
     "default": dj_database_url.config(
-        default="sqlite://:memory:"
-        if IN_TEST
-        else "sqlite:///" + os.path.join(BASE_DIR, "db.sqlite3")
+        default="sqlite:///" + os.path.join(BASE_DIR, "db.sqlite3")
     )
 }
 
 # Set exclusive transactions in 5.1+
 if django.VERSION >= (5, 1) and "sqlite" in DATABASES["default"]["ENGINE"]:
     DATABASES["default"].setdefault("OPTIONS", {})["transaction_mode"] = "EXCLUSIVE"
 
+if "sqlite" in DATABASES["default"]["ENGINE"]:
+    DATABASES["default"]["TEST"] = {"NAME": os.path.join(BASE_DIR, "db-test.sqlite3")}
+
+
 USE_TZ = True
 
 if not IN_TEST:

tests/settings_fast.py

@@ -0,0 +1,5 @@
+from .settings import *
+
+# Unset custom test settings to use in-memory DB
+if "sqlite" in DATABASES["default"]["ENGINE"]:
+    del DATABASES["default"]["TEST"]

tests/tasks.py

@@ -1,3 +1,5 @@
+import time
+
 from django_tasks import task
 
 
@@ -54,3 +56,16 @@ def enqueue_on_commit_task() -> None:
 @task(enqueue_on_commit=False)
 def never_enqueue_on_commit_task() -> None:
     pass
+
+
+@task()
+def hang() -> None:
+    """
+    Do nothing for 5 minutes
+    """
+    time.sleep(300)
+
+
+@task()
+def sleep_for(seconds: float) -> None:
+    time.sleep(seconds)