This document describes the current stable version of Celery (5.2). For development docs, go here.

Source code for

"""Create Celery app instances used for testing."""
import weakref
from contextlib import contextmanager
from copy import deepcopy

from kombu.utils.imports import symbol_by_name

from celery import Celery, _state

#: Contains the default configuration values for the test app.
    'worker_hijack_root_logger': False,
    'worker_log_color': False,
    'accept_content': {'json'},
    'enable_utc': True,
    'timezone': 'UTC',
    'broker_url': 'memory://',
    'result_backend': 'cache+memory://',
    'broker_heartbeat': 0,

[docs]class Trap: """Trap that pretends to be an app but raises an exception instead. This to protect from code that does not properly pass app instances, then falls back to the current_app. """ def __getattr__(self, name): # Workaround to allow unittest.mock to patch this object # in Python 3.8 and above. if name == '_is_coroutine' or name == '__func__': return None print(name) raise RuntimeError('Test depends on current_app')
[docs]class UnitLogging(symbol_by_name(Celery.log_cls)): """Sets up logging for the test application.""" def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) self.already_setup = True
[docs]def TestApp(name=None, config=None, enable_logging=False, set_as_current=False, log=UnitLogging, backend=None, broker=None, **kwargs): """App used for testing.""" from . import tasks # noqa config = dict(deepcopy(DEFAULT_TEST_CONFIG), **config or {}) if broker is not None: config.pop('broker_url', None) if backend is not None: config.pop('result_backend', None) log = None if enable_logging else log test_app = Celery( name or 'celery.tests', set_as_current=set_as_current, log=log, broker=broker, backend=backend, **kwargs) test_app.add_defaults(config) return test_app
[docs]@contextmanager def set_trap(app): """Contextmanager that installs the trap app. The trap means that anything trying to use the current or default app will raise an exception. """ trap = Trap() prev_tls = _state._tls _state.set_default_app(trap) class NonTLS: current_app = trap _state._tls = NonTLS() try: yield finally: _state._tls = prev_tls
[docs]@contextmanager def setup_default_app(app, use_trap=False): """Setup default app for testing. Ensures state is clean after the test returns. """ prev_current_app = _state.get_current_app() prev_default_app = _state.default_app prev_finalizers = set(_state._on_app_finalizers) prev_apps = weakref.WeakSet(_state._apps) try: if use_trap: with set_trap(app): yield else: yield finally: _state.set_default_app(prev_default_app) _state._tls.current_app = prev_current_app if app is not prev_current_app: app.close() _state._on_app_finalizers = prev_finalizers _state._apps = prev_apps