Task deserialization error with SQLAlchemyDatastore

nuno-andre commented 8 months ago

Things to check first

[X] I have checked that my issue does not already have a solution in the FAQ
[X] I have searched the existing issues and didn't find my bug already reported there
[X] I have checked that my bug is still present in the latest release

Version

https://github.com/agronholm/apscheduler/commit/a67a82c821d5eeb882192d453dea215f7e8987bf

What happened?

When the scheduler tries to configure a task created in a previous run raises a validation error. This doesn't happen when the task is created for the first time.

(I've come across this error both with SQLite and PostgreSQL.)

      | Traceback (most recent call last):
      |   File "/home/nuno/repos/fands/_soc-services/aptest/test2.py", line 26, in main
      |     await scheduler.add_schedule(tick, IntervalTrigger(seconds=1), id="tick")
      |   File "/home/nuno/repos/fands/_soc-services/.venv/lib/python3.10/site-packages/apscheduler/_schedulers/async_.py", line 409, in add_schedule
      |     task = await self.configure_task(
      |   File "/home/nuno/repos/fands/_soc-services/.venv/lib/python3.10/site-packages/apscheduler/_schedulers/async_.py", line 308, in configure_task
      |     task.func = func
      |   File "/home/nuno/repos/fands/_soc-services/.venv/lib/python3.10/site-packages/attr/_make.py", line 1068, in __setattr__
      |     nval = hook(self, a, val)
      |   File "/home/nuno/repos/fands/_soc-services/.venv/lib/python3.10/site-packages/attr/setters.py", line 23, in wrapped_pipe
      |     rv = setter(instance, attrib, rv)
      |   File "/home/nuno/repos/fands/_soc-services/.venv/lib/python3.10/site-packages/attr/setters.py", line 52, in validate
      |     v(instance, attrib, new_value)
      |   File "/home/nuno/repos/fands/_soc-services/.venv/lib/python3.10/site-packages/attr/validators.py", line 269, in __call__
      |     self.validator(inst, attr, value)
      |   File "/home/nuno/repos/fands/_soc-services/.venv/lib/python3.10/site-packages/attr/_make.py", line 2927, in __call__
      |     v(inst, attr, value)
      |   File "/home/nuno/repos/fands/_soc-services/.venv/lib/python3.10/site-packages/attr/validators.py", line 100, in __call__
      |     raise TypeError(
      | TypeError: ("'func' must be <class 'str'> (got <function tick at 0x7f8260363d90> that is a <class 'function'>).", Attribute(name='func', default=NOTHING, validator=<optional validator for _AndValidator(_validators=(<instance_of validator for type <class 'str'>>, <matches_re validator for pattern re.compile('.+:.+')>)) or None>, repr=True, eq=False, eq_key=None, order=False, order_key=None, hash=None, init=True, metadata=mappingproxy({}), type='str | None', converter=None, kw_only=True, inherited=False, on_setattr=None, alias='func'), <class 'str'>, <function tick at 0x7f8260363d90>)

Commenting the following lines makes the code to run successfully.

https://github.com/agronholm/apscheduler/blob/a67a82c821d5eeb882192d453dea215f7e8987bf/src/apscheduler/_schedulers/async_.py#L307-L309

How can we reproduce the bug?

Run this code (it will create a new DB), stop it, and run it again (with the previously created DB).

import asyncio
from datetime import datetime

from sqlalchemy.ext.asyncio import create_async_engine
from apscheduler import AsyncScheduler
from apscheduler.datastores.sqlalchemy import SQLAlchemyDataStore
from apscheduler.triggers.interval import IntervalTrigger

def tick():
    print("Hello, the time is", datetime.now())

async def main():
    engine = create_async_engine('sqlite+aiosqlite:///test.sqlite')
    data_store = SQLAlchemyDataStore(engine)
    async with AsyncScheduler(data_store) as scheduler:
        await scheduler.add_schedule(tick, IntervalTrigger(seconds=1), id="tick")
        await scheduler.run_until_stopped()

asyncio.run(main())