remove Python 3.9 and add support for Python 3.14

[sinisaos]

Related to #1264

[sinisaos]

This change was made because Python 3.14 does not allow the type None in pytest.warns() (TypeError: exceptions must be derived from Warning, not <class 'NoneType'>)

[dantownsend]

OK, took me a while, but I get what's going on now.

I was a bit confused by warnings.simplefilter("error"), but that's turning each warning into an exception, so you no longer need to check the length of the warnings.

[sinisaos]

For some reason in Python 3.14 (which I don't understand) the migration table is included in the table storage and the tests fail. I exclude the migration table from table storage to prevent this.

[dantownsend]

Hmmm, interesting. I'll try it locally. I wonder what changed in Python 3.14 to cause this.

[dantownsend]

This works for me locally. Maybe your test database has a stale migration table or something?

[dantownsend]

Ah, OK - I can see it failing now.

[dantownsend]

If I just run that test by itself, it's OK. But if I run the entire test suite then it fails.

[dantownsend]

It might be to do with the newer version of Pytest.

In conftest.py we have drop_tables which is meant to clean up these tables. I wonder if that's not running. Worth investigating.

[dantownsend]

I checked, and drop_tables does get run before the tests run. So the problem is some previous test is creating the migration table but not cleaning it up.

[sinisaos]

If I just run that test by itself, it's OK. But if I run the entire test suite then it fails.

That's exactly what's happening.

[sinisaos]

I don't know if this is a good idea, but we can force the migration table drop in the test setup just to make sure that migration table is dropped. This works in Py3.14 and Py3.12. Something like this

from piccolo.apps.migrations.commands.base import Migration

@engines_only("postgres", "cockroach")
class TestTableStorage(TestCase):
    def setUp(self) -> None:
        Migration.raw("DROP TABLE IF EXISTS migration").run_sync() # here
        self.table_storage = TableStorage()
        for table_class in (Manager, Band):
            table_class.create_table().run_sync()

[dantownsend]

@sinisaos Yes, that works.

I managed to figure out which tests were leaving the migration table in the database. I added this auto fixture to conftest.py:

@pytest.fixture(autouse=True)
def migration_table_detector():
    yield
    response = asyncio.run(
        ENGINE._run_in_new_connection(
            "SELECT * FROM information_schema.tables WHERE table_name = 'migration'"
        )
    )
    if len(response) > 0:
        breakpoint()

There were two tests which ran migration commands, and the migration table was being created.

Maybe in the future we can run each test in a transaction to avoid these kinds of problems, but not a priority right now.

I've been able to fix the relevant tests.

[dantownsend]

I've made a fresh virtual env using Python 3.14, but can't install some of our pip dependencies. Will try again tomorrow.

[sinisaos]

@dantownsend Strange. Now I'm cloned the branch in fresh virtualenv and everything works in my case. Which OS do you use? I use Linux Mint 22.2 Cinnamon which is based on Ubuntu 24.04 LTS.

[dantownsend]

Looks good, thanks! 👍