Database testing

[Anton-Karpenko]

Hello, I really enjoy the ORM.

I've got a problem with the database testing. I need to await some database calls in my tests, but it will require making my tests asynchronous. As I understand, piccolo test runner doesn't support that. Is there a way to force to run async queries in a sync way?

I tried to make my test async using fastapi docs for async testing. Test runner outputs something like:
RuntimeWarning: coroutine 'TestClass.test_method' was never awaited

[dantownsend]

Hi @Anton-Karpenko, I'm glad you're enjoying Piccolo.

When testing async code, there are a few ways to go about it. If you use piccolo tester run it just calls Pytest under the hood.

I see from the FastAPI docs that it recommends using the pytest.mark.anyio decorator. Is this what you're currently using?

I tend to use pytest-asyncio instead, as I don't use Trio.

# test_app.py

import pytest

from my_app.tables import MyTable


@pytest.mark.asyncio
async def test_foo():
    rows = await MyTable.select()
    assert len(rows) == 0

If you prefer using Python's builtin TestCase, you can also do things like this:

# test_app.py

from unittest import TestCase

import pytest
from piccolo.utils.sync import run_sync

from my_app.tables import MyTable

class TestFoo(TestCase):
   
    def test_foo(self):
        async def test():
            rows = await MyTable.select()
            self.assertEqual(len(rows), 0)
        
        run_sync(test())

Does that help at all?

[dantownsend]

Are you on v0.74.4 of Piccolo?

[Anton-Karpenko]

Yes, I am
piccolo==0.74.4

[dantownsend]

I'm struggling to recreate it. Do you just have that one simple test, and it still fails?

Do you have any pytest plugins installed?

[Anton-Karpenko]

I'll provide a repo with the code, it will be much easier

[dantownsend]

Thanks

[Anton-Karpenko]

Probably, the issue was in some fixture. I removed all and readded one by one. It led to a situation where my tests were hanging infinity. Here the problem was that I tried to pass an integer value to an FK field and that the related model's id must be UUID instead of int.

Anyway, thanks a lot for the help!

[dantownsend]

No worries, glad it's sorted!