Add proper error messages and a doc page dedicated for testing about tortoise-orm HOT 3 OPEN

OK, I found initializer and finalizer pattern in the documentation. I think there should be "Testing" tab in the main page. It should have two levels. First explain basics for each main python test framework (pytest, unittest, etc.) with full working examples, how to write an empty test. Then second level on how to integrate with each individual framework (FastAPI, etc.). It should have very basic examples, also including FastAPI websockets.

Anyway, I got back to a place where I try to create an empty test case, this time armed with initialzier and finalizer methods. I have this:

from tortoise.contrib import test
from tortoise.contrib.test import initializer, finalizer


class MyTest(test.TestCase):

    @classmethod
    def setUpClass(cls):
        initializer(
            modules=["db.models"],
            db_url="psycopg://my_user:[email protected]:5432/test_mydb",
        )

    @classmethod
    def tearDownClass(cls):
        finalizer()

    async def test_nothing(self):
        pass

On the DB I ran

CREATE USER 'my_user' with password 'my_pass' 
ALTER USER 'my_user' superuser  ---> this is so it can drop/create the DB

I also created an empty DB with name test_mydb

When I run the above, I'm getting

psycopg.errors.ObjectInUse: cannot drop the currently open database from db_delete method in base_postgres.client()

from tortoise-orm.

I made it!

Apparently, one can't use postgres for the test database. When using default which apparently is sqlite://memory I finally got my empty test to work.

The final version which is working:

from tortoise.contrib import test
from tortoise.contrib.test import initializer, finalizer


class MyTest(test.TestCase):

    @classmethod
    def setUpClass(cls):
        initializer(
            modules=["db.models"]
        )

    @classmethod
    def tearDownClass(cls):
        finalizer()

    async def test_nothing(self):
        pass

from tortoise-orm.

Hi!

Sad to see you struggling like that

Good that you made it work with sqlite, although I think it should work with postgres too.
You issue may be because tortoise initializer/finalizer designed in way, that create and destroy database, so it can fail in the moment of it's creation/deletion.
In your case seems like something else is connected to db in moment of delete, not sure what is it, but maybe you can troubleshoot that on your side, or at least narrow down why it's tortoise fault here

In our internal testcase we use this pytest fixture:

@pytest.fixture(scope="session", autouse=True)
def initialize_tests(request):
    # Reduce the default timeout for psycopg because the tests become very slow otherwise
    try:
        from tortoise.backends.psycopg import PsycopgClient

        PsycopgClient.default_timeout = float(os.environ.get("TORTOISE_POSTGRES_TIMEOUT", "15"))
    except ImportError:
        pass

    db_url = os.environ.get("TORTOISE_TEST_DB", "sqlite://:memory:")
    initializer(["tests.testmodels"], db_url=db_url)
    request.addfinalizer(finalizer)

And it works with all databases that in our testcase

If you have ideas how to improve documentation - I will be glad to accept PR with improvements on this part

from tortoise-orm.