测试中的模型 - Django 1.7问题

Question

I'm trying to port my project to use Django 1.7. Everything is fine except 1 thing. Models inside tests folders.

Django 1.7 new migrations run migrate command internally. Before syncdb was ran. That means if a model is not included in migrations - it won't be populated to DB (and also to test DB). That's exactly what I'm experiencing right now.

What I do is:

In my /app/tests/models.py I have dummy model: class TestBaseImage(BaseImage): pass All it does is to inherit from an abstract BaseImage model.

Then in tests I create instances of that dummy model to test it.

The problem is that it doesn't work any more. It's not included in migrations (that's obvious as I don't want to keep my test models in a production DB). Running my tests causes DB error saying that table does not exist . That makes sense as it's not included in migrations.

Is there any way to make it work with new migrations system? I can't find a way to "fix" that.

Code I use:

app/tests/models.py

from ..models import BaseImage


class TestBaseImage(BaseImage):
    """Dummy model just to test BaseImage abstract class"""
    pass

app/models.py

class BaseImage(models.Model):
    # ... fields ...
    class Meta:
        abstract = True

factories:

class BaseImageFactory(factory.django.DjangoModelFactory):
    """Factory class for Vessel model"""
    FACTORY_FOR = BaseImage
    ABSTRACT_FACTORY = True


class PortImageFactory(BaseImageFactory):
    FACTORY_FOR = PortImage

example test:

def get_model_field(model, field_name):
    """Returns field instance"""
    return model._meta.get_field_by_name(field_name)[0]


def test_owner_field(self):
    """Tests owner field"""
    field = get_model_field(BaseImage, "owner")

    self.assertIsInstance(field, models.ForeignKey)
    self.assertEqual(field.rel.to, get_user_model())

Answer 1

There is a ticket requesting a way to do test-only models here

As a workaround, you can decouple your tests.py and make it an app.

tests
|--migrations
|--__init__.py
|--models.py
|--tests.py

You will end up with something like this:

myapp
|-migrations
|-tests
|--migrations
|--__init__.py
|--models.py
|--tests.py
|-__init__.py
|-models.py
|-views.py

Then you should add it to your INSTALLED_APPS

INSTALLED_APPS = (
    # ...
    'myapp',
    'myapp.tests',
)

You probably don't want to install myapp.tests in production, so you can keep separate settings files. Something like this:

INSTALLED_APPS = (
    # ...
    'myapp',
)

try:
    from local_settings import *
except ImportError:
    pass

Or better yet, create a test runner and install your tests there.

Last but not least, remember to run python manage.py makemigrations

Answer 2

Here's a workaround that seems to work. Trick the migration framework into thinking that there are no migrations for your app. In settings.py :

if 'test' in sys.argv:
    # Only during unittests...

    # myapp uses a test-only model, which won't be loaded if we only load
    # our real migration files, so point to a nonexistent one, which will make
    # the test runner fall back to 'syncdb' behavior.
    MIGRATION_MODULES = {
        'myapp': 'myapp.migrations_not_used_in_tests'
    }

I found the idea on the first post in ths Django dev mailing list thread , and it's also currently being used in Django itself , but it may not work in future versions of Django where migrations are required and the "syncdb fallback" is removed.