Schema tests fail when run in isolation

[Claude Paroz]

Because tables are deleted in tearDown, when running an individual test, the tables are still existing and any create_model operation fail.

[vladiibine]

I've tried to test your scenario, but I think more information.

I dont know if I understood correctly, but I tried to run just one individual test, and use the SchemaEditor.create_model method to create a new model class, and instantiate it.

Here's my code, what works (I can create a dynamic model within the test and instantiate it - no errors)

from django.test import TestCase

from .models import MyModel

class MyTestCase(TestCase):
    def test_1(self):
        from django.db import connection

        with connection.schema_editor() as editor:
            other_model = self.create_model(editor)
            my_model = MyModel.objects.create(name='foo')

        other_model_instance = other_model.objects.create(name='bar')

    def test_2(self):
        my_model = MyModel(name='baz')

    def tearDown(self):
        print '>>>inside tearDown'
        # super(MyTestCase, self).tearDown()

    def create_model(self, editor):
        from django.db import models

        class OtherModel(models.Model):
            name = models.CharField(max_length=30, blank=True)

        editor.create_model(OtherModel)

        return OtherModel

Then from the command line, I ran the test suites with all 3 of these commands:

$ ./manage.py test core.tests.MyTestCase.test_1

$ ./manage.py test core.tests.MyTestCase.test_1 core.tests.MyTestCase.test_2

$ ./manage.py test

Please give more details on how you're getting this issue.

[vladiibine]

Also, I ran this on both the 1.8 branch, and the master on the commit f043434174db3432eb63c341573c1ea89ef59b91, with Python version Python 2.7.5+

I'm releasing this ticket, so that someone else can take a look. If you provide more information, I'll check it out from time to time.

[Simon Charette]

Claude, could you more details on which tests fail when run in isolation.

I couldn't reproduce with:

./runtests.py schema.tests.SchemaTests --settings=test_postgres

or

./runtests.py schema.tests.SchemaTests.test_creation_deletion

or

./runtests.py schema.tests.SchemaTests.test_creation_deletion schema.tests.SchemaTests.test_fk --settings=test_postgres

[Claude Paroz]

I found the issue. The problem happens only with tests using the Note model, and the cause is that the Note model misses the apps = new_apps Meta attribute. I'll fix that ASAP.

[Claude Paroz <claude@…>]

In f54c0ec:

Fixed #24658 -- Added missing Meta attribute in schema tests

Without that, the Note model would be initially created and then
the tests using that model failed when run in isolation.

[Claude Paroz <claude@…>]

In ff6e8681:

[1.8.x] Fixed #24658 -- Added missing Meta attribute in schema tests

Without that, the Note model would be initially created and then
the tests using that model failed when run in isolation.
Backport of f54c0ec06e from master.