How to gracefully change (patch) the Django FileSystemStorage setting in your unit tests?

Question

I ran into the following problem. I have a model that looks something like this:

class Package(models.Model):
    name = models.CharField(max_length=64)
    file = models.FileField(upload_to="subdir",
                            storage=settings.PACKAGE_STORAGE,
                            null=True)

Essential in this example is the argument storage=to the constructor FileField. It is populated with a value from settings.py. It has the following code:

from django.core.files.storage import FileSystemStorage
PACKAGE_STORAGE = FileSystemStorage(location="/var/data", base_url="/")

For production use, this works great. But in my unit tests, the ones I download are now written to /var/data, which contains the production data. I tried replacing PACKAGE_STOREwith packages/tests.pyas follows

from django.conf import settings     # This is line 1
from tempfile import mkdtemp
settings.PACKAGE_STORAGE = FileSystemStorage(location=mkdtemp(), base_url="/")

# rest of the imports and testing code below

, , packages , PACKAGE_STORAGE , m, .

?

Answer 1

, , ...

- :

# test_settings.py

from settings import *

PACKAGE_STORAGE = FileSystemStorage(location='/test/files', base_url="/")

python manage.py test --settings=test_settings.

Answer 2

django,

if 'test' in sys.argv:
    settings.DEFAULT_FILE_STORAGE = FileSystemStorage(location=mkdtemp(), base_url="/")

, ;)

DEFAULT_FILE_STORAGE = FileSystemStorage(location="/var/data", base_url="/")

Answer 3

FileField :

def setUp(self):
     self._field = Package._meta.get_field_by_name('file')[0]
     self._default_storage = self._field.storage
     test_storage = FileSystemStorage(location=mkdtemp(),
                                      base_url="/")

     self._field.storage = test_storage

def tearDown(self):
     self._field = self._default_storage

Answer 4

, . , , . Django. :

import shutil
import tempfile
from django.test.simple import DjangoTestSuiteRunner
from django.conf import settings

class CustomTestRunner(DjangoTestSuiteRunner):

    def setup_test_environment(self, **kwargs):
        super(CustomTestRunner, self).setup_test_environment(**kwargs)
        self.backup = {}
        self.backup['DEFAULT_FILE_STORAGE'] = settings.DEFAULT_FILE_STORAGE
        settings.DEFAULT_FILE_STORAGE = 'django.core.files.storage.FileSystemStorage'
        self.backup['MEDIA_ROOT'] = settings.MEDIA_ROOT
        self.temp_media_root = tempfile.mkdtemp(prefix="myapp-tests")
        settings.MEDIA_ROOT = self.temp_media_root

    def teardown_test_environment(self, **kwargs):
        super(CustomTestRunner, self).teardown_test_environment(**kwargs)
        for name, value in self.backup.iteritems():
            setattr(settings, name, value)

    def run_tests(self, test_labels, **kwargs):
        try:
            test_results = super(CustomTestRunner, self).run_tests(test_labels, **kwargs)
        finally:
            shutil.rmtree(self.temp_media_root, ignore_errors=True)

. setup_test_environment class. teardown_test_environment , . run_tests try/finally, , , .