Package: pytest-django-filefield
pytest-django-filefieldPatch the storage of your models'FileFields effortlessly.Best served withpytest-djangoand your own fixtures.Install and enable the plugin:pipinstallpytest-django-filefieldRoll your fixture:# conftest.pyfromdjango.core.filesimportstoragefromdjango.dbimportmodels@pytest.fixturedeffake_storage(monkeypatch,tmp_path)storage=storage.FileSystemStorage(location=tmp_path)monkeypatch.setattr(models.FileField,"storage",storage)returnstorageHave it scoped however you want, or just mark asautouse=Trueand forget about it.This simple hack is packaged as a pytest plugin to make it work withpytest-django, because there isno simpler way to inject custom code before it callsdjango.setup().Do I even need this?There's a good chance that you don't! But let's first recap on some of the ways to patch the storage, given a model somewhat like below:classContract(models.Model):document=models.FileField(storage=DocumentStorage())Just patch the fieldstorageis an instance attribute of eachFileField, so the most straightforward and robust way would be to just find the field instance and patch the attribute:deftest_document_upload(monkeypatch,my_fake_storage):document_field=Contract._meta.get_field_by_name("document")[0]monkeypatch.setattr(document_field,"storage",my_fake_storage)upload_contract_document()assert_results(my_fake_storage)The requirement here is that you know which fields of which models should be patched, and make sure to get it right for corresponding tests. This could become quite noisy and/or tedious to maintain. However, the approach is beneficial if there is quite a number of different storages, especially different storages used within the same model.If the project uses a single storage for everything, or just a handful of them, such flexibility might be overkill.Define a different storage for testsExtract the name of the storage class intosettings.py, use a different settings file for tests (which you should anyway) with a different value there. This way the storage is replaced before Django is even initialized.# settings.pyDOCUMENT_STORAGE='myapp.storages.DocumentStorage'# settings_test.pyDOCUMENT_STORAGE='myapp.tests.storages.FakeDocumentStorage'# models.pyclassContract(models.Model):document=models.FileField(storage=import_string(settings.DOCUMENT_STORAGE)())# tests/test_contract.pydeftest_document_upload():document_field=Contract._meta.get_field_by_name("document")[0]upload_contract_document()assert_results(document_field.storage)Patching not required, each field still has its own instance of a test storage, but all the objects using that field share the same storage for the whole test session. Which is already good enough and you may just stop here!Patch all the storages, with configurable scopeThis is what the plugin enables. It replacesFileField().storage, which is normally an instance attribute, with a property of the same name. A property is defined in a class, so this forces all the"storage"attribute lookups to be done on a class. You now don't have to hunt down everyFileFieldinstance and can just patch the class property instead.The drawback is that any and allFileFields are patched for duration of the fixture's scope. Since the narrowest scope isfunction, this may (only) be a problem if a single test needs to check the behaviours of multiple storages in isolation.SummaryAs always, choose what works best for your specific project!Manual patchStorage from settingsThis pluginfunction-scoped storagexxfield-scoped storagexno model changes requiredxxlow/no maintenancexx