In [1]: from django.core.files.uploadedfile import SimpleUploadedFile

In [2]: from example.forms import FileFieldForm

In [3]: form = FileFieldForm({}, {"file_field": SimpleUploadedFile("bunny.jpeg", b"bunny")})

In [4]: form.is_valid()
Out[4]: True

In [5]: form.cleaned_data
Out[5]: {'file_field': <SimpleUploadedFile: bunny.jpeg (text/plain)>}

In [1]: from django.core.files.uploadedfile import SimpleUploadedFile

In [2]: from example.forms import FileFieldForm

In [3]: form = FileFieldForm({}, {"file_field": SimpleUploadedFile("bunny.jpeg", b"bunny")})

In [4]: form.is_valid()
Out[4]: True

In [5]: form.cleaned_data
Out[5]: {'file_field': [<SimpleUploadedFile: bunny.jpeg (text/plain)>]}

In [1]: from django.core.files.uploadedfile import SimpleUploadedFile

In [2]: from django.test import RequestFactory

In [3]: from example.views import FileFieldFormView

In [4]: rf = RequestFactory()

In [5]: request = rf.post("/", files={"file_field": SimpleUploadedFile("bunny.jpeg", b"bunny")})

In [6]: FileFieldFormView.as_view()(request)
...
File ~/tmp/multiple-test/example/views.py:22, in FileFieldFormView.form_valid(self, form)
     20 for f in files:
     21     ...  # Do something with each file.
---> 22 return super().form_valid()

TypeError: FormMixin.form_valid() missing 1 required positional argument: 'form'

In [1]: from django.core.files.uploadedfile import SimpleUploadedFile

In [2]: from django.test import RequestFactory

In [3]: from example.views import FileFieldFormView

In [4]: rf = RequestFactory()

In [5]: request = rf.post("/", files={"file_field": SimpleUploadedFile("bunny.jpeg", b"bunny")})

In [6]: FileFieldFormView.as_view()(request)
Out[6]: <HttpResponseRedirect status_code=302, "text/html; charset=utf-8", url="...">