Unit testing file uploads does not populate request.FILES

[w00kie]

Hi, I'm having issues with my unit-testing on file uploads.

I have the following unit-test using the APIClient provided by APITestCase:

@override_settings(MEDIA_ROOT='/tmp/django_test')
def test_attach_file_to_deed(self):
    self._require_login()
    response = self.client.post(
        '/api/deeds/%s/attach_file/' % (self.test_deed.pk, ),
        {
            'file': self.dummyfile,
        },
    )
    self.assertqual(response.status_code, status.HTTP_201_CREATED, 'Error on create.')

But it fails to populate the request.FILES['file'] in the view and gives me the following error:

django.utils.datastructures.MultiValueDictKeyError: "'file'"

My view looks like this:

@action()
def attach_file(self, request, pk=None):
    deed = self.get_object()
    serializer = AttachmentSerializer(
        data={
            'parent': deed.pk,
            'file': request.FILES['file'],
            'original_filename': request.FILES['file'].name,
        },
    )
    if serializer.is_valid():
        serializer.save()
        return Response(serializer.data, status=status.HTTP_201_CREATED)
    else:
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

I could really use a little help debugging this one.

[lovelydinosaur]

Files should be populated with the files argument to serializers, not the data argument. Hope that helps!

[w00kie]

For future reference, using the files parameter in the serializer and setting my APIClient request to format='multipart' fixed all my issues.

[SiddharthMantri]

@w00kie Can I have a look at your Serializer? I'm facing similar issues.

My view

def post(self, request, aid, format='multipart'):
    '''
    Upload New Image
    '''
    business = SomeModel.objects.get(aid=aid)
    serialiser = PictureSerialiser(data={'business': business}, files=request.FILES['image'])
    if serialiser.is_valid():
        serialiser.save()
        return Response(serialiser.data, status=status.HTTP_201_CREATED)
    return Response(serialiser.errors, status=status.HTTP_400_BAD_REQUEST)

My test:

def test_upload_photo(self):
    c = Client()
    test_file = 'path/to/image'
    with open(test_file, 'rb') as data:
        response = c.post(''some_url", {'image': data}, **self.oauth_header)
        self.assertEqual(response.status_code, 201)

[maguri]

Hi,

I would like to test the request.FILES

• How could I do it?

my view looks like this:

@login_required
def upload(request, model_id):
    if not request.POST or not request.FILES:
        return HttpResponseRedirect(reverse('model_detail', args=(model_id,)))
...

I have used this in a previous test to test that a model have a file:

from django.core.files.base import File
...
def test(self):
    with File(file=tempfile.NamedTemporaryFile()) as f:
        ...

Thanks,

[sylwekb]

I know that's an old thread, but I just encountered similar error, I didn't use file serializer though. So, to whom face this issue, there is a solution. To make it work use from django.core.files.uploadedfile import SimpleUploadedFile:

# this is pytest
def test_request_multipart(self, mocker, api_client, video):
    video_upload = SimpleUploadedFile("file.webm", video, content_type="video/webm")

    data = {
        'video_file': video_upload
    }

    response = api_client.post(self.endpoint_url, data, format='multipart')

[hatimbekhushi]

passing format='multipart' argument resolves the error
response = api_client.post(self.endpoint_url, data, format='multipart')

[bukowa]

More information on testing file upload while skipping the view and working directly with the Serializer; also for my future reference:

# drf 3.14
# The same file cannot be used after it has been passed to the RequestFactory, as it probably has been closed. 
# Consider using a factory to create the image.
# import factory
# image = factory.django.ImageField().evaluate(None, None, {})
upfile = BytesIO()
pilimg = Image.new('RGB', (100, 100))
pilimg.save(fp=upfile, format='PNG')
image = SimpleUploadedFile('image.png', upfile.getvalue(), content_type='image/png')

# The default 'content_type' for POST requests in Django's RequestFactory is already 
# the value of 'MULTIPART_CONTENT'.
# While using Django's RequestFactory, we can also set it explicitly, which works.
# However, when using APIRequestFactory, we have to set 'format' to 'multipart' to get the same behavior.
# Trying to set 'content_type' to the value of 'MULTIPART_CONTENT' will not work.

# from django.test.client import RequestFactory
# request = RequestFactory().post(
#     path=None,
#     data={'images': [file], 'name': "test"},
# )

request = APIRequestFactory().post(
    path=None,
    data={'images': [image], 'name': "test"},
    # mandatory for APIRequestFactory
    format='multipart',
)

# By default, DRF serializers do not have access to the request.
# But the serializer needs it to access the request.FILES.
# To simulate what DRF is doing in its request handling, update the request.POST with the request.FILES.
# This is finally passed to the serializer as request.data.
# https://github.com/encode/django-rest-framework/blob/0618fa88e1a8c2cf8a2aab29ef6de66b49e5f7ed/rest_framework/request.py#L274

class Serializer(serializers.Serializer):
    images = serializers.ListField(
        child=serializers.ImageField(),
        allow_empty=False,
    )
    name = serializers.CharField(
    required=True, validators=[lambda x: x == 'test'])


data = request.POST.copy()
data.update(request.FILES)
serializer = Serializer(data=data)
self.assertTrue(serializer.is_valid(), msg=serializer.errors)