Non-obvious behavior of validated_data when using serializer with MultiPartParser.

[blohinn]

Look at my simple test case:

request_factory = RequestFactory()

bed = SimpleUploadedFile('bed.bed', 'bed'.encode())
cov = SimpleUploadedFile('cov.cov', 'cov'.encode())

data = {'name': 'panel', 'slug': 'panel', 'bed': (bed.open('rb')), 'cov': (cov.open('rb'))}
request = request_factory.post('/', data)
drf_request = Request(request, parsers=[MultiPartParser()])

s = CreatePanelSerializer(data=drf_request.data)  # <-- see here
s.is_valid(raise_exception=True)
pprint(s.validated_data)

s = CreatePanelSerializer(data=drf_request.data.dict())  # <-- see here
s.is_valid(raise_exception=True)
pprint(s.validated_data)

I create request with multipart/form-data content and specify 4 fields: name, slug, bed (file) and cov (file).
Then i create a drf-like request object and as a parser i specify MultiPartParser.
Then i pass request data to serializer two different ways:

1. As a usual with drf_request.data
2. Transforming request.data object to dict

Look at validated_data now:
1)

OrderedDict([('name', 'panel'),
             ('slug', 'panel'),
             ('zond', False),
             ('ampl', False),
             ('germ', False),
             ('somat', False),
             ('users', []),
             ('is_active', False),
             ('limited_access', False),
             ('bed', <TemporaryUploadedFile: bed.bed (text/plain)>),
             ('cov', <TemporaryUploadedFile: cov.cov (text/plain)>)])

OrderedDict([('name', 'panel'),
             ('slug', 'panel'),
             ('bed', <TemporaryUploadedFile: bed.bed (text/plain)>),
             ('cov', <TemporaryUploadedFile: cov.cov (text/plain)>)])

Why so unobvious behavior? I pass only 4 fields.

For example, i'am waiting that my zond, ampl, germ, somat fields will be True after creating instance because a have default=True in model fields for this.

I think behavior №2 is more obvious, but default behavior is №1.

As far as I know, JSONParser is more obvious and doesn't try to do more than it needs to.