What is the correct way to simulate filedata for testing a form?

Question

I'm trying to test a self written FormField AudioFileFormField, which checks if a file is an audiofile before storing it. For that i have overwritten the to_python method. Trying to test this FormField i ran into some difficulties.

This is my TestCase so far:

from django import forms
from django.core.files.uploadedfile import SimpleUploadedFile
from django.test import TestCase

class TestAudioFileFormField(TestCase):
    """ test the formfield to use for AudioFile Uploads """

    class TestForm(forms.Form):
        audiofilefield = AudioFileFormField()


    def setUp(self):

        self.AUDIOFILE_TEST_ROOT = os.path.dirname(__file__) + '/data/'
        self.files = audiofile_files


    def test_to_python(self):
        """ assign some files to a form and validate the form """

        f = file(self.AUDIOFILE_TEST_ROOT + self.files[0]) 
        file_data = {'audiofilefield':SimpleUploadedFile( self.files[0],f.read() )}
        data = {}

        form = self.TestForm(data,f)
        form.is_valid()

The line form.is_valid() raises an AttributeError: 'file' object has no attribute 'get'

When i insert a debug trace right before form.is_valid(), this is what i get in that interactive session:

ipdb> form.is_valid()
AttributeError: 'file' object has no attribute 'get'
ipdb> suf = file_data['audiofilefield']
ipdb> suf
<SimpleUploadedFile: invalid_format.mp3 (text/plain)>
ipdb> dir(suf)
[lots of info here]
ipdb> form.is_valid()
True

What exactly did i change in the interactive session, so that the form validation is working? What would be the correct way to pass the file to SimpleUploadedFile to avoid the AttributeError?

Answer 1

Ok, a fresh look can be worth a lot. This is my new test_to_python test, this time it works:

def test_to_python(self):
    f = file(self.AUDIOFILE_TEST_ROOT + self.files[0])
    file_data = {'audiofilefield':SimpleUploadedFile(self.files[0],f.read())}
    data = {}
    form = self.TestForm(data,file_data)
    self.assertTrue( form.is_valid() )

Answer 2

Alternative solution (because this question is the top Google result for "Django test simulate upload"): Django's builtin test client accepts open file objects as POST data:

# the form
class TestForm(forms.Form):
    audiofilefield = AudioFileFormField()

# the view
def upload_view(request):
    form = TestForm(data=request.POST or None, files=request.FILES or None)
    if request.method == 'POST':
         if form.is_valid():
              return HttpResponse('success')
         else:
              return HttpResponse('fail')

# the test function
class UploadTest(TestCase):
    def test_upload(self):
        c = Client() # django.test.client.Client
        formdata = {}
        with open('/my/audiofile.mp3', 'rb') as f:
            formdata['audiofilefield'] = f
            response = c.post('/my-test-view/', formdata)