Django Rest Framework - Image/File upload test

test_image_upload.py

import os
import io

from PIL import Image

from django.core.urlresolvers import reverse
from django.conf import settings

from rest_framework import status
from rest_framework.test import APITestCase
from rest_framework.authtoken.models import Token
from rest_framework.renderers import JSONRenderer

# Custom user model based on Django Auth AbstractUser
from account.models import User

class CrewUploadPhotoTests(APITestCase):

    fixtures = []

    maxDiff = None

    def setUp(self):

        # Normal user
        self.normal_user = User.objects.create(
            first_name="Bob",
            last_name="Green",
            username="[email protected]",
            email="[email protected]",
            is_active=True,
            is_staff=False)
        self.normal_user.set_password('demo1234')
        self.normal_user.save()
        self.normal_token, created = Token.objects.get_or_create(
            user=self.normal_user)

    def generate_photo_file(self):
        file = io.BytesIO()
        image = Image.new('RGBA', size=(100, 100), color=(155, 0, 0))
        image.save(file, 'png')
        file.name = 'test.png'
        file.seek(0)
        return file

    def test_upload_photo(self):
        """
        Test if we can upload a photo
        """

        self.client.credentials(HTTP_AUTHORIZATION='Token ' + self.normal_token.key)

        url = reverse('crew-api:upload-photo', args=[self.normal_user.crew.uuid])

        photo_file = self.generate_photo_file()

        data = {
                'photo':photo_file
            }

        response = self.client.post(url, data, format='multipart')
        self.assertEqual(response.status_code, status.HTTP_200_OK)

def generate_photo_file(self):
       file_obj = StringIO()
       image = Image.new("RGBA", size=(50, 50), color=(256, 0, 0))
       image.save(file_obj, "png")
       file_obj.seek(0)
       file_obj.name = "testasdas.png"
       file_obj.size = 1000
       return file_obj

self.client.post(reverse("registration_register"), data={'photo': self.photo()})

In form I'm getting these values
self.cleaned_data.get('photo').size # I'm getting 144 rather than 1000 why?
But
self.cleaned_data.get('photo').name # I'm getting testasdas.png
I didn't get this? Can anyone tell me the reason for this? Also, how can I mock the size of the file?

.size would give you the file size in bytes, what you are looking for here is the image dimension. For that you need an image library such as Python Pillow to load the file and extract those values for you.
https://pillow.readthedocs.io/en/stable/reference/Image.html

Hope that helps and sorry for responding a year too late 🤦‍♂️

Cool.
The key is generate_photo_file and I should also make the
avatar = factory.Sequence(lambda n: f"{settings.MEDIA_ROOT}/user_avatar/fake_{n}.jpg") correctly.

Great example, thx

You are the best, when i grow up i want to be like you.

Example while testing with raw serializer:

# 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)