inmemory_image_generator.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from __future__ import unicode_literals

from django.core.files.uploadedfile import SimpleUploadedFile
from StringIO import StringIO
from PIL import Image


def get_image_dict():
    """create inmemory dummy image for testing forms which have image field"""
    img_file = StringIO()
    img = Image.new('RGBA', size=(10,10), color=(255, 255, 255))
    img.save(img_file, 'png')
    img_file.name = 'test_img.png'
    img_file.seek(0)
    img_dict = {
            'image': SimpleUploadedFile(
                img_file.name,
                img_file.read(),
                content_type='image/png')}
    return img_dict

Usage

from inmemory_image_generator import get_image_dict

class HogeTest(TestCase):
    def test_hoge(self):
        img_dict = get_image_dict()
        ...
        param = {
            ...
            }
        form = HogeForm(param, img_dict)
        self.assertTrue(form.is_valid())