我正在尝试找到一种方法,在使用Django和sorl-thumbnail的get_thumbnail()方法时如何测试缩略图的生成.

环境：

Django==1.5.5
Pillow==2.1.0
sorl-thumbnail==11.12

简化的测试代码(在测试环境中运行)：

from StringIO import StringIO
from PIL import Image

from django.conf import settings
from django.core.files.uploadedfile import InMemoryUploadedFile
from django.db import models
from sorl.thumbnail import get_thumbnail

# simple class with ImageField
class User(models.Model):
    avatar = models.ImageField(upload_to='avatars', default=None, null=True, blank=True)

    def get_thumbnail_uri(self):
        avatar_thumbnail = get_thumbnail(self.avatar, '100x100')

        return avatar_thumbnail.url

# make sure we're using in-memory test env.
assert settings.THUMBNAIL_STORAGE  == 'inmemorystorage.InMemoryStorage'
assert settings.DEFAULT_FILE_STORAGE == 'inmemorystorage.InMemoryStorage'

# prepare image
fake_file = StringIO()

picture = Image.new(mode='RGBA', size=(500, 500), color=(255, 0, 0, 0))
picture.save(fake_file, 'JPEG')

fake_file.name = 'test.jpg'
fake_file.seek(0)

uploaded_image = InMemoryUploadedFile(fake_file, field_name=None, name='test.jpg',
                                      content_type='image/jpeg', size=fake_file.len,
                                      charset=None)

# add image to user
u = User()
u.avatar = uploaded_image

assert u.get_thumbnail_uri() is not None

以上总是在最后一行失败：

Traceback (most recent call last):
  File "/vagrant/path/to/file.py", line 1440, in test_stackprep
    assert u.get_thumbnail_uri() is not None
  File "/vagrant/path/to/file.py", line 1413, in get_thumbnail_uri
    avatar_thumbnail = get_thumbnail(self.avatar, '100x100')
  File "/home/vagrant/.virtualenv/appname/local/lib/python2.7/site-packages/sorl/thumbnail/shortcuts.py", line 8, in get_thumbnail
    return default.backend.get_thumbnail(file_, geometry_string, **options)
  File "/home/vagrant/.virtualenv/appname/local/lib/python2.7/site-packages/sorl/thumbnail/base.py", line 56, in get_thumbnail
    source_image = default.engine.get_image(source)
  File "/home/vagrant/.virtualenv/appname/local/lib/python2.7/site-packages/sorl/thumbnail/engines/pil_engine.py", line 13, in get_image
    return Image.open(buf)
  File "/home/vagrant/.virtualenv/appname/local/lib/python2.7/site-packages/PIL/Image.py", line 2008, in open
    raise IOError("cannot identify image file")
IOError: cannot identify image file

我假设Django或sorl-thumbnail在运行测试时脱离了内存存储.我已经使用了很长时间,但是除了直接在文件系统上测试东西(我想避免这种情况)之外,我找不到任何有效的配置.

请问有人设法在测试中使用sorl的get_thumbnail()方法吗？

谢谢.

解决方法:

版本11.12是PyPI的最新版本,已有2年历史了.回购中有可用的版本12.0,该版本应该可以正常工作.它不在PyPI上,因为有change of maintainers,我想他们还没有机会这样做.

我尝试了主版本,并且可以在您的示例中正常使用.