如何使用 django-rest-framework 测试客户端测试二进制文件上传？

我有一个 Django 应用程序，其视图接受要上传的文件。使用 Django REST 框架，我对 APIView 进行子类化并实现 post() 方法，如下所示：

class FileUpload(APIView):
    permission_classes = (IsAuthenticated,)

    def post(self, request, *args, **kwargs):
        try:
            image = request.FILES['image']
            # Image processing here.
            return Response(status=status.HTTP_201_CREATED)
        except KeyError:
            return Response(status=status.HTTP_400_BAD_REQUEST, data={'detail' : 'Expected image.'})

现在我正在尝试编写几个单元测试以确保需要身份验证并且上传的文件得到实际处理。

class TestFileUpload(APITestCase):
    def test_that_authentication_is_required(self):
        self.assertEqual(self.client.post('my_url').status_code, status.HTTP_401_UNAUTHORIZED)

    def test_file_is_accepted(self):
        self.client.force_authenticate(self.user)
        image = Image.new('RGB', (100, 100))
        tmp_file = tempfile.NamedTemporaryFile(suffix='.jpg')
        image.save(tmp_file)
        with open(tmp_file.name, 'rb') as data:
            response = self.client.post('my_url', {'image': data}, format='multipart')
            self.assertEqual(status.HTTP_201_CREATED, response.status_code)

但是当 REST 框架尝试对请求进行编码时，就会失败

Traceback (most recent call last):
  File "/home/vagrant/.virtualenvs/myapp/lib/python3.3/site-packages/django/utils/encoding.py", line 104, in force_text
    s = six.text_type(s, encoding, errors)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 118: invalid start byte

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/vagrant/webapp/myproject/myapp/tests.py", line 31, in test_that_jpeg_image_is_accepted
    response = self.client.post('my_url', { 'image': data}, format='multipart')
  File "/home/vagrant/.virtualenvs/myapp/lib/python3.3/site-    packages/rest_framework/test.py", line 76, in post
    return self.generic('POST', path, data, content_type, **extra)
  File "/home/vagrant/.virtualenvs/myapp/lib/python3.3/site-packages/rest_framework/compat.py", line 470, in generic
    data = force_bytes_or_smart_bytes(data, settings.DEFAULT_CHARSET)
  File "/home/vagrant/.virtualenvs/myapp/lib/python3.3/site-packages/django/utils/encoding.py", line 73, in smart_text
    return force_text(s, encoding, strings_only, errors)
  File "/home/vagrant/.virtualenvs/myapp/lib/python3.3/site-packages/django/utils/encoding.py", line 116, in force_text
    raise DjangoUnicodeDecodeError(s, *e.args)
django.utils.encoding.DjangoUnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 118: invalid start byte. You passed in b'--BoUnDaRyStRiNg\r\nContent-Disposition: form-data; name="image"; filename="tmpyz2wac.jpg"\r\nContent-Type: image/jpeg\r\n\r\n\xff\xd8\xff[binary data omitted]' (<class 'bytes'>)

如何让测试客户端发送数据而不尝试将其解码为 UTF-8？

测试文件上传时，您应该将流对象传递到请求中，而不是数据.

评论中指出了这一点@arocks https://stackoverflow.com/users/3107299/arocks

改为传递 { 'image': file}

但这并没有完全解释为什么需要它（而且也不符合问题）。对于这个具体问题，你应该这样做

from PIL import Image

class TestFileUpload(APITestCase):

    def test_file_is_accepted(self):
        self.client.force_authenticate(self.user)

        image = Image.new('RGB', (100, 100))

        tmp_file = tempfile.NamedTemporaryFile(suffix='.jpg')
        image.save(tmp_file)
        tmp_file.seek(0)

        response = self.client.post('my_url', {'image': tmp_file}, format='multipart')

       self.assertEqual(status.HTTP_201_CREATED, response.status_code)

这将匹配标准 Django 请求，其中文件作为流对象传入，并且 Django REST Framework 处理它。当您仅传入文件数据时，Django 和 Django REST Framework 会将其解释为字符串，这会导致问题，因为它需要一个流。

对于那些来这里寻找另一个常见错误的人，为什么文件上传不起作用，但正常形式的数据可以：确保设置format="multipart"创建请求时.

这也给出了类似的问题，并被指出@罗宾埃尔文 https://stackoverflow.com/users/285549/robin-elvin在评论中

这是因为我缺少 format='multipart'