support django 2.1 test client json data automatically serialized

rest_framework/test.py

@@ -151,14 +151,19 @@ def _encode_data(self, data, format=None, content_type=None):
         Encode the data returning a two tuple of (bytes, content_type)
         """
 
-        if data is None:
-            return ('', content_type)
-
         assert format is None or content_type is None, (
             'You may not set both `format` and `content_type`.'
         )
 
         if content_type:
+            try:
+                data = self._encode_json(data, content_type)
+            except AttributeError:
+                pass
+
+            if data is None:
+                data = ''
+
             # Content type specified explicitly, treat data as a raw bytestring
             ret = force_bytes(data, settings.DEFAULT_CHARSET)
 
@@ -176,7 +181,6 @@ def _encode_data(self, data, format=None, content_type=None):
 
             # Use format and render the data into a bytestring
             renderer = self.renderer_classes[format]()
-            ret = renderer.render(data)
 
             # Determine the content-type header from the renderer
             content_type = renderer.media_type
@@ -185,6 +189,11 @@ def _encode_data(self, data, format=None, content_type=None):
                     content_type, renderer.charset
                 )
 
+            if data is None:
+                ret = ''
+            else:
+                ret = renderer.render(data)
+
             # Coerce text to bytes if required.
             if isinstance(ret, str):
                 ret = ret.encode(renderer.charset)

tests/test_testing.py

@@ -1,12 +1,13 @@
 from io import BytesIO
 
+from django import VERSION as DJANGO_VERSION
 from django.contrib.auth.models import User
 from django.shortcuts import redirect
 from django.test import TestCase, override_settings
 from django.urls import path
 
-from rest_framework import fields, serializers
-from rest_framework.decorators import api_view
+from rest_framework import fields, parsers, serializers
+from rest_framework.decorators import api_view, parser_classes
 from rest_framework.response import Response
 from rest_framework.test import (
     APIClient, APIRequestFactory, URLPatternsTestCase, force_authenticate
@@ -46,11 +47,18 @@ def post_view(request):
     return Response(serializer.validated_data)
 
 
+@api_view(['POST'])
+@parser_classes((parsers.JSONParser,))
+def post_json_view(request):
+    return Response(request.data)
+
+
 urlpatterns = [
     path('view/', view),
     path('session-view/', session_view),
     path('redirect-view/', redirect_view),
     path('post-view/', post_view)
+    path('post-json-view/', post_json_view),
 ]
 
 
@@ -200,6 +208,21 @@ def test_empty_post_uses_default_boolean_value(self):
         assert response.status_code == 200
         assert response.data == {"flag": True}
 
+    def test_post_encodes_data_based_on_json_content_type(self):
+        data = {'data': True}
+        response = self.client.post(
+            '/post-json-view/',
+            data=data,
+            content_type='application/json'
+        )
+
+        if DJANGO_VERSION < (2, 1):
+            assert response.status_code == 400
+            assert response.data['detail'].code == 'parse_error'
+        else:
+            assert response.status_code == 200
+            assert response.data == data
+
 
 class TestAPIRequestFactory(TestCase):
     def test_csrf_exempt_by_default(self):