From 4525a0c4669dccb3a4c5d865184f8bb8e4a89ec8 Mon Sep 17 00:00:00 2001
From: Andy McKay <amckay@mozilla.com>
Date: Fri, 8 May 2015 22:33:26 -0700
Subject: [PATCH] Fixed #24773 -- Added a json() method on test client
 responses.

---
 django/test/client.py              |  8 ++++++++
 docs/releases/1.9.txt              |  3 ++-
 docs/topics/testing/tools.txt      | 14 ++++++++++++++
 tests/test_client_regress/tests.py | 10 ++++++++++
 tests/test_client_regress/urls.py  |  1 +
 tests/test_client_regress/views.py |  6 +++++-
 6 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/django/test/client.py b/django/test/client.py
index 043bf884a1b..f8c2705f983 100644
--- a/django/test/client.py
+++ b/django/test/client.py
@@ -1,5 +1,6 @@
 from __future__ import unicode_literals
 
+import json
 import mimetypes
 import os
 import re
@@ -473,6 +474,8 @@ class Client(RequestFactory):
             response.templates = data.get("templates", [])
             response.context = data.get("context")
 
+            response.json = curry(self._parse_json, response)
+
             # Attach the ResolverMatch instance to the response
             response.resolver_match = SimpleLazyObject(
                 lambda: urlresolvers.resolve(request['PATH_INFO']))
@@ -641,6 +644,11 @@ class Client(RequestFactory):
         logout(request)
         self.cookies = SimpleCookie()
 
+    def _parse_json(self, response, **extra):
+        if 'application/json' not in response.get('Content-Type'):
+            raise ValueError('Content-Type header is "{0}", not "application/json"'.format(response.get('Content-Type')))
+        return json.loads(response.content.decode(), **extra)
+
     def _handle_redirects(self, response, **extra):
         "Follows any redirects by requesting responses from the server using GET."
 
diff --git a/docs/releases/1.9.txt b/docs/releases/1.9.txt
index e36c4512ca0..5b58f79fc02 100644
--- a/docs/releases/1.9.txt
+++ b/docs/releases/1.9.txt
@@ -289,7 +289,8 @@ Requests and Responses
 Tests
 ^^^^^
 
-* ...
+* Added the :meth:`json() <django.test.Response.json>` method to test client
+  responses to give access to the response body as JSON.
 
 URLs
 ^^^^
diff --git a/docs/topics/testing/tools.txt b/docs/topics/testing/tools.txt
index aa66afb1d9d..e2ad15d5b50 100644
--- a/docs/topics/testing/tools.txt
+++ b/docs/topics/testing/tools.txt
@@ -425,6 +425,20 @@ Specifically, a ``Response`` object has the following attributes:
             >>> response.context['name']
             'Arthur'
 
+    .. method:: json(**kwargs)
+
+        .. versionadded:: 1.9
+
+        The body of the response, parsed as JSON. Extra keyword arguments are
+        passed to :func:`json.loads`. For example::
+
+            >>> response = client.get('/foo/')
+            >>> response.json()['name']
+            'Arthur'
+
+        If the ``Content-Type`` header is not ``"application/json"``, then a
+        :exc:`ValueError` will be raised when trying to parse the response.
+
     .. attribute:: request
 
         The request data that stimulated the response.
diff --git a/tests/test_client_regress/tests.py b/tests/test_client_regress/tests.py
index f47ae10b56e..efc44289cd8 100644
--- a/tests/test_client_regress/tests.py
+++ b/tests/test_client_regress/tests.py
@@ -1270,6 +1270,16 @@ class RequestMethodStringDataTests(SimpleTestCase):
         response = self.client.head('/body/', data='', content_type='application/json')
         self.assertEqual(response.content, b'')
 
+    def test_json(self):
+        response = self.client.get('/json_response/')
+        self.assertEqual(response.json(), {'key': 'value'})
+
+    def test_json_wrong_header(self):
+        response = self.client.get('/body/')
+        msg = 'Content-Type header is "text/html; charset=utf-8", not "application/json"'
+        with self.assertRaisesMessage(ValueError, msg):
+            self.assertEqual(response.json(), {'key': 'value'})
+
 
 @override_settings(ROOT_URLCONF='test_client_regress.urls',)
 class QueryStringTests(SimpleTestCase):
diff --git a/tests/test_client_regress/urls.py b/tests/test_client_regress/urls.py
index fd7c131797b..9821ea910d7 100644
--- a/tests/test_client_regress/urls.py
+++ b/tests/test_client_regress/urls.py
@@ -30,6 +30,7 @@ urlpatterns = [
     url(r'^request_methods/$', views.request_methods_view),
     url(r'^check_unicode/$', views.return_unicode),
     url(r'^check_binary/$', views.return_undecodable_binary),
+    url(r'^json_response/$', views.return_json_response),
     url(r'^parse_unicode_json/$', views.return_json_file),
     url(r'^check_headers/$', views.check_headers),
     url(r'^check_headers_redirect/$', RedirectView.as_view(url='/check_headers/')),
diff --git a/tests/test_client_regress/views.py b/tests/test_client_regress/views.py
index 6046564ee4c..d21448cba11 100644
--- a/tests/test_client_regress/views.py
+++ b/tests/test_client_regress/views.py
@@ -3,7 +3,7 @@ import json
 from django.conf import settings
 from django.contrib.auth.decorators import login_required
 from django.core.serializers.json import DjangoJSONEncoder
-from django.http import HttpResponse, HttpResponseRedirect
+from django.http import HttpResponse, HttpResponseRedirect, JsonResponse
 from django.shortcuts import render_to_response
 from django.template import RequestContext
 from django.template.loader import render_to_string
@@ -108,6 +108,10 @@ def return_undecodable_binary(request):
     )
 
 
+def return_json_response(request):
+    return JsonResponse({'key': 'value'})
+
+
 def return_json_file(request):
     "A view that parses and returns a JSON string as a file."
     match = CONTENT_TYPE_RE.match(request.META['CONTENT_TYPE'])