Fixed #29082 -- Allowed the test client to encode JSON request data.

AUTHORS

@@ -605,6 +605,7 @@ answer newbie questions, and generally made Django that much better:
     Nick Pope <nick@nickpope.me.uk>
     Nick Presta <nick@nickpresta.ca>
     Nick Sandford <nick.sandford@gmail.com>
+    Nick Sarbicki <nick.a.sarbicki@gmail.com>
     Niclas Olofsson <n@niclasolofsson.se>
     Nicola Larosa <nico@teknico.net>
     Nicolas Lara <nicolaslara@gmail.com>

django/test/client.py

@@ -13,6 +13,7 @@ from urllib.parse import unquote_to_bytes, urljoin, urlparse, urlsplit
 from django.conf import settings
 from django.core.handlers.base import BaseHandler
 from django.core.handlers.wsgi import WSGIRequest
+from django.core.serializers.json import DjangoJSONEncoder
 from django.core.signals import (
     got_request_exception, request_finished, request_started,
 )
@@ -261,7 +262,8 @@ class RequestFactory:
     Once you have a request object you can pass it to any view function,
     just as if that view had been hooked up using a URLconf.
     """
-    def __init__(self, **defaults):
+    def __init__(self, *, json_encoder=DjangoJSONEncoder, **defaults):
+        self.json_encoder = json_encoder
         self.defaults = defaults
         self.cookies = SimpleCookie()
         self.errors = BytesIO()
@@ -310,6 +312,14 @@ class RequestFactory:
                 charset = settings.DEFAULT_CHARSET
             return force_bytes(data, encoding=charset)
 
+    def _encode_json(self, data, content_type):
+        """
+        Return encoded JSON if data is a dict and content_type is
+        application/json.
+        """
+        should_encode = JSON_CONTENT_TYPE_RE.match(content_type) and isinstance(data, dict)
+        return json.dumps(data, cls=self.json_encoder) if should_encode else data
+
     def _get_path(self, parsed):
         path = parsed.path
         # If there are parameters, add them
@@ -332,7 +342,7 @@ class RequestFactory:
     def post(self, path, data=None, content_type=MULTIPART_CONTENT,
              secure=False, **extra):
         """Construct a POST request."""
-        data = {} if data is None else data
+        data = self._encode_json({} if data is None else data, content_type)
         post_data = self._encode_data(data, content_type)
 
         return self.generic('POST', path, post_data, content_type,
@@ -359,18 +369,21 @@ class RequestFactory:
     def put(self, path, data='', content_type='application/octet-stream',
             secure=False, **extra):
         """Construct a PUT request."""
+        data = self._encode_json(data, content_type)
         return self.generic('PUT', path, data, content_type,
                             secure=secure, **extra)
 
     def patch(self, path, data='', content_type='application/octet-stream',
               secure=False, **extra):
         """Construct a PATCH request."""
+        data = self._encode_json(data, content_type)
         return self.generic('PATCH', path, data, content_type,
                             secure=secure, **extra)
 
     def delete(self, path, data='', content_type='application/octet-stream',
                secure=False, **extra):
         """Construct a DELETE request."""
+        data = self._encode_json(data, content_type)
         return self.generic('DELETE', path, data, content_type,
                             secure=secure, **extra)
 

docs/releases/2.1.txt

@@ -208,6 +208,10 @@ Tests
 
 * Added test :class:`~django.test.Client` support for 307 and 308 redirects.
 
+* The test :class:`~django.test.Client` now serializes a request data
+  dictionary as JSON if ``content_type='application/json'``. You can customize
+  the JSON encoder with test client's ``json_encoder`` parameter.
+
 URLs
 ~~~~
 

docs/topics/testing/tools.txt

@@ -109,7 +109,7 @@ Making requests
 
 Use the ``django.test.Client`` class to make requests.
 
-.. class:: Client(enforce_csrf_checks=False, **defaults)
+.. class:: Client(enforce_csrf_checks=False, json_encoder=DjangoJSONEncoder, **defaults)
 
     It requires no arguments at time of construction. However, you can use
     keywords arguments to specify some default headers. For example, this will
@@ -125,6 +125,13 @@ Use the ``django.test.Client`` class to make requests.
     The ``enforce_csrf_checks`` argument can be used to test CSRF
     protection (see above).
 
+    The ``json_encoder`` argument allows setting a custom JSON encoder for
+    the JSON serialization that's described in :meth:`post`.
+
+    .. versionchanged:: 2.1
+
+        The ``json_encoder`` argument was added.
+
     Once you have a ``Client`` instance, you can call any of the following
     methods:
 
@@ -206,9 +213,23 @@ Use the ``django.test.Client`` class to make requests.
 
             name=fred&passwd=secret
 
-        If you provide ``content_type`` (e.g. :mimetype:`text/xml` for an XML
-        payload), the contents of ``data`` will be sent as-is in the POST
-        request, using ``content_type`` in the HTTP ``Content-Type`` header.
+        If you provide ``content_type`` as :mimetype:`application/json`, a
+        ``data`` dictionary is serialized using :func:`json.dumps` with
+        :class:`~django.core.serializers.json.DjangoJSONEncoder`. You can
+        change the encoder by providing a ``json_encoder`` argument to
+        :class:`Client`. This serialization also happens for :meth:`put`,
+        :meth:`patch`, and :meth:`delete` requests.
+
+        .. versionchanged:: 2.1
+
+            The JSON serialization described above was added. In older versions,
+            you can call :func:`json.dumps` on ``data`` before passing it to
+            ``post()`` to achieve the same thing.
+
+        If you provide any other ``content_type`` (e.g. :mimetype:`text/xml`
+        for an XML payload), the contents of ``data`` are sent as-is in the
+        POST request, using ``content_type`` in the HTTP ``Content-Type``
+        header.
 
         If you don't provide a value for ``content_type``, the values in
         ``data`` will be transmitted with a content type of

tests/test_client/tests.py

@@ -21,6 +21,7 @@ rather than the HTML rendered to the end-user.
 """
 import itertools
 import tempfile
+from unittest import mock
 
 from django.contrib.auth.models import User
 from django.core import mail
@@ -86,6 +87,31 @@ class ClientTest(TestCase):
         self.assertEqual(response.templates[0].name, 'POST Template')
         self.assertContains(response, 'Data received')
 
+    def test_json_serialization(self):
+        """The test client serializes JSON data."""
+        methods = ('post', 'put', 'patch', 'delete')
+        for method in methods:
+            with self.subTest(method=method):
+                client_method = getattr(self.client, method)
+                method_name = method.upper()
+                response = client_method('/json_view/', {'value': 37}, content_type='application/json')
+                self.assertEqual(response.status_code, 200)
+                self.assertEqual(response.context['data'], 37)
+                self.assertContains(response, 'Viewing %s page.' % method_name)
+
+    def test_json_encoder_argument(self):
+        """The test Client accepts a json_encoder."""
+        mock_encoder = mock.MagicMock()
+        mock_encoding = mock.MagicMock()
+        mock_encoder.return_value = mock_encoding
+        mock_encoding.encode.return_value = '{"value": 37}'
+
+        client = self.client_class(json_encoder=mock_encoder)
+        # Vendored tree JSON content types are accepted.
+        client.post('/json_view/', {'value': 37}, content_type='application/vnd.api+json')
+        self.assertTrue(mock_encoder.called)
+        self.assertTrue(mock_encoding.encode.called)
+
     def test_trace(self):
         """TRACE a view"""
         response = self.client.trace('/trace_view/')

tests/test_client/urls.py

@@ -25,6 +25,7 @@ urlpatterns = [
     url(r'^form_view/$', views.form_view),
     url(r'^form_view_with_template/$', views.form_view_with_template),
     url(r'^formset_view/$', views.formset_view),
+    url(r'^json_view/$', views.json_view),
     url(r'^login_protected_view/$', views.login_protected_view),
     url(r'^login_protected_method_view/$', views.login_protected_method_view),
     url(r'^login_protected_view_custom_redirect/$', views.login_protected_view_changed_redirect),

tests/test_client/views.py

@@ -1,3 +1,4 @@
+import json
 from urllib.parse import urlencode
 from xml.dom.minidom import parseString
 
@@ -73,7 +74,20 @@ def post_view(request):
     else:
         t = Template('Viewing GET page.', name='Empty GET Template')
         c = Context()
+    return HttpResponse(t.render(c))
+
+
+def json_view(request):
+    """
+    A view that expects a request with the header 'application/json' and JSON
+    data with a key named 'value'.
+    """
+    if request.META.get('CONTENT_TYPE') != 'application/json':
+        return HttpResponse()
 
+    t = Template('Viewing {} page. With data {{ data }}.'.format(request.method))
+    data = json.loads(request.body.decode('utf-8'))
+    c = Context({'data': data['value']})
     return HttpResponse(t.render(c))