Rename loader keyword argument in web.Request.json method.

This adds consistency to the library as:

* `loads` alredy used in `client.Response.json` method
* `dumps` used in `web.json_response` function (introduced in 0.19.0)

aiohttp/web_reqrep.py

@@ -326,10 +326,10 @@ def text(self):
         return bytes_body.decode(encoding)
 
     @asyncio.coroutine
-    def json(self, *, loader=json.loads):
+    def json(self, *, loads=json.loads):
         """Return BODY as JSON."""
         body = yield from self.text()
-        return loader(body)
+        return loads(body)
 
     @asyncio.coroutine
     def post(self):

docs/web_reference.rst

@@ -250,14 +250,14 @@ like one using :meth:`Request.copy`.
          The method **does** store read data internally, subsequent
          :meth:`~Request.text` call will return the same value.
 
-   .. coroutinemethod:: json(*, loader=json.loads)
+   .. coroutinemethod:: json(*, loads=json.loads)
 
       Read request body decoded as *json*.
 
       The method is just a boilerplate :ref:`coroutine <coroutine>`
       implemented as::
 
-         async def json(self, *, loader=json.loads):
+         async def json(self, *, loads=json.loads):
              body = await self.text()
              return loader(body)
 

tests/test_web_functional.py

@@ -142,7 +142,7 @@ def test_post_json(self):
         def handler(request):
             data = yield from request.json()
             self.assertEqual(dct, data)
-            data2 = yield from request.json()
+            data2 = yield from request.json(loads=json.loads)
             self.assertEqual(data, data2)
             resp = web.Response()
             resp.content_type = 'application/json'