Response model now handles the 204 no content

sanic/response.py

@@ -195,8 +195,12 @@ class HTTPResponse(BaseHTTPResponse):
         timeout_header = b''
         if keep_alive and keep_alive_timeout is not None:
             timeout_header = b'Keep-Alive: %d\r\n' % keep_alive_timeout
-        self.headers['Content-Length'] = self.headers.get(
-            'Content-Length', len(self.body))
+
+        content_length = 0
+        if self.status is not 204:
+            content_length = self.headers.get('Content-Length', len(self.body))
+        self.headers['Content-Length'] = content_length
+
         self.headers['Content-Type'] = self.headers.get(
             'Content-Type', self.content_type)
 
@@ -218,7 +222,7 @@ class HTTPResponse(BaseHTTPResponse):
                    b'keep-alive' if keep_alive else b'close',
                    timeout_header,
                    headers,
-                   self.body
+                   self.body if self.status is not 204 else b''
                )
 
     @property
@@ -239,8 +243,7 @@ def json(body, status=200, headers=None,
     :param headers: Custom Headers.
     :param kwargs: Remaining arguments that are passed to the json encoder.
     """
-    _body = dumps(body, **kwargs) if body else None
-    return HTTPResponse(_body, headers=headers,
+    return HTTPResponse(dumps(body, **kwargs), headers=headers,
                         status=status, content_type=content_type)