Raise RuntimeError is you try to set the Content Length with chunked encoding enable

CHANGES.rst

@@ -23,7 +23,7 @@ Changes
 
 -
 
--
+- Raise RuntimeError is you try to set the Content Length and enable chunked encoding at the same time
 
 2.1.0 (2017-05-26)
 ------------------

aiohttp/web_response.py

@@ -111,6 +111,10 @@ def output_length(self):
     def enable_chunked_encoding(self, chunk_size=None):
         """Enables automatic chunked transfer encoding."""
         self._chunked = True
+
+        if hdrs.CONTENT_LENGTH in self._headers:
+            raise RuntimeError("You can't enable chunked encoding when "
+                               "a content length is set")
         if chunk_size is not None:
             warnings.warn('Chunk size is deprecated #1615', DeprecationWarning)
 
@@ -194,7 +198,9 @@ def content_length(self):
     def content_length(self, value):
         if value is not None:
             value = int(value)
-            # TODO: raise error if chunked enabled
+            if self._chunked:
+                raise RuntimeError("You can't set content length when "
+                                   "chunked encoding is enable")
             self._headers[hdrs.CONTENT_LENGTH] = str(value)
         else:
             self._headers.pop(hdrs.CONTENT_LENGTH, None)

tests/test_web_response.py

@@ -86,6 +86,14 @@ def test_content_length_setter():
     assert 234 == resp.content_length
 
 
+def test_content_length_setter_with_enable_chunked_encoding():
+    resp = StreamResponse()
+
+    resp.enable_chunked_encoding()
+    with pytest.raises(RuntimeError):
+        resp.content_length = 234
+
+
 def test_drop_content_length_header_on_setting_len_to_None():
     resp = StreamResponse()
 
@@ -223,6 +231,14 @@ def test_chunked_encoding():
     assert msg.chunked
 
 
+def test_enable_chunked_encoding_with_content_length():
+    resp = StreamResponse()
+
+    resp.content_length = 234
+    with pytest.raises(RuntimeError):
+        resp.enable_chunked_encoding()
+
+
 @asyncio.coroutine
 def test_chunk_size():
     req = make_request('GET', '/', payload_writer=mock.Mock())