Verify that server can send pre-compressed data

docs/server.rst

@@ -85,6 +85,19 @@ params.  However aiohttp does provide a nice
             print("Passed in GET", get_params)
 
 
+Sending pre-compressed data
+---------------------------
+
+To include data in the response that is already compressed, do not call
+`enable_compression`.  Instead, set the `Content-Encoding` header explicitly:
+
+    @asyncio.coroutine
+    def handler(request):
+        headers = {'Content-Encoding': 'gzip'}
+        deflated_data = zlib.compress(b'mydata')
+        return web.Response(body=deflated_data, headers=headers)
+
+
 Handling POST data
 ------------------
 

tests/test_web_functional.py

@@ -5,6 +5,7 @@
 import os.path
 import socket
 import unittest
+import zlib
 from multidict import MultiDict
 from aiohttp import log, web, request, FormData, ClientSession, TCPConnector
 from aiohttp.protocol import HttpVersion, HttpVersion10, HttpVersion11
@@ -792,6 +793,25 @@ def go():
 
         self.loop.run_until_complete(go())
 
+    def test_response_with_precompressed_body(self):
+        @asyncio.coroutine
+        def handler(request):
+            headers = {'Content-Encoding': 'gzip'}
+            deflated_data = zlib.compress(b'mydata')
+            return web.Response(body=deflated_data, headers=headers)
+
+        @asyncio.coroutine
+        def go():
+            _, srv, url = yield from self.create_server('GET', '/', handler)
+            client = ClientSession(loop=self.loop)
+            resp = yield from client.get(url)
+            self.assertEqual(200, resp.status)
+            data = yield from resp.read()
+            self.assertEqual(b'mydata', data)
+            self.assertEqual(resp.headers.get('CONTENT-ENCODING'), 'deflate')
+            yield from resp.release()
+            client.close()
+
     def test_stream_response_multiple_chunks(self):
         @asyncio.coroutine
         def handler(request):