Add test for plaintext upgrade.

Author: Lukasa

test/test_integration.py

@@ -859,6 +859,82 @@ def socket_handler(listener):
 
         self.tear_down()
 
+    def test_upgrade(self):
+        self.set_up(secure=False)
+
+        recv_event = threading.Event()
+        wait_event = threading.Event()
+
+        def socket_handler(listener):
+            sock = listener.accept()[0]
+
+            # First read the HTTP/1.1 request
+            data = b''
+            while not data.endswith(b'\r\n\r\n'):
+                data += sock.recv(65535)
+
+            # Check it's an upgrade.
+            assert b'upgrade: h2c\r\n' in data
+
+            # Send back an upgrade message.
+            data = (
+                b'HTTP/1.1 101 Switching Protocols\r\n'
+                b'Server: some-server\r\n'
+                b'Connection: upgrade\r\n'
+                b'Upgrade: h2c\r\n'
+                b'\r\n'
+            )
+            sock.sendall(data)
+
+            # We get a message for connection open, specifically the preamble.
+            receive_preamble(sock)
+
+            # Now, send the headers for the response. This response has a body.
+            f = build_headers_frame([(':status', '200')])
+            f.stream_id = 1
+            sock.sendall(f.serialize())
+
+            # Send the first two chunks.
+            f = DataFrame(1)
+            f.data = b'hello'
+            sock.sendall(f.serialize())
+            f = DataFrame(1)
+            f.data = b'there'
+            sock.sendall(f.serialize())
+
+            # Now, delay a bit. We want to wait a half a second before we send
+            # the next frame.
+            wait_event.wait(5)
+            time.sleep(0.5)
+            f = DataFrame(1)
+            f.data = b'world'
+            f.flags.add('END_STREAM')
+            sock.sendall(f.serialize())
+
+            # Wait for the message from the main thread.
+            recv_event.set()
+            sock.close()
+
+        self._start_server(socket_handler)
+        conn = hyper.HTTPConnection(self.host, self.port, self.secure)
+        conn.request('GET', '/')
+        resp = conn.get_response()
+
+        # Confirm the status code.
+        assert resp.status == 200
+
+        first_chunk = resp.read(10)
+        wait_event.set()
+        second_chunk = resp.read(5)
+
+        assert first_chunk == b'hellothere'
+        assert second_chunk == b'world'
+
+        # Awesome, we're done now.
+        recv_event.wait(5)
+
+        self.tear_down()
+
 
 class TestRequestsAdapter(SocketLevelTest):
     # This uses HTTP/2.