`binance`: wrap streamer async-gen in `aclosing()`

piker/brokers/binance.py

@@ -26,6 +26,7 @@ from typing import (
 )
 import time
 
+from async_generator import aclosing
 import trio
 from trio_typing import TaskStatus
 import pendulum
@@ -529,19 +530,21 @@ async def stream_quotes(
                 # XXX: do we need to ack the unsub?
                 # await ws.recv_msg()
 
-        async with open_autorecon_ws(
-            'wss://stream.binance.com/ws',
+        async with (
+            open_autorecon_ws(
                 # XXX: see api docs which show diff addr?
                 # https://developers.binance.com/docs/binance-trading-api/websocket_api#general-api-information
                 # 'wss://ws-api.binance.com:443/ws-api/v3',
+                'wss://stream.binance.com/ws',
                 fixture=subscribe,
-        ) as ws:
-
-            # pull a first quote and deliver
-            msg_gen = stream_messages(ws)
+            ) as ws,
 
+            # avoid stream-gen closure from breaking trio..
+            aclosing(stream_messages(ws)) as msg_gen,
+        ):
             typ, quote = await anext(msg_gen)
 
+            # pull a first quote and deliver
             while typ != 'trade':
                 typ, quote = await anext(msg_gen)