Faster HTTP streaming when using ASGI (#318)

src/microdot/asgi.py

@@ -127,19 +127,17 @@ class Microdot(BaseMicrodot):
         monitor_task = asyncio.ensure_future(cancel_monitor())
 
         body_iter = res.body_iter().__aiter__()
-        res_body = b''
         try:
-            res_body = await body_iter.__anext__()
             while not cancelled:  # pragma: no branch
-                next_body = await body_iter.__anext__()
+                res_body = await body_iter.__anext__()
                 await send({'type': 'http.response.body',
                             'body': res_body,
                             'more_body': True})
-                res_body = next_body
         except StopAsyncIteration:
-            await send({'type': 'http.response.body',
-                        'body': res_body,
-                        'more_body': False})
+            pass
+        await send({'type': 'http.response.body',
+                    'body': b'',
+                    'more_body': False})
         if hasattr(body_iter, 'aclose'):  # pragma: no branch
             await body_iter.aclose()
         cancelled = True