fix lint error

mitmproxy/proxy/layers/http/__init__.py

@@ -302,6 +302,7 @@ class HttpStream(layer.Layer):
         if isinstance(event, ResponseData):
             self.response_body_buf += event.data
         elif isinstance(event, ResponseTrailers):
+            assert self.flow.response
             self.flow.response.trailers = event.trailers
             yield HttpResponseTrailersHook(self.flow)
         elif isinstance(event, ResponseEndOfMessage):

mitmproxy/proxy/layers/http/_hooks.py

@@ -44,6 +44,7 @@ class HttpResponseHook(commands.StartHook):
     name = "response"
     flow: http.HTTPFlow
 
+
 @dataclass
 class HttpResponseTrailersHook(commands.StartHook):
     """
@@ -52,6 +53,7 @@ class HttpResponseTrailersHook(commands.StartHook):
     name = "responsetrailers"
     flow: http.HTTPFlow
 
+
 @dataclass
 class HttpErrorHook(commands.StartHook):
     """

mitmproxy/proxy/layers/http/_http2.py

@@ -99,10 +99,7 @@ class Http2Connection(HttpConnection):
                     self.h2_conn.send_data(event.stream_id, event.data)
             elif isinstance(event, ResponseTrailers):
                 if self.is_open_for_us(event.stream_id):
-                    trailers = [
-                    *event.trailers.fields
-                    ]
-                    r = event.trailers.fields
+                    trailers = [*event.trailers.fields]
                     self.h2_conn.send_headers(event.stream_id, trailers, event.end_stream)
             elif isinstance(event, self.SendEndOfMessage):
                 if self.is_open_for_us(event.stream_id):
@@ -458,6 +455,7 @@ class Http2Client(Http2Connection):
         elif isinstance(event, h2.events.TrailersReceived):
             pseudo_trailers, trailers = split_pseudo_headers(event.headers)
             yield ReceiveHttp(ResponseTrailers(event.stream_id, trailers, bool(event.stream_ended)))
+            return False
         elif isinstance(event, h2.events.RequestReceived):
             yield from self.protocol_error(f"HTTP/2 protocol error: received request from server")
             return True

test/mitmproxy/proxy/layers/http/test_http2.py

@@ -35,6 +35,7 @@ example_response_trailers = (
     (b'my-trailer-b', b'0')
 )
 
+
 def decode_frames(data: bytes) -> List[hyperframe.frame.Frame]:
     # swallow preamble
     if data.startswith(b"PRI * HTTP/2.0"):