Faster joins tests: make request handlers more specific

I'm going to add a test which will involve *multiple* /state and /state_ids
requests, so we need to make the registered handlers more selective.

tests/federation_room_join_partial_state_test.go

@@ -589,12 +589,23 @@ func beginPartialStateJoin(t *testing.T, deployment *docker.Deployment, joiningU
 		},
 	}))
 
-	// register a handler for /state_ids requests, which finishes fedStateIdsRequestReceivedWaiter, then
+	// register a handler for /state_ids requests for the most recent event,
+	// which finishes fedStateIdsRequestReceivedWaiter, then
 	// waits for fedStateIdsSendResponseWaiter and sends a reply
-	handleStateIdsRequests(t, result.Server, result.ServerRoom, result.fedStateIdsRequestReceivedWaiter, result.fedStateIdsSendResponseWaiter)
+	lastEvent := result.ServerRoom.Timeline[len(result.ServerRoom.Timeline)-1]
+	currentState := result.ServerRoom.AllCurrentState()
+	handleStateIdsRequests(
+		t, result.Server, result.ServerRoom,
+		lastEvent.EventID(), currentState,
+		result.fedStateIdsRequestReceivedWaiter, result.fedStateIdsSendResponseWaiter,
+	)
 
 	// a handler for /state requests, which sends a sensible response
-	handleStateRequests(t, result.Server, result.ServerRoom, nil, nil)
+	handleStateRequests(
+		t, result.Server, result.ServerRoom,
+		lastEvent.EventID(), currentState,
+		nil, nil,
+	)
 
 	// have joiningUser join the room by room ID.
 	joiningUser.JoinRoom(t, result.ServerRoom.RoomID, []string{result.Server.ServerName()})
@@ -630,16 +641,20 @@ func (psj *partialStateJoinResult) FinishStateRequest() {
 	psj.fedStateIdsSendResponseWaiter.Finish()
 }
 
-// handleStateIdsRequests registers a handler for /state_ids requests for serverRoom.
+// handleStateIdsRequests registers a handler for /state_ids requests for 'eventID'
+//
+// the returned state is as passed in 'roomState'
 //
 // if requestReceivedWaiter is not nil, it will be Finish()ed when the request arrives.
 // if sendResponseWaiter is not nil, we will Wait() for it to finish before sending the response.
 func handleStateIdsRequests(
 	t *testing.T, srv *federation.Server, serverRoom *federation.ServerRoom,
+	eventID string, roomState []*gomatrixserverlib.Event,
 	requestReceivedWaiter *Waiter, sendResponseWaiter *Waiter,
 ) {
-	srv.Mux().Handle(
+	srv.Mux().NewRoute().Methods("GET").Path(
 		fmt.Sprintf("/_matrix/federation/v1/state_ids/%s", serverRoom.RoomID),
+	).Queries("event_id", eventID).Handler(
 		http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 			queryParams := req.URL.Query()
 			t.Logf("Incoming state_ids request for event %s in room %s", queryParams["event_id"], serverRoom.RoomID)
@@ -652,8 +667,8 @@ func handleStateIdsRequests(
 			t.Logf("Replying to /state_ids request")
 
 			res := gomatrixserverlib.RespStateIDs{
-				AuthEventIDs:  eventIDsFromEvents(serverRoom.AuthChain()),
-				StateEventIDs: eventIDsFromEvents(serverRoom.AllCurrentState()),
+				AuthEventIDs:  eventIDsFromEvents(serverRoom.AuthChainForEvents(roomState)),
+				StateEventIDs: eventIDsFromEvents(roomState),
 			}
 			w.WriteHeader(200)
 			jsonb, _ := json.Marshal(res)
@@ -662,19 +677,24 @@ func handleStateIdsRequests(
 				t.Errorf("Error writing to request: %v", err)
 			}
 		}),
-	).Methods("GET")
+	)
+	t.Logf("Registered state_ids handler for event %s", eventID)
 }
 
-// makeStateHandler returns a handler for /state requests for serverRoom.
+// makeStateHandler returns a handler for /state requests for 'eventID'
+//
+// the returned state is as passed in 'roomState'
 //
 // if requestReceivedWaiter is not nil, it will be Finish()ed when the request arrives.
 // if sendResponseWaiter is not nil, we will Wait() for it to finish before sending the response.
 func handleStateRequests(
 	t *testing.T, srv *federation.Server, serverRoom *federation.ServerRoom,
+	eventID string, roomState []*gomatrixserverlib.Event,
 	requestReceivedWaiter *Waiter, sendResponseWaiter *Waiter,
 ) {
-	srv.Mux().Handle(
+	srv.Mux().NewRoute().Methods("GET").Path(
 		fmt.Sprintf("/_matrix/federation/v1/state/%s", serverRoom.RoomID),
+	).Queries("event_id", eventID).Handler(
 		http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 			queryParams := req.URL.Query()
 			t.Logf("Incoming state request for event %s in room %s", queryParams["event_id"], serverRoom.RoomID)
@@ -685,8 +705,8 @@ func handleStateRequests(
 				sendResponseWaiter.Waitf(t, 60*time.Second, "Waiting for /state request")
 			}
 			res := gomatrixserverlib.RespState{
-				AuthEvents:  gomatrixserverlib.NewEventJSONsFromEvents(serverRoom.AuthChain()),
-				StateEvents: gomatrixserverlib.NewEventJSONsFromEvents(serverRoom.AllCurrentState()),
+				AuthEvents:  gomatrixserverlib.NewEventJSONsFromEvents(serverRoom.AuthChainForEvents(roomState)),
+				StateEvents: gomatrixserverlib.NewEventJSONsFromEvents(roomState),
 			}
 			w.WriteHeader(200)
 			jsonb, _ := json.Marshal(res)
@@ -695,7 +715,7 @@ func handleStateRequests(
 				t.Errorf("Error writing to request: %v", err)
 			}
 		}),
-	).Methods("GET")
+	)
 }
 
 func eventIDsFromEvents(he []*gomatrixserverlib.Event) []string {