Added 410 Gone responses to EventSub WebSocket server when trying to subscribe to an event version that was removed

Author: Xemdo

internal/events/types/types.go

@@ -151,3 +151,11 @@ func GetByTriggerAndTransportAndVersion(trigger string, transport string, versio
 	// Default error
 	return nil, errors.New("Invalid event")
 }
+
+// These events were removed from production
+// This does not include any "beta" events, just old production versions
+func RemovedEvents() map[string]string {
+	return map[string]string{
+		"channel.follow": "1",
+	}
+}

internal/events/websocket/mock_server/manager.go

@@ -337,7 +337,14 @@ func subscriptionPageHandlerPost(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// Check if the topic exists
+	// Check if the topic was deprecated/removed
+	for e, v := range types.RemovedEvents() {
+		if body.Type == e && body.Version == v {
+			handlerResponseErrorGone(w)
+			return
+		}
+	}
+
 	_, err = types.GetByTriggerAndTransportAndVersion(body.Type, body.Transport.Method, body.Version)
 	if err != nil {
 		handlerResponseErrorBadRequest(w, "The combination of values in the type and version fields is not valid")
@@ -546,3 +553,13 @@ func handlerResponseErrorInternalServerError(w http.ResponseWriter, message stri
 	})
 	w.Write(bytes)
 }
+
+func handlerResponseErrorGone(w http.ResponseWriter) {
+	w.WriteHeader(http.StatusGone)
+	bytes, _ := json.Marshal(&SubscriptionPostErrorResponse{
+		Error:   "Gone",
+		Message: "This subscription type is not available.",
+		Status:  410,
+	})
+	w.Write(bytes)
+}