reject if app already connected

sdk/apps/base/src/app.test.ts

@@ -52,7 +52,7 @@ describe('Base App tests', () => {
     assert(baseApp2.sessionId == sessionId)
   })
   test('#on("userConnected")', async () => {
-    const baseApp = await BaseApp.build(testAppBaseInitialize)
+    const baseApp = await BaseApp.build({ ...testAppBaseInitialize, persistent: false })
     expect(baseApp).toBeDefined()
     assert(baseApp.sessionId !== '')
     const userConnectedFn = vi.fn()

sdk/apps/base/src/app.ts

@@ -100,6 +100,11 @@ export class BaseApp extends EventEmitter<BaseEvents> {
             case 'UserConnectedEvent': {
               baseApp.connectedPublicKeys = response.publicKeys
               baseApp.emit('userConnected', response)
+              break
+            }
+            case 'AlreadyConnected': {
+              reject(new Error('Already connected'))
+              break
             }
           }
         }

sdk/bindings/AlreadyConnected.ts

@@ -0,0 +1,3 @@
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+
+export interface AlreadyConnected { sessionId: string, }

sdk/bindings/ServerToApp.ts

@@ -1,9 +1,10 @@
 // This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
 import type { AckMessage } from "./AckMessage";
+import type { AlreadyConnected } from "./AlreadyConnected";
 import type { ErrorMessage } from "./ErrorMessage";
 import type { InitializeResponse } from "./InitializeResponse";
 import type { ResponsePayload } from "./ResponsePayload";
 import type { UserConnectedEvent } from "./UserConnectedEvent";
 import type { UserDisconnectedEvent } from "./UserDisconnectedEvent";
 
-export type ServerToApp = { type: "InitializeResponse" } & InitializeResponse | { type: "UserConnectedEvent" } & UserConnectedEvent | { type: "UserDisconnectedEvent" } & UserDisconnectedEvent | { type: "ResponsePayload" } & ResponsePayload | { type: "ErrorMessage" } & ErrorMessage | { type: "AckMessage" } & AckMessage;
+export type ServerToApp = { type: "InitializeResponse" } & InitializeResponse | { type: "UserConnectedEvent" } & UserConnectedEvent | { type: "UserDisconnectedEvent" } & UserDisconnectedEvent | { type: "ResponsePayload" } & ResponsePayload | { type: "ErrorMessage" } & ErrorMessage | { type: "AckMessage" } & AckMessage | { type: "AlreadyConnected" } & AlreadyConnected;

server/bindings/AlreadyConnected.ts

@@ -0,0 +1,3 @@
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+
+export interface AlreadyConnected { sessionId: string, }

server/bindings/InitializeResponse.ts

@@ -1,8 +1,3 @@
 // This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
 
-export interface InitializeResponse {
-  responseId: string
-  sessionId: string
-  createdNew: boolean
-  publicKeys: Array<string>
-}
+export interface InitializeResponse { responseId: string, sessionId: string, createdNew: boolean, publicKeys: Array<string>, }

server/bindings/ServerToApp.ts

@@ -1,9 +1,10 @@
 // This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
 import type { AckMessage } from "./AckMessage";
+import type { AlreadyConnected } from "./AlreadyConnected";
 import type { ErrorMessage } from "./ErrorMessage";
 import type { InitializeResponse } from "./InitializeResponse";
 import type { ResponsePayload } from "./ResponsePayload";
 import type { UserConnectedEvent } from "./UserConnectedEvent";
 import type { UserDisconnectedEvent } from "./UserDisconnectedEvent";
 
-export type ServerToApp = { type: "InitializeResponse" } & InitializeResponse | { type: "UserConnectedEvent" } & UserConnectedEvent | { type: "UserDisconnectedEvent" } & UserDisconnectedEvent | { type: "ResponsePayload" } & ResponsePayload | { type: "ErrorMessage" } & ErrorMessage | { type: "AckMessage" } & AckMessage;
+export type ServerToApp = { type: "InitializeResponse" } & InitializeResponse | { type: "UserConnectedEvent" } & UserConnectedEvent | { type: "UserDisconnectedEvent" } & UserDisconnectedEvent | { type: "ResponsePayload" } & ResponsePayload | { type: "ErrorMessage" } & ErrorMessage | { type: "AckMessage" } & AckMessage | { type: "AlreadyConnected" } & AlreadyConnected;

server/src/app/app_handler.rs

@@ -7,12 +7,14 @@ use axum::{
     },
     response::Response,
 };
-use futures::StreamExt;
+use futures::{SinkExt, StreamExt};
+use log::warn;
 
 use crate::{
     state::{ClientSockets, ClientToSessions, ModifySession, SendToClient, Sessions},
     structs::{
         app_messages::{
+            already_connected::AlreadyConnected,
             app_messages::{AppToServer, ServerToApp},
             initialize::InitializeResponse,
         },
@@ -45,7 +47,7 @@ pub async fn app_handler(
     client_sockets: ClientSockets,
     client_to_sessions: ClientToSessions,
 ) {
-    let (sender, mut receiver) = socket.split();
+    let (mut sender, mut receiver) = socket.split();
     // Handle the new app connection here
     // Wait for initialize message
     let session_id = loop {
@@ -85,8 +87,24 @@ pub async fn app_handler(
                             let mut sessions = sessions.write().await;
                             match sessions.get_mut(session_id.as_str()) {
                                 Some(mut session) => {
-                                    // Close previous app socket
-                                    session.close_app_socket().await;
+                                    // Do not allow to connect to the same session twice
+                                    if session.app_state.app_socket.is_some() {
+                                        warn!("App tried to connect to the same session twice");
+                                        let response =
+                                            ServerToApp::AlreadyConnected(AlreadyConnected {
+                                                session_id: session_id.clone(),
+                                            });
+                                        sender
+                                            .send(Message::Text(
+                                                serde_json::to_string(&response)
+                                                    .expect("Serialization should work"),
+                                            ))
+                                            .await
+                                            .unwrap_or_default();
+                                        sender.close().await.unwrap_or_default();
+                                        return;
+                                    }
+
                                     session.update_status(SessionStatus::AppConnected);
                                     session.app_state = AppState {
                                         metadata: init_data.app_metadata,

server/src/structs/app_messages/already_connected.rs

@@ -0,0 +1,9 @@
+use serde::{Deserialize, Serialize};
+use ts_rs::TS;
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize, TS)]
+#[ts(export)]
+pub struct AlreadyConnected {
+    #[serde(rename = "sessionId")]
+    pub session_id: String,
+}

server/src/structs/app_messages/app_messages.rs

@@ -4,6 +4,7 @@ use ts_rs::TS;
 use crate::structs::common::{AckMessage, ErrorMessage};
 
 use super::{
+    already_connected::AlreadyConnected,
     initialize::{InitializeRequest, InitializeResponse},
     payload::{RequestPayload, ResponsePayload},
     user_connected_event::UserConnectedEvent,
@@ -27,4 +28,5 @@ pub enum ServerToApp {
     ResponsePayload(ResponsePayload),
     ErrorMessage(ErrorMessage),
     AckMessage(AckMessage),
+    AlreadyConnected(AlreadyConnected),
 }

server/src/structs/app_messages/mod.rs

@@ -1,3 +1,4 @@
+pub mod already_connected;
 pub mod app_messages;
 pub mod initialize;
 pub mod payload;