Reset overwrite url if it is invalid (does fail to reach sfu)

locales/en/app.json

@@ -72,6 +72,7 @@
       "save": "Save",
       "saving": "Saving..."
     },
+    "custom_url_update_reason_invalid": "Auto reset, custom url was invalid!",
     "debug_tile_layout_label": "Debug tile layout",
     "device_id": "Device ID: {{id}}",
     "duplicate_tiles_label": "Number of additional tile copies per participant",

src/settings/DeveloperSettingsTab.tsx

@@ -41,6 +41,7 @@ import {
   matrixRTCMode as matrixRTCModeSetting,
   customLivekitUrl as customLivekitUrlSetting,
   MatrixRTCMode,
+  useSettingWithLastUpdateReason,
 } from "./settings";
 import type { Room as LivekitRoom } from "livekit-client";
 import styles from "./DeveloperSettingsTab.module.css";
@@ -92,9 +93,8 @@ export const DeveloperSettingsTab: FC<Props> = ({
     alwaysShowIphoneEarpieceSetting,
   );
 
-  const [customLivekitUrl, setCustomLivekitUrl] = useSetting(
-    customLivekitUrlSetting,
-  );
+  const [customLivekitUrl, setCustomLivekitUrl, customLivekitUrlUpdateReason] =
+    useSettingWithLastUpdateReason(customLivekitUrlSetting);
   const [customLivekitUrlTextBuffer, setCustomLivekitUrlTextBuffer] =
     useState(customLivekitUrl);
   useEffect(() => {
@@ -220,7 +220,8 @@ export const DeveloperSettingsTab: FC<Props> = ({
         onSubmit={(e) => e.preventDefault()}
         helpLabel={
           customLivekitUrl === null
-            ? t("developer_mode.custom_livekit_url.from_config")
+            ? t("developer_mode.custom_livekit_url.from_config") +
+              (customLivekitUrlUpdateReason ?? "")
             : t("developer_mode.custom_livekit_url.current_url") +
               customLivekitUrl
         }

src/settings/settings.ts

@@ -34,15 +34,20 @@ export class Setting<T> {
 
     this._value$ = new BehaviorSubject(initialValue);
     this.value$ = this._value$;
+    this._lastUpdateReason$ = new BehaviorSubject<string | null>(null);
+    this.lastUpdateReason$ = this._lastUpdateReason$;
   }
 
   private readonly key: string;
 
   private readonly _value$: BehaviorSubject<T>;
+  private readonly _lastUpdateReason$: BehaviorSubject<string | null>;
   public readonly value$: Behavior<T>;
+  public readonly lastUpdateReason$: Behavior<string | null>;
 
-  public readonly setValue = (value: T): void => {
+  public readonly setValue = (value: T, reason?: string): void => {
     this._value$.next(value);
+    this._lastUpdateReason$.next(reason ?? null);
     localStorage.setItem(this.key, JSON.stringify(value));
   };
   public readonly getValue = (): T => {
@@ -57,6 +62,19 @@ export function useSetting<T>(setting: Setting<T>): [T, (value: T) => void] {
   return [useBehavior(setting.value$), setting.setValue];
 }
 
+/**
+ * React hook that returns a settings's current value and a setter.
+ */
+export function useSettingWithLastUpdateReason<T>(
+  setting: Setting<T>,
+): [T, (value: T) => void, string | null] {
+  return [
+    useBehavior(setting.value$),
+    setting.setValue,
+    useBehavior(setting.lastUpdateReason$),
+  ];
+}
+
 // null = undecided
 export const optInAnalytics = new Setting<boolean | null>(
   "opt-in-analytics",

src/state/CallViewModel/localMember/LocalTransport.ts

@@ -23,6 +23,7 @@ import {
 } from "rxjs";
 import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
 import { AutoDiscovery } from "matrix-js-sdk/lib/autodiscovery";
+import { t } from "i18next";
 
 import { type Behavior } from "../../Behavior.ts";
 import { type Epoch, type ObservableScope } from "../../ObservableScope.ts";
@@ -178,11 +179,25 @@ async function makeTransport(
 
   if (!transport) throw new MatrixRTCTransportMissingError(domain ?? ""); // this will call the jwt/sfu/get endpoint to pre create the livekit room.
 
-  await getSFUConfigWithOpenID(
-    client,
-    transport.livekit_service_url,
-    transport.livekit_alias,
-  );
+  try {
+    await getSFUConfigWithOpenID(
+      client,
+      transport.livekit_service_url,
+      transport.livekit_alias,
+    );
+  } catch (e) {
+    if (urlFromDevSettings !== undefined) {
+      logger.error(
+        "Failed to get SFU config with dev settings overwrite, Resetting dev settings",
+      );
+      customLivekitUrl.setValue(
+        null,
+        `\n${t("developer_mode.custom_url_update_reason_invalid")}`,
+      );
+    } else {
+      throw e;
+    }
+  }
 
   return transport;
 }