Upgrade eslint-plugin-matrix-org to 1.2.1

This upgrade came with a number of new lints that needed to be fixed across the code base. Primarily: explicit return types on functions, and explicit visibility modifiers on class members.

src/livekit/MediaDevicesContext.tsx

@@ -52,7 +52,7 @@ export interface MediaDevices {
 function useObservableState<T>(
   observable: Observable<T> | undefined,
   startWith: T
-) {
+): T {
   const [state, setState] = useState<T>(startWith);
   useEffect(() => {
     // observable state doesn't run in SSR
@@ -207,7 +207,8 @@ export const MediaDevicesProvider: FC<Props> = ({ children }) => {
   );
 };
 
-export const useMediaDevices = () => useContext(MediaDevicesContext);
+export const useMediaDevices = (): MediaDevices =>
+  useContext(MediaDevicesContext);
 
 /**
  * React hook that requests for the media devices context to be populated with
@@ -215,7 +216,10 @@ export const useMediaDevices = () => useContext(MediaDevicesContext);
  * default because it may involve requesting additional permissions from the
  * user.
  */
-export const useMediaDeviceNames = (context: MediaDevices, enabled = true) =>
+export const useMediaDeviceNames = (
+  context: MediaDevices,
+  enabled = true
+): void =>
   useEffect(() => {
     if (enabled) {
       context.startUsingDeviceNames();

src/livekit/openIDSFU.ts

@@ -43,13 +43,13 @@ export type OpenIDClientParts = Pick<
 export function useOpenIDSFU(
   client: OpenIDClientParts,
   rtcSession: MatrixRTCSession
-) {
+): SFUConfig | undefined {
   const [sfuConfig, setSFUConfig] = useState<SFUConfig | undefined>(undefined);
 
   const activeFocus = useActiveFocus(rtcSession);
 
   useEffect(() => {
-    (async () => {
+    (async (): Promise<void> => {
       const sfuConfig = activeFocus
         ? await getSFUConfigWithOpenID(client, activeFocus)
         : undefined;

src/livekit/options.ts

@@ -1,3 +1,19 @@
+/*
+Copyright 2023 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
 import {
   AudioPresets,
   DefaultReconnectPolicy,

src/livekit/useECConnectionState.ts

@@ -119,7 +119,7 @@ export function useECConnectionState(
         `SFU config changed! URL was ${currentSFUConfig.current?.url} now ${sfuConfig?.url}`
       );
 
-      (async () => {
+      (async (): Promise<void> => {
         setSwitchingFocus(true);
         await livekitRoom?.disconnect();
         setIsInDoConnect(true);

src/livekit/useLiveKit.ts

@@ -156,7 +156,7 @@ export function useLiveKit(
   useEffect(() => {
     // Sync the requested devices with LiveKit's devices
     if (room !== undefined && connectionState === ConnectionState.Connected) {
-      const syncDevice = (kind: MediaDeviceKind, device: MediaDevice) => {
+      const syncDevice = (kind: MediaDeviceKind, device: MediaDevice): void => {
         const id = device.selectedId;
         if (id !== undefined && room.getActiveDevice(kind) !== id) {
           room