MatrixRTC: enforce Promise handling using eslint rules (#4725)

* MatrixRTC: enforce Promise handling using eslint rules

* Fix lints without behaviour change.

* fix not calling functions

---------

Co-authored-by: Timo <toger5@hotmail.de>

.eslintrc.cjs

@@ -154,5 +154,16 @@ module.exports = {
                 "@typescript-eslint/no-empty-object-type": "off",
             },
         },
+        {
+            // Enable stricter promise rules for the MatrixRTC codebase
+            files: ["src/matrixrtc/**/*.ts"],
+            rules: {
+                // Encourage proper usage of Promises:
+                "@typescript-eslint/no-floating-promises": "error",
+                "@typescript-eslint/no-misused-promises": "error",
+                "@typescript-eslint/require-await": "error",
+                "@typescript-eslint/await-thenable": "error",
+            },
+        },
     ],
 };

src/matrixrtc/EncryptionManager.ts

@@ -41,7 +41,7 @@ export type Statistics = {
 export interface IEncryptionManager {
     join(joinConfig: EncryptionConfig | undefined): void;
     leave(): void;
-    onMembershipsUpdate(oldMemberships: CallMembership[]): Promise<void>;
+    onMembershipsUpdate(oldMemberships: CallMembership[]): void;
     /**
      * Process `m.call.encryption_keys` events to track the encryption keys for call participants.
      * This should be called each time the relevant event is received from a room timeline.
@@ -150,7 +150,7 @@ export class EncryptionManager implements IEncryptionManager {
     private isMyMembership = (m: CallMembership): boolean =>
         m.sender === this.client.getUserId() && m.deviceId === this.client.getDeviceId();
 
-    public async onMembershipsUpdate(oldMemberships: CallMembership[]): Promise<void> {
+    public onMembershipsUpdate(oldMemberships: CallMembership[]): void {
         if (this.manageMediaKeys && this.joined) {
             const oldMembershipIds = new Set(
                 oldMemberships.filter((m) => !this.isMyMembership(m)).map(getParticipantIdFromMembership),
@@ -231,14 +231,14 @@ export class EncryptionManager implements IEncryptionManager {
             logger.info("Last encryption key event sent too recently: postponing");
             if (this.keysEventUpdateTimeout === undefined) {
                 this.keysEventUpdateTimeout = setTimeout(
-                    this.sendEncryptionKeysEvent,
+                    () => void this.sendEncryptionKeysEvent(),
                     this.updateEncryptionKeyThrottle,
                 );
             }
             return;
         }
 
-        this.sendEncryptionKeysEvent();
+        void this.sendEncryptionKeysEvent();
     }
 
     /**
@@ -318,7 +318,7 @@ export class EncryptionManager implements IEncryptionManager {
             if (this.keysEventUpdateTimeout === undefined) {
                 const resendDelay = safeGetRetryAfterMs(matrixError, 5000);
                 logger.warn(`Failed to send m.call.encryption_key, retrying in ${resendDelay}`, error);
-                this.keysEventUpdateTimeout = setTimeout(this.sendEncryptionKeysEvent, resendDelay);
+                this.keysEventUpdateTimeout = setTimeout(() => void this.sendEncryptionKeysEvent(), resendDelay);
             } else {
                 logger.info("Not scheduling key resend as another re-send is already pending");
             }
@@ -488,7 +488,7 @@ export class EncryptionManager implements IEncryptionManager {
         const newKeyIndex = this.makeNewSenderKey(true);
         // send immediately: if we're about to start sending with a new key, it's
         // important we get it out to others as soon as we can.
-        this.sendEncryptionKeysEvent(newKeyIndex);
+        void this.sendEncryptionKeysEvent(newKeyIndex);
     };
 }
 

src/matrixrtc/MatrixRTCSession.ts

@@ -458,11 +458,11 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
             logger.info(`Memberships for call in room ${this.room.roomId} have changed: emitting`);
             this.emit(MatrixRTCSessionEvent.MembershipsChanged, oldMemberships, this.memberships);
 
-            this.membershipManager?.onRTCSessionMemberUpdate(this.memberships);
+            void this.membershipManager?.onRTCSessionMemberUpdate(this.memberships);
         }
         // This also needs to be done if `changed` = false
         // A member might have updated their fingerprint (created_ts)
-        this.encryptionManager.onMembershipsUpdate(oldMemberships);
+        void this.encryptionManager.onMembershipsUpdate(oldMemberships);
 
         this.setExpiryTimer();
     };

src/matrixrtc/MatrixRTCSessionManager.ts

@@ -71,7 +71,7 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
 
     public stop(): void {
         for (const sess of this.roomSessions.values()) {
-            sess.stop();
+            void sess.stop();
         }
         this.roomSessions.clear();
 
@@ -108,7 +108,7 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
                     `Decryption failed for event ${event.getId()}: ${event.decryptionFailureReason} will retry once only`,
                 );
                 // retry after 1 second. After this we give up.
-                setTimeout(() => this.consumeCallEncryptionEvent(event, true), 1000);
+                setTimeout(() => void this.consumeCallEncryptionEvent(event, true), 1000);
             } else {
                 logger.warn(`Decryption failed for event ${event.getId()}: ${event.decryptionFailureReason}`);
             }
@@ -128,7 +128,7 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
         this.getRoomSession(room).onCallEncryption(event);
     }
     private onTimeline = (event: MatrixEvent): void => {
-        this.consumeCallEncryptionEvent(event);
+        void this.consumeCallEncryptionEvent(event);
     };
 
     private onRoom = (room: Room): void => {

src/matrixrtc/MembershipManager.ts

@@ -134,7 +134,7 @@ export class LegacyMembershipManager implements IMembershipManager {
         this.relativeExpiry = this.membershipExpiryTimeout;
         // We don't wait for this, mostly because it may fail and schedule a retry, so this
         // function returning doesn't really mean anything at all.
-        this.triggerCallMembershipEventUpdate();
+        void this.triggerCallMembershipEventUpdate();
     }
 
     public async leave(timeout: number | undefined = undefined): Promise<boolean> {
@@ -351,7 +351,7 @@ export class LegacyMembershipManager implements IMembershipManager {
     }
 
     private scheduleDelayDisconnection(): void {
-        this.memberEventTimeout = setTimeout(this.delayDisconnection, this.membershipKeepAlivePeriod);
+        this.memberEventTimeout = setTimeout(() => void this.delayDisconnection(), this.membershipKeepAlivePeriod);
     }
 
     private readonly delayDisconnection = async (): Promise<void> => {