review: count as publishing even if not yet connected to LK

src/state/Connection.test.ts

@@ -35,6 +35,7 @@ import type {
 import {
   type ConnectionOpts,
   type FocusConnectionState,
+  type PublishingParticipant,
   RemoteConnection,
 } from "./Connection.ts";
 import { ObservableScope } from "./ObservableScope.ts";
@@ -454,22 +455,19 @@ describe("Publishing participants observations", () => {
 
     const bobIsAPublisher = Promise.withResolvers<void>();
     const danIsAPublisher = Promise.withResolvers<void>();
-    const observedPublishers: {
-      participant: RemoteParticipant;
-      membership: CallMembership;
-    }[][] = [];
+    const observedPublishers: PublishingParticipant[][] = [];
     const s = connection.publishingParticipants$.subscribe((publishers) => {
       observedPublishers.push(publishers);
       if (
         publishers.some(
-          (p) => p.participant.identity === "@bob:example.org:DEV111",
+          (p) => p.participant?.identity === "@bob:example.org:DEV111",
         )
       ) {
         bobIsAPublisher.resolve();
       }
       if (
         publishers.some(
-          (p) => p.participant.identity === "@dan:example.org:DEV333",
+          (p) => p.participant?.identity === "@dan:example.org:DEV333",
         )
       ) {
         danIsAPublisher.resolve();
@@ -529,7 +527,7 @@ describe("Publishing participants observations", () => {
     await bobIsAPublisher.promise;
     const publishers = observedPublishers.pop();
     expect(publishers?.length).toEqual(1);
-    expect(publishers?.[0].participant.identity).toEqual(
+    expect(publishers?.[0].participant?.identity).toEqual(
       "@bob:example.org:DEV111",
     );
 
@@ -546,12 +544,12 @@ describe("Publishing participants observations", () => {
     expect(twoPublishers?.length).toEqual(2);
     expect(
       twoPublishers?.some(
-        (p) => p.participant.identity === "@bob:example.org:DEV111",
+        (p) => p.participant?.identity === "@bob:example.org:DEV111",
       ),
     ).toBeTruthy();
     expect(
       twoPublishers?.some(
-        (p) => p.participant.identity === "@dan:example.org:DEV333",
+        (p) => p.participant?.identity === "@dan:example.org:DEV333",
       ),
     ).toBeTruthy();
 
@@ -568,12 +566,25 @@ describe("Publishing participants observations", () => {
     );
 
     const updatedPublishers = observedPublishers.pop();
-    expect(updatedPublishers?.length).toEqual(1);
+    // Bob is not connected to the room but he is still in the rtc memberships declaring that
+    // he is using that focus to publish, so he should still appear as a publisher
+    expect(updatedPublishers?.length).toEqual(2);
+    const pp = updatedPublishers?.find(
+      (p) => p.membership.sender == "@bob:example.org",
+    );
+    expect(pp).toBeDefined();
+    expect(pp!.participant).not.toBeDefined();
     expect(
       updatedPublishers?.some(
-        (p) => p.participant.identity === "@dan:example.org:DEV333",
+        (p) => p.participant?.identity === "@dan:example.org:DEV333",
       ),
     ).toBeTruthy();
+    // Now if bob is not in the rtc memberships, he should disappear
+    const noBob = rtcMemberships.filter(
+      ({ membership }) => membership.sender !== "@bob:example.org",
+    );
+    fakeMembershipsFocusMap$.next(noBob);
+    expect(observedPublishers.pop()?.length).toEqual(1);
   });
 
   it("should be scoped to parent scope", (): void => {
@@ -581,10 +592,7 @@ describe("Publishing participants observations", () => {
 
     const connection = setupRemoteConnection();
 
-    let observedPublishers: {
-      participant: RemoteParticipant;
-      membership: CallMembership;
-    }[][] = [];
+    let observedPublishers: PublishingParticipant[][] = [];
     const s = connection.publishingParticipants$.subscribe((publishers) => {
       observedPublishers.push(publishers);
     });
@@ -619,7 +627,7 @@ describe("Publishing participants observations", () => {
     // We should have bob has a publisher now
     const publishers = observedPublishers.pop();
     expect(publishers?.length).toEqual(1);
-    expect(publishers?.[0].participant.identity).toEqual(
+    expect(publishers?.[0].participant?.identity).toEqual(
       "@bob:example.org:DEV111",
     );
 

src/state/Connection.ts

@@ -13,6 +13,7 @@ import {
   ConnectionError,
   type ConnectionState,
   type E2EEOptions,
+  type RemoteParticipant,
   Room as LivekitRoom,
   type RoomOptions,
 } from "livekit-client";
@@ -64,6 +65,21 @@ export type FocusConnectionState =
     }
   | { state: "Stopped"; focus: LivekitTransport };
 
+/**
+ * Represents participant publishing or expected to publish on the connection.
+ * It is paired with its associated rtc membership.
+ */
+export type PublishingParticipant = {
+  /**
+   * The LiveKit participant publishing on this connection, or undefined if the participant is not currently (yet) connected to the livekit room.
+   */
+  participant: RemoteParticipant | undefined;
+  /**
+   * The rtc call membership associated with this participant.
+   */
+  membership: CallMembership;
+};
+
 /**
  * A connection to a Matrix RTC LiveKit backend.
  *
@@ -183,7 +199,7 @@ export class Connection {
    * This is derived from `participantsIncludingSubscribers$` and `remoteTransports$`.
    * It filters the participants to only those that are associated with a membership that claims to publish on this connection.
    */
-  public readonly publishingParticipants$;
+  public readonly publishingParticipants$: Behavior<PublishingParticipant[]>;
 
   /**
    * The focus server to connect to.
@@ -226,10 +242,10 @@ export class Connection {
             )
             // Pair with their associated LiveKit participant (if any)
             // Uses flatMap to filter out memberships with no associated rtc participant ([])
-            .flatMap((membership) => {
+            .map((membership) => {
               const id = `${membership.sender}:${membership.deviceId}`;
               const participant = participants.find((p) => p.identity === id);
-              return participant ? [{ participant, membership }] : [];
+              return { participant, membership };
             }),
       ),
       [],