Disable a bunch of media/event sources when reconnecting

src/utils/observable.test.ts

@@ -0,0 +1,24 @@
+/*
+Copyright 2025 New Vector Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE in the repository root for full details.
+*/
+
+import { test } from "vitest";
+
+import { withTestScheduler } from "./test";
+import { pauseWhen } from "./observable";
+
+test("pauseWhen", () => {
+  withTestScheduler(({ behavior, expectObservable }) => {
+    const inputMarbles = " abcdefgh-i-jk-";
+    const pauseMarbles = " n-y--n-yn-y--n";
+    const outputMarbles = "abc--fgh-i---k";
+    expectObservable(
+      behavior(inputMarbles).pipe(
+        pauseWhen(behavior(pauseMarbles, { y: true, n: false })),
+      ),
+    ).toBe(outputMarbles);
+  });
+});

src/utils/observable.ts

@@ -7,16 +7,21 @@ Please see LICENSE in the repository root for full details.
 
 import {
   type Observable,
+  audit,
   combineLatest,
   concat,
   defer,
+  filter,
   finalize,
   map,
+  of,
   scan,
   startWith,
   takeWhile,
   tap,
+  withLatestFrom,
 } from "rxjs";
+import { Behavior } from "../state/Behavior";
 
 const nothing = Symbol("nothing");
 
@@ -95,3 +100,19 @@ export function getValue<T>(state$: Observable<T>): T {
 export function and$(...inputs: Observable<boolean>[]): Observable<boolean> {
   return combineLatest(inputs, (...flags) => flags.every((flag) => flag));
 }
+
+/**
+ * RxJS operator that pauses all changes in the input value whenever a Behavior
+ * is true. When the Behavior returns to being false, the most recently
+ * suppressed change is emitted as the most recent value.
+ */
+export function pauseWhen<T>(pause$: Behavior<boolean>) {
+  return (value$: Observable<T>): Observable<T> =>
+    value$.pipe(
+      withLatestFrom(pause$),
+      audit(([, pause]) =>
+        pause ? pause$.pipe(filter((pause) => !pause)) : of(null),
+      ),
+      map(([value]) => value),
+    );
+}

src/utils/test.ts

@@ -296,6 +296,7 @@ export async function withRemoteMedia(
       kind: E2eeType.PER_PARTICIPANT,
     },
     mockLivekitRoom({}, { remoteParticipants$: of([remoteParticipant]) }),
+    constant(false),
     constant(roomMember.rawDisplayName ?? "nodisplayname"),
     constant(null),
     constant(null),