[SDK] make stats$ a polled method and add audioLevel$ to audio tracks

sdk/src/utils/LazyBehavior.test.ts

@@ -1,52 +0,0 @@
-/*
-Copyright 2026 Element Creations Ltd.
-
-SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
-Please see LICENSE in the repository root for full details.
-*/
-
-import { describe, expect, it, vi } from "vitest";
-import { Observable, Subject } from "rxjs";
-
-import { LazyBehavior } from "./LazyBehavior";
-
-describe("LazyBehavior", () => {
-  it("runs its source only while subscribed", () => {
-    const teardown = vi.fn();
-    let starts = 0;
-    const values$ = new Subject<number>();
-    const source$ = new Observable<number>((subscriber) => {
-      starts++;
-      const subscription = values$.subscribe(subscriber);
-      return (): void => {
-        teardown();
-        subscription.unsubscribe();
-      };
-    });
-    const lazy$ = new LazyBehavior(source$, 0);
-    expect(starts).toBe(0);
-    expect(lazy$.value).toBe(0);
-
-    const seenByFirst: number[] = [];
-    const first = lazy$.subscribe((v) => seenByFirst.push(v));
-    expect(starts).toBe(1);
-    values$.next(1);
-    expect(seenByFirst).toEqual([0, 1]);
-    expect(lazy$.value).toBe(1);
-
-    const seenBySecond: number[] = [];
-    const second = lazy$.subscribe((v) => seenBySecond.push(v));
-    expect(starts).toBe(1);
-    expect(seenBySecond).toEqual([1]);
-
-    first.unsubscribe();
-    expect(teardown).not.toHaveBeenCalled();
-    second.unsubscribe();
-    expect(teardown).toHaveBeenCalledTimes(1);
-
-    values$.next(2);
-    expect(lazy$.value).toBe(1);
-    lazy$.subscribe().unsubscribe();
-    expect(starts).toBe(2);
-  });
-});

sdk/src/utils/LazyBehavior.ts

@@ -1,53 +0,0 @@
-/*
-Copyright 2026 Element Creations Ltd.
-
-SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
-Please see LICENSE in the repository root for full details.
-*/
-
-import {
-  BehaviorSubject,
-  type Observable,
-  type Subscriber,
-  type Subscription,
-} from "rxjs";
-
-/**
- * A behavior that only runs its source while someone is subscribed. The source
- * is subscribed with the first subscriber and unsubscribed with the last, so a
- * value that is expensive to keep current, such as polled statistics, costs
- * nothing while nobody looks at it. `value` is whatever the source last
- * produced, or the initial value.
- */
-export class LazyBehavior<T> extends BehaviorSubject<T> {
-  private subscribers = 0;
-  private upstream: Subscription | undefined;
-
-  public constructor(
-    private readonly source$: Observable<T>,
-    initialValue: T,
-  ) {
-    super(initialValue);
-  }
-
-  // Every subscription of an Observable goes through this hook, which rxjs
-  // declares as internal and so leaves out of its types. The base class's
-  // version replays the current value and registers the subscriber; it is
-  // wrapped rather than replaced.
-  protected _subscribe(subscriber: Subscriber<T>): Subscription {
-    if (this.subscribers++ === 0)
-      this.upstream = this.source$.subscribe((value) => this.next(value));
-    const subscription = (
-      BehaviorSubject.prototype as unknown as {
-        _subscribe(this: BehaviorSubject<T>, s: Subscriber<T>): Subscription;
-      }
-    )._subscribe.call(this, subscriber);
-    subscription.add(() => {
-      if (--this.subscribers === 0) {
-        this.upstream?.unsubscribe();
-        this.upstream = undefined;
-      }
-    });
-    return subscription;
-  }
-}