element-call/src/lotus/lotusScreenshareWatch.test.ts

/*
Copyright 2026 Lotus Guild

SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
Please see LICENSE in the repository root for full details.
*/

import { RoomEvent, Track } from "livekit-client";
import { BehaviorSubject } from "rxjs";
import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";

import { type CallViewModel } from "../state/CallViewModel/CallViewModel";
import {
  ALONE_MS,
  NO_FRAMES_MS,
  startLotusScreenshareWatch,
} from "./lotusScreenshareWatch";

const sent: unknown[] = [];
vi.mock("../widget", () => ({ widget: { api: {} } }));
vi.mock("./lotusWidget", () => ({
  lotusSendToHost: (action: string, data: unknown): boolean => {
    sent.push({ action, data });
    return true;
  },
}));

class FakeTrack extends EventTarget {}

const makeRoom = (): {
  room: Record<string, unknown>;
  emit: (event: string, ...args: unknown[]) => void;
  remote: Map<string, unknown>;
} => {
  const handlers = new Map<string, ((...args: unknown[]) => void)[]>();
  const remote = new Map<string, unknown>();
  const room = {
    remoteParticipants: remote,
    localParticipant: { trackPublications: new Map() },
    on: (event: string, h: (...args: unknown[]) => void): void => {
      handlers.set(event, [...(handlers.get(event) ?? []), h]);
    },
    off: (event: string, h: (...args: unknown[]) => void): void => {
      handlers.set(
        event,
        (handlers.get(event) ?? []).filter((x) => x !== h),
      );
    },
  };
  return {
    room,
    remote,
    emit: (event, ...args): void => {
      (handlers.get(event) ?? []).forEach((h) => h(...args));
    },
  };
};

describe("startLotusScreenshareWatch", () => {
  let clock = 0;
  beforeEach(() => {
    sent.length = 0;
    clock = 1_000_000;
    vi.useFakeTimers();
  });
  afterEach(() => vi.useRealTimers());

  const start = (): ReturnType<typeof makeRoom> & { stop: () => void } => {
    const fake = makeRoom();
    const connections = new BehaviorSubject({
      getConnections: () => [{ livekitRoom: fake.room }],
    });
    const stop = startLotusScreenshareWatch(
      { allConnections$: connections } as unknown as CallViewModel,
      () => clock,
    );
    return { ...fake, stop };
  };

  it("reports a share whose track ended", () => {
    const { emit, stop } = start();
    const mst = new FakeTrack();
    emit(RoomEvent.LocalTrackPublished, {
      source: Track.Source.ScreenShare,
      track: { mediaStreamTrack: mst },
    });
    mst.dispatchEvent(new Event("ended"));
    expect(sent).toEqual([
      { action: "io.lotus.screenshare_notice", data: { kind: "ended" } },
    ]);
    stop();
  });

  it("reports no frames after a sustained mute, once, and not after an unmute", () => {
    const { emit, stop } = start();
    const mst = new FakeTrack();
    emit(RoomEvent.LocalTrackPublished, {
      source: Track.Source.ScreenShare,
      track: { mediaStreamTrack: mst },
    });
    mst.dispatchEvent(new Event("mute"));
    vi.advanceTimersByTime(NO_FRAMES_MS / 2);
    mst.dispatchEvent(new Event("unmute"));
    vi.advanceTimersByTime(NO_FRAMES_MS);
    expect(sent).toEqual([]);
    mst.dispatchEvent(new Event("mute"));
    vi.advanceTimersByTime(NO_FRAMES_MS);
    mst.dispatchEvent(new Event("mute"));
    vi.advanceTimersByTime(NO_FRAMES_MS);
    expect(sent).toEqual([
      { action: "io.lotus.screenshare_notice", data: { kind: "no-frames" } },
    ]);
    stop();
  });

  it("nudges after 30 min of sharing with nobody else, never while others are present", () => {
    const { emit, remote, stop } = start();
    emit(RoomEvent.LocalTrackPublished, {
      source: Track.Source.ScreenShare,
      track: { mediaStreamTrack: new FakeTrack() },
    });
    remote.set("bob", {});
    clock += ALONE_MS + 60_000;
    vi.advanceTimersByTime(60_000);
    expect(sent).toEqual([]);
    remote.clear();
    vi.advanceTimersByTime(60_000);
    vi.advanceTimersByTime(60_000);
    expect(sent).toEqual([
      { action: "io.lotus.screenshare_notice", data: { kind: "alone" } },
    ]);
    stop();
  });

  it("reports ended from the unpublish when LiveKit's handler ran first", () => {
    const { emit, stop } = start();
    const share = new FakeTrack() as FakeTrack & { readyState: string };
    share.readyState = "ended";
    const pub = {
      source: Track.Source.ScreenShare,
      track: { mediaStreamTrack: share },
    };
    emit(RoomEvent.LocalTrackPublished, pub);
    emit(RoomEvent.LocalTrackUnpublished, pub);
    share.dispatchEvent(new Event("ended"));
    expect(sent).toEqual([
      { action: "io.lotus.screenshare_notice", data: { kind: "ended" } },
    ]);
    stop();
  });

  it("ignores non-screenshare publications and stops watching on unpublish", () => {
    const { emit, stop } = start();
    const cam = new FakeTrack();
    emit(RoomEvent.LocalTrackPublished, {
      source: Track.Source.Camera,
      track: { mediaStreamTrack: cam },
    });
    cam.dispatchEvent(new Event("ended"));
    const share = new FakeTrack();
    const pub = {
      source: Track.Source.ScreenShare,
      track: { mediaStreamTrack: share },
    };
    emit(RoomEvent.LocalTrackPublished, pub);
    emit(RoomEvent.LocalTrackUnpublished, pub);
    share.dispatchEvent(new Event("ended"));
    expect(sent).toEqual([]);
    stop();
  });
});