element-call-Github/sdk/src/session/livekitOptions.test.ts

/*
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 } from "vitest";
import { VideoPresets, type VideoPreset } from "livekit-client";

import { buildLiveKitOptions } from "./livekitOptions";

describe("buildLiveKitOptions", () => {
  it("returns sensible defaults with no config", () => {
    const opts = buildLiveKitOptions();
    expect(opts.adaptiveStream).toBe(true);
    expect(opts.dynacast).toBe(true);
    expect(opts.videoCaptureDefaults?.resolution).toEqual(
      VideoPresets.h720.resolution,
    );
    expect(opts.publishDefaults?.videoCodec).toBe("vp8");
    expect(opts.publishDefaults?.videoEncoding).toEqual({
      maxBitrate: 1_700_000,
      maxFramerate: 30,
    });
    expect(opts.publishDefaults?.screenShareEncoding).toEqual({
      maxBitrate: 5_000_000,
      maxFramerate: 30,
    });
    expect(opts.publishDefaults?.videoSimulcastLayers).toEqual([
      VideoPresets.h180,
      VideoPresets.h360,
    ]);
  });

  it("applies video codec from config", () => {
    const opts = buildLiveKitOptions({ video_codec: "vp9" });
    expect(opts.publishDefaults?.videoCodec).toBe("vp9");
  });

  it("applies video resolution and encoding from config", () => {
    const baseVideoConfig = {
      max_resolution: 1080,
      max_bitrate: 3_000_000,
      max_framerate: 60,
    };
    const opts1080 = buildLiveKitOptions({
      video: baseVideoConfig,
    });
    const opts1440 = buildLiveKitOptions({
      video: { ...baseVideoConfig, max_resolution: 1440 },
    });
    const opts2160 = buildLiveKitOptions({
      video: { ...baseVideoConfig, max_resolution: 2160 },
    });
    expect(opts1080.videoCaptureDefaults?.resolution).toEqual(
      VideoPresets.h1080.resolution,
    );
    expect(opts1440.videoCaptureDefaults?.resolution).toEqual(
      VideoPresets.h1440.resolution,
    );
    expect(opts2160.videoCaptureDefaults?.resolution).toEqual(
      VideoPresets.h2160.resolution,
    );
    expect(opts1080.publishDefaults?.videoEncoding).toEqual({
      maxBitrate: 3_000_000,
      maxFramerate: 60,
    });
  });

  it("applies screen share encoding from config", () => {
    const opts = buildLiveKitOptions({
      screen_share: {
        max_bitrate: 8_000_000,
        max_framerate: 15,
      },
    });
    expect(opts.publishDefaults?.screenShareEncoding).toEqual({
      maxBitrate: 8_000_000,
      maxFramerate: 15,
    });
  });

  it("uses DEFAULT_CONFIG defaults when only resolution is set", () => {
    const opts = buildLiveKitOptions({
      screen_share: {
        max_resolution: 720,
      },
    });
    // Bitrate and framerate fall back to DEFAULT_CONFIG, not the preset
    expect(opts.publishDefaults?.screenShareEncoding).toEqual({
      maxBitrate: 5_000_000,
      maxFramerate: 30,
    });
  });

  it("maps low resolutions to the closest preset, rounding up", () => {
    const expectations: [number, VideoPreset][] = [
      [180, VideoPresets.h180],
      [360, VideoPresets.h360],
      [480, VideoPresets.h540],
      [540, VideoPresets.h540],
      [720, VideoPresets.h720],
    ];
    for (const [height, preset] of expectations) {
      const opts = buildLiveKitOptions({ video: { max_resolution: height } });
      expect(opts.videoCaptureDefaults?.resolution).toEqual(preset.resolution);
    }
  });

  it("screen share layers fall back to max_framerate, then 30", () => {
    const fromMax = buildLiveKitOptions({
      screen_share: {
        max_framerate: 15,
        simulcast_layers: [{ height: 540, bitrate: 1_000_000 }],
      },
    });
    expect(
      fromMax.publishDefaults?.screenShareSimulcastLayers?.[0],
    ).toMatchObject({ encoding: { maxFramerate: 15 } });

    const fromDefault = buildLiveKitOptions({
      screen_share: {
        simulcast_layers: [{ height: 540, bitrate: 1_000_000 }],
      },
    });
    expect(
      fromDefault.publishDefaults?.screenShareSimulcastLayers?.[0],
    ).toMatchObject({ encoding: { maxFramerate: 30 } });
  });

  it("applies custom video simulcast layers", () => {
    const opts = buildLiveKitOptions({
      video: {
        simulcast_layers: [
          { height: 180, bitrate: 100_000 },
          { height: 360, bitrate: 300_000 },
          { height: 540, bitrate: 600_000 },
        ],
        max_framerate: 24,
      },
    });
    const layers = opts.publishDefaults?.videoSimulcastLayers;
    expect(layers).toHaveLength(3);
    expect(layers?.[0]).toMatchObject({
      width: 320,
      height: 180,
      encoding: { maxBitrate: 100_000, maxFramerate: 24 },
    });
    expect(layers?.[2]).toMatchObject({
      width: 960,
      height: 540,
      encoding: { maxBitrate: 600_000, maxFramerate: 24 },
    });
  });

  it("applies custom screen share simulcast layers", () => {
    const opts = buildLiveKitOptions({
      screen_share: {
        simulcast_layers: [{ height: 540, bitrate: 1_000_000, framerate: 5 }],
      },
    });
    const layers = opts.publishDefaults?.screenShareSimulcastLayers;
    expect(layers).toHaveLength(1);
    expect(layers?.[0]).toMatchObject({
      width: 960,
      height: 540,
      encoding: { maxBitrate: 1_000_000, maxFramerate: 5 },
    });
  });

  it("does not include screenShareSimulcastLayers when not configured", () => {
    const opts = buildLiveKitOptions();
    expect(opts.publishDefaults?.screenShareSimulcastLayers).toBeUndefined();
  });

  it("backupCodec always uses stock VP8 720p encoding", () => {
    const opts = buildLiveKitOptions({
      video_codec: "av1",
      video: { max_bitrate: 10_000_000, max_framerate: 60 },
    });
    const backup = opts.publishDefaults?.backupCodec as {
      codec: string;
      encoding: { maxBitrate: number; maxFramerate: number };
    };
    expect(backup.codec).toBe("vp8");
    expect(backup.encoding).toEqual(VideoPresets.h720.encoding);
  });
});