feuerwerk/tests/core/recording.test.ts

import { describe, expect, it } from 'vitest';
import {
  avcCodec,
  FrameGate,
  isKeyFrame,
  pictureTransform,
  RecordingClock,
  recordingName,
  recordingSettingsOf,
  recordingSize,
} from '../../src/core/recording/recording';
import { runDef, fakeContext } from '../helpers';

describe('recording settings (#405)', () => {
  it('names a recording after its start when no name is given', () => {
    const at = new Date(2026, 9, 11, 16, 42, 5);
    expect(recordingName('', at)).toBe('Recording 2026-10-11 16:42:05');
    expect(recordingName('  ', at)).toBe('Recording 2026-10-11 16:42:05');
    expect(recordingName(' Boss fight ', at)).toBe('Boss fight');
  });

  it('reads what the node hands over, an unknown choice as the default', () => {
    expect(recordingSettingsOf(' Run ', '1080p', '30')).toEqual({
      name: 'Run',
      resolution: '1080p',
      fps: 30,
    });
    expect(recordingSettingsOf('', 'huge', 25)).toEqual({ name: '', resolution: 'view', fps: 60 });
  });

  it('records the game view at its size on screen, even on both sides', () => {
    expect(recordingSize('view', { w: 1279, h: 721 }, { w: 1279, h: 721 })).toEqual({ w: 1280, h: 722 });
    // A 5K screen is held to 4K.
    expect(recordingSize('view', { w: 5120, h: 2880 }, { w: 5120, h: 2880 })).toEqual({ w: 3840, h: 2160 });
  });

  it('holds the height of 720p and 1080p and takes the width from the camera', () => {
    expect(recordingSize('1080p', { w: 800, h: 450 }, { w: 800, h: 450 })).toEqual({ w: 1920, h: 1080 });
    expect(recordingSize('720p', { w: 400, h: 400 }, { w: 400, h: 400 })).toEqual({ w: 720, h: 720 });
    // 4:3 at 720p, and the camera's whole picture rules where the screen cuts it.
    expect(recordingSize('720p', { w: 300, h: 400 }, { w: 640, h: 480 })).toEqual({ w: 960, h: 720 });
  });

  it('picks the lowest H.264 level that takes the frames', () => {
    expect(avcCodec(1280, 720, 30)).toBe('avc1.64001f');
    expect(avcCodec(1920, 1080, 30)).toBe('avc1.640028');
    expect(avcCodec(1920, 1080, 60)).toBe('avc1.64002a');
    expect(avcCodec(2560, 1440, 60)).toBe('avc1.640033');
    expect(avcCodec(3840, 2160, 60)).toBe('avc1.640034');
  });

  it('starts a group every two seconds', () => {
    expect([0, 1, 119, 120, 240].map((i) => isKeyFrame(i, 60))).toEqual([true, false, false, true, true]);
    expect(isKeyFrame(60, 30)).toBe(true);
  });
});

describe('RecordingClock', () => {
  it('counts from the start and leaves the editor pause out', () => {
    const clock = new RecordingClock();
    expect(clock.at(500)).toBe(0);
    clock.start(1000);
    expect(clock.at(1500)).toBe(500);
    clock.pause(2000);
    expect(clock.at(5000)).toBe(1000);
    clock.resume(6000);
    expect(clock.at(6500)).toBe(1500);
    // Pausing twice and resuming once still takes out the whole pause.
    clock.pause(7000);
    clock.pause(7500);
    clock.resume(8000);
    expect(clock.at(8000)).toBe(2000);
  });

  it('leaves a hold before the first frame out of the time, not off it', () => {
    const clock = new RecordingClock();
    clock.pause(0);
    clock.resume(2000);
    clock.start(2000);
    expect(clock.at(2500)).toBe(500);
  });
});

describe('FrameGate', () => {
  const taken = (fps: number, frameMs: number, seconds: number, jitter = 0) => {
    const gate = new FrameGate(fps);
    let count = 0;
    for (let i = 0; i * frameMs < seconds * 1000; i++) {
      const wobble = jitter ? ((i * 7919) % 11) / 10 - 0.5 : 0;
      if (gate.take(Math.max(0, i * frameMs + wobble * jitter))) count++;
    }
    return count;
  };

  it('takes every frame at 60 on a 60 Hz screen, however unevenly they come', () => {
    expect(taken(60, 1000 / 60, 10)).toBe(600);
    expect(taken(60, 1000 / 60, 10, 6)).toBe(600);
  });

  it('takes every other at 30', () => {
    expect(taken(30, 1000 / 60, 10)).toBe(300);
  });

  it('takes about 60 a second from a 144 Hz screen', () => {
    expect(Math.abs(taken(60, 1000 / 144, 10) - 600)).toBeLessThanOrEqual(6);
  });
});

describe('pictureTransform', () => {
  it('maps the picture onto the whole frame', () => {
    // A picture of 640x360 CSS pixels centred at (400, 300), recorded at 1080p.
    const area = { x: 400, y: 300, w: 640, h: 360 };
    const m = pictureTransform(area, { w: 1920, h: 1080 });
    const at = (x: number, y: number) => ({ x: m.a * x + m.tx, y: m.d * y + m.ty });
    expect(at(80, 120)).toEqual({ x: 0, y: 0 });
    expect(at(720, 480)).toEqual({ x: 1920, y: 1080 });
    expect(at(400, 300)).toEqual({ x: 960, y: 540 });
  });
});

describe('the recording nodes', () => {
  it('Start recording hands its settings over and flows on', () => {
    const ctx = fakeContext();
    const result = runDef('StartRecording', ctx, { name: 'Intro', resolution: '720p', fps: '30' }, {});
    expect(result.next).toBe('exec');
    expect(ctx.recordings).toEqual([{ name: 'Intro', resolution: '720p', fps: 30 }]);
  });

  it('Start recording asks for the game view at 60 by default', () => {
    const ctx = fakeContext();
    runDef('StartRecording', ctx, {}, {});
    expect(ctx.recordings).toEqual([{ name: '', resolution: 'view', fps: 60 }]);
  });

  it('Stop recording asks for the stop and flows on', () => {
    const ctx = fakeContext();
    expect(runDef('StopRecording', ctx, {}, {}).next).toBe('exec');
    expect(ctx.recordings).toEqual(['stop']);
  });
});