Portfolio/tests/unit/adaptive-mixer.test.ts

import { describe, expect, it } from 'vitest';
import { createAdaptiveMixer } from '@/audio/adaptive-mixer';
import { MUSIC_BEAT_SECONDS } from '@/audio/soundtrack-transport';
import {
  createFakeAudioHarness,
  type FakeAudioHarness,
  type FakeAudioParamRecord,
} from '../helpers/fake-audio-context';

function recordFor(
  harness: FakeAudioHarness,
  parameter: AudioParam,
): FakeAudioParamRecord {
  const record = harness.params.find((candidate) => candidate.param === parameter);
  if (record === undefined) throw new Error('Missing fake AudioParam record.');
  return record;
}

describe('adaptive mixer', () => {
  it('ramps only the four approved mood controls over 1.4 seconds', () => {
    const harness = createFakeAudioHarness();
    const mixer = createAdaptiveMixer(harness.context, harness.destination);
    harness.setCurrentTime(2);
    mixer.setChapterIntent({
      sectionId: 'toolkit',
      mood: 'resolve',
      atStart: false,
      entryPhrase: 6,
      generation: 1,
    });
    const events = harness.params.flatMap((record) => record.events);
    expect(events.filter((event) => event.kind === 'linear' && event.at === 3.4))
      .toHaveLength(4);
  });

  it('arms lift after sustained physical input but never for navigation', () => {
    const harness = createFakeAudioHarness();
    const mixer = createAdaptiveMixer(harness.context, harness.destination);
    const liftGate = harness.gainNodes[3]!.gain;
    mixer.setTransportAnchor(0);
    mixer.setDriveLiftAvailableAt(0);

    harness.setCurrentTime(1);
    mixer.setDriveEnergy({ energy: 1, source: 'navigation' });
    expect(recordFor(harness, liftGate).events)
      .not.toContainEqual(expect.objectContaining({ kind: 'linear', value: 1 }));

    mixer.setDriveEnergy({ energy: 0.7, source: 'physical' });
    expect(recordFor(harness, liftGate).events).toContainEqual({
      kind: 'linear',
      value: 1,
      at: 4 * MUSIC_BEAT_SECONDS,
    });
  });

  it('cancels an unsustained entry and schedules hysteretic exit', () => {
    const harness = createFakeAudioHarness();
    const mixer = createAdaptiveMixer(harness.context, harness.destination);
    const liftGate = harness.gainNodes[3]!.gain;
    mixer.setTransportAnchor(0);
    mixer.setDriveLiftAvailableAt(0);
    harness.setCurrentTime(1);
    mixer.setDriveEnergy({ energy: 0.7, source: 'physical' });
    harness.setCurrentTime(1.2);
    mixer.setDriveEnergy({ energy: 0.5, source: 'physical' });
    expect(recordFor(harness, liftGate).events)
      .toContainEqual({ kind: 'hold', at: 1.2 });

    harness.setCurrentTime(2);
    mixer.setDriveEnergy({ energy: 0.7, source: 'physical' });
    harness.setCurrentTime(5);
    mixer.setDriveEnergy({ energy: 0.2, source: 'physical' });
    expect(recordFor(harness, liftGate).events)
      .toContainEqual(expect.objectContaining({ kind: 'linear', value: 0 }));
  });

  it('finishes an audible lift entry smoothly before scheduling its exit', () => {
    const harness = createFakeAudioHarness();
    const mixer = createAdaptiveMixer(harness.context, harness.destination);
    const liftGate = harness.gainNodes[3]!.gain;
    const liftEvents = recordFor(harness, liftGate).events;
    mixer.setTransportAnchor(0);
    mixer.setDriveLiftAvailableAt(0);
    harness.setCurrentTime(1);
    mixer.setDriveEnergy({ energy: 0.7, source: 'physical' });
    const eventsBeforeDrop = liftEvents.length;

    const entryMidpoint = 3.5 * MUSIC_BEAT_SECONDS;
    harness.setCurrentTime(entryMidpoint);
    mixer.setDriveEnergy({ energy: 0.2, source: 'physical' });

    expect(liftEvents).toContainEqual({
      kind: 'linear',
      value: 1,
      at: 4 * MUSIC_BEAT_SECONDS,
    });
    expect(liftEvents.slice(eventsBeforeDrop)).toEqual([
      { kind: 'set', value: 1, at: 5 * MUSIC_BEAT_SECONDS },
      { kind: 'linear', value: 0, at: 6 * MUSIC_BEAT_SECONDS },
    ]);
  });

  it('replays cached strong drive only after a late loop source is ready', () => {
    const harness = createFakeAudioHarness();
    const mixer = createAdaptiveMixer(harness.context, harness.destination);
    const liftGate = harness.gainNodes[3]!.gain;
    mixer.setDriveEnergy({ energy: 0.8, source: 'physical' });
    mixer.setTransportAnchor(0);
    expect(recordFor(harness, liftGate).events)
      .not.toContainEqual(expect.objectContaining({ kind: 'linear', value: 1 }));

    harness.setCurrentTime(5);
    mixer.setDriveLiftAvailableAt(5.08);
    const entryEnd = recordFor(harness, liftGate).events.findLast(
      (event) => event.kind === 'linear' && event.value === 1,
    );
    expect(entryEnd).toBeDefined();
    expect(entryEnd!.at).toBeGreaterThan(5.08 + 0.45);
    expect(entryEnd!.at / MUSIC_BEAT_SECONDS).toBeCloseTo(
      Math.round(entryEnd!.at / MUSIC_BEAT_SECONDS),
      8,
    );
  });

  it('disposes each owned mixer node once without disconnecting the destination', () => {
    const harness = createFakeAudioHarness();
    const mixer = createAdaptiveMixer(harness.context, harness.destination);
    const destination = harness.destination as AudioNode & { disconnectCount: number };
    mixer.dispose();
    mixer.dispose();

    expect(harness.gainNodes).toHaveLength(8);
    for (const node of harness.gainNodes) {
      expect((node as GainNode & { disconnectCount: number }).disconnectCount).toBe(1);
    }
    expect(destination.disconnectCount).toBe(0);
  });
});