feuerwerk/tests/core/instrument.test.ts

/**
 * An instrument (#331) is a graph that makes a note a sound: Notes nodes bring the note in, Samples
 * play sounds for it, the effects of a sound FX shape them and the Output sums them. It is compiled
 * once per note; a trigger is on only for the notes it stands for.
 */
import { describe, expect, it } from 'vitest';
import { CreateAssetCommand, CreateSoundCommand } from '../../src/core/commands/assetCommands';
import { ConnectCommand } from '../../src/core/commands/graphCommands';
import {
  AddPortCommand,
  RenamePortCommand,
  SetPortDefaultCommand,
} from '../../src/core/commands/portCommands';
import { callProblem, resolveDef, soundFxParamsMismatch } from '../../src/core/graph';
import { createEmptyGraph, portsCompatible } from '../../src/core/graph/Graph';
import {
  compileInstrument,
  instrumentBuildFor,
  instrumentSourcesOf,
} from '../../src/core/instrument/compile';
import { VELOCITY_PARAM } from '../../src/core/instrument/nodes';
import { heldNote, noteFrequency, noteName } from '../../src/core/instrument/notes';
import type { BehaviorAsset, InstrumentAsset, SoundFxAsset } from '../../src/core/model/Asset';
import { isPlaceableType } from '../../src/core/model/AssetTypes';
import { graphLookup } from '../../src/core/model/graphLookup';
import { fxChainOf, type FxPlan } from '../../src/core/soundfx/nodes';
import { paletteEntries } from '../../src/editor/graph/paletteEntries';
import { keyboardLayout, noteAt, trackerNote } from '../../src/editor/instrument/keys';
import type { AudioSink } from '../../src/runtime/systems/Audio';
import { playNote } from '../../src/runtime/systems/behaviorContext';
import { graphEditor, makeProject, type ProjectFixture, roundTrip } from '../helpers';

const KICK = `${'a1'.repeat(32)}.wav`;
const SNARE = `${'b2'.repeat(32)}.wav`;

function makeInstrument(f: ProjectFixture = makeProject()) {
  const command = new CreateAssetCommand('instrument', 'Piano');
  f.stack.execute(command);
  const instrument = command.asset as InstrumentAsset;
  const sound = (name: string, file: string) => {
    const made = new CreateSoundCommand(name, file);
    f.stack.execute(made);
    return made.asset;
  };
  return { ...f, instrument, sound, edit: graphEditor(f, instrument as unknown as BehaviorAsset) };
}

/** An instrument with nothing in it yet, for a test that builds its own graph. */
function emptyInstrument() {
  const f = makeInstrument();
  f.instrument.graph = createEmptyGraph();
  return f;
}

const nodeOf = (f: { instrument: InstrumentAsset }, type: string) =>
  f.instrument.graph.nodes.find((n) => n.type === type)!;

const compile = (f: ProjectFixture & { instrument: InstrumentAsset }, note: number) =>
  compileInstrument(f.instrument.graph, note, instrumentSourcesOf(f.project));

const way = (plan: FxPlan | undefined) => (plan && 'pitch' in plan ? plan : undefined);

describe('notes', () => {
  it('count as MIDI does: C4 is 60, A4 is 440 Hz, the lowest is C-1, sharps only', () => {
    expect(noteName(60)).toBe('C4');
    expect(noteName(61)).toBe('C#4');
    expect(noteName(0)).toBe('C-1');
    expect(noteName(127)).toBe('G9');
    expect(noteFrequency(69)).toBe(440);
    expect(noteFrequency(81)).toBeCloseTo(880, 9);
    expect(heldNote(200)).toBe(127);
    expect(heldNote(Number.NaN)).toBe(60);
  });
});

describe('the instrument asset', () => {
  it('is not placeable and starts as Notes into a Sample into the Output', () => {
    expect(isPlaceableType('instrument')).toBe(false);
    const f = makeInstrument();
    expect(f.instrument.graph.nodes.map((n) => n.type)).toEqual([
      'InstrumentNotes',
      'InstrumentSample',
      'InstrumentOutput',
    ]);
    expect(f.instrument.graph.edges.map((e) => `${e.from.port}>${e.to.port}`)).toEqual([
      'any>trigger',
      'out>in',
    ]);
    // Its Sample has no sound yet, and says so.
    expect(compile(f, 60)).toMatchObject({ layers: [], reason: 'No sound picked' });
  });

  it('survives a round trip, keeping its own nodes and the effects it shares with a sound FX', () => {
    const f = makeInstrument();
    f.edit.addNode('SoundFxGain', { gain: -6 });
    const back = roundTrip(f.project).assets.find((a) => a.id === f.instrument.id) as InstrumentAsset;
    expect(back.graph.nodes.map((n) => n.type)).toEqual([
      'InstrumentNotes',
      'InstrumentSample',
      'InstrumentOutput',
      'SoundFxGain',
    ]);
    expect(back.graph.edges).toHaveLength(2);
  });

  it('offers its own nodes and the effects, but no Input and no second Output', () => {
    const f = makeInstrument();
    const offered = paletteEntries(f.project, f.instrument).map((e) => e.id);
    expect(offered).toEqual(
      expect.arrayContaining(['InstrumentNotes', 'InstrumentSample', 'InstrumentParameters', 'SoundFxDelay']),
    );
    expect(offered).not.toContain('InstrumentOutput');
    expect(offered).not.toContain('SoundFxInput');
    expect(offered).not.toContain('SoundFxOutput');
  });
});

describe('compiling a note', () => {
  it('plays a Sample at its root as it is, and other notes shifted by the distance', () => {
    const f = makeInstrument();
    const piano = f.sound('Piano C4', KICK);
    nodeOf(f, 'InstrumentSample').params.sound = piano.id;
    const root = compile(f, 60);
    expect(root.reason).toBe('');
    expect(root.layers).toHaveLength(1);
    expect(way(root.layers[0])).toMatchObject({
      pitch: [],
      source: { file: KICK, volume: 1, loop: false, gate: true },
    });
    expect(way(compile(f, 64).layers[0])?.pitch).toEqual([{ value: 4 }]);
    expect(way(compile(f, 67).layers[0])?.pitch).toEqual([{ value: 7 }]);
  });

  it('plays nothing for a note outside the range of its Notes node – silence, not a problem', () => {
    const f = makeInstrument();
    nodeOf(f, 'InstrumentSample').params.sound = f.sound('Piano', KICK).id;
    expect(compile(f, 72)).toEqual({ layers: [], problems: {}, reason: '' });
    expect(compile(f, 59).layers).toEqual([]);
    expect(compile(f, 71).layers).toHaveLength(1);
  });

  it.each([
    ['gate', { loop: false, gate: true }],
    ['oneshot', { loop: false, gate: false }],
    ['loop', { loop: true, gate: true, loopStart: 0.25, loopEnd: 1 }],
    // Looping, not ending with the note: the player leaves the loop on a release.
    ['release', { loop: true, gate: false, loopStart: 0.25, loopEnd: 1 }],
  ])('plays a Sample set to %s as such', (play, source) => {
    const f = makeInstrument();
    Object.assign(nodeOf(f, 'InstrumentSample').params, {
      sound: f.sound('Pad', KICK).id,
      play,
      loopStart: 0.25,
      loopEnd: 1,
    });
    expect(way(compile(f, 60).layers[0])?.source).toMatchObject(source);
  });

  it.each([
    [{ mode: 'gate' }, 'gate'],
    [{ mode: 'oneshot' }, 'oneshot'],
    [{ mode: 'gate', loop: true }, 'loop'],
    // It ran until it was stopped; that is gone, and Loop is the nearest.
    [{ mode: 'oneshot', loop: true }, 'loop'],
  ])('loads a Sample saved with %o before "Play" as %s', (old, play) => {
    const f = makeInstrument();
    const sample = nodeOf(f, 'InstrumentSample');
    delete sample.params.play;
    Object.assign(sample.params, old);
    const back = roundTrip(f.project).assets.find((a) => a.id === f.instrument.id) as InstrumentAsset;
    const params = back.graph.nodes.find((n) => n.type === 'InstrumentSample')!.params;
    expect(params.play).toBe(play);
    expect(params).not.toHaveProperty('mode');
    expect(params).not.toHaveProperty('loop');
  });

  it('plays a Sample that does not follow the note the same for every note', () => {
    const f = makeInstrument();
    Object.assign(nodeOf(f, 'InstrumentSample').params, {
      sound: f.sound('Kick', KICK).id,
      followNote: false,
    });
    expect(way(compile(f, 67).layers[0])?.pitch).toEqual([]);
  });

  it('a drum kit: one Notes node with single notes, a Sample on each, both into the Output', () => {
    const f = emptyInstrument();
    const notes = f.edit.addNode('InstrumentNotes', {
      from: '36',
      to: '47',
      singleNotes: true,
      name36: 'Kick',
    });
    const kick = f.edit.addNode('InstrumentSample', { sound: f.sound('Kick', KICK).id, followNote: false });
    const snare = f.edit.addNode('InstrumentSample', { sound: f.sound('Snare', SNARE).id, play: 'oneshot' });
    const output = f.edit.addNode('InstrumentOutput');
    f.edit.connect(notes, 'n36', kick, 'trigger');
    f.edit.connect(notes, 'n38', snare, 'trigger');
    f.edit.connect(kick, 'out', output, 'in');
    f.edit.connect(snare, 'out', output, 'in');
    // The Output takes both: a second edge into it does not replace the first.
    expect(f.instrument.graph.edges.filter((e) => e.to.node === output.id)).toHaveLength(2);
    const files = (note: number) => compile(f, note).layers.map((plan) => way(plan)?.source?.file);
    expect(files(36)).toEqual([KICK]);
    expect(files(38)).toEqual([SNARE]);
    expect(files(37)).toEqual([]);
    expect(way(compile(f, 38).layers[0])?.source?.gate).toBe(false);
    // The node names its output after the note's own name, the others after the note.
    const def = resolveDef(notes, f.instrument.graph, graphLookup(f.project))!;
    expect(def.outputs.map((p) => p.label).slice(0, 7)).toEqual([
      'any',
      'note',
      'frequency',
      'velocity',
      'Kick',
      'C#2',
      'D2',
    ]);
    expect(def.outputs).toHaveLength(4 + 12);
  });

  it('two Notes nodes over one Sample: a trigger takes more than one edge, either one plays it', () => {
    const f = emptyInstrument();
    const low = f.edit.addNode('InstrumentNotes', { from: '48', to: '52' });
    const high = f.edit.addNode('InstrumentNotes', { from: '70', to: '72' });
    const sample = f.edit.addNode('InstrumentSample', { sound: f.sound('Piano', KICK).id });
    const output = f.edit.addNode('InstrumentOutput');
    f.edit.wire([
      [low, 'any', sample, 'trigger'],
      [high, 'any', sample, 'trigger'],
      [sample, 'out', output, 'in'],
    ]);
    expect(compile(f, 50).layers).toHaveLength(1);
    expect(compile(f, 71).layers).toHaveLength(1);
    expect(compile(f, 60).layers).toHaveLength(0);
  });

  it('a Mix with one silent side is its other side', () => {
    const f = emptyInstrument();
    const notes = f.edit.addNode('InstrumentNotes', { from: '60', to: '62', singleNotes: true });
    const a = f.edit.addNode('InstrumentSample', { sound: f.sound('A', KICK).id });
    const b = f.edit.addNode('InstrumentSample', { sound: f.sound('B', SNARE).id });
    const mix = f.edit.addNode('SoundFxMix', { mix: 0.5 });
    const output = f.edit.addNode('InstrumentOutput');
    f.edit.wire([
      [notes, 'n60', a, 'trigger'],
      [notes, 'any', b, 'trigger'],
      [a, 'out', mix, 'a'],
      [b, 'out', mix, 'b'],
      [mix, 'out', output, 'in'],
    ]);
    const both = compile(f, 60).layers[0]!;
    expect('mix' in both).toBe(true);
    const only = compile(f, 61).layers[0];
    expect(way(only)?.source?.file).toBe(SNARE);
  });

  it('leaves velocity and the parameters open for the voice, and fills in note and frequency', () => {
    const f = makeInstrument();
    nodeOf(f, 'InstrumentSample').params.sound = f.sound('Piano', KICK).id;
    const params = f.edit.addNode('InstrumentParameters');
    f.stack.execute(new AddPortCommand(f.instrument.id, params.id, { key: 'level', kind: 'number' }));
    f.stack.execute(new SetPortDefaultCommand(f.instrument.id, params.id, 'level', -3));
    const sample = nodeOf(f, 'InstrumentSample');
    const output = nodeOf(f, 'InstrumentOutput');
    const notes = nodeOf(f, 'InstrumentNotes');
    f.instrument.graph.edges = f.instrument.graph.edges.filter((e) => e.to.node !== output.id);
    const byVelocity = f.edit.addNode('SoundFxGain');
    const byParam = f.edit.addNode('SoundFxGain');
    const byNote = f.edit.addNode('SoundFxEq');
    f.stack.execute(
      new ConnectCommand(
        f.instrument.id,
        { node: sample.id, port: 'out' },
        { node: byVelocity.id, port: 'in' },
      ),
    );
    f.edit.wire([
      [notes, 'velocity', byVelocity, 'gain'],
      [byVelocity, 'out', byParam, 'in'],
      [params, 'level', byParam, 'gain'],
      [byParam, 'out', byNote, 'in'],
      [notes, 'note', byNote, 'high'],
      [byNote, 'out', output, 'in'],
    ]);
    const plan = compile(f, 62).layers[0]!;
    expect(plan.stages).toEqual([
      { kind: 'gain', db: { value: 1, param: VELOCITY_PARAM, min: -120, max: 24 } },
      { kind: 'gain', db: { value: -3, param: 'level', min: -120, max: 24 } },
      // The note is a number by now: 62, held to the band's row.
      { kind: 'filter', filter: 'highshelf', frequency: 12000, gain: { value: 24 }, q: 1 },
    ]);
    const chain = fxChainOf(plan, { [VELOCITY_PARAM]: -6, level: -9 });
    expect(chain.stages.map((s) => ('gain' in s ? s.gain : 0))).toEqual([
      10 ** (-6 / 20),
      10 ** (-9 / 20),
      24,
    ]);
  });

  it('sends a sound through a sound FX, its parameters bound to the inputs of the node', () => {
    const f = makeInstrument();
    nodeOf(f, 'InstrumentSample').params.sound = f.sound('Piano', KICK).id;
    // The FX: Input, a Gain fed by its parameter "depth" (default -6), a Pitch of 12, Output.
    const made = new CreateAssetCommand('soundfx', 'Cave');
    f.stack.execute(made);
    const fx = made.asset as SoundFxAsset;
    const fxEdit = graphEditor(f, fx as unknown as BehaviorAsset);
    const input = fxEdit.addNode('SoundFxInput');
    f.stack.execute(new AddPortCommand(fx.id, input.id, { key: 'depth', kind: 'number' }));
    f.stack.execute(new SetPortDefaultCommand(fx.id, input.id, 'depth', -6));
    const gain = fxEdit.addNode('SoundFxGain');
    const pitch = fxEdit.addNode('SoundFxPitch', { semitones: 12 });
    const fxOut = fxEdit.addNode('SoundFxOutput');
    fxEdit.wire([
      [input, 'out', gain, 'in'],
      [input, 'depth', gain, 'gain'],
      [gain, 'out', pitch, 'in'],
      [pitch, 'out', fxOut, 'in'],
    ]);
    // In the instrument: Sample → Sound FX → Output.
    const sample = nodeOf(f, 'InstrumentSample');
    const output = nodeOf(f, 'InstrumentOutput');
    f.instrument.graph.edges = f.instrument.graph.edges.filter((e) => e.to.node !== output.id);
    const through = f.edit.addNode('InstrumentSoundFx', { fx: fx.id });
    f.edit.wire([
      [sample, 'out', through, 'in'],
      [through, 'out', output, 'in'],
    ]);
    const lookup = graphLookup(f.project);
    const def = resolveDef(through, f.instrument.graph, lookup)!;
    expect(def.label).toBe('Cave');
    expect(def.inputs.map((p) => [p.key, p.default])).toEqual([
      ['in', undefined],
      ['depth', -6],
    ]);

    // Left open, the parameter is the FX's default.
    const open = way(compile(f, 64).layers[0])!;
    expect(open.pitch).toEqual([{ value: 4 }, { value: 12 }]);
    expect(open.stages).toEqual([{ kind: 'gain', db: { value: -6 } }]);
    expect(open.source?.file).toBe(KICK);

    // Typed in at the node, it is a number – held to the FX's row.
    through.params.depth = -500;
    expect(way(compile(f, 64).layers[0])!.stages).toEqual([{ kind: 'gain', db: { value: -120 } }]);

    // Fed from the instrument's own parameter, it is that one.
    const params = f.edit.addNode('InstrumentParameters');
    f.stack.execute(new AddPortCommand(f.instrument.id, params.id, { key: 'dark', kind: 'number' }));
    f.edit.connect(params, 'dark', through, 'depth');
    expect(way(compile(f, 64).layers[0])!.stages).toEqual([
      { kind: 'gain', db: { value: 0, param: 'dark', min: -120, max: 24 } },
    ]);

    // Renaming the FX's parameter takes the edge into the node along.
    f.stack.execute(new RenamePortCommand(fx.id, input.id, 'depth', 'floor'));
    expect(f.instrument.graph.edges.some((e) => e.to.node === through.id && e.to.port === 'floor')).toBe(
      true,
    );
    expect(callProblem(through, lookup, f.instrument.id)).toBeNull();
    through.params.fx = '';
    expect(callProblem(through, lookup, f.instrument.id)).toBe('No sound FX picked');
  });

  it('says what keeps it from compiling: a Sample nothing triggers, a sound that is gone', () => {
    const f = makeInstrument();
    const sample = nodeOf(f, 'InstrumentSample');
    sample.params.sound = 'gone';
    expect(compile(f, 60).problems[sample.id]).toBe('That sound is gone');
    sample.params.sound = f.sound('Piano', KICK).id;
    f.instrument.graph.edges = f.instrument.graph.edges.filter((e) => e.to.node !== sample.id);
    expect(compile(f, 60).problems[sample.id]).toBe('Nothing triggers it: connect it to a Notes node');
  });

  it('is compiled again when a sound it plays changes, not on every note', () => {
    const f = makeInstrument();
    const piano = f.sound('Piano', KICK);
    nodeOf(f, 'InstrumentSample').params.sound = piano.id;
    const sources = instrumentSourcesOf(f.project);
    const first = instrumentBuildFor(f.instrument, 60, sources);
    expect(instrumentBuildFor(f.instrument, 60, sources)).toBe(first);
    piano.file = SNARE;
    const again = instrumentBuildFor(f.instrument, 60, instrumentSourcesOf(f.project));
    expect(way(again.layers[0])?.source?.file).toBe(SNARE);
  });
});

describe('ports of an instrument', () => {
  it('a trigger fits only a trigger', () => {
    expect(portsCompatible('trigger', 'trigger')).toBe(true);
    expect(portsCompatible('trigger', 'boolean')).toBe(false);
    expect(portsCompatible('trigger', 'any')).toBe(false);
    expect(portsCompatible('audio', 'trigger')).toBe(false);
  });

  it('a Sample keeps every trigger connected to it, a Gain still only one sound', () => {
    const f = makeInstrument();
    const notes = nodeOf(f, 'InstrumentNotes');
    notes.params.singleNotes = true;
    const sample = nodeOf(f, 'InstrumentSample');
    f.edit.connect(notes, 'n61', sample, 'trigger');
    expect(f.instrument.graph.edges.filter((e) => e.to.node === sample.id)).toHaveLength(2);
    const gain = f.edit.addNode('SoundFxGain');
    f.edit.connect(sample, 'out', gain, 'in');
    const other = f.edit.addNode('InstrumentSample');
    f.edit.connect(other, 'out', gain, 'in');
    expect(f.instrument.graph.edges.filter((e) => e.to.node === gain.id)).toHaveLength(1);
  });
});

describe('Play note', () => {
  function sink() {
    const notes: {
      name: string;
      layers: readonly FxPlan[];
      params: object;
      volume: number;
      duration: number;
    }[] = [];
    const audio = {
      playNote: (
        name: string,
        layers: readonly FxPlan[],
        params: object,
        volume: number,
        _o: string,
        duration: number,
      ) => notes.push({ name, layers, params, volume, duration }),
    } as unknown as AudioSink;
    return { audio, notes };
  }

  it('hands the sink the layers of the note, its velocity as loudness and as a value, held to 0..1', () => {
    const f = makeInstrument();
    nodeOf(f, 'InstrumentSample').params.sound = f.sound('Piano', KICK).id;
    const { audio, notes } = sink();
    const struck = { note: 64, velocity: 0.5, volume: 0.8, duration: 0.25 };
    expect(playNote({ project: f.project, audio }, f.instrument.id, struck, '', { cut: 1 })).toBe(1);
    expect(notes[0]).toMatchObject({
      name: `instrument:${f.instrument.id}`,
      params: { cut: 1, [VELOCITY_PARAM]: 0.5 },
      volume: 0.4,
      duration: 0.25,
    });
    expect(way(notes[0]!.layers[0])?.pitch).toEqual([{ value: 4 }]);
    playNote({ project: f.project, audio }, f.instrument.id, { ...struck, velocity: 3, volume: 2 }, '', {});
    expect(notes[1]).toMatchObject({ volume: 1, params: { [VELOCITY_PARAM]: 1 } });
  });

  it('plays nothing for a note the instrument has nothing for, or an instrument that is gone', () => {
    const f = makeInstrument();
    nodeOf(f, 'InstrumentSample').params.sound = f.sound('Piano', KICK).id;
    const { audio, notes } = sink();
    const struck = { note: 30, velocity: 1, volume: 1, duration: 0 };
    expect(playNote({ project: f.project, audio }, f.instrument.id, struck, '', {})).toBe(0);
    expect(playNote({ project: f.project, audio }, 'gone', { ...struck, note: 60 }, '', {})).toBe(0);
    expect(notes).toEqual([]);
  });

  it('warns where its parameters come from a node naming another instrument', () => {
    const f = makeInstrument();
    const behavior = new CreateAssetCommand('behavior', 'B');
    f.stack.execute(behavior);
    const asset = behavior.asset as BehaviorAsset;
    const edit = graphEditor(f, asset);
    const play = edit.addNode('PlayNote', { instrument: f.instrument.id });
    const values = edit.addNode('InstrumentParameterValues', { soundFxAsset: 'other' });
    edit.connect(values, 'params', play, 'fxParams');
    expect(soundFxParamsMismatch(play, asset.graph)).toBe('The parameters are for another instrument');
    values.params.soundFxAsset = f.instrument.id;
    expect(soundFxParamsMismatch(play, asset.graph)).toBeNull();
    expect(callProblem(values, graphLookup(f.project))).toBeNull();
  });

  it('an Instrument parameters node offers what the Parameters node declares, and follows a rename', () => {
    const f = makeInstrument();
    const params = f.edit.addNode('InstrumentParameters');
    f.stack.execute(new AddPortCommand(f.instrument.id, params.id, { key: 'cut', kind: 'number' }));
    f.stack.execute(new SetPortDefaultCommand(f.instrument.id, params.id, 'cut', 0.7));
    expect(graphLookup(f.project).soundFx(f.instrument.id)?.params).toEqual([
      { key: 'cut', kind: 'number', default: 0.7 },
    ]);
    const behavior = new CreateAssetCommand('behavior', 'B');
    f.stack.execute(behavior);
    const asset = behavior.asset as BehaviorAsset;
    const values = graphEditor(f, asset).addNode('InstrumentParameterValues', {
      soundFxAsset: f.instrument.id,
    });
    f.stack.execute(new AddPortCommand(asset.id, values.id, { key: 'cut', kind: 'number' }));
    const def = resolveDef(values, asset.graph, graphLookup(f.project))!;
    expect(def.inputs.map((p) => [p.key, p.default])).toEqual([['cut', 0.7]]);
    f.stack.execute(new RenamePortCommand(f.instrument.id, params.id, 'cut', 'bright'));
    expect(values.ports?.map((p) => p.key)).toEqual(['bright']);
  });
});

describe('the keys of the tab', () => {
  it('lays out all 128 notes, black over white, and finds the note under a point', () => {
    const keys = keyboardLayout(750, 60);
    expect(keys).toHaveLength(128);
    expect(keys.filter((k) => k.black)).toHaveLength(53);
    const c4 = keys.find((k) => k.note === 60)!;
    const cSharp4 = keys.find((k) => k.note === 61)!;
    expect(noteAt(keys, c4.x + 1, 55)).toBe(60);
    // Up top, the black key lies over the edge of the white one.
    expect(noteAt(keys, cSharp4.x + cSharp4.w / 2, 5)).toBe(61);
    expect(noteAt(keys, 800, 10)).toBeNull();
  });

  it('plays the computer keyboard by where a key is, as a tracker does', () => {
    expect(trackerNote('KeyZ', 3)).toBe(48);
    expect(trackerNote('KeyS', 3)).toBe(49);
    expect(trackerNote('KeyQ', 3)).toBe(60);
    expect(trackerNote('Digit2', 3)).toBe(61);
    expect(trackerNote('KeyP', 3)).toBe(76);
    expect(trackerNote('KeyA', 3)).toBeNull();
    expect(trackerNote('KeyP', 8)).toBeNull();
  });
});