feuerwerk/tools/e2e/34-sound.mjs

import { edge, node, port, variable, written } from '../lib/builders.mjs';
import { LANES, MAKE_OBJECT, pickAssetType } from './lib/scaffold.mjs';

/**
 * Sound assets (#45): uploaded like a typeface – picked from what the server holds through
 * "+ → Sound", or dropped onto the editor – and played by a graph through `Play sound`. Nothing
 * wears a sound and nothing places it; the asset says how loud it is and whether it loops, and the
 * node scales the one and can overrule the other in either direction.
 *
 * Nothing is ever *heard* here: CI runs the browser muted (see tools/lib/browser.mjs). The witness
 * is `__gm.sound.stats()` – voices started, stopped and in flight – the way `renderStats` is the
 * witness for a repaint that did not happen. No pixel check could see any of this.
 *
 * The seed puts two generated WAVs on the server without making assets of them: a 0.25 s blip and
 * a 0.75 s drone, told apart by their exact size rather than by their name.
 */
const LANE = LANES.sound;
const BLIP_BYTES = 4044;
const DRONE_BYTES = 12044;

export async function sound(t) {
  const { check, sleep, json, evaluate, mutate, click, clickText, press, play, stop, shot, showTab } = t;
  const { select } = t;
  const assetsOfType = (type) =>
    json(`__gm.state.project.assets.filter((a) => a.type === ${JSON.stringify(type)})
      .map((a) => ({ id: a.id, name: a.name, file: a.file, props: a.props }))`);
  const stats = () => json('__gm.sound.stats()');
  /** A voice starts only once its bytes have been decoded, so what it changes is awaited. */
  const waitFor = async (read, done, tries = 25) => {
    let value = await read();
    for (let i = 0; i < tries && !done(value); i++) {
      await sleep(150);
      value = await read();
    }
    return value;
  };
  // Every reading up to the one `done` takes: a check holds each against its own time on the audio
  // clock, however late the first one comes in.
  const trace = async (read, done, tries = 40) => {
    const seen = [await read()];
    for (let i = 0; i < tries && !done(seen.at(-1)); i++) {
      await sleep(150);
      seen.push(await read());
    }
    return seen;
  };

  await press('Escape');
  await evaluate('document.activeElement instanceof HTMLElement && document.activeElement.blur()');
  await evaluate('__gm.state.select(null)');
  await showTab('scene');

  // 34a. What the server holds, straight from the API: the two files the seed put there.
  const stored = await evaluate(`fetch('/game-maker/api/index.php?r=sounds').then((r) => r.json())`);
  const blip = stored.find((item) => item.bytes === BLIP_BYTES);
  const drone = stored.find((item) => item.bytes === DRONE_BYTES);
  check(
    'the server holds the two seeded sounds, named by their content',
    Boolean(blip && drone) && /^[a-f0-9]{64}\.wav$/.test(blip.file),
    JSON.stringify({ blip: blip?.file, drone: drone?.file, count: stored.length }),
  );
  if (!blip || !drone) return;
  check(
    'the listing carries the name each file was uploaded under',
    blip.name === 'blip.wav' && drone.name === 'drone.wav',
    JSON.stringify({ blip: blip.name, drone: drone.name }),
  );

  // 34b. "+ → Sound" offers them; a sound is picked rather than created empty, like a typeface.
  await clickText('+');
  await pickAssetType(t, 'Sound');
  await sleep(500);
  const picker = await json('__gm.soundPicker()');
  check(
    'the + menu opens the sound picker on what the server holds, none of it in the project yet',
    Boolean(picker) && picker.files.includes(blip.file) && picker.used.length === 0,
    JSON.stringify(picker),
  );
  check(
    'a row nobody uses yet is captioned with the name the file was uploaded under',
    picker.captions[picker.files.indexOf(blip.file)] === 'blip.wav',
    JSON.stringify(picker.captions),
  );
  await shot('34-sound-picker');

  // 34c. The ▶ at a row's left is a preview: it plays that file without choosing it.
  const playAt = await json(`__gm.soundPickerPlay(${JSON.stringify(drone.file)})`);
  await click(playAt.x, playAt.y);
  const previewed = await waitFor(stats, (s) => s.started > 0);
  const afterPreview = await json('__gm.soundPicker()');
  check(
    'pressing a row’s ▶ plays that file and picks nothing',
    previewed.started === 1 &&
      previewed.last?.file === drone.file &&
      afterPreview.played === drone.file &&
      afterPreview.selected === null,
    JSON.stringify({ previewed, selected: afterPreview.selected, played: afterPreview.played }),
  );

  const row = await json(`__gm.soundPickerRow(${JSON.stringify(blip.file)})`);
  await click(row.x, row.y);
  await clickText('Use sound');
  const sounds = await assetsOfType('sound');
  check(
    'picking a row makes a sound asset of that file, named after the file rather than "Sound"',
    sounds.length === 1 && sounds[0].file === blip.file && sounds[0].name === 'blip',
    JSON.stringify(sounds),
  );
  if (sounds.length !== 1) return;
  const soundId = sounds[0].id;
  check(
    'a fresh sound asset is full volume and one-shot',
    sounds[0].props.volume === 1 && sounds[0].props.loop === false,
    JSON.stringify(sounds[0].props),
  );
  // Closing the picker silences its preview; nothing it started may outlive the dialog.
  check(
    'closing the picker leaves nothing playing',
    (await stats()).playing === 0,
    JSON.stringify(await stats()),
  );

  // 34d. Its inspector: the two rows, and the preview that is the only way to tell which sound it is.
  await select({ kind: 'asset', assetId: soundId });
  const volumeRow = await json("__gm.inspectorField('Volume', true)");
  const loopRow = await json("__gm.inspectorField('Loop', true)");
  check(
    'a sound asset has a Volume row and a Loop row',
    Boolean(volumeRow) && Boolean(loopRow),
    JSON.stringify({ volumeRow, loopRow }),
  );
  await shot('34-sound-asset');

  // 34e. A graph plays it. The behavior sits in its own lane; the node's volume is a factor on the
  //      asset's, so 0.5 × 0.4 has to reach the library as 0.2 rather than as either of the two.
  await mutate(`
    const p = __gm.state.project;
    const scene = __gm.state.activeScene;
    p.assets.find((a) => a.id === ${JSON.stringify(soundId)}).props.volume = 0.4;
    const asset = structuredClone(p.assets.find((a) => a.id === 'mover'));
    Object.assign(asset, {
      id: 'sn-logic',
      name: 'Noisy',
      props: { enabled: true, runInEditor: false },
      variables: [],
      graph: ${JSON.stringify({
        nodes: [
          node('sn-start', 'OnStart', 0, 0),
          node('sn-play', 'PlaySound', 260, 0, { sound: soundId, volume: 0.5, loop: '' }),
        ],
        edges: [edge('sn-e1', 'sn-start', 'exec', 'sn-play', 'exec')],
      })},
    });
    p.assets.unshift(asset);
    ${MAKE_OBJECT}
    scene.objects.push(
      make('sn-box', 'crate', '', ${LANE}, 'Noisy box'),
      make('sn-brain', 'sn-logic', 'sn-box', 0, 'Noisy'),
    );
    __gm.lookAt(0, ${LANE});`);

  await evaluate('__gm.sound.stopAll()');
  const before = await stats();
  await play();
  const played = await waitFor(stats, (s) => s.started > before.started);
  check(
    'a graph playing a sound reaches the library, at the asset volume scaled by the node’s',
    played.started === before.started + 1 &&
      played.last?.file === blip.file &&
      Math.abs(played.last.volume - 0.2) < 0.001 &&
      played.last.loop === false,
    JSON.stringify(played),
  );
  await stop();

  // 34f. A looping sound is music: it plays on, and ending the run ends it – nothing may outlive
  //      the world that started it.
  await mutate(`
    const p = __gm.state.project;
    p.assets.find((a) => a.id === ${JSON.stringify(soundId)}).props.loop = true;`);
  await play();
  const looping = await waitFor(stats, (s) => s.playing > 0 && s.last?.loop === true);
  check(
    'the asset’s own loop flag reaches the library even though the node never asked for one',
    looping.playing >= 1 && looping.last?.loop === true,
    JSON.stringify(looping),
  );
  // Well past the blip's own 0.25 s, so a one-shot would have ended by itself here.
  await sleep(700);
  const stillLooping = await stats();
  await stop();
  const afterStop = await stats();
  check(
    'a loop keeps playing while the run is on and ends with it',
    stillLooping.playing >= 1 && afterStop.playing === 0,
    JSON.stringify({ stillLooping, afterStop }),
  );

  // 34f-2. The node overrules the asset in both directions – the reason `loop` is a choice of three
  //        and not a checkbox: music has to be playable as a one-shot.
  const setNodeLoop = (value) =>
    mutate(`
      const p = __gm.state.project;
      const graph = p.assets.find((a) => a.id === 'sn-logic').graph;
      graph.nodes.find((n) => n.id === 'sn-play').params.loop = ${JSON.stringify(value)};`);
  await setNodeLoop('false');
  const beforeOnce = await stats();
  await play();
  const once = await waitFor(stats, (s) => s.started > beforeOnce.started);
  check('a node saying "off" plays a looping asset once', once.last?.loop === false, JSON.stringify(once));
  await stop();
  await setNodeLoop('');

  // 34g. `Stop sound` silences it from inside the graph, without ending the run.
  await mutate(`
    const p = __gm.state.project;
    const graph = p.assets.find((a) => a.id === 'sn-logic').graph;
    graph.nodes.push(${JSON.stringify(node('sn-stop', 'StopSound', 520, 0, { sound: soundId }))});
    graph.nodes.push(${JSON.stringify(node('sn-key', 'OnKeyDown', 260, 220, { key: 's' }))});
    graph.edges.push(${JSON.stringify(edge('sn-e2', 'sn-key', 'exec', 'sn-stop', 'exec'))});`);
  await play();
  await waitFor(stats, (s) => s.playing > 0);
  await press('s');
  const silenced = await waitFor(stats, (s) => s.playing === 0);
  check(
    'Stop sound silences a looping sound while the run carries on',
    silenced.playing === 0 && (await json('__gm.playInfo()')).playing === true,
    JSON.stringify(silenced),
  );
  await stop();

  // 34g-2. A voice belongs to the behavior playing it: destroy the object and its sounds go with it,
  //        without any `Stop sound` in the graph. `detached` is the one way out, for the death
  //        sound of an object that destroys itself.
  await mutate(`
    const p = __gm.state.project;
    const graph = p.assets.find((a) => a.id === 'sn-logic').graph;
    graph.nodes.push(
      ${JSON.stringify(node('sn-key2', 'OnKeyDown', 260, 440, { key: 'd' }))},
      ${JSON.stringify(node('sn-owner', 'Owner', 260, 620))},
      ${JSON.stringify(node('sn-destroy', 'Destroy', 520, 440))},
    );
    graph.edges.push(
      ${JSON.stringify(edge('sn-e3', 'sn-key2', 'exec', 'sn-destroy', 'exec'))},
      ${JSON.stringify(edge('sn-e4', 'sn-owner', 'object', 'sn-destroy', 'object'))},
    );`);
  await play();
  await waitFor(stats, (s) => s.playing > 0);
  await press('d');
  const destroyed = await waitFor(stats, (s) => s.playing === 0);
  check(
    'destroying the object silences the looping sound its behavior was playing',
    destroyed.playing === 0 && (await json('__gm.playInfo()')).playing === true,
    JSON.stringify(destroyed),
  );
  await stop();

  const setDetached = (value) =>
    mutate(`
      const p = __gm.state.project;
      const graph = p.assets.find((a) => a.id === 'sn-logic').graph;
      graph.nodes.find((n) => n.id === 'sn-play').params.detached = ${JSON.stringify(value)};`);
  await setDetached(true);
  await play();
  await waitFor(stats, (s) => s.playing > 0);
  await press('d');
  // Long enough that the reaping frame has been and gone – a voice still here now is here on purpose.
  await sleep(600);
  const detached = await stats();
  check(
    'a detached voice is nobody’s and plays on after the object that started it is gone',
    detached.playing >= 1,
    JSON.stringify(detached),
  );
  await stop();
  check(
    'ending the run silences a detached voice too',
    (await stats()).playing === 0,
    JSON.stringify(await stats()),
  );
  await setDetached(false);

  // 34g-3. A sound FX asset (#311): "+ → Sound FX" opens its tab, which says what keeps the graph
  //        from compiling; built into Input → Pitch → Gain → Output, the header plays the sound
  //        through it, and a `Play sound` naming it sends the game's voice the same way. The pitch
  //        comes from a parameter `depth` of the Input: the header has a field for it, and a
  //        `Sound FX parameters` node hands the game's value in.
  await showTab('scene');
  await clickText('+');
  await pickAssetType(t, 'Sound FX');
  const fxCreated = await json(`{
    tab: __gm.tab(),
    current: __gm.soundfx.current(),
    info: __gm.soundfx.info(),
    preview: __gm.soundfx.preview(),
    assets: __gm.state.project.assets.filter((a) => a.type === 'soundfx').map((a) => a.id),
  }`);
  check(
    'the + menu creates a sound FX asset and opens its tab, with no Output to compile and no Play',
    fxCreated.tab === 'soundfx' &&
      fxCreated.assets.length === 1 &&
      fxCreated.current === fxCreated.assets[0] &&
      fxCreated.info === 'No Output node' &&
      fxCreated.preview.sound === soundId &&
      fxCreated.preview.play === false,
    JSON.stringify(fxCreated),
  );
  const fxId = fxCreated.assets[0];
  const fxCanvas = await json('__gm.soundfx.canvasRect()');
  await click(fxCanvas.x + 80, fxCanvas.y + 60, 'right');
  const fxPalette = await json('__gm.overlayTexts()');
  check(
    'its palette offers the sound effects and no behavior node',
    ['Input', 'Output', 'Gain', 'Pitch', '5-Band-EQ', 'Mix', 'Delay'].every((label) =>
      fxPalette.includes(label),
    ) && !fxPalette.includes('Branch'),
    JSON.stringify(fxPalette.slice(0, 12)),
  );
  await press('Escape');
  await mutate(`
    const fx = __gm.state.project.assets.find((a) => a.id === ${JSON.stringify(fxId)});
    fx.name = 'Low';
    fx.graph = ${JSON.stringify({
      nodes: [
        node('fx-in', 'SoundFxInput', 0, 0, {}, [{ key: 'depth', kind: 'number', default: -12 }]),
        node('fx-pitch', 'SoundFxPitch', 220, 0),
        node('fx-gain', 'SoundFxGain', 440, 0, { gain: -6 }),
        node('fx-out', 'SoundFxOutput', 660, 0),
      ],
      edges: [
        edge('fx-e1', 'fx-in', 'out', 'fx-pitch', 'in'),
        edge('fx-e2', 'fx-pitch', 'out', 'fx-gain', 'in'),
        edge('fx-e3', 'fx-gain', 'out', 'fx-out', 'in'),
        edge('fx-e4', 'fx-in', 'depth', 'fx-pitch', 'semitones'),
      ],
    })};`);
  const fxBuilt = await json(
    '{ info: __gm.soundfx.info(), preview: __gm.soundfx.preview(), params: __gm.soundfx.params() }',
  );
  check(
    'Input → Pitch → Gain → Output compiles to two effects, Play is offered, depth starts at its default',
    fxBuilt.info === '2 effects' && fxBuilt.preview.play === true && fxBuilt.params.depth === -12,
    JSON.stringify(fxBuilt),
  );
  await evaluate('__gm.sound.stopAll()');
  const beforeFx = await stats();
  const fxPlayAt = await json('__gm.soundfx.playAt()');
  await click(fxPlayAt.x, fxPlayAt.y);
  const heardFx = await waitFor(stats, (s) => s.started > beforeFx.started);
  const blipSeconds = await json(`__gm.sound.duration(${JSON.stringify(blip.file)})`);
  check(
    'the tab’s Play sends the sound through the graph: an octave down, as long as before, one gain stage',
    heardFx.last?.file === blip.file &&
      heardFx.last.pitches.join() === '-12' &&
      heardFx.last.duration === blipSeconds &&
      heardFx.last.stages === 1,
    JSON.stringify({ ...heardFx, blipSeconds }),
  );
  await evaluate('__gm.sound.stopAll()');
  await evaluate('__gm.soundfx.setParam("depth", 5)');
  const beforeParam = await stats();
  await click(fxPlayAt.x, fxPlayAt.y);
  const heardParam = await waitFor(stats, (s) => s.started > beforeParam.started);
  check(
    'the header plays with the value its depth field is set to',
    heardParam.last?.pitches.join() === '5' && heardParam.last.stages === 1,
    JSON.stringify(heardParam),
  );
  await evaluate('__gm.sound.stopAll()');
  // #316: the Pitch → Gain way and the dry Input meet in a Mix – two sources, one per pitch.
  await mutate(`
    const graph = __gm.state.project.assets.find((a) => a.id === ${JSON.stringify(fxId)}).graph;
    graph.nodes.push(${JSON.stringify(node('fx-mix', 'SoundFxMix', 550, 0, { mix: 0.5 }))});
    graph.edges = graph.edges.filter((e) => e.id !== 'fx-e3');
    graph.edges.push(
      ${JSON.stringify(edge('fx-e5', 'fx-gain', 'out', 'fx-mix', 'a'))},
      ${JSON.stringify(edge('fx-e6', 'fx-in', 'out', 'fx-mix', 'b'))},
      ${JSON.stringify(edge('fx-e7', 'fx-mix', 'out', 'fx-out', 'in'))},
    );`);
  const mixInfo = await json('__gm.soundfx.info()');
  const beforeMix = await stats();
  await click(fxPlayAt.x, fxPlayAt.y);
  const heardMix = await waitFor(stats, (s) => s.started > beforeMix.started);
  check(
    'a Mix of the pitched way and the dry Input plays one voice from two sources of the same length',
    mixInfo === '3 effects' &&
      heardMix.last?.pitches.join() === '5,0' &&
      heardMix.last.stages === 1 &&
      heardMix.last.duration === blipSeconds,
    JSON.stringify({ mixInfo, ...heardMix }),
  );
  await evaluate('__gm.sound.stopAll()');
  await mutate(`
    const graph = __gm.state.project.assets.find((a) => a.id === ${JSON.stringify(fxId)}).graph;
    graph.nodes = graph.nodes.filter((n) => n.id !== 'fx-mix');
    graph.edges = graph.edges.filter((e) => !['fx-e5', 'fx-e6', 'fx-e7'].includes(e.id));
    graph.edges.push(${JSON.stringify(edge('fx-e3', 'fx-gain', 'out', 'fx-out', 'in'))});`);
  // #324, #327: a ping-pong Delay behind the gain. The blip is a quarter of a second, its echoes come
  //             0.3 s apart, each half as loud as the one before: nine are heard, 2.7 s – the voice
  //             stays that long after its sound and goes then. Asked to let ring, only the sound
  //             stops and the voice stays; a stop after that cuts it.
  await mutate(`
    const graph = __gm.state.project.assets.find((a) => a.id === ${JSON.stringify(fxId)}).graph;
    graph.nodes.push(${JSON.stringify(
      node('fx-delay', 'SoundFxDelay', 550, 0, { time: 0.3, feedback: 0.5, mix: 0.5, pingPong: true }),
    )});
    graph.edges = graph.edges.filter((e) => e.id !== 'fx-e3');
    graph.edges.push(
      ${JSON.stringify(edge('fx-e8', 'fx-gain', 'out', 'fx-delay', 'in'))},
      ${JSON.stringify(edge('fx-e9', 'fx-delay', 'out', 'fx-out', 'in'))},
    );`);
  const delayInfo = await json('__gm.soundfx.info()');
  await evaluate('__gm.sound.stopAll()');
  const beforeEcho = await stats();
  await click(fxPlayAt.x, fxPlayAt.y);
  const echoStarted = await waitFor(stats, (s) => s.started > beforeEcho.started);
  // Timed on the audio clock: the page's can fall behind it (task 523 saw a 2.95 s tail end 1 s in).
  const audioNow = () => json('({ playing: __gm.sound.stats().playing, clock: __gm.sound.clock() })');
  const startedAt = (await audioNow()).clock;
  const echoLevels = await json(`__gm.sound.levels(${JSON.stringify(blip.file)})`);
  const ringing = await waitFor(audioNow, (s) => s.clock - startedAt >= 1);
  const quiet = await waitFor(audioNow, (s) => s.playing === 0, 40);
  const rangFor = quiet.clock - startedAt;
  const echoKnobs = echoLevels?.[0]?.slice(2) ?? [];
  check(
    'a Delay keeps the voice after its sound has ended, until its echoes have faded',
    delayInfo === '3 effects' &&
      echoStarted.last?.stages === 2 &&
      echoKnobs.length === 4 &&
      Math.abs(echoKnobs[0] - 0.3) < 1e-6 &&
      Math.abs(echoKnobs[1] - 0.5) < 1e-6 &&
      Math.abs(echoKnobs[2] / (20000 * 0.025 ** 0.3) - 1) < 1e-3 &&
      Math.abs(echoKnobs[3] - 0.5) < 1e-6 &&
      ringing.playing === 1 &&
      ringing.clock - startedAt < 2.4 &&
      quiet.playing === 0 &&
      rangFor > 2.4 &&
      rangFor < 4.5,
    JSON.stringify({ delayInfo, last: echoStarted.last, echoLevels, ringing, startedAt, rangFor }),
  );
  await click(fxPlayAt.x, fxPlayAt.y);
  await waitFor(stats, (s) => s.playing === 1);
  const beforeLetRing = await stats();
  await evaluate(`__gm.sound.stop(${JSON.stringify(blip.file)}, true)`);
  await sleep(500);
  const letRing = await stats();
  await evaluate(`__gm.sound.stop(${JSON.stringify(blip.file)})`);
  const cut = await stats();
  check(
    'Let ring stops the sound and keeps the voice for its echoes; a stop after that cuts it',
    letRing.playing === 1 &&
      letRing.stopped === beforeLetRing.stopped + 1 &&
      cut.playing === 0 &&
      cut.stopped === beforeLetRing.stopped + 2,
    JSON.stringify({ before: beforeLetRing.stopped, letRing, cut }),
  );
  await mutate(`
    const graph = __gm.state.project.assets.find((a) => a.id === ${JSON.stringify(fxId)}).graph;
    graph.nodes = graph.nodes.filter((n) => n.id !== 'fx-delay');
    graph.edges = graph.edges.filter((e) => !['fx-e8', 'fx-e9'].includes(e.id));
    graph.edges.push(${JSON.stringify(edge('fx-e3', 'fx-gain', 'out', 'fx-out', 'in'))});`);
  await showTab('scene');
  await mutate(`
    const graph = __gm.state.project.assets.find((a) => a.id === 'sn-logic').graph;
    Object.assign(graph.nodes.find((n) => n.id === 'sn-play').params, { loop: 'false', fx: ${JSON.stringify(fxId)} });`);
  const beforeGameFx = await stats();
  await play();
  const gameFx = await waitFor(stats, (s) => s.started > beforeGameFx.started);
  check(
    'a Play sound naming the asset plays the game’s voice through it',
    gameFx.last?.pitches.join() === '-12' && gameFx.last.stages === 1,
    JSON.stringify(gameFx),
  );
  await stop();
  await mutate(`
    const graph = __gm.state.project.assets.find((a) => a.id === 'sn-logic').graph;
    graph.nodes.push(${JSON.stringify(
      node('sn-fxp', 'SoundFxParameters', 0, 120, { soundFxAsset: fxId, depth: 7 }, [
        { key: 'depth', kind: 'number' },
      ]),
    )});
    graph.edges.push(${JSON.stringify(edge('sn-e-fxp', 'sn-fxp', 'params', 'sn-play', 'fxParams'))});`);
  const beforeGameParam = await stats();
  await play();
  const gameParam = await waitFor(stats, (s) => s.started > beforeGameParam.started);
  check(
    'a Sound FX parameters node hands depth 7 to the game’s voice',
    gameParam.last?.pitches.join() === '7' && gameParam.last.stages === 1,
    JSON.stringify(gameParam),
  );
  await stop();
  // #315: two looping voices of the same sound start at depth 7, the first keeps its number in a
  //       variable, and `Set sound FX parameters` hands that one voice depth 3 every frame. In a
  //       real AudioContext the first one's pitch – the AudioParam of its worklet (#317), in
  //       semitones – glides there, the second one's stays put.
  const tuneIds = ['sn-keep', 'sn-play2', 'sn-tick', 'sn-read', 'sn-tune', 'sn-fxp2'];
  const tuneEdges = [
    'sn-e-keep',
    'sn-e-voice',
    'sn-e-play2',
    'sn-e-fxp3',
    'sn-e-tick',
    'sn-e-read',
    'sn-e-fxp2',
  ];
  await mutate(`
    const logic = __gm.state.project.assets.find((a) => a.id === 'sn-logic');
    logic.variables = [${JSON.stringify(variable('voice', 'number', 0))}];
    const graph = logic.graph;
    const play = graph.nodes.find((n) => n.id === 'sn-play');
    play.params.loop = 'true';
    graph.nodes.push(
      ${JSON.stringify(node('sn-keep', 'Variables', 520, 0, {}, [written('voice', 'number')]))},
      { ...structuredClone(play), id: 'sn-play2', x: 780 },
      ${JSON.stringify(node('sn-tick', 'OnUpdate', 0, 300))},
      ${JSON.stringify(node('sn-read', 'Variables', 0, 420, {}, [port('voice', 'number')]))},
      ${JSON.stringify(node('sn-tune', 'SetSoundFxParameters', 260, 300))},
      ${JSON.stringify(
        node('sn-fxp2', 'SoundFxParameters', 0, 540, { soundFxAsset: fxId, depth: 3 }, [
          { key: 'depth', kind: 'number' },
        ]),
      )},
    );
    graph.edges.push(
      ${JSON.stringify(edge('sn-e-keep', 'sn-play', 'exec', 'sn-keep', 'exec'))},
      ${JSON.stringify(edge('sn-e-voice', 'sn-play', 'voice', 'sn-keep', 'voice'))},
      ${JSON.stringify(edge('sn-e-play2', 'sn-keep', 'exec', 'sn-play2', 'exec'))},
      ${JSON.stringify(edge('sn-e-fxp3', 'sn-fxp', 'params', 'sn-play2', 'fxParams'))},
      ${JSON.stringify(edge('sn-e-tick', 'sn-tick', 'exec', 'sn-tune', 'exec'))},
      ${JSON.stringify(edge('sn-e-read', 'sn-read', 'voice', 'sn-tune', 'voice'))},
      ${JSON.stringify(edge('sn-e-fxp2', 'sn-fxp2', 'params', 'sn-tune', 'fxParams'))},
    );`);
  const beforeTune = await stats();
  await play();
  const tunedStats = await waitFor(
    stats,
    (s) => s.tuned > beforeTune.tuned && s.started >= beforeTune.started + 2,
  );
  const glided = (levels) =>
    Array.isArray(levels) && levels.length === 2 && Math.abs(levels[0][0] - 3) < 0.05;
  const levels = await waitFor(() => json(`__gm.sound.levels(${JSON.stringify(blip.file)})`), glided);
  check(
    'Set sound FX parameters moves the one voice whose number it holds from depth 7 to 3, not the other',
    tunedStats.last?.pitches.join() === '7' &&
      tunedStats.last.loop === true &&
      tunedStats.worklet === true &&
      glided(levels) &&
      Math.abs(levels[0][1] - 10 ** (-6 / 20)) < 0.001 &&
      levels[1][0] === 7,
    JSON.stringify({ last: tunedStats.last, tuned: tunedStats.tuned, worklet: tunedStats.worklet, levels }),
  );
  await stop();
  // A `time` of 2 s takes the same voice from depth 7 to -5 evenly on the audio clock, 6 semitones
  // a second: half a second in it is still well above the end, where a quick glide would be there.
  await mutate(`
    const graph = __gm.state.project.assets.find((a) => a.id === 'sn-logic').graph;
    graph.nodes.find((n) => n.id === 'sn-tune').params.time = 2;
    graph.nodes.find((n) => n.id === 'sn-fxp2').params.depth = -5;`);
  await play();
  const pitch = async () => (await json(`__gm.sound.levels(${JSON.stringify(blip.file)})`))?.[0]?.[0];
  const early = await waitFor(pitch, (s) => typeof s === 'number' && s < 6.9);
  const later = await waitFor(pitch, (s) => typeof s === 'number' && s < early - 0.6);
  await new Promise((resolve) => setTimeout(resolve, 500));
  const afterHalf = await pitch();
  check(
    'Set sound FX parameters with a time ramps the pitch over that time instead of jumping',
    early > -1.8 && later > -3.3 && afterHalf > -4.3 && afterHalf < later,
    JSON.stringify({ early, later, afterHalf }),
  );
  await stop();
  // The easings of an animation key: Quad in hands the clock a curve, 7 - 3 * t^2 towards -5 in 2 s,
  // where linear is 7 - 6 * t. Each reading is timed on the audio clock from the voice's start, so a
  // first one that comes in late is held against where the curve is then. Between 0.3 and 1.7 s the
  // curve is more than a semitone above linear, and it never falls below it.
  await mutate(`
    const tune = __gm.state.project.assets.find((a) => a.id === 'sn-logic').graph.nodes.find((n) => n.id === 'sn-tune');
    Object.assign(tune.params, { ease: 'quad', direction: 'in' });`);
  await play();
  const pitchNow = () =>
    json(`({ pitch: __gm.sound.levels(${JSON.stringify(blip.file)})?.[0]?.[0], clock: __gm.sound.clock() })`);
  const sinceStart = async (seen, since = 'start') => {
    const now = await stats();
    const from = since === 'tune' ? now.tunedAt : now.last.at;
    return seen
      .filter((s) => typeof s.pitch === 'number')
      .map((s) => ({ t: +(s.clock - from).toFixed(3), pitch: +s.pitch.toFixed(3) }));
  };
  const sweep = await sinceStart(await trace(pitchNow, (s) => typeof s.pitch === 'number' && s.pitch < -4.3));
  const midway = sweep.filter(({ t }) => t > 0.3 && t < 1.7);
  check(
    'Set sound FX parameters with Quad in ramps slowly first, then on to the end',
    midway.length > 0 &&
      midway.every(({ t, pitch }) => pitch > 7 - 6 * t + 1) &&
      sweep.every(({ t, pitch }) => pitch > 7 - 6 * t - 0.1) &&
      sweep.at(-1).pitch < -4.3,
    JSON.stringify(sweep),
  );
  await stop();
  // Step holds the pitch for the whole time and then jumps there: every reading before 2 s on the
  // audio clock is still 7, the first one past it is the end. Timed from the change, not from the
  // start of the voice: task 529 saw it arrive 80 ms later and the 7 held, rightly, to 2.08 s.
  await mutate(`
    const tune = __gm.state.project.assets.find((a) => a.id === 'sn-logic').graph.nodes.find((n) => n.id === 'sn-tune');
    Object.assign(tune.params, { ease: 'step', time: 2 });`);
  await play();
  const steps = await sinceStart(
    await trace(pitchNow, (s) => typeof s.pitch === 'number' && s.pitch < 6),
    'tune',
  );
  const held = steps.filter(({ pitch }) => pitch === 7);
  const jumped = steps.find(({ pitch }) => pitch < 6);
  check(
    'Set sound FX parameters with Step holds the pitch for the time, then jumps to the end',
    held.length > 0 &&
      held.every(({ t }) => t < 2.05) &&
      jumped !== undefined &&
      jumped.t > 1.95 &&
      Math.abs(jumped.pitch + 5) < 0.001,
    JSON.stringify(steps),
  );
  await stop();
  // #317: the worklet itself, rendered in an offline context of this browser – what a muted check
  //       can hear. A second of 440 Hz an octave up is 880 Hz and still a second long; a sweep from
  //       0 to -12 over it keeps that second too. Then 16 stereo voices at +5 for 2 s, timed, for
  //       how many this machine plays at once.
  const offline = await evaluate(`
    (async () => {
      const RATE = 48000;
      const render = async (voices, seconds, channels, shape) => {
        const context = new OfflineAudioContext(channels, RATE * seconds, RATE);
        await context.audioWorklet.addModule(__gm.sound.pitchWorkletUrl());
        const tone = new Float32Array(RATE * seconds);
        for (let i = 0; i < tone.length; i++) tone[i] = Math.sin((2 * Math.PI * 440 * i) / RATE) * 0.5;
        for (let v = 0; v < voices; v++) {
          const node = new AudioWorkletNode(context, 'pitch-player', {
            numberOfInputs: 0,
            outputChannelCount: [channels],
            parameterData: { pitch: shape.from },
            processorOptions: { file: 'probe', channels: v === 0 ? Array(channels).fill(tone) : undefined, step: 1, loop: false },
          });
          if (shape.to !== shape.from)
            node.parameters.get('pitch').setValueAtTime(shape.from, 0).linearRampToValueAtTime(shape.to, seconds);
          node.connect(context.destination);
        }
        const started = performance.now();
        const out = (await context.startRendering()).getChannelData(0);
        return { out, ms: performance.now() - started };
      };
      const rises = (out, from, to) => {
        let count = 0;
        for (let i = from + 1; i < to; i++) if (out[i - 1] < 0 && out[i] >= 0) count++;
        return count / ((to - from) / RATE);
      };
      const heard = (out) => {
        let last = out.length;
        while (last > 0 && Math.abs(out[last - 1]) <= 1e-4) last--;
        return last;
      };
      const up = await render(1, 1, 1, { from: 12, to: 12 });
      const sweep = await render(1, 1, 1, { from: 0, to: -12 });
      const load = await render(16, 2, 2, { from: 5, to: 5 });
      return {
        upHz: rises(up.out, 12000, 36000),
        upLength: heard(up.out),
        sweepEarlyHz: rises(sweep.out, 6000, 12000),
        sweepLateHz: rises(sweep.out, 36000, 42000),
        sweepLength: heard(sweep.out),
        voices: 16,
        renderMs: Math.round(load.ms),
        realTimeVoices: Math.round((16 * 2000) / load.ms),
      };
    })()`);
  check(
    'the pitch worklet plays an octave up at the length of the sound, and a sweep down keeps it too',
    Math.abs(offline.upHz / 880 - 1) < 0.02 &&
      offline.upLength > 48000 - 100 &&
      offline.sweepEarlyHz > offline.sweepLateHz * 1.3 &&
      offline.sweepLength > 48000 - 100,
    JSON.stringify(offline),
  );
  // #327: the player's own echo, rendered offline. A 10 ms burst into a ping-pong Delay (0.3 s,
  //       feedback 0.5, mix 0.5) comes back left at 0.3 s at half its level, right at 0.6 s at
  //       half of that, left again at 0.9 s – in Chrome each round 128 samples later than that. Then
  //       64 stereo voices of it for 2 s, timed, for how many this machine plays at once (#324).
  const echo = await evaluate(`
    (async () => {
      const RATE = 48000;
      const echoOf = (pingPong) => ({ kind: 'delay', time: 0.3, feedback: 0.5, damping: 20000, mix: 0.5, pingPong });
      const render = async (voices, seconds, stage = echoOf(true)) => {
        const context = new OfflineAudioContext(2, RATE * seconds, RATE);
        const burst = context.createBuffer(1, RATE * 0.01, RATE);
        burst.getChannelData(0).fill(0.5);
        for (let v = 0; v < voices; v++) {
          const source = context.createBufferSource();
          source.buffer = burst;
          const nodes = __gm.sound.stageNodes(context, stage);
          source.connect(nodes.input);
          nodes.output.connect(context.destination);
          source.start();
        }
        const started = performance.now();
        const out = await context.startRendering();
        return { left: out.getChannelData(0), right: out.getChannelData(1), ms: performance.now() - started };
      };
      // The middle of the burst: its edges ring a little through the damping.
      const peak = (data, at) => {
        let sum = 0;
        const from = Math.round((at + 0.003) * RATE);
        const to = Math.round((at + 0.007) * RATE);
        for (let i = from; i < to; i++) sum += Math.abs(data[i]);
        return Math.round((sum / (to - from)) * 1000) / 1000;
      };
      // Samples from where each echo is due to where it is heard, in both kinds of echo.
      const late = ({ left, right }) => {
        const found = [];
        for (let k = 1; k <= 4; k++) {
          const from = Math.round((k * 0.3 - 0.05) * RATE);
          let at = from;
          while (at < from + RATE * 0.1 && Math.abs(left[at]) <= 0.002 && Math.abs(right[at]) <= 0.002) at++;
          found.push(at - Math.round(k * 0.3 * RATE));
        }
        return found;
      };
      const one = await render(1, 1.3);
      const plain = await render(1, 1.3, echoOf(false));
      const load = await render(64, 2);
      const lateBy = late(one);
      const at = (k) => k * 0.3 + lateBy[k - 1] / RATE;
      return {
        late: lateBy,
        latePlain: late(plain),
        dry: [peak(one.left, 0), peak(one.right, 0)],
        first: [peak(one.left, at(1)), peak(one.right, at(1))],
        second: [peak(one.left, at(2)), peak(one.right, at(2))],
        third: [peak(one.left, at(3)), peak(one.right, at(3))],
        between: [peak(one.left, 0.45), peak(one.right, 0.45)],
        voices: 64,
        renderMs: Math.round(load.ms),
        realTimeVoices: Math.round((64 * 2000) / load.ms),
      };
    })()`);
  const near = (value, to) => Math.abs(value - to) < 0.02;
  check(
    'the player’s ping-pong echo comes back left, then right, then left, each round half as loud',
    near(echo.dry[0], 0.5) &&
      near(echo.dry[1], 0.5) &&
      near(echo.first[0], 0.25) &&
      echo.first[1] < 0.005 &&
      echo.second[0] < 0.005 &&
      near(echo.second[1], 0.125) &&
      near(echo.third[0], 0.0625) &&
      echo.third[1] < 0.005 &&
      echo.between.every((v) => v < 0.005) &&
      // Chrome takes a render quantum more for every round of a feedback loop.
      [echo.late, echo.latePlain].every((late) => late.every((n, k) => n === 0 || n === k * 128)),
    JSON.stringify(echo),
  );
  // A Mix "Both at center", rendered offline: a steady 1 on a and 0.5 on b in two channels, so each
  // share reads off as it is. Then mix glides 0 → 1 over a second: at its middle both stay full.
  const atCenter = await evaluate(`
    (async () => {
      const RATE = 48000;
      const render = async (mix, glide) => {
        const context = new OfflineAudioContext(2, RATE, RATE);
        const merger = context.createChannelMerger(2);
        merger.connect(context.destination);
        const shareA = context.createGain();
        const shareB = context.createGain();
        shareA.gain.value = 0;
        shareB.gain.value = 0;
        const driver = __gm.sound.bothAtCenter(context, mix, shareA, shareB);
        for (const [share, level, side] of [[shareA, 1, 0], [shareB, 0.5, 1]]) {
          const steady = context.createConstantSource();
          steady.offset.value = level;
          steady.connect(share).connect(merger, 0, side);
          steady.start();
        }
        if (glide) driver.offset.setValueAtTime(0, 0).linearRampToValueAtTime(1, 1);
        driver.start();
        const out = await context.startRendering();
        const at = (s) => [out.getChannelData(0)[Math.round(s * RATE)], out.getChannelData(1)[Math.round(s * RATE)] * 2];
        return glide ? [0.25, 0.5, 0.75].map(at) : at(0.5);
      };
      const round = (pair) => pair.map((v) => Math.round(v * 1000) / 1000);
      const fixed = {};
      for (const mix of [0, 0.25, 0.5, 0.75, 1]) fixed[mix] = round(await render(mix, false));
      return { fixed, glide: (await render(0, true)).map(round) };
    })()`);
  const pairNear = (pair, a, b) => near(pair[0], a) && near(pair[1], b);
  check(
    'a Mix "Both at center" keeps a full up to the middle and b full from it, also while mix glides',
    pairNear(atCenter.fixed[0], 1, 0) &&
      pairNear(atCenter.fixed[0.25], 1, 0.5) &&
      pairNear(atCenter.fixed[0.5], 1, 1) &&
      pairNear(atCenter.fixed[0.75], 0.5, 1) &&
      pairNear(atCenter.fixed[1], 0, 1) &&
      pairNear(atCenter.glide[0], 1, 0.5) &&
      pairNear(atCenter.glide[1], 1, 1) &&
      pairNear(atCenter.glide[2], 0.5, 1),
    JSON.stringify(atCenter),
  );
  await mutate(`
    const logic = __gm.state.project.assets.find((a) => a.id === 'sn-logic');
    logic.variables = [];
    const graph = logic.graph;
    graph.nodes = graph.nodes.filter((n) => !${JSON.stringify(tuneIds)}.includes(n.id));
    graph.edges = graph.edges.filter((e) => !${JSON.stringify(tuneEdges)}.includes(e.id));`);
  await mutate(`
    const graph = __gm.state.project.assets.find((a) => a.id === 'sn-logic').graph;
    graph.nodes = graph.nodes.filter((n) => n.id !== 'sn-fxp');
    graph.edges = graph.edges.filter((e) => e.id !== 'sn-e-fxp');
    Object.assign(graph.nodes.find((n) => n.id === 'sn-play').params, { loop: '', fx: '' });
    const project = __gm.state.project;
    project.assets = project.assets.filter((a) => a.id !== ${JSON.stringify(fxId)});`);

  // 34g-5. An instrument (#331): "+ → Instrument" opens its tab on Notes → Sample → Output, which
  //        plays nothing until the Sample has a sound. With the blip, looped, every key of C4–B4
  //        sounds; a key held by the pointer plays until it is let go, the computer keyboard plays
  //        as a tracker does, and a game's `Play note` releases its note after its duration.
  await showTab('scene');
  await clickText('+');
  await pickAssetType(t, 'Instrument');
  const insCreated = await json(`{
    tab: __gm.tab(),
    current: __gm.instrument.current(),
    info: __gm.instrument.info(),
    keys: __gm.instrument.keys(),
    assets: __gm.state.project.assets.filter((a) => a.type === 'instrument')
      .map((a) => ({ id: a.id, nodes: a.graph.nodes.map((n) => n.type) })),
  }`);
  check(
    'the + menu creates an instrument, Notes → Sample → Output, and opens its tab; no key sounds yet',
    insCreated.tab === 'instrument' &&
      insCreated.assets.length === 1 &&
      insCreated.current === insCreated.assets[0].id &&
      insCreated.assets[0].nodes.join() === 'InstrumentNotes,InstrumentSample,InstrumentOutput' &&
      insCreated.info === 'No sound picked' &&
      insCreated.keys.sounding.length === 0,
    JSON.stringify(insCreated),
  );
  const insId = insCreated.assets[0]?.id;
  // Bottom left: the fitted graph is one row of three nodes, its links among them.
  const insCanvas = await json('__gm.instrument.canvasRect()');
  await click(insCanvas.x + 30, insCanvas.y + insCanvas.h - 30, 'right');
  const insPalette = await json('__gm.overlayTexts()');
  check(
    'its palette offers its own nodes and the effects, but no Input and no behavior node',
    ['Notes', 'Sample', 'Parameters', 'Sound FX', 'Envelope', 'Gain', 'Filter', 'Delay'].every((label) =>
      insPalette.includes(label),
    ) &&
      !insPalette.includes('Input') &&
      !insPalette.includes('Branch'),
    JSON.stringify(insPalette.slice(0, 14)),
  );
  await press('Escape');
  await mutate(`
    const ins = __gm.state.project.assets.find((a) => a.id === ${JSON.stringify(insId)});
    Object.assign(ins.graph.nodes.find((n) => n.type === 'InstrumentSample').params, {
      sound: ${JSON.stringify(soundId)},
      play: 'loop',
    });`);
  const insReady = await json('{ info: __gm.instrument.info(), keys: __gm.instrument.keys() }');
  check(
    'with a sound picked the twelve keys from C4 to B4 sound, the others stay grey',
    insReady.info === '12 notes' &&
      insReady.keys.sounding.join() === [60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71].join(),
    JSON.stringify(insReady),
  );
  await shot('34-instrument');

  await evaluate('__gm.sound.stopAll()');
  const beforeKey = await stats();
  const e4 = await json('__gm.instrument.keyAt(64)');
  await t.mouse('mouseMoved', e4.x, e4.y);
  await t.mouse('mousePressed', e4.x, e4.y);
  const heldKey = await waitFor(stats, (s) => s.started > beforeKey.started);
  // Longer than the blip: a looped note that ended with its sound would be gone by now.
  await sleep(600);
  const stillHeld = await json('{ stats: __gm.sound.stats(), keys: __gm.instrument.keys() }');
  check(
    'holding E4 plays the blip four semitones up, looped, as one layer of the instrument, and lights the key',
    heldKey.last?.file === `instrument:${insId}` &&
      heldKey.last.pitches.join() === '4' &&
      heldKey.last.layers === 1 &&
      stillHeld.stats.playing === 1 &&
      stillHeld.keys.held.join() === '64',
    JSON.stringify({ heldKey, stillHeld }),
  );
  await t.mouse('mouseReleased', e4.x, e4.y);
  const letGo = await waitFor(stats, (s) => s.playing === 0);
  check(
    'letting go of the key ends the note: its sample fades out and the voice goes',
    letGo.playing === 0 && (await json('__gm.instrument.keys()')).held.length === 0,
    JSON.stringify(letGo),
  );

  // "Loop, then release": held, it loops 0.05 to 0.1 s; let go, it plays the 0.15 s after the loop.
  const setPlay = (fields) =>
    mutate(`
      const ins = __gm.state.project.assets.find((a) => a.id === ${JSON.stringify(insId)});
      Object.assign(ins.graph.nodes.find((n) => n.type === 'InstrumentSample').params, ${JSON.stringify(fields)});`);
  await setPlay({ play: 'release', loopStart: 0.05, loopEnd: 0.1 });
  const beforeRelease = await stats();
  await t.mouse('mousePressed', e4.x, e4.y);
  await waitFor(stats, (s) => s.started > beforeRelease.started);
  await sleep(600);
  const heldLoop = await stats();
  await t.mouse('mouseReleased', e4.x, e4.y);
  const leftAt = await audioNow();
  const ringingKeys = await json('__gm.instrument.keys()');
  const playedOut = await waitFor(audioNow, (s) => s.playing === 0);
  const afterKeys = await waitFor(
    () => json('__gm.instrument.keys()'),
    (keys) => keys.ringing.length === 0,
  );
  // 0.15 s after the loop, up to two rounds more (the one it is in, the one the worklet read into)
  // and the 150 ms waitFor polls at: a fade would be gone in 0.01 s.
  const outFor = playedOut.clock - leftAt.clock;
  check(
    '"Loop, then release" loops while held, and let go plays on past the loop with its key half lit',
    heldLoop.playing === 1 &&
      ringingKeys.held.length === 0 &&
      ringingKeys.ringing.join() === '64' &&
      outFor > 0.12 &&
      outFor < 0.5 &&
      afterKeys.ringing.length === 0,
    JSON.stringify({ heldLoop: heldLoop.playing, ringingKeys, outFor, afterKeys }),
  );
  await setPlay({ play: 'loop', loopStart: 0, loopEnd: 0 });

  // The click left the keys focused. Z is C3 there – no sound in this instrument –, one octave up C4.
  const beforeZ = await stats();
  await press('z');
  await sleep(200);
  const lowZ = await stats();
  await press('ArrowRight');
  await t.keyDown('z');
  const typed = await waitFor(stats, (s) => s.started > lowZ.started);
  const typedKeys = await json('__gm.instrument.keys()');
  await t.keyUp('z');
  const typedOff = await waitFor(stats, (s) => s.playing === 0);
  check(
    'the computer keyboard plays as a tracker: Z is C3 and silent here, one octave up it is C4 until let go',
    lowZ.started === beforeZ.started &&
      typedKeys.octave === 4 &&
      typedKeys.held.join() === '60' &&
      typed.last?.pitches.join() === '0' &&
      typedOff.playing === 0,
    JSON.stringify({ beforeZ: beforeZ.started, lowZ: lowZ.started, typed, typedKeys, typedOff }),
  );
  await press('ArrowLeft');

  await mutate(`
    const graph = __gm.state.project.assets.find((a) => a.id === 'sn-logic').graph;
    graph.nodes.push(${JSON.stringify(
      node('sn-note', 'PlayNote', 260, 220, { instrument: insId, note: 67, duration: 1.5 }),
    )});
    graph.edges.find((e) => e.id === 'sn-e1').to = { node: 'sn-note', port: 'exec' };`);
  await showTab('scene');
  await evaluate('__gm.sound.stopAll()');
  const beforeNote = await stats();
  await play();
  // The sample loops, so only the release after 1.5 s on the audio clock ends the note: it is heard
  // well past the 0.25 s of the blip, never past its duration, and is gone soon after.
  const noteNow = () => json('({ stats: __gm.sound.stats(), clock: __gm.sound.clock() })');
  const noted = await waitFor(noteNow, (s) => s.stats.started > beforeNote.started);
  const heard = await trace(noteNow, (s) => s.stats.playing === 0);
  const noteAt = noted.stats.last?.at ?? 0;
  const heardAt = heard.filter((s) => s.stats.playing === 1).map((s) => +(s.clock - noteAt).toFixed(3));
  const goneAt = +(heard.at(-1).clock - noteAt).toFixed(3);
  check(
    'a game’s Play note plays G4 – the blip seven semitones up – and lets it go after its duration',
    noted.stats.last?.file === `instrument:${insId}` &&
      noted.stats.last.pitches.join() === '7' &&
      heardAt.some((t) => t > 0.5) &&
      heardAt.every((t) => t < 1.6) &&
      heard.at(-1).stats.playing === 0 &&
      goneAt < 3,
    JSON.stringify({ last: noted.stats.last, heardAt, goneAt }),
  );
  await stop();

  // #332: the scheduler, driven by the hook – nothing in the editor plays a sequence yet. A bar of
  //       quarters at 150 BPM in a loop: every note is planned before its second comes, each 0.4 s
  //       after the one before, also across the seam into the next round. Where the music stands
  //       is the audio clock less the output latency, counted from the first note.
  const bar = [60, 62, 64, 65].map((pitch, i) => ({
    tick: i * 480,
    length: 240,
    note: pitch,
    velocity: 1,
    instrument: insId,
  }));
  await evaluate(
    `__gm.music.play(${JSON.stringify({ notes: bar })}, { tempo: 150, loop: { start: 0, end: 1920 } })`,
  );
  const planned = await waitFor(
    () => json('__gm.music.planned()'),
    (p) => p.length >= 9,
    40,
  );
  const where = await json(
    '({ position: __gm.music.position(), clock: __gm.sound.clock(), latency: __gm.music.latency() })',
  );
  await evaluate('__gm.music.stop()');
  const musicOff = await waitFor(stats, (s) => s.playing === 0);
  const apart = planned.slice(1, 9).map((p, i) => +(p.at - planned[i].at).toFixed(6));
  const ahead = planned.map((p) => +(p.at - p.planned).toFixed(3));
  const heardTicks = (((where.clock - where.latency - planned[0].at) * 150 * 480) / 60) % 1920;
  check(
    'the scheduler plans a looped bar on the audio clock: every note ahead of its second, 0.4 s apart across the seam',
    planned.length >= 9 &&
      planned
        .slice(0, 9)
        .map((p) => p.note)
        .join() === '60,62,64,65,60,62,64,65,60' &&
      planned.every((p) => p.voice > 0 && Math.abs(p.duration - 0.2) < 1e-9 && p.tempo === 150) &&
      apart.every((gap) => Math.abs(gap - 0.4) < 1e-6) &&
      ahead.every((s) => s > 0 && s <= 0.16) &&
      Math.abs(where.position.ticks - heardTicks) < 1 &&
      where.position.bar === 1 &&
      musicOff.playing === 0 &&
      (await json('__gm.music.playing()')) === false,
    JSON.stringify({ apart, ahead, where, heardTicks, playing: musicOff.playing }),
  );

  // A note planned ahead through the pitch worklet starts on its sample, also inside a render block:
  // rendered offline at pitch 0, which plays the sound as it is, so the first sample heard is it.
  const onsets = await evaluate(`
    (async () => {
      const RATE = 48000;
      const onset = async (startAt) => {
        const context = new OfflineAudioContext(1, RATE / 2, RATE);
        await context.audioWorklet.addModule(__gm.sound.pitchWorkletUrl());
        const node = new AudioWorkletNode(context, 'pitch-player', {
          numberOfInputs: 0,
          outputChannelCount: [1],
          parameterData: { pitch: 0 },
          processorOptions: { file: 'onset', channels: [new Float32Array(RATE).fill(0.5)], step: 1, loop: false, startAt },
        });
        node.connect(context.destination);
        const out = (await context.startRendering()).getChannelData(0);
        return out.findIndex((v) => Math.abs(v) > 1e-6);
      };
      const at = [0.0123, 0.25, 0.05 + 0.4 * 2 / 3];
      return { expected: at.map((s) => Math.round(s * RATE)), heard: await Promise.all(at.map(onset)) };
    })()`);
  check(
    'a pitched note planned ahead starts on its very sample, inside a render block too',
    onsets.heard.join() === onsets.expected.join() && onsets.expected.some((i) => i % 128 !== 0),
    JSON.stringify(onsets),
  );

  // #335: an Envelope's curve as Chrome renders it – up in the attack, easing towards the sustain,
  //       and from wherever it is when the note ends down to silence in the release, mid-attack too –
  //       and a Gain it moves through a WaveShaper, from a quarter to full in equal ratios.
  const curves = await evaluate(`
    (async () => {
      const RATE = 48000;
      const envelope = { id: 'e', attack: 0.1, decay: 0.2, sustain: 0.5, release: 0.3 };
      const render = async (releaseAt, moved) => {
        const context = new OfflineAudioContext(1, RATE, RATE);
        const driver = __gm.sound.envelopeDriver(context, envelope, 0);
        if (releaseAt !== null) __gm.sound.releaseEnvelope(driver.offset, envelope, 0, releaseAt);
        if (moved) {
          const steady = context.createConstantSource();
          const stage = { kind: 'gain', gain: 1, mod: { envelope, from: 0.25, to: 1 } };
          const made = __gm.sound.stageWith(context, stage, driver);
          steady.connect(made.input);
          made.output.connect(context.destination);
          steady.start();
        } else driver.connect(context.destination);
        driver.start();
        const out = (await context.startRendering()).getChannelData(0);
        return (s) => Math.round(out[Math.round(s * RATE)] * 10000) / 10000;
      };
      const held = await render(0.5, false);
      const early = await render(0.05, false);
      const gain = await render(null, true);
      return {
        held: [0.05, 0.1, 0.3, 0.5, 0.65, 0.8].map(held),
        early: [0.05, 0.15, 0.35].map(early),
        gain: [0.05, 0.1, 0.9].map(gain),
      };
    })()`);
  const closeTo = (values, expected) => values.every((v, i) => Math.abs(v - expected[i]) < 0.002);
  check(
    'an Envelope rises, eases to its sustain and releases from where it is, and moves a Gain with that curve',
    closeTo(curves.held, [0.5, 1, 0.5005, 0.5, 0.0158, 0.0005]) &&
      closeTo(curves.early, [0.5, 0.05, 0.0005]) &&
      closeTo(curves.gain, [0.5, 1, 0.5]),
    JSON.stringify(curves),
  );

  // A note of 0.2 s through an Envelope with a release of 1 s: the looped blip plays on through the
  //  release, and the voice goes with it – without one it would end 10 ms after the note.
  await mutate(`
    const graph = __gm.state.project.assets.find((a) => a.id === ${JSON.stringify(insId)}).graph;
    const into = graph.edges.find((e) => e.to.node === graph.nodes.find((n) => n.type === 'InstrumentOutput').id);
    graph.nodes.push(${JSON.stringify(node('ins-env', 'InstrumentEnvelope', 300, 120, { release: 1 }))});
    graph.edges.push({ id: 'ins-e-env', from: { node: 'ins-env', port: 'out' }, to: { ...into.to } });
    into.to = { node: 'ins-env', port: 'in' };`);
  await evaluate('__gm.sound.stopAll()');
  const beforeShaped = await stats();
  await evaluate(
    `__gm.music.play(${JSON.stringify({ notes: [{ tick: 0, length: 240, note: 60, velocity: 1, instrument: insId }] })}, { tempo: 150 })`,
  );
  const shaped = await waitFor(noteNow, (s) => s.stats.started > beforeShaped.started);
  const ringOut = await trace(noteNow, (s) => s.stats.playing === 0);
  await evaluate('__gm.music.stop()');
  const shapedAt = shaped.stats.last?.at ?? 0;
  const shapedGone = +(ringOut.at(-1).clock - shapedAt).toFixed(3);
  // 0.2 s of note and 1 s of release; up to the 150 ms waitFor polls at on top.
  check(
    'a note through an Envelope plays on through its release and goes with it',
    shaped.stats.last?.envelopes === 1 &&
      ringOut.some((s) => s.stats.playing === 1 && s.clock - shapedAt > 0.8) &&
      ringOut.at(-1).stats.playing === 0 &&
      shapedGone > 1.15 &&
      shapedGone < 1.6,
    JSON.stringify({ last: shaped.stats.last, shapedGone }),
  );

  await mutate(`
    const graph = __gm.state.project.assets.find((a) => a.id === 'sn-logic').graph;
    graph.nodes = graph.nodes.filter((n) => n.id !== 'sn-note');
    graph.edges.find((e) => e.id === 'sn-e1').to = { node: 'sn-play', port: 'exec' };
    const project = __gm.state.project;
    project.assets = project.assets.filter((a) => a.id !== ${JSON.stringify(insId)});`);

  // 34h. Dropping a sound file onto the editor uploads it and makes an asset named after the file.
  const dropped = await evaluate(`
    (async () => {
      const bytes = await fetch('/game-maker/data/sounds/${drone.file}').then((r) => r.arrayBuffer());
      const file = new File([bytes], 'drone.wav', { type: 'audio/wav' });
      const data = new DataTransfer();
      data.items.add(file);
      const canvas = document.querySelector('canvas');
      canvas.dispatchEvent(new DragEvent('drop', { dataTransfer: data, bubbles: true, cancelable: true }));
      return file.size;
    })()`);
  await waitFor(
    () => assetsOfType('sound'),
    (list) => list.length === 2,
  );
  const both = await assetsOfType('sound');
  check(
    'a dropped sound is uploaded and becomes an asset named after the file',
    dropped === DRONE_BYTES &&
      both.length === 2 &&
      both.some((a) => a.file === drone.file && a.name === 'drone'),
    JSON.stringify({ dropped, both, notice: await json('__gm.state.notice') }),
  );

  // 34i. The step takes back everything it made, so the steps after it see the fixture again.
  await mutate(`
    const gone = new Set(['sn-logic', ...${JSON.stringify(both.map((a) => a.id))}]);
    const project = __gm.state.project;
    project.assets = project.assets.filter((a) => !gone.has(a.id));
    __gm.state.activeScene.objects = __gm.state.activeScene.objects.filter(
      (o) => !['sn-box', 'sn-brain'].includes(o.id));
    __gm.state.select(null);
    __gm.lookAt(0, 0);`);
  check(
    'the step leaves nothing of its own behind',
    (await assetsOfType('sound')).length === 0 && (await stats()).playing === 0,
    JSON.stringify(await assetsOfType('sound')),
  );
}