ken107

function getStream(stream: Readable): Promise<Buffer> {
  return new Promise((fulfill, reject) => {
    const chunks: Buffer[] = []
    let totalLength = 0
    stream.on("data", chunk => {
      chunks.push(chunk)
      totalLength += chunk.length
    })
    stream.once("end", () => fulfill(Buffer.concat(chunks, totalLength)))
    stream.once("error", reject)

ken107

export function createWavHeader(dataLength: number, sampleRate: number, bitDepth: number, channels: number) {
  const headerLength = 44; // Standard size of WAV header
  const totalLength = headerLength + dataLength;

  const buffer = new ArrayBuffer(headerLength);
  const view = new DataView(buffer);

  // RIFF chunk descriptor
  writeString(view, 0, 'RIFF'); // ChunkID
  view.setUint32(4, totalLength - 8, true); // ChunkSize (file size - 8 bytes)

ken107

function makeAudioPlayer(audio) {
  audio.oncanplay = () => sm.trigger("onCanPlay")
  audio.onerror = () => sm.trigger("onError", new Error(audio.error.message || audio.error.code))
  audio.onended = () => sm.trigger("onEnd")

  const sm = new StateMachine({
    IDLE: {
      load(url) {
        audio.src = url
        return "LOADING_PAUSED"

ken107

export function makeValidGetter<T extends {isValid(): boolean}>(generator: () => Promise<T>): () => Promise<T> {
  let value: T|undefined
  let promise: Promise<T>|undefined
  return async function() {
    if (value?.isValid()) return value
    if (promise) return await promise
    promise = generator()
      .then(result => {
        value = result
        promise = undefined

ken107

function simulate(element, eventName, options) {
    var opt = {
        pointerX: 0,
        pointerY: 0,
        button: 0,
        ctrlKey: false,
        altKey: false,
        shiftKey: false,
        metaKey: false,
        bubbles: true,

ken107

/**
 * Repeat an action
 * @param {Object} opt - options
 * @param {Function} opt.action - action to repeat
 * @param {Function} opt.until - termination condition
 * @param {Number} opt.delay - delay between actions
 * @param {Number} opt.max - maximum number of repetitions
 * @returns {Promise}
 */
function repeat(opt) {

ken107

function detectUserIdle(periodOfInactivity) {
  return rxjs.merge(
    rxjs.timer(periodOfInactivity),
    rxjs.merge(
      rxjs.fromEvent(document, "mousemove"),
      rxjs.fromEvent(document, "keydown"),
      rxjs.fromEvent(document, "touchstart")
    )
  ).pipe(
    rxjs.switchMap(event => !event ? rxjs.of(true) : rxjs.concat(rxjs.of(false), rxjs.throwError(() => "reset"))),