buggy behaviour in part.onStep()

the pattern below has 8 beats, play() is called 8 times but part.onStep is called 7 times. When the part is looping, part.onStep is still only called 7 times.

let sound, m = 0, n = 0;

function setup () {
  masterVolume(0.4);

  const pat = [1,1,1,1,1,1,1,1];
  const phrase = new p5.Phrase('phrase', play, pat);

  const part = new p5.Part();
  part.onStep(() => {
    console.log(`step ${++n}`);
  });
  part.addPhrase(phrase);
  part.setBPM(60);
  part.start();
  // part.loop();
  
  sound = new p5.MonoSynth();

  userStartAudio().then(() => {
     console.log("user start audio");
   });
}

function draw () {
  background(0);
}

function play (time, notused) {
  console.log(`play ${++m}`);
  sound.play('D4');
}

[crcdng]

I just checked with p5.js 1.0.0 and the problem still persists.

The expected behavior in the example above would be: part.onStep should be called 8 times.

Using part.loop() instead of part.start(), part.onStep should be called 8 times for each loop as long as it is looping.

[crcdng]

Hi, the above code was my program demonstrating the problem.