example.js

var code = new Processing.Sketch(function(processing) { 
  function setup() { 
    processing.size(300, 300); 
    processing.noStroke(); 
    processing.frameRate(60); 
  } 
  processing.setup = setup; 
  function draw() { 
    processing.background(220,220,220); 
    processing.stroke(0); 
    processing.strokeWeight(2); 
    processing.fill(60, 90, 100); 
    processing.rect(30,30,55,55); 
    processing.noStroke(); 
    processing.rect(90,30,55,55); 
    processing.line(120, 120, 200, 180); 
    processing.stroke(0); 
    processing.strokeWeight(1); 
    processing.line(150, 30, 200, 30); 
  } 
  processing.draw = draw;
});
code.options.cripsLines = true;

this.processingControl = Processing(document.getElementById('nostroke'), code);

example.pjs

/* @pjs crisp=true; */
void setup() {
  size(300, 300);
  noStroke();
  frameRate(60);
}

void draw() {
  background(220,220,220);
  stroke(0);
  strokeWeight(2);
  fill(60, 90, 100);
  rect(30,30,55,55);
  noStroke(); // p.strokeWeight(0) would work;
  
  // expecting p.rect with no border and no visible line
  rect(90,30,55,55);
  line(120, 120, 200, 180);
  
  stroke(0); // reactivate stroke
  strokeWeight(1);
  // expecting the horizontal line to be drawn next to the rectangle at using a whole pixel
  line(150, 30, 200, 30); // p.line(150, 30.5, 200, 30.5); would work
};