[p5.js 2.0+ Bug Report]: strands not handling comma operator (common in minified js)

Most appropriate sub-area of p5.js?

• Accessibility
• Color
• Core/Environment/Rendering
• Data
• DOM
• Events
• Image
• IO
• Math
• Typography
• Utilities
• WebGL
• WebGPU
• p5.strands
• Build process
• Unit testing
• Internationalization
• Friendly errors
• Other (specify if possible)

p5.js version

2.3.2

Web browser and version

All

Operating system

All

Steps to reproduce this

A common thing you'll see in some JavaScript minifiers is to collapse multiple statements (things separated by semicolons generally) into one expression (something that evaluates to a single value) via the comma operator. E.g. something like this:

let a
if (something) {
  someThingIsTrue();
  a = 1;
} else {
  somethingElse();
  a = 2;
}

...might get compressed into this:

let a = something ? (somethingIsTrue(), 1) : (somethingElse(), 2);

Anyway it seems p5.strands does not handle comma operators well. In the example below, simulating something a minifier produced while using strands at work, transpiles to invalid javascript:

let gradientShader

function setup() {
  createCanvas(400, 400, WEBGL)
  gradientShader = buildMaterialShader(() => {
    let pos = sharedVec4()

    worldInputs.begin(), pos = [worldInputs.position/200, 1], worldInputs.end()
    
    pixelInputs.begin(), pixelInputs.color = pos, pixelInputs.end()
  })
}

function draw() {
  clear()
  shader(gradientShader)
  noStroke()
  plane(width, height)
}

Live: https://editor.p5js.org/davepagurek/sketches/zNjhdJCGO

This transpiles to:

let pos = sharedVec4('pos');
    worldInputs.begin(), pos.bridge(__p5.strandsNode([
        __p5.strandsNode(worldInputs.position).div(200),
        1
    ]));, worldInputs.end();
    pixelInputs.begin(), pixelInputs.color = pos.getValue(), pixelInputs.end();

Note that there's a ;, in there. I think a few spots in our transpiler code have the assumption that each line is its own statement and is emitting semicolons where it shouldn't. We should do a little audit for those and create some test cases and fixes.