import assert from 'node:assert/strict';
const inputs = [[1,2], [250,10], [100,0], [255,255]];
let s1 = null, s2 = null;
const seen = [];
for (let edge = 0; edge < 6; edge++) {
  if (s2 !== null) seen.push({ edge, ...s2 });
  const next2 = s1 === null ? null : {
    tag: s1.tag, y: (s1.sum * 3) % 256
  };
  const next1 = edge < inputs.length ? {
    tag: edge, sum: inputs[edge][0] + inputs[edge][1]
  } : null;
  s1 = next1;
  s2 = next2;
}
assert.deepEqual(seen, [
  { edge: 2, tag: 0, y: 9 },
  { edge: 3, tag: 1, y: 12 },
  { edge: 4, tag: 2, y: 44 },
  { edge: 5, tag: 3, y: 250 }
]);
assert.equal(s1, null);
assert.equal(s2, null);
console.log('PIPELINE PASS: 4 ordered results, latency=2');