Function assert

packages/react-ui/check-css-artifacts.js:16–18

(cond, msg)

const read = (rel) => fs.readFileSync(path.join(dist, rel), "utf8");
const assert = (cond, msg) => {
  if (!cond) failures.push(msg);
};

assert(
  !/^\s*@layer/.test(read("components/index.css")),