fail.js

/** @type {(...args: any[]) => never} */
const fail = (...args) => {
  console.error(...args)
  throw new Error(args.join(''))
}

warn.ts

export const warn = (...args: unknown[]): void => {
  console.warn(...args)
  if (window.location.origin.startsWith('localhost:')) {
    throw new Error('refusing to render locally with warnings')
  }
}