Function assertMissing

fs/unstable_write_file_test.ts:24–28

(path: string | URL)

const isBun = navigator.userAgent.includes("Bun/");

function assertMissing(path: string | URL) {
  if (pathExists(path)) {
    throw new Error("File: ${path} exists");
  }
}

function pathExists(path: string | URL): boolean {
  try {