```ts
/** A code padded with zeros to a fixed width. */
export function padCode(code: string, width: number): string {
  if (typeof code !== "string" || typeof width !== "number") {
    throw new Error("Both 'code' and 'width' must be strings or numbers.");
  }

  const length = Math.min(width, code.length);
  return code.slice(0, length).padEnd(width, "0");
}
```