Function expandEnvString

src/utils/env-expand.ts:20–27

(s: string, env: NodeJS.ProcessEnv = process.env)

 * to prevent the bug from silently regressing during refactors.
 */
export function expandEnvString(s: string, env: NodeJS.ProcessEnv = process.env): string {
  if (typeof s !== 'string') return s;
  return s
    .replace(/\$\$/g, '\u0000DOLLAR\u0000')                              // escape $$ temporarily
    .replace(/\$\{([A-Za-z_][A-Za-z0-9_]*)\}/g, (_, name) => env[name] ?? '')
    .replace(/\$([A-Za-z_][A-Za-z0-9_]*)/g, (_, name) => env[name] ?? '')
    .replace(/\u0000DOLLAR\u0000/g, '$');
}

/** Apply expandEnvString to every value in a string-keyed map. */
export function expandEnvObject(