export interface Util { formDataToJson: (formData: FormData) => T; } export const util: Util = { formDataToJson, }; function formDataToJson(formData: FormData) { const json: Record = {}; for (const pair of formData.entries()) { const k = pair[0] as string; if (k in json) { if (!Array.isArray(json[k])) { json[k] = [json[k]]; } (json[k] as unknown[]).push(pair[1]); } else { json[k] = pair[1]; } } return json as T; }