Make PUT and POST requests with fetch

serialize.ts

type ContentType = 'application/x-www-form-urlencoded' | 'application/json';

/**
 * POJO payloads used to make PUT and POST requests made with `fetch`
 * need to be converted to a format `fetch` accepts first.
 */
export const serialize = (payload: object, type: ContentType): string => {
  switch (type) {
    case 'application/x-www-form-urlencoded':
      return Object.entries(payload)
        .map(([key, value]) => `${encodeURIComponent(key)}=${encodeURIComponent(value)}`)
        .join('&');
    case 'application/json':
      return JSON.stringify(payload);
  }
};