[mikewhy]

That's a whole lot of code / diatribe for what is:

    const _fetch = window.fetch

    /** Fetch overload that handles error status */
    export function fetch(input: RequestInfo, init?: RequestInit) {
      return _fetch(input, init).then(checkResponseCode)
    }

    function checkResponseCode(response: Response) {
      if (response.status >= 400) {
        const err = new Error(`Error ${response.status} from ${response.url}`) as any
        err.fetchHttpResponse = response
        throw err
      }

      return response
    }

    /** Convenience method */
    export function getJson<TJsonBody = any>(
      input: RequestInfo,
      init?: RequestInitJson,
    ) {
      return fetch(input, init).then((response) => response.json()) as Promise<TJsonBody>
    }