A(uthorized) Fetch used for fast prototyping. We need only `{ error: boolean; message: string }` if there's an error on the API.

afetch.ts

// a(uthorized)fetch

function getAccessToken() {
  return localStorage.getItem("@project/accessToken");
}

function setAccessToken(token: string) {
  localStorage.setItem("@project/accessToken", token);
}

function clearAccessToken() {
  localStorage.removeItem("@project/accessToken");
}

export const AccessToken = {
  get: getAccessToken,
  set: setAccessToken,
  clear: clearAccessToken,
};

async function __fetch<T>(
  method: "GET" | "POST" | "PATCH" | "DELETE" | "PUT",
  input: RequestInfo,
  body?: any,
  init?: RequestInit
) {
  let accessToken = AccessToken.get();

  let response = await fetch(input, {
    method,
    headers: {
      "Content-Type": "application/json",
      // If I have an accessToken, use it
      ...(accessToken && { Authorization: `Bearer ${accessToken}` }),
    },

    // If my method has data, and it's not a get, use it
    ...(method !== "GET" && body && { body: JSON.stringify(body) }),

    // More options
    ...init,
  });

  let responseJSON = await response.json();

  if (response.status !== 200) {
    return {
      error: true,
      ...responseJSON,
    } as T & { error: true };
  } else {
    return responseJSON as T & { error: false };
  }
}

const afetch = {
  post: <T>(input: RequestInfo, body?: any, init?: RequestInit) =>
    __fetch<T>("POST", input, body, init),
  get: <T>(input: RequestInfo, body?: any, init?: RequestInit) =>
    __fetch<T>("GET", input, body, init),
  patch: <T>(input: RequestInfo, body?: any, init?: RequestInit) =>
    __fetch<T>("PATCH", input, body, init),
  put: <T>(input: RequestInfo, body?: any, init?: RequestInit) =>
    __fetch<T>("PUT", input, body, init),
  delete: <T>(input: RequestInfo, body?: any, init?: RequestInit) =>
    __fetch<T>("DELETE", input, body, init),
};

export default afetch;

Usage:

async function createForward(forward: Omit<Forward, "forwardId">) {
  let createForwardResponse = await afetch.post<{
    accessToken: string;
    message?: string;
  }>(`${BASE_URL}/url/forward`, {
    ...forward,
  });

  if (createForwardResponse.error) {
    alert(createForwardResponse.message);
    return;
  } else {
    return { ok: true };
  }
}