Get exchange rates

type Stripe = {

  token: string;

};

/**

 * Get exchange rates

 * Returns a list of objects that contain the rates at which foreign currencies are converted to one another. Only shows the currencies for which Stripe supports.

 */

export async function main(

  auth: Stripe,

  ending_before: string | undefined,

  expand: any,

  limit: string | undefined,

  starting_after: string | undefined

) {

  const url = new URL(`https://api.stripe.com/v1/exchange_rates`);

  for (const [k, v] of [

    ["ending_before", ending_before],

    ["limit", limit],

    ["starting_after", starting_after],

  ]) {

    if (v !== undefined && v !== "") {

      url.searchParams.append(k, v);

    }

  }

  encodeParams({ expand }).forEach((v, k) => {

    if (v !== undefined && v !== "") {

      url.searchParams.append(k, v);

    }

  });

  const response = await fetch(url, {

    method: "GET",

    headers: {

      "Content-Type": "application/x-www-form-urlencoded",

      Authorization: "Bearer " + auth.token,

    },

    body: undefined,

  });

  if (!response.ok) {

    const text = await response.text();

    throw new Error(`${response.status} ${text}`);

  }

  return await response.json();

}

function encodeParams(o: any) {

  function iter(o: any, path: string) {

    if (Array.isArray(o)) {

      o.forEach(function (a) {

        iter(a, path + "[]");

      });

      return;

    }

    if (o !== null && typeof o === "object") {

      Object.keys(o).forEach(function (k) {

        iter(o[k], path + "[" + k + "]");

      });

      return;

    }

    data.push(path + "=" + o);

  }

  const data: string[] = [];

  Object.keys(o).forEach(function (k) {

    if (o[k] !== undefined) {

      iter(o[k], k);

    }

  });

  return new URLSearchParams(data.join("&"));

}