utils.ts

const NANOID_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_";
const NANOID_LENGTH = 21;

function getRandomInt() {
  return Math.floor(Math.random() * NANOID_CHARS.length);
}

export function nanoid() {
  return Array.from({ length: NANOID_LENGTH })
    .map(() => NANOID_CHARS[getRandomInt()])
    .join("");
}

export function getWorkflowRunId(id?: string): string {
  return `wfr_${id ?? nanoid()}`;
}

/**
 * When the base64 string has unicode characters, atob doesn't decode
 * them correctly since it only outputs ASCII characters. Therefore,
 * instead of using atob, we properly decode them.
 *
 * If the decoding into unicode somehow fails, returns the result of atob
 *
 * https://developer.mozilla.org/en-US/docs/Glossary/Base64#the_unicode_problem
 *
 * @param base64 encoded string
 */
export function decodeBase64(base64: string) {
  const binString = atob(base64);
  try {
    // @ts-expect-error m will always be defined
    const intArray = Uint8Array.from(binString, (m) => m.codePointAt(0));
    return new TextDecoder().decode(intArray);
  } catch (error) {
    // this error should never happen essentially. It's only a failsafe
    console.warn(
      `Upstash Qstash: Failed while decoding base64 "${base64}".` +
        ` Decoding with atob and returning it instead. ${error}`
    );
    return binString;
  }
}