Function jwtDecode

lib/index.ts:64–97

(
  token: string,
  options?: JwtDecodeOptions,
)

): T;
export function jwtDecode<T = JwtPayload>(token: string, options?: JwtDecodeOptions): T;
export function jwtDecode<T = JwtHeader | JwtPayload>(
  token: string,
  options?: JwtDecodeOptions,
): T {
  if (typeof token !== "string") {
    throw new InvalidTokenError("Invalid token specified: must be a string");
  }

  options ||= {};

  const pos = options.header === true ? 0 : 1;
  const part = token.split(".")[pos];

  if (typeof part !== "string") {
    throw new InvalidTokenError(`Invalid token specified: missing part #${pos + 1}`);
  }

  let decoded: string;
  try {
    decoded = base64UrlDecode(part);
  } catch (e) {
    throw new InvalidTokenError(
      `Invalid token specified: invalid base64 for part #${pos + 1} (${(e as Error).message})`,
    );
  }

  try {
    return JSON.parse(decoded) as T;
  } catch (e) {
    throw new InvalidTokenError(
      `Invalid token specified: invalid json for part #${pos + 1} (${(e as Error).message})`,
    );
  }
}