rsnext/packages/next/next-server/lib/to-base-64.ts

/**
 * Isomorphic base64 that works on the server and client
 */
export function toBase64(str: string) {
  if (typeof window === 'undefined') {
    return Buffer.from(str).toString('base64')
  } else {
    return window.btoa(str)
  }
}