'use strict';

const Buffer = require('buffer').Buffer;

/**
 * Makes sure that, if a Uint8Array is passed in, it is wrapped in a Buffer.
 *
 * @param {Buffer|Uint8Array} potentialBuffer The potential buffer
 * @returns {Buffer} the input if potentialBuffer is a buffer, or a buffer that
 * wraps a passed in Uint8Array
 * @throws {TypeError} If anything other than a Buffer or Uint8Array is passed in
 */
module.exports = function ensureBuffer(potentialBuffer) {
  if (potentialBuffer instanceof Buffer) {
    return potentialBuffer;
  }

  if (potentialBuffer instanceof Uint8Array) {
    return Buffer.from(potentialBuffer.buffer);
  }

  throw new TypeError('Must use either Buffer or Uint8Array');
};