metamask-extension/test/lib/mock-encryptor.js

const mockHex = '0xabcdef0123456789';
const mockKey = Buffer.alloc(32);
let cacheVal;

const mockEncryptor = {
  encrypt(_, dataObj) {
    cacheVal = dataObj;
    return Promise.resolve(mockHex);
  },

  decrypt() {
    return Promise.resolve(cacheVal || {});
  },

  encryptWithKey(key, dataObj) {
    return this.encrypt(key, dataObj);
  },

  decryptWithKey(key, text) {
    return this.decrypt(key, text);
  },

  keyFromPassword() {
    return Promise.resolve(mockKey);
  },

  generateSalt() {
    return 'WHADDASALT!';
  },

  getRandomValues() {
    return 'SOO RANDO!!!1';
  },
};

export default mockEncryptor;