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