问用dwyl/ AWS模拟aws-模拟不工作

EN

TypeError: Attempted to wrap undefined property S3 as function
      at checkWrappedMethod (node_modules/aws-sdk-mock/node_modules/sinon/lib/sinon/util/core.js:78:29)
      at Object.wrapMethod (node_modules/aws-sdk-mock/node_modules/sinon/lib/sinon/util/core.js:121:21)
      at Object.stub (node_modules/aws-sdk-mock/node_modules/sinon/lib/sinon/stub.js:67:26)
      at mockService (node_modules/aws-sdk-mock/index.js:67:27)
      at Object.AWS.mock (node_modules/aws-sdk-mock/index.js:43:5)
      at Context.<anonymous> (myModule.spec.js:14:9)

var AWS = require('aws-sdk')
const https = require('https')

module.exports = function () {
    var s3 = new AWS.S3({
      httpOptions: {
        agent: new https.Agent()
      },
      signatureVersion: 'v4'
    })
    return s3.getObject({Bucket: 'somebucket', Key: 'somekey'}).promise()
}

const chai = require('chai')
const chaiAsPromised = require('chai-as-promised')

const AWS = require('aws-sdk-mock')
const myFunc = require('./myModule')

chai.use(chaiAsPromised)
const expect = chai.expect
chai.should()

describe('Get MMS API Key', function () {

  before(function () {
    AWS.mock('S3', 'getObject', function (params, callback) {
      callback(null, 'dummy-data')
    })
  })

  it('Should get dummy data', function () {
    myFunc().should.eventually.equal('dummy-data')
  })

  after(function () {
    AWS.restore('S3', 'getObject')
  })
})