how to run nuxt ava e2e tests

Question

I'm trying to follow the example here, but I get the following errors in my project:

$ ava --serial --verbose

Error occurred when calling nuxtServerInit:  Cannot read property 'user' of undefined
  ✖ Route / exits and render HTML Rejected promise returned by test
Error occurred when calling nuxtServerInit:  Cannot read property 'user' of undefined
  ✖ Route / exits and render HTML with CSS applied Rejected promise returned by test

  2 tests failed

  Route / exits and render HTML

  .../../server.js:1

  Rejected promise returned by test. Reason:

  TypeError {
    message: 'Cannot read property \'user\' of undefined',
  }

  Store.nuxtServerInit (server.js:1:0)
  Array.wrappedActionHandler (node_modules/vuex/dist/vuex.common.js:734:23)
  Store.dispatch (node_modules/vuex/dist/vuex.common.js:439:15)
  Store.boundDispatch [as dispatch] (node_modules/vuex/dist/vuex.common.js:333:21)
  t.default (server.js:1:0)

Do you have an idea what am I doing wrong?