How to unit test a bootfile with Jest?

[Ceriel]

I would like to test axios response interceptors and routeguard, for which I have created boot files.

How do I test these type of files in Jest? Since the logic lives in the export default callback.

import {
  Notify
} from 'quasar'

import {
  i18n
} from 'boot/i18n.js'
import {
  axiosInstance
} from 'boot/axios'

export default ({
  router,
  store
}) => {
  axiosInstance.interceptors.response.use(response => {
    return response
  }, error => {
    if (error.response.status === 401) {
      Notify.create({
        progress: true,
        message: i18n.t('response.status-code-401'),
        icon: 'error',
        color: 'white',
        textColor: 'primary'
      })

      setTimeout(() => {
        store.dispatch('auth/logout')
      }, 5000)

      return Promise.reject(error)
    }
    // TODO: Notify for other status codes
  })

  /**
   * Set route guard
   */
  router.beforeEach((to, from, next) => {
    const requiresAuth = to.matched.some(record => record.meta.requiresAuth)

    if (requiresAuth) {
      store.dispatch('auth/fetchUser').then(() => {
        if (!store.getters['auth/isLoggedIn']) {
          next({
            path: '/login',
            query: {
              redirect: to.fullPath
            }
          })
        } else {
          next()
        }
      })
    } else {
      next()
    }
  })
}

[DavidGo]

I also want to test my router guards. @Ceriel have you figured out how to do this?