title: Vuex: getters should be function but "getters.default" in module "customer" is {}
body: <p>I structured my Vuex store in several modules and now I'm facing a strange Vuex error that I am unable to solve:</p>
  
  <pre><code>Uncaught Error: [vuex] getters should be function but "getters.default" in module "customer" is {}.
  at assert (vuex.esm.js?358c:97)
  at eval (vuex.esm.js?358c:271)
  at eval (vuex.esm.js?358c:85)
  at Array.forEach (&lt;anonymous&gt;)
  at forEachValue (vuex.esm.js?358c:85)
  at eval (vuex.esm.js?358c:270)
  at Array.forEach (&lt;anonymous&gt;)
  at assertRawModule (vuex.esm.js?358c:265)
  at ModuleCollection.register (vuex.esm.js?358c:191)
  at eval (vuex.esm.js?358c:205)
  </code></pre>
  
  <p>The Structure of my Vuex store is build on the following pattern</p>
  
  <pre><code>- store
  -- index.js
  -- modules
  --- customer
  ---- index.js
  ---- actions.js
  ---- getters.js
  ---- mutations.js
  </code></pre>
  
  <p>Here is my sores basic index.js:</p>
  
  <pre><code>import Vue from 'vue'
  import Vuex from 'vuex'
  import customerModule from './modules/customer/index'
  import globalModule from './modules/global/index'
  import projectModule from './modules/project/index'
  
  Vue.use(Vuex)
  
  export default new Vuex.Store({
    modules: {
      customer: customerModule,
      global: globalModule,
      project: projectModule
    }
  })
  </code></pre>
  
  <p>my modules/customer/index.js:</p>
  
  <pre><code>import * as actions from './actions'
  import * as getters from './getters'
  import * as mutations from './mutations'
  
  const state = {
    customers: []
  }
  
  export default {
    namespaced: true,
    state: state,
    actions: actions,
    mutations: mutations,
    getters: getters
  }
  </code></pre>
  
  <p>my modules/customer/getters.js:</p>
  
  <pre><code>const customers = state =&gt; state.customers
  
  export default {
    customers
  }
  </code></pre>
  
  <p>I'm not quite sure what is going on here uand why I get this strange error.</p>
  
  <p>Any ideas?</p>