Better error message for Vuex mapActions typo

[elithecho]

What problem does this feature solve?

While working using Vuex, I came across an error which took me quite a chunk of time to debug and I thought this deserves a better error messages.

While using map actions ...mapActions('select'Filter) - notice the mistake with no square brackets in Listings -> Filters -> SelectFilter component. The error went up to top level component and appears as below.

vue.runtime.esm.js:587 [Vue warn]: Failed to resolve async component: function Listings() {
      return __webpack_require__.e/* import() */(0).then(__webpack_require__.bind(null, /*! @/pages/Listings/index.vue */ "./app/javascript/pages/Listings/index.vue"));
    }
Reason: TypeError: Cannot convert undefined or null to object

What does the proposed API look like?

Show shows error message pointing to correct file and line.

[winniehell]

similar issue for mapState: #1162

[ktsn]

fixed via #1297