:bug: fix for sort check

vue-theme/src/pages/list.vue

 import sidebar from '@/components/sidebars/sidebar'
 import { postTypeGetters, scrollTop, heroUtils } from './mixin-post-types'
 
-import { postTypes, sortTypes, convertTitleCase, typeFromRoute } from '@/utils/helpers'
+import { postTypes, sortTypes, convertTitleCase, typeFromRoute, sortFromRoute } from '@/utils/helpers'
 
 const TIMEOUT = 1
 const INTERSECT_SELECTOR = '.page--list > article footer'
         _getSortBy() {
             return this.sortBy
                 ? this.sortBy
-                : this.$route.path
-                      .split('/')
-                      .filter(p => p)
-                      .pop()
+                : sortFromRoute(this.$route)
         },
         _getDispatchParams(perPage) {
             return {
         // and the post type has changed
         type(newType, oldType) {
             if(!postTypes.includes(newType)) return console.warn('type not found...')
-
             this.clearAndInitPostList('type watcher')
         },
         // Only fire if the sort type has changed
         // and the post type is the same
+        // and both sorts are valid
         $route(to, from) {
-            const findSortBy = route => {
-                return route.sortBy ? route.sortBy : route.fullPath
-                    .split('/')
-                    .filter(p => p)
-                    .pop()
-            }
+            const validSorts = Object.values(sortTypes)
             if (
-                findSortBy(to) != findSortBy(from) &&
                 typeFromRoute(to) == typeFromRoute(from) &&
-                // Post slug sometimes appears as a sort
-                sortTypes.includes(findSortBy(to)) && sortTypes.includes(findSortBy(from))
+                sortFromRoute(to) != sortFromRoute(from) &&
+                // Post slug sometimes appears as a sort so we check it against known sorts
+                validSorts.includes(sortFromRoute(to)) && validSorts.includes(sortFromRoute(from))
             ) {
                 this.clearAndInitPostList('$route watcher')
             } 

vue-theme/src/utils/helpers.js

     return type
 }
 
+const sortFromRoute = route => {
+    return route.sortBy ? route.sortBy : route.fullPath
+        .split('/')
+        .filter(p => p)
+        .pop()
+}
+
 const ytThumbnail = (url, desiredSize) => {
     const remove = [
         '',
     convertTitleCase,
     dePluralize,
     typeFromRoute,
+    sortFromRoute,
     sortTypes,
     postTypes,
     ytThumbnail,