chore: tweaks

Author: ulivz

packages/@vuepress/core/lib/app/redirect.js

@@ -4,7 +4,7 @@
 //   - `/foo.html` means your source file is `/foo.md`
 //
 // The original design of VuePress relied on above two styles
-// of routing, especially the routing calculations involved in
+// of routing, especially the calculation involved of routes at
 // default theme. so we can't easily modify `/foo.html` directly
 // to `/foo` (i.e. remove html suffix)
 //
@@ -17,15 +17,14 @@
 //
 // For unknown request `/foo/`
 //   - redirect to `/foo.html` if it exists
+//
+// If all the above redirect rules don't exist, you'll get a 404
 
 export default function handleRedirect (router) {
   router.beforeEach((to, from, next) => {
     if (isRouteExists(router, to.path)) {
       next()
     } else {
-      // For unknown request `/foo`
-      // redirect to /foo/ if exists
-      // redirect to /foo.html if exists
       if (!/(\/|\.html)$/.test(to.path)) {
         const endingSlashUrl = to.path + '/'
         const endingHtmlUrl = to.path + '.html'
@@ -36,8 +35,6 @@ export default function handleRedirect (router) {
         } else {
           next()
         }
-        // For unknown request `/foo/`
-        // redirect to /foo.html if exists
       } else if (/\/$/.test(to.path)) {
         const endingHtmlUrl = to.path.replace(/\/$/, '') + '.html'
         if (isRouteExists(router, endingHtmlUrl)) {