added some small code improvements

index.js

@@ -272,7 +272,7 @@ async function fastifyStatic (fastify, opts) {
   }
 
   const errorHandler = (error, request, reply) => {
-    if (error && error.code === 'ERR_STREAM_PREMATURE_CLOSE') {
+    if (error?.code === 'ERR_STREAM_PREMATURE_CLOSE') {
       reply.request.raw.destroy()
       return
     }

lib/dirList.js

@@ -16,7 +16,7 @@ const dirList = {
     const entries = { dirs: [], files: [] }
     let files = await fs.readdir(dir)
     if (dotfiles === 'deny' || dotfiles === 'ignore') {
-      files = files.filter(f => f.charAt(0) !== '.')
+      files = files.filter(file => file.charAt(0) !== '.')
     }
     if (files.length < 1) {
       return entries
@@ -92,6 +92,7 @@ const dirList = {
 
     entries.dirs.sort((a, b) => a.name.localeCompare(b.name))
     entries.files.sort((a, b) => a.name.localeCompare(b.name))
+
     return entries
   },
 
@@ -141,7 +142,7 @@ const dirList = {
    * @return {ListFile}
    */
   htmlInfo: function (entry, route, prefix, options) {
-    if (options.names && options.names.includes(path.basename(route))) {
+    if (options.names?.includes(path.basename(route))) {
       route = path.normalize(path.join(route, '..'))
     }
     return {
@@ -156,15 +157,12 @@ const dirList = {
    * say if the route can be handled by dir list or not
    * @param {string} route request route
    * @param {(boolean | ListOptionsJsonFormat | ListOptionsHtmlFormat)} options
-   * @return {boolean}
+   * @return {boolean | undefined}
    */
   handle: function (route, options) {
-    if (!options.names) {
-      return false
-    }
-    return options.names.includes(path.basename(route)) ||
+    return options.names?.includes(path.basename(route)) ||
       // match trailing slash
-      (options.names.includes('/') && route[route.length - 1] === '/')
+      (options.names?.includes('/') && route[route.length - 1] === '/') || false
   },
 
   /**