From becaa021ba47725e142bedfae9b7fbd576008a97 Mon Sep 17 00:00:00 2001
From: abeltay <abel.tay@gmail.com>
Date: Mon, 5 Feb 2018 13:27:28 +0800
Subject: [PATCH] Call NotFound on folder listing (#11)

---
 web/fileserver.go | 37 +++++++++++++++++++++++++------------
 1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/web/fileserver.go b/web/fileserver.go
index d7415da..a371898 100644
--- a/web/fileserver.go
+++ b/web/fileserver.go
@@ -6,29 +6,42 @@ import (
 	"strings"
 )
 
-// FileServerHandler creates a file server that serves files from from a "Root" folder.
-// It will call "NotFound" HandlerFunc if the path contains '..' or if the file cannot be found on the system.
-type FileServerHandler struct {
+type fileHandler struct {
 	Root     string
 	NotFound http.HandlerFunc
 }
 
-// FileServer creates a FileServer that returns http.NotFound if the file cannot be found on the system
-func FileServer(root http.Dir) http.Handler {
-	return FileServerHandler{
-		Root:     string(root),
+// FileServer is a FileServerHandler with the NotFound handler set to http.NotFound.
+func FileServer(root string) http.Handler {
+	return fileHandler{
+		Root:     root,
 		NotFound: http.NotFound,
 	}
 }
 
-func (f FileServerHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+// FileServerHandler creates a file server that serves files from from a "Root" folder.
+// It will call "NotFound" HandlerFunc if the file cannot be found on the system.
+// In the event where the path is a directory, it will not redirect and instead call "NotFound" HandlerFunc.
+func FileServerHandler(root string, notFound http.HandlerFunc) http.Handler {
+	if notFound == nil {
+		return FileServer(root)
+	}
+	return fileHandler{
+		Root:     root,
+		NotFound: notFound,
+	}
+}
+
+func (h fileHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	if containsDotDot(r.URL.Path) {
-		f.NotFound(w, r)
+		h.NotFound(w, r)
 		return
 	}
-	name := f.Root + r.URL.Path
-	if _, err := os.Stat(name); os.IsNotExist(err) {
-		f.NotFound(w, r)
+
+	name := h.Root + r.URL.Path
+	info, err := os.Stat(name)
+	if os.IsNotExist(err) || info.IsDir() {
+		h.NotFound(w, r)
 		return
 	}
 	http.ServeFile(w, r, name)