Add normal neutered filesystem variant

http/http-filesystem.go

@@ -0,0 +1,36 @@
+package http
+
+import (
+	"net/http"
+	"path/filepath"
+)
+
+type NeuteredHttpFileSystem struct {
+	fs http.FileSystem
+}
+
+func New(fs http.FileSystem) NeuteredHttpFileSystem {
+	return NeuteredHttpFileSystem{fs}
+}
+
+func (nfs NeuteredHttpFileSystem) Open(name string) (http.File, error) {
+	f, err := nfs.fs.Open(name)
+	if err != nil {
+		return nil, err
+	}
+
+	s, err := f.Stat()
+	if s.IsDir() {
+		index := filepath.Join(name, "index.html")
+		if _, err := nfs.fs.Open(index); err != nil {
+			closeErr := f.Close()
+			if closeErr != nil {
+				return nil, closeErr
+			}
+
+			return nil, err
+		}
+	}
+
+	return f, nil
+}

neutered-filesystem.go

@@ -1,19 +1,19 @@
 package neutered_filesystem
 
 import (
-	"net/http"
+	"io/fs"
 	"path/filepath"
 )
 
 type NeuteredFileSystem struct {
-	fs http.FileSystem
+	fs fs.FS
 }
 
-func New(fs http.FileSystem) NeuteredFileSystem {
+func New(fs fs.FS) NeuteredFileSystem {
 	return NeuteredFileSystem{fs}
 }
 
-func (nfs NeuteredFileSystem) Open(name string) (http.File, error) {
+func (nfs NeuteredFileSystem) Open(name string) (fs.File, error) {
 	f, err := nfs.fs.Open(name)
 	if err != nil {
 		return nil, err