From d2001de5f3c71d4edf081866ba16059d1cb88bf9 Mon Sep 17 00:00:00 2001
From: Adnan Maolood <me@adnano.co>
Date: Tue, 16 Feb 2021 18:53:41 -0500
Subject: [PATCH] fs: Replace FileSystem with io/fs.FS

---
 fs.go | 58 ++++++++--------------------------------------------------
 1 file changed, 8 insertions(+), 50 deletions(-)

diff --git a/fs.go b/fs.go
index 2a33e3d..7ebe82d 100644
--- a/fs.go
+++ b/fs.go
@@ -2,8 +2,8 @@ package gemini
 
 import (
 	"io"
+	"io/fs"
 	"mime"
-	"os"
 	"path"
 )
 
@@ -13,60 +13,18 @@ func init() {
 	mime.AddExtensionType(".gemini", "text/gemini")
 }
 
-// A FileSystem implements access to a collection of named files. The elements
-// in a file path are separated by slash ('/', U+002F) characters, regardless
-// of host operating system convention.
-type FileSystem interface {
-	Open(name string) (File, error)
-}
-
-// A File is returned by a FileSystem's Open method and can be served by the
-// FileServer implementation.
-//
-// The methods should behave the same as those on an *os.File.
-type File interface {
-	Stat() (os.FileInfo, error)
-	Read([]byte) (int, error)
-	Close() error
-}
-
-// A Dir implements FileSystem using the native file system restricted
-// to a specific directory tree.
-//
-// While the FileSystem.Open method takes '/'-separated paths, a Dir's string
-// value is a filename on the native file system, not a URL, so it is separated
-// by filepath.Separator, which isn't necessarily '/'.
-//
-// Note that Dir could expose sensitive files and directories. Dir will follow
-// symlinks pointing out of the directory tree, which can be especially
-// dangerous if serving from a directory in which users are able to create
-// arbitrary symlinks. Dir will also allow access to files and directories
-// starting with a period, which could expose sensitive directories like .git
-// or sensitive files like .htpasswd. To exclude files with a leading period,
-// remove the files/directories from the server or create a custom FileSystem
-// implementation.
-//
-// An empty Dir is treated as ".".
-type Dir string
-
-// Open implements FileSystem using os.Open, opening files for reading
-// rooted and relative to the directory d.
-func (d Dir) Open(name string) (File, error) {
-	return os.Open(path.Join(string(d), name))
-}
-
 // FileServer returns a handler that serves Gemini requests with the contents
 // of the provided file system.
 //
-// To use the operating system's file system implementation, use gemini.Dir:
+// To use the operating system's file system implementation, use os.DirFS:
 //
-//     gemini.FileServer(gemini.Dir("/tmp"))
-func FileServer(fsys FileSystem) Handler {
+//     gemini.FileServer(os.DirFS("/tmp"))
+func FileServer(fsys fs.FS) Handler {
 	return fileServer{fsys}
 }
 
 type fileServer struct {
-	FileSystem
+	fs.FS
 }
 
 func (fs fileServer) ServeGemini(w ResponseWriter, r *Request) {
@@ -80,7 +38,7 @@ func (fs fileServer) ServeGemini(w ResponseWriter, r *Request) {
 // relative to the current directory and may ascend to parent directories. If
 // the provided name is constructed from user input, it should be sanitized
 // before calling ServeFile.
-func ServeFile(w ResponseWriter, fsys FileSystem, name string) {
+func ServeFile(w ResponseWriter, fsys fs.FS, name string) {
 	f, err := openFile(fsys, name)
 	if err != nil {
 		w.Status(StatusNotFound)
@@ -94,7 +52,7 @@ func ServeFile(w ResponseWriter, fsys FileSystem, name string) {
 	_, _ = io.Copy(w, f)
 }
 
-func openFile(fsys FileSystem, name string) (File, error) {
+func openFile(fsys fs.FS, name string) (fs.File, error) {
 	f, err := fsys.Open(name)
 	if err != nil {
 		return nil, err
@@ -123,5 +81,5 @@ func openFile(fsys FileSystem, name string) (File, error) {
 		}
 	}
 
-	return nil, os.ErrNotExist
+	return nil, fs.ErrNotExist
 }