lib/memfs: trim trailing slash ("/") in the path of Get method

The MemFS always store directory without slash.
If caller request a directory node with slash, it will always return nil.

lib/http/server.go

@@ -345,24 +345,20 @@ func (srv *Server) Stop(wait time.Duration) (err error) {
 // [ServerOptions.EnableIndexHTML] is true, server will generate list of
 // content for index.html.
 func (srv *Server) getFSNode(reqPath string) (node *memfs.Node, isDir bool) {
-	var (
-		nodeIndexHTML *memfs.Node
-		pathHTML      string
-		err           error
-	)
-
 	if srv.Options.Memfs == nil {
 		return nil, false
 	}
 
-	pathHTML = path.Join(reqPath, `index.html`)
+	var err error
 
 	node, err = srv.Options.Memfs.Get(reqPath)
 	if err != nil {
 		if !errors.Is(err, os.ErrNotExist) {
 			return nil, false
 		}
 
+		var pathHTML = path.Join(reqPath, `index.html`)
+
 		node, err = srv.Options.Memfs.Get(pathHTML)
 		if err != nil {
 			pathHTML = reqPath + `.html`
@@ -375,16 +371,24 @@ func (srv *Server) getFSNode(reqPath string) (node *memfs.Node, isDir bool) {
 	}
 
 	if node.IsDir() {
+		var (
+			pathHTML      = path.Join(reqPath, `index.html`)
+			nodeIndexHTML *memfs.Node
+		)
+
 		nodeIndexHTML, err = srv.Options.Memfs.Get(pathHTML)
 		if err == nil {
-			return nodeIndexHTML, true
+			return nodeIndexHTML, false
 		}
 
 		if !srv.Options.EnableIndexHTML {
 			return nil, false
 		}
 
 		node.GenerateIndexHTML()
+
+		// Do not return isDir=true, to prevent the caller check and
+		// redirect the user to path with slash.
 	}
 
 	return node, false

lib/memfs/memfs.go

@@ -204,6 +204,9 @@ func (mfs *MemFS) Get(path string) (node *Node, err error) {
 	if len(path) == 0 {
 		return nil, fmt.Errorf(`%s: empty path`, logp)
 	}
+	if path != `/` {
+		path = strings.TrimSuffix(path, `/`)
+	}
 
 	node = mfs.PathNodes.Get(path)
 	if node != nil {

lib/memfs/memfs_test.go

@@ -290,6 +290,8 @@ func TestMemFS_Get(t *testing.T) {
 		},
 	}, {
 		path: "/include",
+	}, {
+		path: "/include/",
 	}, {
 		path:   "/include/dir",
 		expErr: os.ErrNotExist.Error(),