static: only strip if the file path is not a single slash (#171)

static.go

@@ -97,8 +97,12 @@ func Static(opts ...StaticOptions) Handler {
 			}
 		}
 
-		// The go embed file system returns an error when the path ends with a slash.
-		file = strings.TrimRight(file, "/")
+		// The go embed file system returns an error when the path ends with a slash or the path is empty.
+		if file == "/" {
+			file = "."
+		} else {
+			file = strings.TrimRight(file, "/")
+		}
 
 		f, err := opt.FileSystem.Open(file)
 		if err != nil {

static_test.go

@@ -16,7 +16,7 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-//go:embed internal
+//go:embed internal README.md
 var embedFS embed.FS
 
 func TestStatic(t *testing.T) {
@@ -142,6 +142,11 @@ func TestStatic_Options(t *testing.T) {
 				index:          "README.md",
 				wantStatusCode: http.StatusOK,
 			},
+			{
+				uri:            "/embed/",
+				index:          "README.md",
+				wantStatusCode: http.StatusOK,
+			},
 		}
 		for _, test := range tests {
 			t.Run(test.index, func(t *testing.T) {