package neutered_filesystem import ( "io/fs" "path/filepath" ) type NeuteredFileSystem struct { fs fs.FS } func New(fs fs.FS) NeuteredFileSystem { return NeuteredFileSystem{fs} } func (nfs NeuteredFileSystem) Open(name string) (fs.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 }