filelist/*: implement FileLister in existing types

internal/filelist/hookfiles/hookfiles.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path/filepath"
 
+	"gitlab.com/postmarketOS/postmarketos-mkinitfs/internal/filelist"
 	"gitlab.com/postmarketOS/postmarketos-mkinitfs/internal/misc"
 )
 
@@ -22,13 +23,13 @@ func New(filePath string) *HookFiles {
 	}
 }
 
-func (h *HookFiles) List() ([]string, error) {
+func (h *HookFiles) List() (*filelist.FileList, error) {
 	log.Println("- Including files")
 	fileInfo, err := os.ReadDir(h.filePath)
 	if err != nil {
 		return nil, fmt.Errorf("getHookFiles: unable to read hook file dir: %w", err)
 	}
-	files := []string{}
+	files := filelist.NewFileList()
 	for _, file := range fileInfo {
 		path := filepath.Join(h.filePath, file.Name())
 		f, err := os.Open(path)
@@ -40,10 +41,12 @@ func (h *HookFiles) List() ([]string, error) {
 		log.Printf("-- Including files from: %s\n", path)
 		s := bufio.NewScanner(f)
 		for s.Scan() {
-			if filelist, err := misc.GetFiles([]string{s.Text()}, true); err != nil {
+			if fFiles, err := misc.GetFiles([]string{s.Text()}, true); err != nil {
 				return nil, fmt.Errorf("getHookFiles: unable to add file %q required by %q: %w", s.Text(), path, err)
 			} else {
-				files = append(files, filelist...)
+				for _, file := range fFiles {
+					files.Add(file, file)
+				}
 			}
 		}
 		if err := s.Err(); err != nil {