fix(scanner): make sure we roll back invalid parents

fixes #402

scanner/scanner.go

@@ -231,17 +231,13 @@ func (s *Scanner) scanCallback(c *Context, absPath string, d fs.DirEntry, err er
 
 	log.Printf("processing folder %q", absPath)
 
-	tx := s.db.Begin()
+	return s.db.Transaction(func(tx *db.DB) error {
 		if err := s.scanDir(tx, c, absPath); err != nil {
 			c.errs = append(c.errs, fmt.Errorf("%q: %w", absPath, err))
-		tx.Rollback()
 			return nil
 		}
-	if err := tx.Commit().Error; err != nil {
-		return fmt.Errorf("commit tx: %w", err)
-	}
-
 		return nil
+	})
 }
 
 func (s *Scanner) scanDir(tx *db.DB, c *Context, absPath string) error {

scanner/scanner_test.go

@@ -767,3 +767,23 @@ func TestMultiArtistPreload(t *testing.T) {
 		}
 	}
 }
+
+// https://github.com/sentriz/gonic/issues/402
+func TestRootNoClobberOnError(t *testing.T) {
+	t.Parallel()
+	m := mockfs.New(t)
+
+	m.AddItems()
+
+	m.SetTags("artist-0/album-0/track-0.flac", func(tags *mockfs.TagInfo) { tags.Error = fmt.Errorf("no") }) // give a track an error
+	m.AddCover("artist-0/album-0/Artwork/cover.png")                                                         // and add an extra cover dir
+
+	_, err := m.ScanAndCleanErr()
+	require.Error(t, err)
+
+	var roots []*db.Album
+	require.NoError(t, m.DB().Find(&roots, "parent_id IS NULL").Error)
+	require.Len(t, roots, 1)
+	require.Equal(t, ".", roots[0].RightPath)
+	require.Equal(t, 0, roots[0].ParentID)
+}