fix: focus diffview when showFileTree is false

pkg/ui/tui.go

@@ -98,10 +98,15 @@ type mainModel struct {
 }
 
 func New(input string, cfg config.Config) mainModel {
+	initialPanel := FileTreePanel
+	if !cfg.UI.ShowFileTree {
+		initialPanel = DiffViewerPanel
+	}
+
 	m := mainModel{
 		input:             input,
 		isShowingFileTree: cfg.UI.ShowFileTree,
-		activePanel:       FileTreePanel,
+		activePanel:       initialPanel,
 		config:            cfg,
 		iconStyle:         cfg.UI.Icons,
 		sideBySide:        cfg.UI.SideBySide,

pkg/ui/tui_test.go

@@ -181,6 +181,30 @@ func TestSearchSidebarDragMotionIsIgnored(t *testing.T) {
 	}
 }
 
+func TestInitialActivePanelWhenFileTreeIsHidden(t *testing.T) {
+	zone.NewGlobal()
+
+	cfg := config.DefaultConfig()
+	cfg.UI.ShowFileTree = false
+
+	data, err := os.ReadFile("../../examples/multiple_files.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	m := New(string(data), cfg)
+
+	if m.activePanel != DiffViewerPanel {
+		t.Fatalf(
+			"expected activePanel to be DiffViewerPanel when showFileTree is false, got %v",
+			m.activePanel,
+		)
+	}
+	if m.isShowingFileTree {
+		t.Fatal("expected file tree to be hidden when showFileTree is false")
+	}
+}
+
 func newTestMainModel(t *testing.T) mainModel {
 	t.Helper()
 	zone.NewGlobal()