Preview filter while browsing an open dropdown; Esc closes only the list

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/ui/form_test.go

@@ -1,6 +1,7 @@
 package ui
 
 import (
+	"reflect"
 	"testing"
 
 	"github.com/gdamore/tcell/v2"
@@ -12,7 +13,7 @@ func TestArrowNavigation(t *testing.T) {
 		AddDropDown("A", []string{"x", "y", "z"}, 0, nil).
 		AddCheckbox("B", true, nil).
 		AddButton("Add", nil).AddButton("Cancel", nil)
-	arrowNavigation(f)
+	arrowNavigation(f, nil, nil)
 	var focus func(p tview.Primitive)
 	focus = func(p tview.Primitive) { p.Focus(focus) }
 	f.Focus(focus)
@@ -56,7 +57,7 @@ func TestSearchNowFollowsMonitored(t *testing.T) {
 		AddCheckbox("M", true, nil).
 		AddCheckbox("S", true, nil).
 		AddButton("Add", nil)
-	arrowNavigation(f)
+	arrowNavigation(f, nil, nil)
 	var focus func(p tview.Primitive)
 	focus = func(p tview.Primitive) { p.Focus(focus) }
 	f.Focus(focus)
@@ -108,3 +109,53 @@ func TestSearchNowFollowsMonitored(t *testing.T) {
 		t.Error("Search now should return to its previous choice")
 	}
 }
+
+func TestBrowseOpenDropDown(t *testing.T) {
+	f := tview.NewForm().AddDropDown("D", []string{"any", "a", "b", "c"}, 0, nil)
+	var seen []int
+	aborted, cancelled := 0, 0
+	arrowNavigation(f, func() { cancelled++ }, &browseHooks{
+		browse: func(_ *tview.DropDown, i int) { seen = append(seen, i) },
+		abort:  func() { aborted++ },
+	})
+	var focus func(p tview.Primitive)
+	focus = func(p tview.Primitive) { p.Focus(focus) }
+	f.Focus(focus)
+	send := func(k tcell.Key) { f.InputHandler()(tcell.NewEventKey(k, 0, 0), focus) }
+	dd := f.GetFormItem(0).(*tview.DropDown)
+
+	send(tcell.KeyEnter) // open
+	if !dd.IsOpen() {
+		t.Fatal("dropdown did not open")
+	}
+	send(tcell.KeyDown)
+	send(tcell.KeyDown)
+	send(tcell.KeyUp)
+	send(tcell.KeyUp)
+	send(tcell.KeyUp) // wraps to the last entry
+	if want := []int{1, 2, 1, 0, 3}; !reflect.DeepEqual(seen, want) {
+		t.Fatalf("browse saw %v, want %v", seen, want)
+	}
+	send(tcell.KeyEnter) // select what the highlight is on
+	if i, _ := dd.GetCurrentOption(); i != 3 {
+		t.Errorf("selected option %d, want 3: the mirrored highlight drifted from the real list", i)
+	}
+
+	seen = nil
+	send(tcell.KeyEnter)
+	send(tcell.KeyDown) // wraps to 0
+	send(tcell.KeyEscape)
+	if cancelled != 0 {
+		t.Error("Esc on an open list must only close the list")
+	}
+	send(tcell.KeyEscape) // list closed: now Esc cancels the form
+	if cancelled != 1 {
+		t.Errorf("cancelled=%d, want 1", cancelled)
+	}
+	if aborted != 1 || !reflect.DeepEqual(seen, []int{0}) {
+		t.Errorf("aborted=%d seen=%v", aborted, seen)
+	}
+	if i, _ := dd.GetCurrentOption(); i != 3 {
+		t.Errorf("Esc must keep the committed option, got %d", i)
+	}
+}