fix(tui): avoid redundant frames for hidden-sidebar usage updates

pkg/tui/tui.go

@@ -874,7 +874,7 @@ func (m *appModel) update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	if _, ok := msg.(tea.MouseMotionMsg); !ok {
 		m.hasPointer = false
 	}
-	if _, isTick := msg.(animation.TickMsg); !isTick {
+	if _, isTick := msg.(animation.TickMsg); !isTick && !m.canReuseUsageView(msg) {
 		m.viewCacheValid = false
 	}
 	// In lean mode, silently drop messages for features that don't exist.
@@ -2526,6 +2526,18 @@ func (m *appModel) switchFocus() (tea.Model, tea.Cmd) {
 	return m, nil
 }
 
+func (m *appModel) canReuseUsageView(msg tea.Msg) bool {
+	// Usage only changes accounting and sidebar state; dialogs may show live costs.
+	if (!m.leanMode && !m.hideSidebar) || m.dialogMgr.Open() {
+		return false
+	}
+	if routed, ok := msg.(messages.RoutedMsg); ok {
+		msg = routed.Inner
+	}
+	_, ok := msg.(*runtime.TokenUsageEvent)
+	return ok
+}
+
 func sidebarVisualGeneration(page chat.Page) uint64 {
 	if page, ok := page.(interface{ SidebarVisualGeneration() uint64 }); ok {
 		return page.SidebarVisualGeneration()

pkg/tui/usage_render_test.go

@@ -0,0 +1,101 @@
+package tui
+
+import (
+	"testing"
+
+	tea "charm.land/bubbletea/v2"
+	"github.com/charmbracelet/x/ansi"
+	"github.com/stretchr/testify/require"
+
+	chattypes "github.com/docker/docker-agent/pkg/chat"
+	agentruntime "github.com/docker/docker-agent/pkg/runtime"
+	"github.com/docker/docker-agent/pkg/tui/dialog"
+	"github.com/docker/docker-agent/pkg/tui/messages"
+	"github.com/docker/docker-agent/pkg/tui/page/chat"
+)
+
+func TestTokenUsageWithoutSidebarReusesRootView(t *testing.T) {
+	for _, lean := range []bool{false, true} {
+		for _, routed := range []bool{false, true} {
+			name := map[bool]string{false: "sidebar disabled", true: "lean"}[lean]
+			name += map[bool]string{false: "/direct", true: "/routed"}[routed]
+			t.Run(name, func(t *testing.T) {
+				root, _, _ := frozenClockRoot(t, 120, 40)
+				root.leanMode = lean
+				if lean {
+					root.hideSidebar = false
+					root.activeTab.chatPage = chat.New(root.ar, t.Context(), root.application, root.activeTab.sessionState, chat.WithLeanMode())
+					root.handleWindowResize(120, 40)
+				}
+				root.activeTab.state = root.supervisor.GetRunner("profile").State
+				page := &deferredRenderPage{Page: root.activeTab.chatPage}
+				root.activeTab.chatPage = page
+				_, _ = root.Update(agentruntime.StreamStarted("profile", "root"))
+				before := root.View()
+				require.NotNil(t, before.ProgressBar)
+				views := page.views
+
+				for i := range 1100 {
+					var msg tea.Msg = agentruntime.NewTokenUsageEvent("profile", "root", &agentruntime.Usage{
+						InputTokens: int64(i + 1), OutputTokens: int64(i + 2), Cost: float64(i + 1),
+						LastMessage: &agentruntime.MessageUsage{Model: "test-model", Cost: 1, Usage: chattypes.Usage{InputTokens: 1}},
+					})
+					if routed {
+						msg = messages.RoutedMsg{SessionID: "profile", Inner: msg}
+					}
+					_, _ = root.Update(msg)
+					require.True(t, root.viewCacheValid, "accounting alone must not invalidate the frame")
+					require.Equal(t, before, root.View())
+				}
+				require.Equal(t, views, page.views, "usage backlog must not compose frames")
+				input, output := root.application.Session().Usage()
+				require.Equal(t, int64(1100), input)
+				require.Equal(t, int64(1101), output)
+				require.Len(t, root.application.Session().MessageUsageHistorySnapshot(), 1100, "every per-message record must survive")
+				cost, ok := root.activeTab.sessionState.AgentCost("root")
+				require.True(t, ok)
+				require.InDelta(t, 1100.0, cost, 0)
+
+				_, _ = root.Update(agentruntime.AgentChoice("root", "profile", "FINAL-RESPONSE-AFTER-USAGE", "answer"))
+				_, _ = root.Update(agentruntime.StreamStopped("profile", "root", "normal"))
+				require.False(t, root.activeTab.chatPage.IsWorking())
+				after := root.View()
+				require.Nil(t, after.ProgressBar)
+				require.NotEqual(t, before.WindowTitle, after.WindowTitle)
+				require.Contains(t, ansi.Strip(after.Content), "FINAL-RESPONSE-AFTER-USAGE")
+			})
+		}
+	}
+}
+
+func TestTokenUsageRefreshesVisibleUsage(t *testing.T) {
+	for _, costDialog := range []bool{false, true} {
+		t.Run(map[bool]string{false: "sidebar", true: "cost dialog"}[costDialog], func(t *testing.T) {
+			root, _, _ := frozenClockRoot(t, 120, 40)
+			if costDialog {
+				_, _ = root.Update(dialog.OpenDialogMsg{Model: dialog.NewCostDialog(root.application.Session())})
+			} else {
+				root.hideSidebar = false
+				root.activeTab.chatPage = chat.New(root.ar, t.Context(), root.application, root.activeTab.sessionState)
+				root.handleWindowResize(120, 40)
+			}
+			before := root.View()
+			_, _ = root.Update(messages.RoutedMsg{SessionID: "profile", Inner: agentruntime.NewTokenUsageEvent("profile", "root", &agentruntime.Usage{
+				InputTokens: 100, OutputTokens: 20, ContextLength: 120, ContextLimit: 1000, Cost: 0.25,
+				LastMessage: &agentruntime.MessageUsage{Model: "test-model", Cost: 0.25, Usage: chattypes.Usage{InputTokens: 100, OutputTokens: 20}},
+			})})
+			require.False(t, root.viewCacheValid, "visible accounting must refresh")
+			after := root.View().Content
+			require.NotEqual(t, before.Content, after)
+			require.Contains(t, ansi.Strip(after), "$0.25")
+		})
+	}
+}
+
+func TestTokenUsagePreservesPendingVisualChanges(t *testing.T) {
+	root, _, _ := frozenClockRoot(t, 120, 40)
+	_, _ = root.Update(agentruntime.AgentChoice("root", "profile", "PENDING-CONTENT"))
+	_, _ = root.Update(messages.RoutedMsg{SessionID: "profile", Inner: agentruntime.NewTokenUsageEvent("profile", "root", &agentruntime.Usage{})})
+	require.False(t, root.viewCacheValid)
+	require.Contains(t, ansi.Strip(root.View().Content), "PENDING-CONTENT")
+}