Redraw only the spinner when nothing else has changed

pkg/config/user_config_validation.go

@@ -1,13 +1,16 @@
 package config
 
 import (
+	"errors"
 	"fmt"
 	"log"
 	"reflect"
 	"slices"
 	"strings"
 
 	"github.com/jesseduffield/lazygit/pkg/constants"
+	"github.com/jesseduffield/lazygit/pkg/utils"
+	"github.com/samber/lo"
 )
 
 func (config *UserConfig) Validate() error {
@@ -49,6 +52,22 @@ func (config *UserConfig) Validate() error {
 	if err := validateCustomCommands(config.CustomCommands); err != nil {
 		return err
 	}
+	if err := validateSpinner(config.Gui.Spinner); err != nil {
+		return err
+	}
+	return nil
+}
+
+func validateSpinner(spinner SpinnerConfig) error {
+	if len(spinner.Frames) == 0 {
+		return errors.New("gui.spinner.frames must not be empty.")
+	}
+	firstWidth := utils.StringWidth(spinner.Frames[0])
+	if lo.SomeBy(spinner.Frames, func(frame string) bool {
+		return utils.StringWidth(frame) != firstWidth
+	}) {
+		return errors.New("All gui.spinner.frames entries must have the same width.")
+	}
 	return nil
 }
 

pkg/config/user_config_validation_test.go

@@ -289,3 +289,33 @@ func TestUserConfigValidate_enums(t *testing.T) {
 		})
 	}
 }
+
+func TestUserConfigValidate_spinnerFrames(t *testing.T) {
+	scenarios := []struct {
+		name   string
+		frames []string
+		valid  bool
+	}{
+		{name: "empty", frames: []string{}, valid: false},
+		{name: "single frame", frames: []string{"|"}, valid: true},
+		{name: "all same width", frames: []string{"|", "/", "-", "\\"}, valid: true},
+		{name: "all same width, multi-char", frames: []string{".  ", ".. ", "..."}, valid: true},
+		{name: "all same width, wide runes", frames: []string{"⠋", "⠙", "⠹"}, valid: true},
+		{name: "differing widths", frames: []string{"|", "//"}, valid: false},
+		{name: "first differs from rest", frames: []string{"||", "/", "-"}, valid: false},
+	}
+
+	for _, s := range scenarios {
+		t.Run(s.name, func(t *testing.T) {
+			config := GetDefaultConfig()
+			config.Gui.Spinner.Frames = s.frames
+			err := config.Validate()
+
+			if s.valid {
+				assert.NoError(t, err)
+			} else {
+				assert.Error(t, err)
+			}
+		})
+	}
+}

pkg/gocui/flush_test.go

@@ -0,0 +1,202 @@
+package gocui
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func newTestGui(t *testing.T) *Gui {
+	t.Helper()
+	g, err := NewGui(NewGuiOpts{
+		OutputMode: OutputNormal,
+		Headless:   true,
+		Width:      80,
+		Height:     24,
+	})
+	assert.NoError(t, err)
+	t.Cleanup(func() { g.Close() })
+	return g
+}
+
+// setupViews creates a few views and does an initial full flush so all views
+// start in a clean (non-tainted) state.
+func setupViews(t *testing.T, g *Gui) (*View, *View) {
+	t.Helper()
+
+	status, _ := g.SetView("status", 0, 22, 40, 24, 0)
+	status.Frame = false
+	main, _ := g.SetView("main", 0, 0, 80, 22, 0)
+
+	// Initial content
+	status.SetContent("Ready")
+	main.SetContent("hello world")
+
+	// Full flush to draw everything and clear tainted flags
+	assert.NoError(t, g.flush())
+
+	return status, main
+}
+
+// pushContentOnly pushes a content-only event directly to the channel
+// (synchronous, deterministic — unlike Update which spawns a goroutine).
+func pushContentOnly(g *Gui, f func(*Gui) error) {
+	g.userEvents <- userEvent{f: f, task: g.NewTask(), contentOnly: true}
+}
+
+// pushRegular pushes a regular event directly to the channel.
+func pushRegular(g *Gui, f func(*Gui) error) {
+	g.userEvents <- userEvent{f: f, task: g.NewTask(), contentOnly: false}
+}
+
+func TestFlushContentOnly_SkipsUntaintedViews(t *testing.T) {
+	g := newTestGui(t)
+	status, main := setupViews(t, g)
+
+	// After initial flush, both views should be untainted
+	assert.False(t, status.IsTainted(), "status view should not be tainted after flush")
+	assert.False(t, main.IsTainted(), "main view should not be tainted after flush")
+
+	// Modify only the status view
+	status.SetContent("Fetching /")
+
+	assert.True(t, status.IsTainted(), "status view should be tainted after SetContent")
+	assert.False(t, main.IsTainted(), "main view should not be tainted (was not modified)")
+
+	// flushContentOnly should succeed and clear status tainted flag
+	assert.NoError(t, g.flushContentOnly(g.views))
+
+	assert.False(t, status.IsTainted(), "status view should not be tainted after flushContentOnly")
+	assert.False(t, main.IsTainted(), "main view should not be tainted after flushContentOnly")
+}
+
+func TestFlushContentOnly_WritesCorrectContent(t *testing.T) {
+	g := newTestGui(t)
+	status, _ := setupViews(t, g)
+
+	status.SetContent("Fetching |")
+	assert.NoError(t, g.flushContentOnly(g.views))
+
+	assert.Equal(t, "Fetching |", status.Buffer())
+}
+
+func TestProcessEvent_ContentOnlyEvent_SkipsTaintedCheck(t *testing.T) {
+	g := newTestGui(t)
+	status, main := setupViews(t, g)
+
+	// Send a content-only event that modifies only the status view
+	pushContentOnly(g, func(gui *Gui) error {
+		status.SetContent("Fetching /")
+		return nil
+	})
+
+	assert.NoError(t, g.processEvent())
+
+	// status was modified and drawn → tainted cleared
+	assert.False(t, status.IsTainted(), "status should not be tainted after processEvent with contentOnly")
+	// main was NOT modified → should still be untainted
+	assert.False(t, main.IsTainted(), "main should not be tainted after processEvent with contentOnly")
+}
+
+func TestProcessEvent_RegularEvent_UsesFullFlush(t *testing.T) {
+	g := newTestGui(t)
+	status, _ := setupViews(t, g)
+
+	// Regular event (not content-only) should trigger full flush
+	pushRegular(g, func(gui *Gui) error {
+		status.SetContent("Fetching \\")
+		return nil
+	})
+
+	assert.NoError(t, g.processEvent())
+
+	assert.False(t, status.IsTainted(), "status should not be tainted after full flush")
+}
+
+func TestProcessEvent_MixedBatch_UsesFullFlush(t *testing.T) {
+	g := newTestGui(t)
+	status, main := setupViews(t, g)
+
+	// Queue a content-only event followed by a regular event.
+	// processEvent picks up the first; processRemainingEvents picks up
+	// the second. Since the second is not contentOnly, full flush runs.
+	pushContentOnly(g, func(gui *Gui) error {
+		status.SetContent("Fetching -")
+		return nil
+	})
+	pushRegular(g, func(gui *Gui) error {
+		main.SetContent("updated main")
+		return nil
+	})
+
+	assert.NoError(t, g.processEvent())
+
+	// Both views were modified and should have been drawn by full flush
+	assert.False(t, status.IsTainted(), "status should not be tainted after full flush")
+	assert.False(t, main.IsTainted(), "main should not be tainted after full flush")
+}
+
+func TestProcessEvent_RegularThenContentOnly_UsesFullFlush(t *testing.T) {
+	g := newTestGui(t)
+	status, main := setupViews(t, g)
+
+	// Even if a regular event comes first and the remaining are contentOnly,
+	// the batch must use full flush.
+	pushRegular(g, func(gui *Gui) error {
+		main.SetContent("new main content")
+		return nil
+	})
+	pushContentOnly(g, func(gui *Gui) error {
+		status.SetContent("Fetching |")
+		return nil
+	})
+
+	assert.NoError(t, g.processEvent())
+
+	assert.False(t, status.IsTainted(), "status should not be tainted after full flush")
+	assert.False(t, main.IsTainted(), "main should not be tainted after full flush")
+}
+
+func TestProcessRemainingEvents_AllContentOnly_ReturnsTrue(t *testing.T) {
+	g := newTestGui(t)
+	status, _ := setupViews(t, g)
+
+	pushContentOnly(g, func(gui *Gui) error {
+		status.SetContent("a")
+		return nil
+	})
+	pushContentOnly(g, func(gui *Gui) error {
+		status.SetContent("b")
+		return nil
+	})
+
+	contentOnly, err := g.processRemainingEvents()
+	assert.NoError(t, err)
+	assert.True(t, contentOnly, "should return true when all events are contentOnly")
+}
+
+func TestProcessRemainingEvents_MixedEvents_ReturnsFalse(t *testing.T) {
+	g := newTestGui(t)
+	status, _ := setupViews(t, g)
+
+	pushContentOnly(g, func(gui *Gui) error {
+		status.SetContent("a")
+		return nil
+	})
+	pushRegular(g, func(gui *Gui) error {
+		status.SetContent("b")
+		return nil
+	})
+
+	contentOnly, err := g.processRemainingEvents()
+	assert.NoError(t, err)
+	assert.False(t, contentOnly, "should return false when any event is not contentOnly")
+}
+
+func TestProcessRemainingEvents_EmptyQueue_ReturnsTrue(t *testing.T) {
+	g := newTestGui(t)
+
+	contentOnly, err := g.processRemainingEvents()
+	assert.NoError(t, err)
+	assert.True(t, contentOnly, "should return true when no events are queued")
+}