refactor: major code reorganization, file splitting, deduping

README.md

@@ -196,8 +196,8 @@ Configuration values are applied in this order (later sources override earlier o
 | ------------------ | -------------------------------- |
 | `r`, `Ctrl-r`      | Reload (re-run command)          |
 | `R`                | Reload & clear all lines         |
-| `Del`              | Delete selected line             |
+| `d`, `Del`         | Delete selected line             |
-| `Ctrl-Del`         | Clear all lines (with confirm)   |
+| `D`                | Clear all lines                  |
 | `c`                | Stop running command             |
 | `q`, `Esc`         | Quit                             |
 | `j`, `k`           | Move down/up                     |

internal/ui/actions.go

@@ -0,0 +1,153 @@
+package ui
+
+import (
+	"time"
+
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+func (m *model) actionReload() (tea.Model, tea.Cmd) {
+	m.refreshGeneration++
+	cmd := m.startStreaming()
+	return m, tea.Batch(cmd, m.spinnerTickCmd())
+}
+
+func (m *model) actionReloadClear() (tea.Model, tea.Cmd) {
+	m.lines = nil
+	m.updateFiltered()
+	return m.actionReload()
+}
+
+func (m *model) actionDeleteLine() (tea.Model, tea.Cmd) {
+	if len(m.filtered) > 0 && m.cursor >= 0 && m.cursor < len(m.filtered) {
+		idx := m.filtered[m.cursor]
+		if idx < len(m.lines) {
+			m.lines = append(m.lines[:idx], m.lines[idx+1:]...)
+			m.updateFiltered()
+		}
+	}
+	return m, nil
+}
+
+func (m *model) actionClearAllLines() (tea.Model, tea.Cmd) {
+	m.confirmMode = true
+	m.confirmMessage = "Clear all lines? (y/N)"
+	m.confirmAction = func(m *model) (tea.Model, tea.Cmd) {
+		m.lines = nil
+		m.updateFiltered()
+		m.statusMsg = "All lines cleared"
+		return m, m.statusTimeoutCmd()
+	}
+	return m, nil
+}
+
+func (m *model) actionStopCommand() (tea.Model, tea.Cmd) {
+	if m.streaming {
+		m.cancel()
+		m.statusMsg = "Command stopped"
+		return m, m.statusTimeoutCmd()
+	}
+	return m, nil
+}
+
+func (m *model) actionTogglePreview() (tea.Model, tea.Cmd) {
+	m.showPreview = !m.showPreview
+	m.adjustOffset()
+	return m, nil
+}
+
+func (m *model) actionIncreasePreview() (tea.Model, tea.Cmd) {
+	if m.showPreview {
+		m.config.PreviewSize += previewSizeStep(m.config.PreviewSizeIsPercent)
+		m.adjustOffset()
+	}
+	return m, nil
+}
+
+func (m *model) actionDecreasePreview() (tea.Model, tea.Cmd) {
+	if m.showPreview {
+		step := previewSizeStep(m.config.PreviewSizeIsPercent)
+		if m.config.PreviewSize > step {
+			m.config.PreviewSize -= step
+			m.adjustOffset()
+		}
+	}
+	return m, nil
+}
+
+func (m *model) actionGoToFirst() (tea.Model, tea.Cmd) {
+	m.userScrolled = true
+	m.previewOffset = 0
+	m.cursor = 0
+	m.offset = 0
+	return m, nil
+}
+
+func (m *model) actionGoToLast() (tea.Model, tea.Cmd) {
+	m.userScrolled = false
+	m.previewOffset = 0
+	if len(m.filtered) > 0 {
+		m.cursor = len(m.filtered) - 1
+		m.adjustOffset()
+	}
+	return m, nil
+}
+
+func (m *model) actionEnterFilter() (tea.Model, tea.Cmd) {
+	m.filterMode = true
+	m.filterCursor = len(m.filter)
+	return m, nil
+}
+
+func (m *model) actionToggleRegexFilter() (tea.Model, tea.Cmd) {
+	m.filterMode = true
+	m.filterRegex = !m.filterRegex
+	m.filterRegexErr = nil
+	m.filterCursor = len(m.filter)
+	m.updateFiltered()
+	return m, nil
+}
+
+func (m *model) actionCopyLine(plain bool) (tea.Model, tea.Cmd) {
+	if len(m.filtered) > 0 && m.cursor >= 0 && m.cursor < len(m.filtered) {
+		idx := m.filtered[m.cursor]
+		if idx < len(m.lines) {
+			content := m.lines[idx].Content
+			if plain {
+				content = stripANSI(content)
+			}
+			if err := copyToClipboard(content); err != nil {
+				m.statusMsg = "Failed to copy"
+			} else if plain {
+				m.statusMsg = "Copied to clipboard (plain)"
+			} else {
+				m.statusMsg = "Copied to clipboard"
+			}
+			return m, m.statusTimeoutCmd()
+		}
+	}
+	return m, nil
+}
+
+func (m *model) actionShowHelp() (tea.Model, tea.Cmd) {
+	m.showHelp = true
+	return m, nil
+}
+
+func (m *model) actionQuit() (tea.Model, tea.Cmd) {
+	m.cancel()
+	return m, tea.Quit
+}
+
+func (m *model) actionOpenPalette() (tea.Model, tea.Cmd) {
+	m.cmdPaletteMode = true
+	m.cmdPaletteFilter = ""
+	m.cmdPaletteCursor = 0
+	m.cmdPaletteSelected = 0
+	return m, nil
+}
+
+// statusTimeoutCmd returns a command that clears the status message after 2 seconds.
+func (m model) statusTimeoutCmd() tea.Cmd {
+	return tea.Tick(2*time.Second, func(t time.Time) tea.Msg { return clearStatusMsg{} })
+}

internal/ui/actions_test.go

@@ -0,0 +1,197 @@
+package ui
+
+import (
+	"testing"
+
+	"github.com/chenasraf/watchr/internal/runner"
+)
+
+func TestActionReload(t *testing.T) {
+	m := testModelWithLines()
+	_, cmd := m.actionReload()
+	if m.refreshGeneration != 1 {
+		t.Errorf("expected refreshGeneration 1, got %d", m.refreshGeneration)
+	}
+	if cmd == nil {
+		t.Error("expected command to be returned")
+	}
+}
+
+func TestActionReloadClear(t *testing.T) {
+	m := testModelWithLines()
+	originalLines := len(m.lines)
+	if originalLines == 0 {
+		t.Fatal("expected lines to be populated")
+	}
+
+	_, cmd := m.actionReloadClear()
+	if m.lines != nil {
+		t.Errorf("expected lines nil, got %d", len(m.lines))
+	}
+	if m.refreshGeneration != 1 {
+		t.Errorf("expected refreshGeneration 1, got %d", m.refreshGeneration)
+	}
+	if cmd == nil {
+		t.Error("expected command to be returned")
+	}
+}
+
+func TestActionDeleteLine(t *testing.T) {
+	m := testModelWithLines()
+	m.cursor = 1 // "foo bar"
+	m.actionDeleteLine()
+
+	for _, line := range m.lines {
+		if line.Content == "foo bar" {
+			t.Error("expected 'foo bar' to be deleted")
+		}
+	}
+	if len(m.lines) != 3 {
+		t.Errorf("expected 3 lines, got %d", len(m.lines))
+	}
+}
+
+func TestActionDeleteLineEmpty(t *testing.T) {
+	cfg := Config{Command: "echo test", Shell: "sh"}
+	m := testModel(cfg)
+	// Should not panic
+	m.actionDeleteLine()
+}
+
+func TestActionClearAllLines(t *testing.T) {
+	m := testModelWithLines()
+	m.actionClearAllLines()
+
+	if !m.confirmMode {
+		t.Error("expected confirmMode true")
+	}
+	if m.confirmMessage != "Clear all lines? (y/N)" {
+		t.Errorf("expected confirm message, got %q", m.confirmMessage)
+	}
+}
+
+func TestActionStopCommand(t *testing.T) {
+	m := testModelWithCancel()
+	m.streaming = true
+
+	_, cmd := m.actionStopCommand()
+	if m.statusMsg != "Command stopped" {
+		t.Errorf("expected 'Command stopped', got %q", m.statusMsg)
+	}
+	if cmd == nil {
+		t.Error("expected timeout command")
+	}
+}
+
+func TestActionStopCommandNotStreaming(t *testing.T) {
+	m := testModelWithCancel()
+	m.streaming = false
+
+	_, cmd := m.actionStopCommand()
+	if m.statusMsg != "" {
+		t.Errorf("expected empty status, got %q", m.statusMsg)
+	}
+	if cmd != nil {
+		t.Error("expected nil command when not streaming")
+	}
+}
+
+func TestActionTogglePreview(t *testing.T) {
+	m := testModelWithLines()
+	m.showPreview = false
+
+	m.actionTogglePreview()
+	if !m.showPreview {
+		t.Error("expected showPreview true")
+	}
+
+	m.actionTogglePreview()
+	if m.showPreview {
+		t.Error("expected showPreview false")
+	}
+}
+
+func TestActionPreviewResize(t *testing.T) {
+	m := testModelWithLines()
+	m.showPreview = true
+	m.config.PreviewSize = 10
+	m.config.PreviewSizeIsPercent = false
+
+	m.actionIncreasePreview()
+	if m.config.PreviewSize != 12 {
+		t.Errorf("expected 12, got %d", m.config.PreviewSize)
+	}
+
+	m.actionDecreasePreview()
+	if m.config.PreviewSize != 10 {
+		t.Errorf("expected 10, got %d", m.config.PreviewSize)
+	}
+}
+
+func TestActionGoToFirstLast(t *testing.T) {
+	m := testModelWithLines()
+	m.cursor = 2
+
+	m.actionGoToFirst()
+	if m.cursor != 0 {
+		t.Errorf("expected cursor 0, got %d", m.cursor)
+	}
+
+	m.actionGoToLast()
+	if m.cursor != len(m.filtered)-1 {
+		t.Errorf("expected cursor %d, got %d", len(m.filtered)-1, m.cursor)
+	}
+}
+
+func TestActionCopyLine(t *testing.T) {
+	m := testModelWithLines()
+	m.cursor = 0
+
+	// Test copy (may succeed or fail depending on clipboard availability)
+	_, cmd := m.actionCopyLine(false)
+	if m.statusMsg == "" {
+		t.Error("expected statusMsg to be set")
+	}
+	if cmd == nil {
+		t.Error("expected timeout command")
+	}
+}
+
+func TestActionCopyLinePlain(t *testing.T) {
+	m := testModelWithLines()
+	m.lines = []runner.Line{{Number: 1, Content: "\x1b[31mred\x1b[0m"}}
+	m.updateFiltered()
+	m.cursor = 0
+
+	_, cmd := m.actionCopyLine(true)
+	if m.statusMsg == "" {
+		t.Error("expected statusMsg to be set")
+	}
+	if cmd == nil {
+		t.Error("expected timeout command")
+	}
+}
+
+func TestActionShowHelp(t *testing.T) {
+	m := testModelWithLines()
+	m.actionShowHelp()
+	if !m.showHelp {
+		t.Error("expected showHelp true")
+	}
+}
+
+func TestActionOpenPalette(t *testing.T) {
+	m := testModelWithLines()
+	m.actionOpenPalette()
+	if !m.cmdPaletteMode {
+		t.Error("expected cmdPaletteMode true")
+	}
+}
+
+func TestActionEnterFilter(t *testing.T) {
+	m := testModelWithLines()
+	m.actionEnterFilter()
+	if !m.filterMode {
+		t.Error("expected filterMode true")
+	}
+}

internal/ui/commands.go

@@ -0,0 +1,79 @@
+package ui
+
+import (
+	"fmt"
+	"os/exec"
+	"runtime"
+	"strings"
+
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+// command represents a command palette entry
+type command struct {
+	name     string // display name
+	shortcut string // keybinding hint
+	action   func(m *model) (tea.Model, tea.Cmd)
+}
+
+// commands returns the list of available command palette entries.
+func commands() []command {
+	return []command{
+		{"Reload command", "r / Ctrl+r", (*model).actionReload},
+		{"Reload & clear lines", "R", (*model).actionReloadClear},
+		{"Delete selected line", "d / Del", (*model).actionDeleteLine},
+		{"Clear all lines", "D", (*model).actionClearAllLines},
+		{"Stop running command", "c", (*model).actionStopCommand},
+		{"Toggle preview pane", "p", (*model).actionTogglePreview},
+		{"Increase preview size", "+", (*model).actionIncreasePreview},
+		{"Decrease preview size", "-", (*model).actionDecreasePreview},
+		{"Go to first line", "g", (*model).actionGoToFirst},
+		{"Go to last line", "G", (*model).actionGoToLast},
+		{"Enter filter mode", "/", (*model).actionEnterFilter},
+		{"Toggle regex filter", "//", (*model).actionToggleRegexFilter},
+		{"Copy line to clipboard", "y", func(m *model) (tea.Model, tea.Cmd) { return m.actionCopyLine(false) }},
+		{"Copy line (plain text)", "Y", func(m *model) (tea.Model, tea.Cmd) { return m.actionCopyLine(true) }},
+		{"Show help", "?", (*model).actionShowHelp},
+		{"Quit", "q", (*model).actionQuit},
+	}
+}
+
+// filteredCommands returns commands matching the current palette filter.
+func (m *model) filteredCommands() []command {
+	all := commands()
+	if m.cmdPaletteFilter == "" {
+		return all
+	}
+	filter := strings.ToLower(m.cmdPaletteFilter)
+	var result []command
+	for _, c := range all {
+		if strings.Contains(strings.ToLower(c.name), filter) {
+			result = append(result, c)
+		}
+	}
+	return result
+}
+
+// copyToClipboard copies text to the system clipboard using OS-specific commands
+func copyToClipboard(text string) error {
+	var cmd *exec.Cmd
+
+	switch runtime.GOOS {
+	case "darwin":
+		cmd = exec.Command("pbcopy")
+	case "linux":
+		// Try xclip first, fall back to xsel
+		if _, err := exec.LookPath("xclip"); err == nil {
+			cmd = exec.Command("xclip", "-selection", "clipboard")
+		} else {
+			cmd = exec.Command("xsel", "--clipboard", "--input")
+		}
+	case "windows":
+		cmd = exec.Command("clip")
+	default:
+		return fmt.Errorf("unsupported platform: %s", runtime.GOOS)
+	}
+
+	cmd.Stdin = strings.NewReader(text)
+	return cmd.Run()
+}

internal/ui/commands_test.go

@@ -0,0 +1,59 @@
+package ui
+
+import (
+	"testing"
+)
+
+func TestCommandsCount(t *testing.T) {
+	cmds := commands()
+	if len(cmds) != 16 {
+		t.Errorf("expected 16 commands, got %d", len(cmds))
+	}
+}
+
+func TestFilteredCommandsNoFilter(t *testing.T) {
+	m := testModelWithLines()
+	m.cmdPaletteFilter = ""
+	filtered := m.filteredCommands()
+	all := commands()
+	if len(filtered) != len(all) {
+		t.Errorf("expected %d commands with no filter, got %d", len(all), len(filtered))
+	}
+}
+
+func TestFilteredCommandsWithFilter(t *testing.T) {
+	m := testModelWithLines()
+	m.cmdPaletteFilter = "reload"
+	filtered := m.filteredCommands()
+	// "Reload command" and "Reload & clear lines"
+	if len(filtered) != 2 {
+		t.Errorf("expected 2 commands matching 'reload', got %d", len(filtered))
+	}
+}
+
+func TestFilteredCommandsCaseInsensitive(t *testing.T) {
+	m := testModelWithLines()
+	m.cmdPaletteFilter = "QUIT"
+	filtered := m.filteredCommands()
+	if len(filtered) != 1 {
+		t.Errorf("expected 1 command matching 'QUIT', got %d", len(filtered))
+	}
+}
+
+func TestCommandPaletteTogglePreview(t *testing.T) {
+	m := testModelWithLines()
+	m.showPreview = false
+
+	// Find and execute "Toggle preview pane" command
+	cmds := commands()
+	for _, cmd := range cmds {
+		if cmd.name == "Toggle preview pane" {
+			cmd.action(m)
+			break
+		}
+	}
+
+	if !m.showPreview {
+		t.Error("expected showPreview true after toggle command")
+	}
+}

internal/ui/helpers_test.go

@@ -0,0 +1,36 @@
+package ui
+
+import (
+	"context"
+
+	"github.com/chenasraf/watchr/internal/runner"
+)
+
+func testModel(cfg Config) *model {
+	m := initialModel(cfg)
+	return &m
+}
+
+func testModelWithLines() *model {
+	cfg := Config{Command: "echo test", Shell: "sh"}
+	m := testModel(cfg)
+	m.lines = []runner.Line{
+		{Number: 1, Content: "hello world"},
+		{Number: 2, Content: "foo bar"},
+		{Number: 3, Content: "hello foo"},
+		{Number: 4, Content: "baz qux"},
+	}
+	m.height = 30
+	m.width = 80
+	m.updateFiltered()
+	return m
+}
+
+func testModelWithCancel() *model {
+	cfg := Config{Command: "echo test", Shell: "sh"}
+	m := initialModel(cfg)
+	ctx, cancel := context.WithCancel(context.Background())
+	m.ctx = ctx
+	m.cancel = cancel
+	return &m
+}

internal/ui/keys.go

@@ -0,0 +1,230 @@
+package ui
+
+import (
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+func (m *model) handleKeyPress(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
+	if m.showHelp {
+		return m.handleHelpMode(msg)
+	}
+	if m.confirmMode {
+		return m.handleConfirmMode(msg)
+	}
+	if m.cmdPaletteMode {
+		return m.handleCmdPaletteMode(msg)
+	}
+	if m.filterMode {
+		return m.handleFilterMode(msg)
+	}
+	return m.handleNormalMode(msg)
+}
+
+func (m *model) handleHelpMode(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
+	switch msg.String() {
+	case "?", "esc", "q", "enter":
+		m.showHelp = false
+	}
+	return m, nil
+}
+
+func (m *model) handleConfirmMode(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
+	switch msg.String() {
+	case "y", "Y":
+		m.confirmMode = false
+		if m.confirmAction != nil {
+			return m.confirmAction(m)
+		}
+	default:
+		m.confirmMode = false
+	}
+	return m, nil
+}
+
+func (m *model) handleCmdPaletteMode(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
+	switch msg.Type {
+	case tea.KeyEsc:
+		m.cmdPaletteMode = false
+		m.cmdPaletteFilter = ""
+		m.cmdPaletteCursor = 0
+		m.cmdPaletteSelected = 0
+		return m, nil
+	case tea.KeyEnter:
+		filtered := m.filteredCommands()
+		if len(filtered) > 0 && m.cmdPaletteSelected < len(filtered) {
+			m.cmdPaletteMode = false
+			cmd := filtered[m.cmdPaletteSelected]
+			m.cmdPaletteFilter = ""
+			m.cmdPaletteCursor = 0
+			m.cmdPaletteSelected = 0
+			return cmd.action(m)
+		}
+		return m, nil
+	case tea.KeyUp:
+		if m.cmdPaletteSelected > 0 {
+			m.cmdPaletteSelected--
+		}
+		return m, nil
+	case tea.KeyDown:
+		filtered := m.filteredCommands()
+		if m.cmdPaletteSelected < len(filtered)-1 {
+			m.cmdPaletteSelected++
+		}
+		return m, nil
+	case tea.KeyLeft:
+		if msg.Alt {
+			m.cmdPaletteCursor = wordBoundaryLeft(m.cmdPaletteFilter, m.cmdPaletteCursor)
+		} else if m.cmdPaletteCursor > 0 {
+			m.cmdPaletteCursor--
+		}
+		return m, nil
+	case tea.KeyRight:
+		if msg.Alt {
+			m.cmdPaletteCursor = wordBoundaryRight(m.cmdPaletteFilter, m.cmdPaletteCursor)
+		} else if m.cmdPaletteCursor < len(m.cmdPaletteFilter) {
+			m.cmdPaletteCursor++
+		}
+		return m, nil
+	case tea.KeyBackspace:
+		if msg.Alt {
+			m.cmdPaletteFilter, m.cmdPaletteCursor = textBackspaceWord(m.cmdPaletteFilter, m.cmdPaletteCursor)
+		} else {
+			m.cmdPaletteFilter, m.cmdPaletteCursor = textBackspace(m.cmdPaletteFilter, m.cmdPaletteCursor)
+		}
+		m.cmdPaletteSelected = 0
+		return m, nil
+	default:
+		if len(msg.Runes) > 0 {
+			m.cmdPaletteFilter, m.cmdPaletteCursor = textInsert(m.cmdPaletteFilter, string(msg.Runes), m.cmdPaletteCursor)
+			m.cmdPaletteSelected = 0
+		}
+		return m, nil
+	}
+}
+
+func (m *model) handleFilterMode(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
+	switch msg.Type {
+	case tea.KeyEsc:
+		m.filterMode = false
+		m.filter = ""
+		m.filterCursor = 0
+		m.filterRegex = false
+		m.filterRegexErr = nil
+		m.updateFiltered()
+		return m, nil
+	case tea.KeyEnter:
+		m.filterMode = false
+		return m, nil
+	case tea.KeyLeft:
+		if msg.Alt {
+			m.filterCursor = wordBoundaryLeft(m.filter, m.filterCursor)
+		} else if m.filterCursor > 0 {
+			m.filterCursor--
+		}
+		return m, nil
+	case tea.KeyRight:
+		if msg.Alt {
+			m.filterCursor = wordBoundaryRight(m.filter, m.filterCursor)
+		} else if m.filterCursor < len(m.filter) {
+			m.filterCursor++
+		}
+		return m, nil
+	case tea.KeyBackspace:
+		if msg.Alt {
+			m.filter, m.filterCursor = textBackspaceWord(m.filter, m.filterCursor)
+		} else {
+			m.filter, m.filterCursor = textBackspace(m.filter, m.filterCursor)
+		}
+		m.updateFiltered()
+		return m, nil
+	default:
+		if len(msg.Runes) > 0 {
+			s := string(msg.Runes)
+			if s == "/" && m.filter == "" {
+				m.filterRegex = !m.filterRegex
+				m.filterRegexErr = nil
+			} else {
+				m.filter, m.filterCursor = textInsert(m.filter, s, m.filterCursor)
+			}
+			m.updateFiltered()
+		}
+		return m, nil
+	}
+}
+
+func (m *model) handleNormalMode(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
+	switch msg.String() {
+	case "q", "ctrl+c":
+		return m.actionQuit()
+	case "esc":
+		if m.filter != "" || m.filterRegex {
+			m.filter = ""
+			m.filterCursor = 0
+			m.filterRegex = false
+			m.filterRegexErr = nil
+			m.updateFiltered()
+			return m, nil
+		}
+		return m.actionQuit()
+
+	case "j", "down", "ctrl+n":
+		m.userScrolled = true
+		m.moveCursor(1)
+	case "k", "up", "ctrl+p":
+		m.userScrolled = true
+		m.moveCursor(-1)
+	case "g", "home":
+		return m.actionGoToFirst()
+	case "G", "end":
+		return m.actionGoToLast()
+	case "ctrl+d":
+		m.userScrolled = true
+		m.moveCursor(m.visibleLines() / 2)
+	case "ctrl+u":
+		m.userScrolled = true
+		m.moveCursor(-m.visibleLines() / 2)
+	case "J":
+		if m.showPreview {
+			m.previewOffset++
+			m.clampPreviewOffset()
+		}
+	case "K":
+		if m.showPreview && m.previewOffset > 0 {
+			m.previewOffset--
+		}
+	case "pgdown", "ctrl+f":
+		m.userScrolled = true
+		m.moveCursor(m.visibleLines())
+	case "pgup", "ctrl+b":
+		m.userScrolled = true
+		m.moveCursor(-m.visibleLines())
+	case "p":
+		return m.actionTogglePreview()
+	case "+", "=":
+		return m.actionIncreasePreview()
+	case "-":
+		return m.actionDecreasePreview()
+	case "r", "ctrl+r":
+		return m.actionReload()
+	case "R":
+		return m.actionReloadClear()
+	case "d", "delete":
+		return m.actionDeleteLine()
+	case "D":
+		return m.actionClearAllLines()
+	case "c":
+		return m.actionStopCommand()
+	case "/":
+		return m.actionEnterFilter()
+	case ":":
+		return m.actionOpenPalette()
+	case "?":
+		return m.actionShowHelp()
+	case "y":
+		return m.actionCopyLine(false)
+	case "Y":
+		return m.actionCopyLine(true)
+	}
+
+	return m, nil
+}

internal/ui/keys_test.go

@@ -0,0 +1,793 @@
+package ui
+
+import (
+	"context"
+	"testing"
+
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/chenasraf/watchr/internal/runner"
+)
+
+func TestFilterCursorMovement(t *testing.T) {
+	cfg := Config{Command: "echo test", Shell: "sh"}
+	m := testModel(cfg)
+	m.filterMode = true
+	m.filter = "hello"
+	m.filterCursor = 5
+
+	// Left arrow moves cursor left
+	keyMsg := tea.KeyMsg{Type: tea.KeyLeft}
+	result, _ := m.handleKeyPress(keyMsg)
+	m = result.(*model)
+	if m.filterCursor != 4 {
+		t.Errorf("expected filterCursor 4 after left, got %d", m.filterCursor)
+	}
+
+	// Left again
+	result, _ = m.handleKeyPress(keyMsg)
+	m = result.(*model)
+	if m.filterCursor != 3 {
+		t.Errorf("expected filterCursor 3 after second left, got %d", m.filterCursor)
+	}
+
+	// Left doesn't go below 0
+	m.filterCursor = 0
+	result, _ = m.handleKeyPress(keyMsg)
+	m = result.(*model)
+	if m.filterCursor != 0 {
+		t.Errorf("expected filterCursor 0 (clamped), got %d", m.filterCursor)
+	}
+
+	// Right arrow moves cursor right
+	m.filterCursor = 2
+	keyMsg = tea.KeyMsg{Type: tea.KeyRight}
+	result, _ = m.handleKeyPress(keyMsg)
+	m = result.(*model)
+	if m.filterCursor != 3 {
+		t.Errorf("expected filterCursor 3 after right, got %d", m.filterCursor)
+	}
+
+	// Right doesn't go past end
+	m.filterCursor = 5
+	result, _ = m.handleKeyPress(keyMsg)
+	m = result.(*model)
+	if m.filterCursor != 5 {
+		t.Errorf("expected filterCursor 5 (clamped), got %d", m.filterCursor)
+	}
+}
+
+func TestFilterAltLeftRight(t *testing.T) {
+	cfg := Config{Command: "echo test", Shell: "sh"}
+
+	t.Run("alt+left jumps to previous word boundary", func(t *testing.T) {
+		m := testModel(cfg)
+		m.filterMode = true
+		m.filter = "foo bar baz"
+		m.filterCursor = 11 // end
+
+		keyMsg := tea.KeyMsg{Type: tea.KeyLeft, Alt: true}
+		result, _ := m.handleKeyPress(keyMsg)
+		m = result.(*model)
+		if m.filterCursor != 8 {
+			t.Errorf("expected filterCursor 8, got %d", m.filterCursor)
+		}
+
+		result, _ = m.handleKeyPress(keyMsg)
+		m = result.(*model)
+		if m.filterCursor != 4 {
+			t.Errorf("expected filterCursor 4, got %d", m.filterCursor)
+		}
+
+		result, _ = m.handleKeyPress(keyMsg)
+		m = result.(*model)
+		if m.filterCursor != 0 {
+			t.Errorf("expected filterCursor 0, got %d", m.filterCursor)
+		}
+
+		// Already at start, stays at 0
+		result, _ = m.handleKeyPress(keyMsg)
+		m = result.(*model)
+		if m.filterCursor != 0 {
+			t.Errorf("expected filterCursor 0 (clamped), got %d", m.filterCursor)
+		}
+	})
+
+	t.Run("alt+right jumps to next word boundary", func(t *testing.T) {
+		m := testModel(cfg)
+		m.filterMode = true
+		m.filter = "foo bar baz"
+		m.filterCursor = 0
+
+		keyMsg := tea.KeyMsg{Type: tea.KeyRight, Alt: true}
+		result, _ := m.handleKeyPress(keyMsg)
+		m = result.(*model)
+		if m.filterCursor != 4 {
+			t.Errorf("expected filterCursor 4, got %d", m.filterCursor)
+		}
+
+		result, _ = m.handleKeyPress(keyMsg)
+		m = result.(*model)
+		if m.filterCursor != 8 {
+			t.Errorf("expected filterCursor 8, got %d", m.filterCursor)
+		}
+
+		result, _ = m.handleKeyPress(keyMsg)
+		m = result.(*model)
+		if m.filterCursor != 11 {
+			t.Errorf("expected filterCursor 11, got %d", m.filterCursor)
+		}
+
+		// Already at end, stays at 11
+		result, _ = m.handleKeyPress(keyMsg)
+		m = result.(*model)
+		if m.filterCursor != 11 {
+			t.Errorf("expected filterCursor 11 (clamped), got %d", m.filterCursor)
+		}
+	})
+
+	t.Run("alt+left skips trailing spaces", func(t *testing.T) {
+		m := testModel(cfg)
+		m.filterMode = true
+		m.filter = "foo   bar"
+		m.filterCursor = 6 // middle of spaces, before "bar"
+
+		keyMsg := tea.KeyMsg{Type: tea.KeyLeft, Alt: true}
+		result, _ := m.handleKeyPress(keyMsg)
+		m = result.(*model)
+		if m.filterCursor != 0 {
+			t.Errorf("expected filterCursor 0, got %d", m.filterCursor)
+		}
+	})
+
+	t.Run("alt+right skips trailing spaces", func(t *testing.T) {
+		m := testModel(cfg)
+		m.filterMode = true
+		m.filter = "foo   bar"
+		m.filterCursor = 3 // end of "foo"
+
+		keyMsg := tea.KeyMsg{Type: tea.KeyRight, Alt: true}
+		result, _ := m.handleKeyPress(keyMsg)
+		m = result.(*model)
+		if m.filterCursor != 6 {
+			t.Errorf("expected filterCursor 6, got %d", m.filterCursor)
+		}
+	})
+}
+
+func TestFilterInsertAtCursor(t *testing.T) {
+	cfg := Config{Command: "echo test", Shell: "sh"}
+	m := testModel(cfg)
+	m.filterMode = true
+	m.filter = "helo"
+	m.filterCursor = 3
+
+	// Insert 'l' at position 3 -> "hello"
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'l'}}
+	result, _ := m.handleKeyPress(keyMsg)
+	m = result.(*model)
+	if m.filter != "hello" {
+		t.Errorf("expected filter 'hello', got %q", m.filter)
+	}
+	if m.filterCursor != 4 {
+		t.Errorf("expected filterCursor 4, got %d", m.filterCursor)
+	}
+}
+
+func TestFilterBackspaceAtCursor(t *testing.T) {
+	cfg := Config{Command: "echo test", Shell: "sh"}
+	m := testModel(cfg)
+	m.filterMode = true
+	m.filter = "hello"
+	m.filterCursor = 3
+
+	// Backspace at position 3 -> "helo"
+	keyMsg := tea.KeyMsg{Type: tea.KeyBackspace}
+	result, _ := m.handleKeyPress(keyMsg)
+	m = result.(*model)
+	if m.filter != "helo" {
+		t.Errorf("expected filter 'helo', got %q", m.filter)
+	}
+	if m.filterCursor != 2 {
+		t.Errorf("expected filterCursor 2, got %d", m.filterCursor)
+	}
+
+	// Backspace at position 0 does nothing
+	m.filterCursor = 0
+	result, _ = m.handleKeyPress(keyMsg)
+	m = result.(*model)
+	if m.filter != "helo" {
+		t.Errorf("expected filter 'helo' (unchanged), got %q", m.filter)
+	}
+	if m.filterCursor != 0 {
+		t.Errorf("expected filterCursor 0, got %d", m.filterCursor)
+	}
+}
+
+func TestFilterAltBackspace(t *testing.T) {
+	cfg := Config{Command: "echo test", Shell: "sh"}
+
+	tests := []struct {
+		name           string
+		filter         string
+		cursor         int
+		expectedFilter string
+		expectedCursor int
+	}{
+		{"delete last word", "hello world", 11, "hello ", 6},
+		{"delete middle word", "foo bar baz", 7, "foo  baz", 4},
+		{"delete first word", "hello world", 5, " world", 0},
+		{"delete with trailing spaces", "hello   ", 8, "", 0},
+		{"cursor at start", "hello", 0, "hello", 0},
+		{"single word", "hello", 5, "", 0},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			m := testModel(cfg)
+			m.filterMode = true
+			m.filter = tt.filter
+			m.filterCursor = tt.cursor
+
+			keyMsg := tea.KeyMsg{Type: tea.KeyBackspace, Alt: true}
+			result, _ := m.handleKeyPress(keyMsg)
+			newModel := result.(*model)
+
+			if newModel.filter != tt.expectedFilter {
+				t.Errorf("expected filter %q, got %q", tt.expectedFilter, newModel.filter)
+			}
+			if newModel.filterCursor != tt.expectedCursor {
+				t.Errorf("expected filterCursor %d, got %d", tt.expectedCursor, newModel.filterCursor)
+			}
+		})
+	}
+}
+
+func TestFilterRegexToggle(t *testing.T) {
+	cfg := Config{Command: "echo test", Shell: "sh"}
+	m := testModel(cfg)
+	m.filterMode = true
+	m.filter = ""
+	m.filterCursor = 0
+
+	// Type '/' on empty filter toggles regex mode on
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'/'}}
+	result, _ := m.handleKeyPress(keyMsg)
+	m = result.(*model)
+	if !m.filterRegex {
+		t.Error("expected filterRegex to be true after typing /")
+	}
+	if m.filter != "" {
+		t.Errorf("expected empty filter, got %q", m.filter)
+	}
+
+	// Type '/' again on empty filter toggles regex mode off
+	result, _ = m.handleKeyPress(keyMsg)
+	m = result.(*model)
+	if m.filterRegex {
+		t.Error("expected filterRegex to be false after second /")
+	}
+
+	// Type '/' when filter is non-empty adds it to filter
+	m.filterRegex = true
+	m.filter = "abc"
+	m.filterCursor = 3
+	result, _ = m.handleKeyPress(keyMsg)
+	m = result.(*model)
+	if m.filter != "abc/" {
+		t.Errorf("expected filter 'abc/', got %q", m.filter)
+	}
+	if !m.filterRegex {
+		t.Error("expected filterRegex to remain true")
+	}
+}
+
+func TestFilterEscClearsRegex(t *testing.T) {
+	cfg := Config{Command: "echo test", Shell: "sh"}
+	m := testModel(cfg)
+	m.filterMode = true
+	m.filter = "test"
+	m.filterCursor = 4
+	m.filterRegex = true
+
+	// Esc in filter mode clears everything
+	keyMsg := tea.KeyMsg{Type: tea.KeyEsc}
+	result, _ := m.handleKeyPress(keyMsg)
+	m = result.(*model)
+
+	if m.filterMode {
+		t.Error("expected filterMode to be false")
+	}
+	if m.filter != "" {
+		t.Errorf("expected empty filter, got %q", m.filter)
+	}
+	if m.filterCursor != 0 {
+		t.Errorf("expected filterCursor 0, got %d", m.filterCursor)
+	}
+	if m.filterRegex {
+		t.Error("expected filterRegex to be false")
+	}
+}
+
+func TestStopCommandKeybinding(t *testing.T) {
+	cfg := Config{
+		Command: "echo test",
+		Shell:   "sh",
+	}
+
+	t.Run("stops running command when streaming", func(t *testing.T) {
+		m := initialModel(cfg)
+		// Set up a cancellable context to track if cancel was called
+		ctx, cancel := context.WithCancel(context.Background())
+		m.ctx = ctx
+		m.cancel = cancel
+		m.streaming = true
+		m.statusMsg = ""
+
+		// Simulate pressing 'c'
+		keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'c'}}
+		result, cmd := m.handleKeyPress(keyMsg)
+		newModel := result.(*model)
+
+		// Should set status message
+		if newModel.statusMsg != "Command stopped" {
+			t.Errorf("expected statusMsg 'Command stopped', got %q", newModel.statusMsg)
+		}
+
+		// Should return a command (the tick for clearing status)
+		if cmd == nil {
+			t.Error("expected a command to be returned for status message timeout")
+		}
+
+		// Context should be cancelled
+		select {
+		case <-ctx.Done():
+			// Good, context was cancelled
+		default:
+			t.Error("expected context to be cancelled")
+		}
+	})
+
+	t.Run("does nothing when not streaming", func(t *testing.T) {
+		m := initialModel(cfg)
+		ctx, cancel := context.WithCancel(context.Background())
+		m.ctx = ctx
+		m.cancel = cancel
+		m.streaming = false
+		m.statusMsg = ""
+
+		// Simulate pressing 'c'
+		keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'c'}}
+		result, cmd := m.handleKeyPress(keyMsg)
+		newModel := result.(*model)
+
+		// Should not set status message
+		if newModel.statusMsg != "" {
+			t.Errorf("expected empty statusMsg, got %q", newModel.statusMsg)
+		}
+
+		// Should not return a command
+		if cmd != nil {
+			t.Error("expected no command to be returned when not streaming")
+		}
+
+		// Context should NOT be cancelled
+		select {
+		case <-ctx.Done():
+			t.Error("expected context to NOT be cancelled when not streaming")
+		default:
+			// Good, context is still active
+		}
+	})
+}
+
+// New keybinding tests
+
+func TestKeyReloadClear(t *testing.T) {
+	m := testModelWithLines()
+	if len(m.lines) == 0 {
+		t.Fatal("expected lines to be populated")
+	}
+
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'R'}}
+	result, cmd := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+
+	if newModel.lines != nil {
+		t.Errorf("expected lines to be nil after R, got %d lines", len(newModel.lines))
+	}
+	if newModel.refreshGeneration != 1 {
+		t.Errorf("expected refreshGeneration 1, got %d", newModel.refreshGeneration)
+	}
+	if cmd == nil {
+		t.Error("expected a command to be returned")
+	}
+}
+
+func TestKeyDelete(t *testing.T) {
+	m := testModelWithLines()
+	originalLen := len(m.lines)
+	m.cursor = 1 // select "foo bar"
+
+	keyMsg := tea.KeyMsg{Type: tea.KeyDelete}
+	result, _ := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+
+	if len(newModel.lines) != originalLen-1 {
+		t.Errorf("expected %d lines after delete, got %d", originalLen-1, len(newModel.lines))
+	}
+	// The second line ("foo bar") should be gone
+	for _, line := range newModel.lines {
+		if line.Content == "foo bar" {
+			t.Error("expected 'foo bar' to be deleted")
+		}
+	}
+}
+
+func TestKeyDeleteEmpty(t *testing.T) {
+	cfg := Config{Command: "echo test", Shell: "sh"}
+	m := testModel(cfg)
+	m.height = 30
+	m.width = 80
+
+	// No lines, should not panic
+	keyMsg := tea.KeyMsg{Type: tea.KeyDelete}
+	result, _ := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+	if len(newModel.lines) != 0 {
+		t.Errorf("expected 0 lines, got %d", len(newModel.lines))
+	}
+}
+
+func TestKeyCtrlDelete(t *testing.T) {
+	m := testModelWithLines()
+	// ctrl+delete is hard to simulate via tea.KeyMsg, so test the confirm flow directly
+	m.confirmMode = true
+	m.confirmMessage = "Clear all lines? (y/N)"
+	m.confirmAction = func(m *model) (tea.Model, tea.Cmd) {
+		m.lines = nil
+		m.updateFiltered()
+		m.statusMsg = "All lines cleared"
+		return m, nil
+	}
+
+	// Test confirmation with 'y'
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'y'}}
+	result, _ := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+	if newModel.lines != nil {
+		t.Errorf("expected lines to be nil after confirm, got %d", len(newModel.lines))
+	}
+	if newModel.statusMsg != "All lines cleared" {
+		t.Errorf("expected status 'All lines cleared', got %q", newModel.statusMsg)
+	}
+}
+
+func TestKeyConfirmDialog(t *testing.T) {
+	t.Run("y confirms action", func(t *testing.T) {
+		m := testModelWithLines()
+		confirmed := false
+		m.confirmMode = true
+		m.confirmMessage = "Test?"
+		m.confirmAction = func(m *model) (tea.Model, tea.Cmd) {
+			confirmed = true
+			return m, nil
+		}
+
+		keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'y'}}
+		result, _ := m.handleKeyPress(keyMsg)
+		newModel := result.(*model)
+
+		if !confirmed {
+			t.Error("expected confirm action to be called")
+		}
+		if newModel.confirmMode {
+			t.Error("expected confirmMode to be false after confirm")
+		}
+	})
+
+	t.Run("other key cancels", func(t *testing.T) {
+		m := testModelWithLines()
+		confirmed := false
+		m.confirmMode = true
+		m.confirmMessage = "Test?"
+		m.confirmAction = func(m *model) (tea.Model, tea.Cmd) {
+			confirmed = true
+			return m, nil
+		}
+
+		keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'n'}}
+		result, _ := m.handleKeyPress(keyMsg)
+		newModel := result.(*model)
+
+		if confirmed {
+			t.Error("expected confirm action NOT to be called")
+		}
+		if newModel.confirmMode {
+			t.Error("expected confirmMode to be false after cancel")
+		}
+	})
+}
+
+func TestKeyGoToFirstLast(t *testing.T) {
+	m := testModelWithLines()
+	m.cursor = 2
+
+	// Go to first line with 'g'
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'g'}}
+	result, _ := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+
+	if newModel.cursor != 0 {
+		t.Errorf("expected cursor 0 after 'g', got %d", newModel.cursor)
+	}
+	if newModel.offset != 0 {
+		t.Errorf("expected offset 0 after 'g', got %d", newModel.offset)
+	}
+	if !newModel.userScrolled {
+		t.Error("expected userScrolled true after 'g'")
+	}
+
+	// Go to last line with 'G'
+	keyMsg = tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'G'}}
+	result, _ = newModel.handleKeyPress(keyMsg)
+	newModel = result.(*model)
+
+	if newModel.cursor != len(newModel.filtered)-1 {
+		t.Errorf("expected cursor at last line (%d), got %d", len(newModel.filtered)-1, newModel.cursor)
+	}
+	if newModel.userScrolled {
+		t.Error("expected userScrolled false after 'G' (resume following)")
+	}
+}
+
+func TestKeyPreviewScrollJK(t *testing.T) {
+	m := testModelWithLines()
+	m.showPreview = true
+	m.config.PreviewSize = 5
+	m.config.PreviewSizeIsPercent = false
+	m.config.PreviewPosition = PreviewBottom
+
+	// J scrolls preview down
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'J'}}
+	result, _ := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+	// previewOffset might be clamped to 0 for short content, but the code path runs
+	if newModel.previewOffset < 0 {
+		t.Errorf("expected previewOffset >= 0, got %d", newModel.previewOffset)
+	}
+
+	// Set offset to 1 and test K scrolls up
+	newModel.previewOffset = 1
+	keyMsg = tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'K'}}
+	result, _ = newModel.handleKeyPress(keyMsg)
+	newModel = result.(*model)
+	if newModel.previewOffset != 0 {
+		t.Errorf("expected previewOffset 0 after K, got %d", newModel.previewOffset)
+	}
+}
+
+func TestKeyPreviewScrollJKWithoutPreview(t *testing.T) {
+	m := testModelWithLines()
+	m.showPreview = false
+
+	// J should not change previewOffset when preview is hidden
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'J'}}
+	result, _ := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+	if newModel.previewOffset != 0 {
+		t.Errorf("expected previewOffset 0 when preview hidden, got %d", newModel.previewOffset)
+	}
+}
+
+func TestKeyTogglePreview(t *testing.T) {
+	m := testModelWithLines()
+	if m.showPreview {
+		t.Fatal("expected showPreview false initially")
+	}
+
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'p'}}
+	result, _ := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+	if !newModel.showPreview {
+		t.Error("expected showPreview true after 'p'")
+	}
+
+	result, _ = newModel.handleKeyPress(keyMsg)
+	newModel = result.(*model)
+	if newModel.showPreview {
+		t.Error("expected showPreview false after second 'p'")
+	}
+}
+
+func TestKeyResizePreview(t *testing.T) {
+	m := testModelWithLines()
+	m.showPreview = true
+	m.config.PreviewSize = 10
+	m.config.PreviewSizeIsPercent = false
+
+	// '+' increases
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'+'}}
+	result, _ := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+	if newModel.config.PreviewSize != 12 {
+		t.Errorf("expected PreviewSize 12 after '+', got %d", newModel.config.PreviewSize)
+	}
+
+	// '-' decreases
+	keyMsg = tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'-'}}
+	result, _ = newModel.handleKeyPress(keyMsg)
+	newModel = result.(*model)
+	if newModel.config.PreviewSize != 10 {
+		t.Errorf("expected PreviewSize 10 after '-', got %d", newModel.config.PreviewSize)
+	}
+
+	// '-' doesn't go below step
+	newModel.config.PreviewSize = 2
+	result, _ = newModel.handleKeyPress(keyMsg)
+	newModel = result.(*model)
+	if newModel.config.PreviewSize != 2 {
+		t.Errorf("expected PreviewSize 2 (minimum), got %d", newModel.config.PreviewSize)
+	}
+}
+
+func TestKeyCmdPaletteOpenAndNav(t *testing.T) {
+	m := testModelWithLines()
+
+	// ':' opens command palette
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{':'}}
+	result, _ := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+	if !newModel.cmdPaletteMode {
+		t.Error("expected cmdPaletteMode true after ':'")
+	}
+
+	// Down arrow moves selection
+	keyMsg = tea.KeyMsg{Type: tea.KeyDown}
+	result, _ = newModel.handleKeyPress(keyMsg)
+	newModel = result.(*model)
+	if newModel.cmdPaletteSelected != 1 {
+		t.Errorf("expected cmdPaletteSelected 1, got %d", newModel.cmdPaletteSelected)
+	}
+
+	// Up arrow moves selection back
+	keyMsg = tea.KeyMsg{Type: tea.KeyUp}
+	result, _ = newModel.handleKeyPress(keyMsg)
+	newModel = result.(*model)
+	if newModel.cmdPaletteSelected != 0 {
+		t.Errorf("expected cmdPaletteSelected 0, got %d", newModel.cmdPaletteSelected)
+	}
+
+	// Typing filters
+	keyMsg = tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'r'}}
+	result, _ = newModel.handleKeyPress(keyMsg)
+	newModel = result.(*model)
+	if newModel.cmdPaletteFilter != "r" {
+		t.Errorf("expected cmdPaletteFilter 'r', got %q", newModel.cmdPaletteFilter)
+	}
+
+	// Esc closes palette
+	keyMsg = tea.KeyMsg{Type: tea.KeyEsc}
+	result, _ = newModel.handleKeyPress(keyMsg)
+	newModel = result.(*model)
+	if newModel.cmdPaletteMode {
+		t.Error("expected cmdPaletteMode false after Esc")
+	}
+}
+
+func TestKeyHelpToggle(t *testing.T) {
+	m := testModelWithLines()
+
+	// '?' opens help
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'?'}}
+	result, _ := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+	if !newModel.showHelp {
+		t.Error("expected showHelp true after '?'")
+	}
+
+	// '?' closes help
+	result, _ = newModel.handleKeyPress(keyMsg)
+	newModel = result.(*model)
+	if newModel.showHelp {
+		t.Error("expected showHelp false after second '?'")
+	}
+}
+
+func TestKeyQuit(t *testing.T) {
+	m := testModelWithCancel()
+
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'q'}}
+	_, cmd := m.handleKeyPress(keyMsg)
+
+	if cmd == nil {
+		t.Error("expected quit command to be returned")
+	}
+}
+
+func TestKeyFilterMode(t *testing.T) {
+	m := testModelWithLines()
+
+	// '/' enters filter mode
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'/'}}
+	result, _ := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+	if !newModel.filterMode {
+		t.Error("expected filterMode true after '/'")
+	}
+}
+
+func TestKeyResizePreviewNoEffect(t *testing.T) {
+	// '+' and '-' do nothing when preview is not shown
+	m := testModelWithLines()
+	m.showPreview = false
+	m.config.PreviewSize = 10
+
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'+'}}
+	result, _ := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+	if newModel.config.PreviewSize != 10 {
+		t.Errorf("expected PreviewSize unchanged at 10, got %d", newModel.config.PreviewSize)
+	}
+}
+
+func TestKeyNavigationJK(t *testing.T) {
+	m := testModelWithLines()
+	m.cursor = 0
+
+	// 'j' moves down
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'j'}}
+	result, _ := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+	if newModel.cursor != 1 {
+		t.Errorf("expected cursor 1 after 'j', got %d", newModel.cursor)
+	}
+	if !newModel.userScrolled {
+		t.Error("expected userScrolled true after 'j'")
+	}
+
+	// 'k' moves up
+	keyMsg = tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'k'}}
+	result, _ = newModel.handleKeyPress(keyMsg)
+	newModel = result.(*model)
+	if newModel.cursor != 0 {
+		t.Errorf("expected cursor 0 after 'k', got %d", newModel.cursor)
+	}
+}
+
+func TestKeyYank(t *testing.T) {
+	m := testModelWithLines()
+	m.cursor = 0
+
+	// 'y' should set a status message (clipboard may or may not work in test env)
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'y'}}
+	result, cmd := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+
+	// Should have set some status message (either success or failure)
+	if newModel.statusMsg == "" {
+		t.Error("expected statusMsg to be set after 'y'")
+	}
+	if cmd == nil {
+		t.Error("expected a command for status timeout")
+	}
+}
+
+func TestKeyYankPlain(t *testing.T) {
+	m := testModelWithLines()
+	m.lines = []runner.Line{
+		{Number: 1, Content: "\x1b[31mred text\x1b[0m"},
+	}
+	m.updateFiltered()
+	m.cursor = 0
+
+	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'Y'}}
+	result, cmd := m.handleKeyPress(keyMsg)
+	newModel := result.(*model)
+
+	if newModel.statusMsg == "" {
+		t.Error("expected statusMsg to be set after 'Y'")
+	}
+	if cmd == nil {
+		t.Error("expected a command for status timeout")
+	}
+}

internal/ui/layout.go

@@ -0,0 +1,161 @@
+package ui
+
+import (
+	"regexp"
+	"strings"
+)
+
+func (m *model) moveCursor(delta int) {
+	m.previewOffset = 0
+	m.cursor += delta
+	if m.cursor < 0 {
+		m.cursor = 0
+	}
+	if m.cursor >= len(m.filtered) {
+		m.cursor = len(m.filtered) - 1
+	}
+	if m.cursor < 0 {
+		m.cursor = 0
+	}
+	m.adjustOffset()
+}
+
+func (m *model) adjustOffset() {
+	visible := m.visibleLines()
+	if visible <= 0 {
+		return
+	}
+
+	// Try to center the cursor
+	idealOffset := m.cursor - visible/2
+
+	// Clamp to valid range
+	idealOffset = max(idealOffset, 0)
+	maxOffset := max(len(m.filtered)-visible, 0)
+	idealOffset = min(idealOffset, maxOffset)
+
+	m.offset = idealOffset
+}
+
+func previewSizeStep(isPercent bool) int {
+	if isPercent {
+		return 5
+	}
+	return 2
+}
+
+// clampPreviewOffset computes the actual preview content size and clamps
+// previewOffset so it can't exceed the scrollable range.
+func (m *model) clampPreviewOffset() {
+	if !m.showPreview || m.cursor < 0 || m.cursor >= len(m.filtered) {
+		m.previewOffset = 0
+		return
+	}
+	idx := m.filtered[m.cursor]
+	if idx >= len(m.lines) {
+		m.previewOffset = 0
+		return
+	}
+
+	content := highlightJSON(m.lines[idx].Content)
+	innerWidth := m.width - 2
+
+	var previewW, visibleH int
+	switch m.config.PreviewPosition {
+	case PreviewTop, PreviewBottom:
+		previewW = innerWidth
+		visibleH = m.previewSize()
+	case PreviewLeft:
+		previewW = m.previewSize()
+		visibleH = m.visibleLines()
+	case PreviewRight:
+		previewW = m.previewSize()
+		visibleH = m.visibleLines()
+	}
+
+	previewLines := wrapPreviewContent(content, previewW)
+	maxOffset := max(len(previewLines)-visibleH, 0)
+	if m.previewOffset > maxOffset {
+		m.previewOffset = maxOffset
+	}
+}
+
+// applyPreviewOffset slices previewLines based on the current preview scroll
+// offset, clamping the offset so it doesn't scroll past the content.
+func (m *model) applyPreviewOffset(previewLines []string, visibleH int) []string {
+	maxOffset := max(len(previewLines)-visibleH, 0)
+	if m.previewOffset > maxOffset {
+		m.previewOffset = maxOffset
+	}
+	if m.previewOffset > 0 {
+		previewLines = previewLines[m.previewOffset:]
+	}
+	return previewLines
+}
+
+func (m model) previewSize() int {
+	if m.config.PreviewSizeIsPercent {
+		if m.config.PreviewPosition == PreviewLeft || m.config.PreviewPosition == PreviewRight {
+			return m.width * m.config.PreviewSize / 100
+		}
+		return m.height * m.config.PreviewSize / 100
+	}
+	return m.config.PreviewSize
+}
+
+func (m model) visibleLines() int {
+	// Fixed lines: top border (1) + header (1) + separator (1) + bottom border (1) + prompt (1) = 5
+	fixedLines := 5
+	if m.showPreview && (m.config.PreviewPosition == PreviewTop || m.config.PreviewPosition == PreviewBottom) {
+		// Add preview height + separator between content and preview
+		return m.height - fixedLines - m.previewSize() - 1
+	}
+	return m.height - fixedLines
+}
+
+func (m *model) updateFiltered() {
+	m.filtered = []int{}
+	m.filterRegexErr = nil
+
+	if m.filterRegex && m.filter != "" {
+		re, err := regexp.Compile("(?i)" + m.filter)
+		if err != nil {
+			m.filterRegexErr = err
+			// Show all lines when regex is invalid
+			for i := range m.lines {
+				m.filtered = append(m.filtered, i)
+			}
+		} else {
+			for i, line := range m.lines {
+				if re.MatchString(line.Content) {
+					m.filtered = append(m.filtered, i)
+				}
+			}
+		}
+	} else {
+		filter := strings.ToLower(m.filter)
+		for i, line := range m.lines {
+			if m.filter == "" || strings.Contains(strings.ToLower(line.Content), filter) {
+				m.filtered = append(m.filtered, i)
+			}
+		}
+	}
+
+	// Reset cursor if out of bounds
+	if m.cursor >= len(m.filtered) {
+		m.cursor = len(m.filtered) - 1
+	}
+	if m.cursor < 0 {
+		m.cursor = 0
+	}
+
+	// Clamp offset to valid bounds instead of resetting to 0
+	// This preserves scroll position during streaming updates
+	visible := m.visibleLines()
+	if visible > 0 {
+		maxOffset := max(len(m.filtered)-visible, 0)
+		if m.offset > maxOffset {
+			m.offset = maxOffset
+		}
+	}
+}

internal/ui/layout_test.go

@@ -0,0 +1,363 @@
+package ui
+
+import (
+	"testing"
+
+	"github.com/chenasraf/watchr/internal/runner"
+)
+
+func TestModelUpdateFiltered(t *testing.T) {
+	cfg := Config{
+		Command: "echo test",
+		Shell:   "sh",
+	}
+
+	m := initialModel(cfg)
+
+	// Add some test lines
+	m.lines = []runner.Line{
+		{Number: 1, Content: "hello world"},
+		{Number: 2, Content: "foo bar"},
+		{Number: 3, Content: "hello foo"},
+		{Number: 4, Content: "baz qux"},
+	}
+
+	// Test with no filter
+	m.filter = ""
+	m.updateFiltered()
+
+	if len(m.filtered) != 4 {
+		t.Errorf("expected 4 filtered lines, got %d", len(m.filtered))
+	}
+
+	// Test with filter
+	m.filter = "hello"
+	m.updateFiltered()
+
+	if len(m.filtered) != 2 {
+		t.Errorf("expected 2 filtered lines for 'hello', got %d", len(m.filtered))
+	}
+
+	// Test case insensitive
+	m.filter = "HELLO"
+	m.updateFiltered()
+
+	if len(m.filtered) != 2 {
+		t.Errorf("expected 2 filtered lines for 'HELLO' (case insensitive), got %d", len(m.filtered))
+	}
+
+	// Test no matches
+	m.filter = "xyz"
+	m.updateFiltered()
+
+	if len(m.filtered) != 0 {
+		t.Errorf("expected 0 filtered lines for 'xyz', got %d", len(m.filtered))
+	}
+}
+
+func TestModelMoveCursor(t *testing.T) {
+	cfg := Config{
+		Command: "echo test",
+		Shell:   "sh",
+	}
+
+	m := initialModel(cfg)
+	m.filtered = []int{0, 1, 2, 3, 4}
+	m.height = 100 // enough height for all lines
+
+	// Move down
+	m.moveCursor(1)
+	if m.cursor != 1 {
+		t.Errorf("expected cursor at 1, got %d", m.cursor)
+	}
+
+	// Move down more
+	m.moveCursor(2)
+	if m.cursor != 3 {
+		t.Errorf("expected cursor at 3, got %d", m.cursor)
+	}
+
+	// Move past end
+	m.moveCursor(10)
+	if m.cursor != 4 {
+		t.Errorf("expected cursor at 4 (clamped), got %d", m.cursor)
+	}
+
+	// Move up
+	m.moveCursor(-2)
+	if m.cursor != 2 {
+		t.Errorf("expected cursor at 2, got %d", m.cursor)
+	}
+
+	// Move past beginning
+	m.moveCursor(-10)
+	if m.cursor != 0 {
+		t.Errorf("expected cursor at 0 (clamped), got %d", m.cursor)
+	}
+}
+
+func TestVisibleLines(t *testing.T) {
+	cfg := Config{
+		Command:              "echo test",
+		Shell:                "sh",
+		PreviewSize:          40,
+		PreviewSizeIsPercent: true,
+		PreviewPosition:      PreviewBottom,
+	}
+
+	m := initialModel(cfg)
+	m.height = 100
+
+	// Fixed lines: top border (1) + header (1) + separator (1) + bottom border (1) + prompt (1) = 5
+	fixedLines := 5
+
+	// Without preview
+	m.showPreview = false
+	visible := m.visibleLines()
+	expected := 100 - fixedLines
+	if visible != expected {
+		t.Errorf("expected %d visible lines without preview, got %d", expected, visible)
+	}
+
+	// With preview at bottom (percentage)
+	m.showPreview = true
+	visible = m.visibleLines()
+	previewHeight := 100 * 40 / 100 // 40%
+	// Add 1 for the separator between content and preview
+	expected = 100 - fixedLines - previewHeight - 1
+	if visible != expected {
+		t.Errorf("expected %d visible lines with preview, got %d", expected, visible)
+	}
+
+	// With preview using absolute size
+	m.config.PreviewSizeIsPercent = false
+	m.config.PreviewSize = 10
+	visible = m.visibleLines()
+	// Add 1 for the separator between content and preview
+	expected = 100 - fixedLines - 10 - 1
+	if visible != expected {
+		t.Errorf("expected %d visible lines with absolute preview size, got %d", expected, visible)
+	}
+}
+
+func TestUpdateFilteredPreservesOffset(t *testing.T) {
+	cfg := Config{
+		Command: "echo test",
+		Shell:   "sh",
+	}
+
+	m := initialModel(cfg)
+	m.height = 20 // Enough for visibleLines to return > 0
+
+	// Add many test lines
+	for i := 1; i <= 100; i++ {
+		m.lines = append(m.lines, runner.Line{Number: i, Content: "line content"})
+	}
+
+	// Set initial state with offset
+	m.filter = ""
+	m.updateFiltered()
+	m.offset = 50
+	m.cursor = 55
+
+	// Simulate streaming update - add more lines without changing filter
+	m.lines = append(m.lines, runner.Line{Number: 101, Content: "new line"})
+	m.updateFiltered()
+
+	// Offset should be preserved (or clamped if necessary)
+	if m.offset < 50 {
+		t.Errorf("expected offset to be preserved (>= 50), got %d", m.offset)
+	}
+
+	// Cursor should be preserved
+	if m.cursor != 55 {
+		t.Errorf("expected cursor to be preserved at 55, got %d", m.cursor)
+	}
+}
+
+func TestUpdateFilteredClampsOffsetWhenNeeded(t *testing.T) {
+	cfg := Config{
+		Command: "echo test",
+		Shell:   "sh",
+	}
+
+	m := initialModel(cfg)
+	m.height = 20
+
+	// Add test lines
+	for i := 1; i <= 100; i++ {
+		m.lines = append(m.lines, runner.Line{Number: i, Content: "line content"})
+	}
+
+	m.filter = ""
+	m.updateFiltered()
+	m.offset = 90
+	m.cursor = 95
+
+	// Now filter to fewer lines
+	m.filter = "xyz" // No matches
+	m.updateFiltered()
+
+	// Offset should be clamped to valid range
+	if m.offset != 0 {
+		t.Errorf("expected offset to be clamped to 0, got %d", m.offset)
+	}
+
+	// Cursor should be clamped
+	if m.cursor != 0 {
+		t.Errorf("expected cursor to be clamped to 0, got %d", m.cursor)
+	}
+}
+
+func TestFilterRegexMatching(t *testing.T) {
+	cfg := Config{Command: "echo test", Shell: "sh"}
+	m := initialModel(cfg)
+	m.lines = []runner.Line{
+		{Number: 1, Content: "hello world"},
+		{Number: 2, Content: "foo bar"},
+		{Number: 3, Content: "hello foo"},
+		{Number: 4, Content: "baz 123 qux"},
+	}
+
+	// Regex filter matching
+	m.filterRegex = true
+	m.filter = "hello.*foo"
+	m.updateFiltered()
+	if len(m.filtered) != 1 {
+		t.Errorf("expected 1 match for regex 'hello.*foo', got %d", len(m.filtered))
+	}
+	if len(m.filtered) > 0 && m.filtered[0] != 2 {
+		t.Errorf("expected match at index 2, got %d", m.filtered[0])
+	}
+
+	// Regex with character class
+	m.filter = "\\d+"
+	m.updateFiltered()
+	if len(m.filtered) != 1 {
+		t.Errorf("expected 1 match for regex '\\d+', got %d", len(m.filtered))
+	}
+
+	// Regex is case insensitive
+	m.filter = "HELLO"
+	m.updateFiltered()
+	if len(m.filtered) != 2 {
+		t.Errorf("expected 2 matches for case-insensitive regex 'HELLO', got %d", len(m.filtered))
+	}
+}
+
+func TestFilterRegexInvalid(t *testing.T) {
+	cfg := Config{Command: "echo test", Shell: "sh"}
+	m := initialModel(cfg)
+	m.lines = []runner.Line{
+		{Number: 1, Content: "hello world"},
+		{Number: 2, Content: "foo bar"},
+	}
+
+	m.filterRegex = true
+	m.filter = "[invalid"
+	m.updateFiltered()
+
+	// Should have an error
+	if m.filterRegexErr == nil {
+		t.Error("expected filterRegexErr to be non-nil for invalid regex")
+	}
+
+	// Should show all lines when regex is invalid
+	if len(m.filtered) != 2 {
+		t.Errorf("expected all 2 lines shown for invalid regex, got %d", len(m.filtered))
+	}
+
+	// Valid regex clears the error
+	m.filter = "hello"
+	m.updateFiltered()
+	if m.filterRegexErr != nil {
+		t.Errorf("expected filterRegexErr to be nil for valid regex, got %v", m.filterRegexErr)
+	}
+}
+
+func TestPreviewSizeStep(t *testing.T) {
+	if previewSizeStep(true) != 5 {
+		t.Errorf("expected 5 for percent mode, got %d", previewSizeStep(true))
+	}
+	if previewSizeStep(false) != 2 {
+		t.Errorf("expected 2 for absolute mode, got %d", previewSizeStep(false))
+	}
+}
+
+func TestClampPreviewOffset(t *testing.T) {
+	m := testModelWithLines()
+	m.showPreview = true
+	m.config.PreviewPosition = PreviewBottom
+	m.config.PreviewSize = 5
+	m.config.PreviewSizeIsPercent = false
+
+	// Set an excessively high offset
+	m.previewOffset = 100
+	m.clampPreviewOffset()
+
+	// Should be clamped to a valid range (0 for short content)
+	if m.previewOffset > 0 {
+		t.Errorf("expected previewOffset clamped to 0 for short content, got %d", m.previewOffset)
+	}
+}
+
+func TestClampPreviewOffsetNoPreview(t *testing.T) {
+	m := testModelWithLines()
+	m.showPreview = false
+	m.previewOffset = 5
+
+	m.clampPreviewOffset()
+	if m.previewOffset != 0 {
+		t.Errorf("expected previewOffset reset to 0 when preview hidden, got %d", m.previewOffset)
+	}
+}
+
+func TestApplyPreviewOffset(t *testing.T) {
+	m := testModelWithLines()
+	lines := []string{"a", "b", "c", "d", "e"}
+
+	// No offset
+	m.previewOffset = 0
+	result := m.applyPreviewOffset(lines, 3)
+	if len(result) != 5 {
+		t.Errorf("expected 5 lines with no offset, got %d", len(result))
+	}
+
+	// With offset
+	m.previewOffset = 2
+	result = m.applyPreviewOffset(lines, 3)
+	if len(result) != 3 || result[0] != "c" {
+		t.Errorf("expected lines starting at 'c', got %v", result)
+	}
+
+	// Offset clamped if too high
+	m.previewOffset = 10
+	_ = m.applyPreviewOffset(lines, 3)
+	if m.previewOffset != 2 {
+		t.Errorf("expected previewOffset clamped to 2, got %d", m.previewOffset)
+	}
+}
+
+func TestAdjustOffset(t *testing.T) {
+	m := testModelWithLines()
+	m.height = 15 // visibleLines = 15 - 5 = 10
+
+	// Cursor near start - offset should be 0
+	m.cursor = 0
+	m.adjustOffset()
+	if m.offset != 0 {
+		t.Errorf("expected offset 0 for cursor at start, got %d", m.offset)
+	}
+
+	// Cursor in middle of many lines
+	for i := range 50 {
+		m.filtered = append(m.filtered, i)
+	}
+	m.cursor = 25
+	m.adjustOffset()
+	// Should center the cursor
+	expected := 25 - m.visibleLines()/2
+	if m.offset != expected {
+		t.Errorf("expected offset %d for centered cursor, got %d", expected, m.offset)
+	}
+}

internal/ui/model.go

@@ -0,0 +1,98 @@
+package ui
+
+import (
+	"context"
+	"time"
+
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/chenasraf/watchr/internal/runner"
+)
+
+// PreviewPosition defines where the preview panel is displayed
+type PreviewPosition string
+
+const (
+	PreviewBottom PreviewPosition = "bottom"
+	PreviewTop    PreviewPosition = "top"
+	PreviewLeft   PreviewPosition = "left"
+	PreviewRight  PreviewPosition = "right"
+)
+
+// Config holds the UI configuration
+type Config struct {
+	Command              string
+	Shell                string
+	PreviewSize          int
+	PreviewSizeIsPercent bool
+	PreviewPosition      PreviewPosition
+	ShowLineNums         bool
+	LineNumWidth         int
+	Prompt               string
+	RefreshInterval      time.Duration
+	RefreshFromStart     bool // If true, refresh timer starts when command starts; if false, when command ends (default)
+	Interactive          bool
+}
+
+// model represents the application state
+type model struct {
+	config            Config
+	lines             []runner.Line
+	filtered          []int // indices into lines that match filter
+	cursor            int   // cursor position in filtered list
+	offset            int   // scroll offset for visible window
+	filter            string
+	filterCursor      int // cursor position within filter string
+	filterMode        bool
+	filterRegex       bool  // true when filter is in regex mode
+	filterRegexErr    error // non-nil when regex pattern is invalid
+	showPreview       bool
+	previewOffset     int  // scroll offset for preview pane
+	showHelp          bool // help overlay visible
+	width             int
+	height            int
+	runner            *runner.Runner
+	ctx               context.Context
+	cancel            context.CancelFunc
+	loading           bool
+	streaming         bool                    // true while command is running (streaming output)
+	streamResult      *runner.StreamingResult // current streaming result
+	lastLineCount     int                     // track line count for updates
+	userScrolled      bool                    // true if user manually scrolled during streaming
+	refreshGeneration int                     // incremented on manual refresh to reset timer
+	refreshStartTime  time.Time               // when the refresh timer was started
+	spinnerFrame      int                     // current spinner animation frame
+	errorMsg          string
+	statusMsg         string // temporary status message (e.g., "Yanked!")
+	exitCode          int    // last command exit code
+
+	cmdPaletteMode     bool   // whether command palette is open
+	cmdPaletteFilter   string // current filter text
+	cmdPaletteCursor   int    // cursor position within filter string
+	cmdPaletteSelected int    // selected item index in filtered list
+
+	confirmMode    bool   // whether a confirmation dialog is visible
+	confirmMessage string // message to display in confirmation dialog
+	confirmAction  func(m *model) (tea.Model, tea.Cmd)
+}
+
+// messages
+type resultMsg struct {
+	lines    []runner.Line
+	exitCode int
+}
+type errMsg struct{ err error }
+type tickMsg struct {
+	generation int
+}
+type clearStatusMsg struct{}
+type spinnerTickMsg time.Time
+type streamTickMsg time.Time   // periodic check for streaming updates
+type startStreamMsg struct{}   // trigger to start streaming
+type countdownTickMsg struct { // periodic update for refresh countdown display
+	generation int
+}
+
+// Spinner frames for the loading animation
+var spinnerFrames = []string{"⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"}
+
+func (e errMsg) Error() string { return e.err.Error() }

internal/ui/model_test.go

@@ -0,0 +1,210 @@
+package ui
+
+import (
+	"testing"
+	"time"
+)
+
+func TestConfig(t *testing.T) {
+	cfg := Config{
+		Command:              "echo test",
+		Shell:                "sh",
+		PreviewSize:          40,
+		PreviewSizeIsPercent: true,
+		PreviewPosition:      PreviewBottom,
+		ShowLineNums:         true,
+		LineNumWidth:         6,
+		Prompt:               "watchr> ",
+		RefreshInterval:      5 * time.Second,
+	}
+
+	if cfg.Command != "echo test" {
+		t.Errorf("expected command 'echo test', got %q", cfg.Command)
+	}
+
+	if cfg.Shell != "sh" {
+		t.Errorf("expected shell 'sh', got %q", cfg.Shell)
+	}
+
+	if cfg.PreviewSize != 40 {
+		t.Errorf("expected preview size 40, got %d", cfg.PreviewSize)
+	}
+
+	if !cfg.PreviewSizeIsPercent {
+		t.Error("expected PreviewSizeIsPercent to be true")
+	}
+
+	if cfg.PreviewPosition != PreviewBottom {
+		t.Errorf("expected preview position 'bottom', got %q", cfg.PreviewPosition)
+	}
+
+	if !cfg.ShowLineNums {
+		t.Error("expected ShowLineNums to be true")
+	}
+
+	if cfg.LineNumWidth != 6 {
+		t.Errorf("expected line num width 6, got %d", cfg.LineNumWidth)
+	}
+
+	if cfg.Prompt != "watchr> " {
+		t.Errorf("expected prompt 'watchr> ', got %q", cfg.Prompt)
+	}
+
+	if cfg.RefreshInterval != 5*time.Second {
+		t.Errorf("expected refresh interval 5s, got %v", cfg.RefreshInterval)
+	}
+}
+
+func TestPreviewPositionConstants(t *testing.T) {
+	tests := []struct {
+		pos  PreviewPosition
+		want string
+	}{
+		{PreviewBottom, "bottom"},
+		{PreviewTop, "top"},
+		{PreviewLeft, "left"},
+		{PreviewRight, "right"},
+	}
+
+	for _, tt := range tests {
+		if string(tt.pos) != tt.want {
+			t.Errorf("PreviewPosition %v != %q", tt.pos, tt.want)
+		}
+	}
+}
+
+func TestConfigDefaults(t *testing.T) {
+	// Test with zero values
+	cfg := Config{}
+
+	if cfg.Command != "" {
+		t.Errorf("expected empty command, got %q", cfg.Command)
+	}
+
+	if cfg.Shell != "" {
+		t.Errorf("expected empty shell, got %q", cfg.Shell)
+	}
+
+	if cfg.PreviewSize != 0 {
+		t.Errorf("expected preview size 0, got %d", cfg.PreviewSize)
+	}
+
+	if cfg.PreviewSizeIsPercent {
+		t.Error("expected PreviewSizeIsPercent to be false")
+	}
+
+	if cfg.PreviewPosition != "" {
+		t.Errorf("expected empty preview position, got %q", cfg.PreviewPosition)
+	}
+
+	if cfg.ShowLineNums {
+		t.Error("expected ShowLineNums to be false")
+	}
+
+	if cfg.LineNumWidth != 0 {
+		t.Errorf("expected line num width 0, got %d", cfg.LineNumWidth)
+	}
+
+	if cfg.Prompt != "" {
+		t.Errorf("expected empty prompt, got %q", cfg.Prompt)
+	}
+}
+
+func TestInitialModel(t *testing.T) {
+	cfg := Config{
+		Command:              "echo test",
+		Shell:                "sh",
+		PreviewSize:          40,
+		PreviewSizeIsPercent: true,
+		PreviewPosition:      PreviewBottom,
+		ShowLineNums:         true,
+		LineNumWidth:         6,
+		Prompt:               "watchr> ",
+	}
+
+	m := initialModel(cfg)
+
+	if m.config.Command != cfg.Command {
+		t.Errorf("expected command %q, got %q", cfg.Command, m.config.Command)
+	}
+
+	if m.cursor != 0 {
+		t.Errorf("expected cursor at 0, got %d", m.cursor)
+	}
+
+	if m.offset != 0 {
+		t.Errorf("expected offset at 0, got %d", m.offset)
+	}
+
+	if m.filterMode {
+		t.Error("expected filterMode to be false")
+	}
+
+	if m.showPreview {
+		t.Error("expected showPreview to be false")
+	}
+
+	if !m.loading {
+		t.Error("expected loading to be true initially")
+	}
+}
+
+func TestConfigRefreshFromStart(t *testing.T) {
+	// Test with RefreshFromStart false (default)
+	cfg := Config{
+		Command:          "echo test",
+		Shell:            "sh",
+		RefreshInterval:  5 * time.Second,
+		RefreshFromStart: false,
+	}
+
+	if cfg.RefreshFromStart {
+		t.Error("expected RefreshFromStart to be false by default")
+	}
+
+	// Test with RefreshFromStart true
+	cfg.RefreshFromStart = true
+	if !cfg.RefreshFromStart {
+		t.Error("expected RefreshFromStart to be true after setting")
+	}
+}
+
+func TestModelUserScrolled(t *testing.T) {
+	cfg := Config{
+		Command: "echo test",
+		Shell:   "sh",
+	}
+
+	m := initialModel(cfg)
+
+	// Initially should be false
+	if m.userScrolled {
+		t.Error("expected userScrolled to be false initially")
+	}
+
+	// After setting, should be true
+	m.userScrolled = true
+	if !m.userScrolled {
+		t.Error("expected userScrolled to be true after setting")
+	}
+}
+
+func TestModelRefreshGeneration(t *testing.T) {
+	cfg := Config{
+		Command: "echo test",
+		Shell:   "sh",
+	}
+
+	m := initialModel(cfg)
+
+	// Initially should be 0
+	if m.refreshGeneration != 0 {
+		t.Errorf("expected refreshGeneration to be 0 initially, got %d", m.refreshGeneration)
+	}
+
+	// After incrementing
+	m.refreshGeneration++
+	if m.refreshGeneration != 1 {
+		t.Errorf("expected refreshGeneration to be 1 after increment, got %d", m.refreshGeneration)
+	}
+}

internal/ui/text.go

@@ -0,0 +1,346 @@
+package ui
+
+import (
+	"strings"
+
+	"github.com/charmbracelet/lipgloss"
+)
+
+const ellipsis = "…"
+
+// truncateToWidth truncates a string to fit within the given visual width,
+// adding an ellipsis if truncation occurs. Uses visual width, not byte count.
+func truncateToWidth(s string, maxWidth int) string {
+	if maxWidth <= 0 {
+		return ""
+	}
+	sw := lipgloss.Width(s)
+	if sw <= maxWidth {
+		return s
+	}
+	// Need to truncate - leave room for ellipsis (1 char wide)
+	targetWidth := maxWidth - 1
+	if targetWidth <= 0 {
+		return ellipsis
+	}
+
+	// Truncate rune by rune until we fit
+	var result strings.Builder
+	currentWidth := 0
+	for _, r := range s {
+		runeWidth := lipgloss.Width(string(r))
+		if currentWidth+runeWidth > targetWidth {
+			break
+		}
+		result.WriteRune(r)
+		currentWidth += runeWidth
+	}
+	return result.String() + ellipsis
+}
+
+// wrapText wraps text to fit within the given width, returning multiple lines.
+// It is ANSI-aware: escape sequences are preserved intact and don't count
+// toward the visible width. When a line wraps, any active ANSI state is
+// carried over so colours continue on the next line.
+func wrapText(s string, width int) []string {
+	if width <= 0 {
+		return nil
+	}
+	if s == "" {
+		return []string{""}
+	}
+
+	var lines []string
+	var currentLine strings.Builder
+	currentWidth := 0
+	// Track the last seen ANSI escape so we can re-apply it after a wrap
+	var activeANSI string
+
+	i := 0
+	runes := []rune(s)
+	for i < len(runes) {
+		// Check for ANSI escape sequence: ESC [ ... final_byte
+		if runes[i] == '\033' && i+1 < len(runes) && runes[i+1] == '[' {
+			// Consume entire escape sequence
+			var seq strings.Builder
+			seq.WriteRune(runes[i]) // ESC
+			i++
+			seq.WriteRune(runes[i]) // [
+			i++
+			for i < len(runes) {
+				seq.WriteRune(runes[i])
+				// Final byte of CSI sequence is in range 0x40-0x7E
+				if runes[i] >= 0x40 && runes[i] <= 0x7E {
+					i++
+					break
+				}
+				i++
+			}
+			seqStr := seq.String()
+			currentLine.WriteString(seqStr)
+			// Track reset vs color sequences
+			if seqStr == "\033[0m" || seqStr == "\033[m" {
+				activeANSI = ""
+			} else {
+				activeANSI = seqStr
+			}
+			continue
+		}
+
+		r := runes[i]
+		runeWidth := lipgloss.Width(string(r))
+		if currentWidth+runeWidth > width {
+			// Close any active ANSI on this line before wrapping
+			if activeANSI != "" {
+				currentLine.WriteString("\033[0m")
+			}
+			lines = append(lines, currentLine.String())
+			currentLine.Reset()
+			currentWidth = 0
+			// Re-apply active ANSI on the new line
+			if activeANSI != "" {
+				currentLine.WriteString(activeANSI)
+			}
+		}
+		currentLine.WriteRune(r)
+		currentWidth += runeWidth
+		i++
+	}
+	// Don't forget the last line
+	if currentLine.Len() > 0 {
+		lines = append(lines, currentLine.String())
+	}
+
+	return lines
+}
+
+// wrapPreviewContent splits multi-line content (e.g. pretty-printed JSON) by
+// newlines first, then wraps each line to fit within the given width.
+func wrapPreviewContent(s string, width int) []string {
+	var result []string
+	for line := range strings.SplitSeq(s, "\n") {
+		if line == "" {
+			result = append(result, "")
+			continue
+		}
+		wrapped := wrapText(line, width)
+		result = append(result, wrapped...)
+	}
+	return result
+}
+
+// splitAtVisualWidth splits a string at a visual width position, handling ANSI codes
+// Returns (left part, right part) where left has exactly targetWidth visual width
+func splitAtVisualWidth(s string, targetWidth int) (string, string) {
+	var left, right strings.Builder
+	visualWidth := 0
+	inEscape := false
+	runes := []rune(s)
+
+	i := 0
+	// Build left part up to targetWidth
+	for i < len(runes) && visualWidth < targetWidth {
+		r := runes[i]
+
+		if r == '\x1b' {
+			// Start of ANSI escape sequence - include it in left part
+			left.WriteRune(r)
+			i++
+			for i < len(runes) && !isAnsiTerminator(runes[i]) {
+				left.WriteRune(runes[i])
+				i++
+			}
+			if i < len(runes) {
+				left.WriteRune(runes[i]) // terminator
+				i++
+			}
+			continue
+		}
+
+		runeWidth := lipgloss.Width(string(r))
+		if visualWidth+runeWidth <= targetWidth {
+			left.WriteRune(r)
+			visualWidth += runeWidth
+			i++
+		} else {
+			break
+		}
+	}
+
+	// Pad left if needed
+	for visualWidth < targetWidth {
+		left.WriteRune(' ')
+		visualWidth++
+	}
+
+	// Skip runes in the "overlay zone" - we don't need them for right part calculation
+	// The caller will handle inserting the overlay content
+
+	// Build right part from remaining
+	for ; i < len(runes); i++ {
+		r := runes[i]
+		if r == '\x1b' {
+			right.WriteRune(r)
+			i++
+			for i < len(runes) && !isAnsiTerminator(runes[i]) {
+				right.WriteRune(runes[i])
+				i++
+			}
+			if i < len(runes) {
+				right.WriteRune(runes[i])
+			}
+			continue
+		}
+		right.WriteRune(r)
+	}
+
+	_ = inEscape // unused but kept for clarity
+	return left.String(), right.String()
+}
+
+// skipVisualWidth skips a number of visual width units in a string, handling ANSI codes
+// It preserves and returns ANSI sequences encountered during skipping so styling can be restored
+func skipVisualWidth(s string, skipWidth int) string {
+	var result strings.Builder
+	var ansiState strings.Builder // collect ANSI codes while skipping
+	visualWidth := 0
+	runes := []rune(s)
+
+	i := 0
+	// Skip until we've passed skipWidth, but collect ANSI codes
+	for i < len(runes) && visualWidth < skipWidth {
+		r := runes[i]
+
+		if r == '\x1b' {
+			// ANSI escape - collect it (don't count visual width)
+			ansiState.WriteRune(r)
+			i++
+			for i < len(runes) && !isAnsiTerminator(runes[i]) {
+				ansiState.WriteRune(runes[i])
+				i++
+			}
+			if i < len(runes) {
+				ansiState.WriteRune(runes[i]) // terminator
+				i++
+			}
+			continue
+		}
+
+		runeWidth := lipgloss.Width(string(r))
+		visualWidth += runeWidth
+		i++
+	}
+
+	// Prepend collected ANSI state to restore styling
+	result.WriteString(ansiState.String())
+
+	// Output the rest
+	for ; i < len(runes); i++ {
+		result.WriteRune(runes[i])
+	}
+
+	return result.String()
+}
+
+// wordBoundaryLeft returns the cursor position after jumping left to the previous word boundary.
+func wordBoundaryLeft(s string, pos int) int {
+	for pos > 0 && s[pos-1] == ' ' {
+		pos--
+	}
+	for pos > 0 && s[pos-1] != ' ' {
+		pos--
+	}
+	return pos
+}
+
+// wordBoundaryRight returns the cursor position after jumping right to the next word boundary.
+func wordBoundaryRight(s string, pos int) int {
+	for pos < len(s) && s[pos] != ' ' {
+		pos++
+	}
+	for pos < len(s) && s[pos] == ' ' {
+		pos++
+	}
+	return pos
+}
+
+// textInsert inserts a string at the cursor position, returning new text and cursor.
+func textInsert(text, insert string, cursor int) (string, int) {
+	return text[:cursor] + insert + text[cursor:], cursor + len(insert)
+}
+
+// textBackspace deletes one character before the cursor, returning new text and cursor.
+func textBackspace(text string, cursor int) (string, int) {
+	if cursor <= 0 {
+		return text, cursor
+	}
+	return text[:cursor-1] + text[cursor:], cursor - 1
+}
+
+// textBackspaceWord deletes the word before the cursor, returning new text and cursor.
+func textBackspaceWord(text string, cursor int) (string, int) {
+	if cursor <= 0 {
+		return text, cursor
+	}
+	newPos := wordBoundaryLeft(text, cursor)
+	return text[:newPos] + text[cursor:], newPos
+}
+
+func isAnsiTerminator(r rune) bool {
+	return (r >= 'A' && r <= 'Z') || (r >= 'a' && r <= 'z')
+}
+
+// overlayBox composites an overlay box on top of a base view
+func overlayBox(base string, box string, boxWidth, boxHeight, screenWidth, screenHeight int) string {
+	// ANSI reset sequence to stop any styling from bleeding into overlay
+	const ansiReset = "\x1b[0m"
+
+	// Split base into lines
+	baseLines := strings.Split(base, "\n")
+
+	// Ensure we have enough lines
+	for len(baseLines) < screenHeight {
+		baseLines = append(baseLines, "")
+	}
+
+	// Split box into lines
+	boxLines := strings.Split(box, "\n")
+
+	// Calculate center position
+	startX := (screenWidth - boxWidth) / 2
+	startY := (screenHeight - boxHeight) / 2
+
+	if startX < 0 {
+		startX = 0
+	}
+	if startY < 0 {
+		startY = 0
+	}
+
+	// Overlay box onto base
+	for i, boxLine := range boxLines {
+		y := startY + i
+		if y >= len(baseLines) {
+			break
+		}
+
+		baseLine := baseLines[y]
+		baseVisualWidth := lipgloss.Width(baseLine)
+
+		// Get left part (before overlay)
+		leftPart, _ := splitAtVisualWidth(baseLine, startX)
+
+		// Get right part (after overlay)
+		endX := startX + boxWidth
+		var rightPart string
+		if endX < baseVisualWidth {
+			rightPart = skipVisualWidth(baseLine, endX)
+		}
+
+		// Combine: left + reset + box + right
+		// Reset before overlay to stop highlight bleeding into overlay
+		baseLines[y] = leftPart + ansiReset + boxLine + rightPart
+	}
+
+	return strings.Join(baseLines, "\n")
+}

internal/ui/text_test.go

@@ -0,0 +1,205 @@
+package ui
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestTruncateToWidth(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		maxWidth int
+		want     string
+	}{
+		{"empty maxWidth", "hello", 0, ""},
+		{"no truncation needed", "hello", 10, "hello"},
+		{"exact fit", "hello", 5, "hello"},
+		{"truncate with ellipsis", "hello world", 8, "hello w…"},
+		{"maxWidth 1", "hello", 1, "…"},
+		{"empty string", "", 10, ""},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := truncateToWidth(tt.input, tt.maxWidth)
+			if got != tt.want {
+				t.Errorf("truncateToWidth(%q, %d) = %q, want %q", tt.input, tt.maxWidth, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestSplitAtVisualWidth(t *testing.T) {
+	t.Run("plain text", func(t *testing.T) {
+		left, right := splitAtVisualWidth("hello world", 5)
+		if left != "hello" {
+			t.Errorf("expected left 'hello', got %q", left)
+		}
+		if right != " world" {
+			t.Errorf("expected right ' world', got %q", right)
+		}
+	})
+
+	t.Run("pads if short", func(t *testing.T) {
+		left, right := splitAtVisualWidth("hi", 5)
+		if left != "hi   " {
+			t.Errorf("expected left 'hi   ', got %q", left)
+		}
+		if right != "" {
+			t.Errorf("expected empty right, got %q", right)
+		}
+	})
+
+	t.Run("with ANSI codes", func(t *testing.T) {
+		input := "\x1b[31mhello\x1b[0m world"
+		left, _ := splitAtVisualWidth(input, 5)
+		// Left should contain the ANSI code and "hello"
+		if !strings.Contains(left, "\x1b[31m") {
+			t.Error("expected left to contain ANSI color code")
+		}
+		if !strings.Contains(left, "hello") {
+			t.Error("expected left to contain 'hello'")
+		}
+	})
+}
+
+func TestSkipVisualWidth(t *testing.T) {
+	t.Run("plain text", func(t *testing.T) {
+		result := skipVisualWidth("hello world", 6)
+		if result != "world" {
+			t.Errorf("expected 'world', got %q", result)
+		}
+	})
+
+	t.Run("preserves ANSI state", func(t *testing.T) {
+		input := "\x1b[31mhello world\x1b[0m"
+		result := skipVisualWidth(input, 6)
+		// Should preserve the ANSI code encountered during skip
+		if !strings.Contains(result, "\x1b[31m") {
+			t.Error("expected ANSI state to be preserved")
+		}
+	})
+}
+
+func TestIsAnsiTerminator(t *testing.T) {
+	// Letters are terminators
+	if !isAnsiTerminator('m') {
+		t.Error("expected 'm' to be terminator")
+	}
+	if !isAnsiTerminator('A') {
+		t.Error("expected 'A' to be terminator")
+	}
+	if !isAnsiTerminator('z') {
+		t.Error("expected 'z' to be terminator")
+	}
+
+	// Digits are not terminators
+	if isAnsiTerminator('0') {
+		t.Error("expected '0' not to be terminator")
+	}
+	if isAnsiTerminator(';') {
+		t.Error("expected ';' not to be terminator")
+	}
+}
+
+func TestWordBoundaryLeft(t *testing.T) {
+	tests := []struct {
+		name string
+		s    string
+		pos  int
+		want int
+	}{
+		{"end of string", "foo bar baz", 11, 8},
+		{"middle of word", "foo bar baz", 9, 8},
+		{"at word boundary", "foo bar baz", 8, 4},
+		{"at start", "foo bar", 0, 0},
+		{"with multiple spaces", "foo   bar", 9, 6},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := wordBoundaryLeft(tt.s, tt.pos)
+			if got != tt.want {
+				t.Errorf("wordBoundaryLeft(%q, %d) = %d, want %d", tt.s, tt.pos, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestWordBoundaryRight(t *testing.T) {
+	tests := []struct {
+		name string
+		s    string
+		pos  int
+		want int
+	}{
+		{"start of string", "foo bar baz", 0, 4},
+		{"middle of word", "foo bar baz", 1, 4},
+		{"at word boundary", "foo bar baz", 4, 8},
+		{"at end", "foo bar", 7, 7},
+		{"with multiple spaces", "foo   bar", 3, 6},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := wordBoundaryRight(tt.s, tt.pos)
+			if got != tt.want {
+				t.Errorf("wordBoundaryRight(%q, %d) = %d, want %d", tt.s, tt.pos, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestTextInsert(t *testing.T) {
+	text, cursor := textInsert("helo", "l", 3)
+	if text != "hello" || cursor != 4 {
+		t.Errorf("got %q cursor %d, want 'hello' cursor 4", text, cursor)
+	}
+}
+
+func TestTextBackspace(t *testing.T) {
+	text, cursor := textBackspace("hello", 3)
+	if text != "helo" || cursor != 2 {
+		t.Errorf("got %q cursor %d, want 'helo' cursor 2", text, cursor)
+	}
+
+	// At start, no change
+	text, cursor = textBackspace("hello", 0)
+	if text != "hello" || cursor != 0 {
+		t.Errorf("got %q cursor %d, want 'hello' cursor 0", text, cursor)
+	}
+}
+
+func TestTextBackspaceWord(t *testing.T) {
+	text, cursor := textBackspaceWord("hello world", 11)
+	if text != "hello " || cursor != 6 {
+		t.Errorf("got %q cursor %d, want 'hello ' cursor 6", text, cursor)
+	}
+
+	// At start, no change
+	text, cursor = textBackspaceWord("hello", 0)
+	if text != "hello" || cursor != 0 {
+		t.Errorf("got %q cursor %d, want 'hello' cursor 0", text, cursor)
+	}
+}
+
+func TestOverlayBox(t *testing.T) {
+	base := "aaaaaaaaaa\naaaaaaaaaa\naaaaaaaaaa\naaaaaaaaaa\naaaaaaaaaa"
+	box := "XX\nXX"
+
+	result := overlayBox(base, box, 2, 2, 10, 5)
+	lines := strings.Split(result, "\n")
+
+	if len(lines) != 5 {
+		t.Errorf("expected 5 lines, got %d", len(lines))
+	}
+
+	// The overlay should appear in the middle rows
+	// Center: startY = (5-2)/2 = 1, startX = (10-2)/2 = 4
+	// Lines 1 and 2 should contain the overlay
+	if !strings.Contains(lines[1], "XX") {
+		t.Errorf("expected overlay in line 1, got %q", lines[1])
+	}
+	if !strings.Contains(lines[2], "XX") {
+		t.Errorf("expected overlay in line 2, got %q", lines[2])
+	}
+}

internal/ui/ui_test.go

@@ -1,860 +0,0 @@
-package ui
-
-import (
-	"context"
-	"testing"
-	"time"
-
-	tea "github.com/charmbracelet/bubbletea"
-	"github.com/chenasraf/watchr/internal/runner"
-)
-
-func TestConfig(t *testing.T) {
-	cfg := Config{
-		Command:              "echo test",
-		Shell:                "sh",
-		PreviewSize:          40,
-		PreviewSizeIsPercent: true,
-		PreviewPosition:      PreviewBottom,
-		ShowLineNums:         true,
-		LineNumWidth:         6,
-		Prompt:               "watchr> ",
-		RefreshInterval:      5 * time.Second,
-	}
-
-	if cfg.Command != "echo test" {
-		t.Errorf("expected command 'echo test', got %q", cfg.Command)
-	}
-
-	if cfg.Shell != "sh" {
-		t.Errorf("expected shell 'sh', got %q", cfg.Shell)
-	}
-
-	if cfg.PreviewSize != 40 {
-		t.Errorf("expected preview size 40, got %d", cfg.PreviewSize)
-	}
-
-	if !cfg.PreviewSizeIsPercent {
-		t.Error("expected PreviewSizeIsPercent to be true")
-	}
-
-	if cfg.PreviewPosition != PreviewBottom {
-		t.Errorf("expected preview position 'bottom', got %q", cfg.PreviewPosition)
-	}
-
-	if !cfg.ShowLineNums {
-		t.Error("expected ShowLineNums to be true")
-	}
-
-	if cfg.LineNumWidth != 6 {
-		t.Errorf("expected line num width 6, got %d", cfg.LineNumWidth)
-	}
-
-	if cfg.Prompt != "watchr> " {
-		t.Errorf("expected prompt 'watchr> ', got %q", cfg.Prompt)
-	}
-
-	if cfg.RefreshInterval != 5*time.Second {
-		t.Errorf("expected refresh interval 5s, got %v", cfg.RefreshInterval)
-	}
-}
-
-func TestPreviewPositionConstants(t *testing.T) {
-	tests := []struct {
-		pos  PreviewPosition
-		want string
-	}{
-		{PreviewBottom, "bottom"},
-		{PreviewTop, "top"},
-		{PreviewLeft, "left"},
-		{PreviewRight, "right"},
-	}
-
-	for _, tt := range tests {
-		if string(tt.pos) != tt.want {
-			t.Errorf("PreviewPosition %v != %q", tt.pos, tt.want)
-		}
-	}
-}
-
-func TestConfigDefaults(t *testing.T) {
-	// Test with zero values
-	cfg := Config{}
-
-	if cfg.Command != "" {
-		t.Errorf("expected empty command, got %q", cfg.Command)
-	}
-
-	if cfg.Shell != "" {
-		t.Errorf("expected empty shell, got %q", cfg.Shell)
-	}
-
-	if cfg.PreviewSize != 0 {
-		t.Errorf("expected preview size 0, got %d", cfg.PreviewSize)
-	}
-
-	if cfg.PreviewSizeIsPercent {
-		t.Error("expected PreviewSizeIsPercent to be false")
-	}
-
-	if cfg.PreviewPosition != "" {
-		t.Errorf("expected empty preview position, got %q", cfg.PreviewPosition)
-	}
-
-	if cfg.ShowLineNums {
-		t.Error("expected ShowLineNums to be false")
-	}
-
-	if cfg.LineNumWidth != 0 {
-		t.Errorf("expected line num width 0, got %d", cfg.LineNumWidth)
-	}
-
-	if cfg.Prompt != "" {
-		t.Errorf("expected empty prompt, got %q", cfg.Prompt)
-	}
-}
-
-func TestInitialModel(t *testing.T) {
-	cfg := Config{
-		Command:              "echo test",
-		Shell:                "sh",
-		PreviewSize:          40,
-		PreviewSizeIsPercent: true,
-		PreviewPosition:      PreviewBottom,
-		ShowLineNums:         true,
-		LineNumWidth:         6,
-		Prompt:               "watchr> ",
-	}
-
-	m := initialModel(cfg)
-
-	if m.config.Command != cfg.Command {
-		t.Errorf("expected command %q, got %q", cfg.Command, m.config.Command)
-	}
-
-	if m.cursor != 0 {
-		t.Errorf("expected cursor at 0, got %d", m.cursor)
-	}
-
-	if m.offset != 0 {
-		t.Errorf("expected offset at 0, got %d", m.offset)
-	}
-
-	if m.filterMode {
-		t.Error("expected filterMode to be false")
-	}
-
-	if m.showPreview {
-		t.Error("expected showPreview to be false")
-	}
-
-	if !m.loading {
-		t.Error("expected loading to be true initially")
-	}
-}
-
-func TestModelUpdateFiltered(t *testing.T) {
-	cfg := Config{
-		Command: "echo test",
-		Shell:   "sh",
-	}
-
-	m := initialModel(cfg)
-
-	// Add some test lines
-	m.lines = []runner.Line{
-		{Number: 1, Content: "hello world"},
-		{Number: 2, Content: "foo bar"},
-		{Number: 3, Content: "hello foo"},
-		{Number: 4, Content: "baz qux"},
-	}
-
-	// Test with no filter
-	m.filter = ""
-	m.updateFiltered()
-
-	if len(m.filtered) != 4 {
-		t.Errorf("expected 4 filtered lines, got %d", len(m.filtered))
-	}
-
-	// Test with filter
-	m.filter = "hello"
-	m.updateFiltered()
-
-	if len(m.filtered) != 2 {
-		t.Errorf("expected 2 filtered lines for 'hello', got %d", len(m.filtered))
-	}
-
-	// Test case insensitive
-	m.filter = "HELLO"
-	m.updateFiltered()
-
-	if len(m.filtered) != 2 {
-		t.Errorf("expected 2 filtered lines for 'HELLO' (case insensitive), got %d", len(m.filtered))
-	}
-
-	// Test no matches
-	m.filter = "xyz"
-	m.updateFiltered()
-
-	if len(m.filtered) != 0 {
-		t.Errorf("expected 0 filtered lines for 'xyz', got %d", len(m.filtered))
-	}
-}
-
-func TestModelMoveCursor(t *testing.T) {
-	cfg := Config{
-		Command: "echo test",
-		Shell:   "sh",
-	}
-
-	m := initialModel(cfg)
-	m.filtered = []int{0, 1, 2, 3, 4}
-	m.height = 100 // enough height for all lines
-
-	// Move down
-	m.moveCursor(1)
-	if m.cursor != 1 {
-		t.Errorf("expected cursor at 1, got %d", m.cursor)
-	}
-
-	// Move down more
-	m.moveCursor(2)
-	if m.cursor != 3 {
-		t.Errorf("expected cursor at 3, got %d", m.cursor)
-	}
-
-	// Move past end
-	m.moveCursor(10)
-	if m.cursor != 4 {
-		t.Errorf("expected cursor at 4 (clamped), got %d", m.cursor)
-	}
-
-	// Move up
-	m.moveCursor(-2)
-	if m.cursor != 2 {
-		t.Errorf("expected cursor at 2, got %d", m.cursor)
-	}
-
-	// Move past beginning
-	m.moveCursor(-10)
-	if m.cursor != 0 {
-		t.Errorf("expected cursor at 0 (clamped), got %d", m.cursor)
-	}
-}
-
-func TestVisibleLines(t *testing.T) {
-	cfg := Config{
-		Command:              "echo test",
-		Shell:                "sh",
-		PreviewSize:          40,
-		PreviewSizeIsPercent: true,
-		PreviewPosition:      PreviewBottom,
-	}
-
-	m := initialModel(cfg)
-	m.height = 100
-
-	// Fixed lines: top border (1) + header (1) + separator (1) + bottom border (1) + prompt (1) = 5
-	fixedLines := 5
-
-	// Without preview
-	m.showPreview = false
-	visible := m.visibleLines()
-	expected := 100 - fixedLines
-	if visible != expected {
-		t.Errorf("expected %d visible lines without preview, got %d", expected, visible)
-	}
-
-	// With preview at bottom (percentage)
-	m.showPreview = true
-	visible = m.visibleLines()
-	previewHeight := 100 * 40 / 100 // 40%
-	// Add 1 for the separator between content and preview
-	expected = 100 - fixedLines - previewHeight - 1
-	if visible != expected {
-		t.Errorf("expected %d visible lines with preview, got %d", expected, visible)
-	}
-
-	// With preview using absolute size
-	m.config.PreviewSizeIsPercent = false
-	m.config.PreviewSize = 10
-	visible = m.visibleLines()
-	// Add 1 for the separator between content and preview
-	expected = 100 - fixedLines - 10 - 1
-	if visible != expected {
-		t.Errorf("expected %d visible lines with absolute preview size, got %d", expected, visible)
-	}
-}
-
-func TestUpdateFilteredPreservesOffset(t *testing.T) {
-	cfg := Config{
-		Command: "echo test",
-		Shell:   "sh",
-	}
-
-	m := initialModel(cfg)
-	m.height = 20 // Enough for visibleLines to return > 0
-
-	// Add many test lines
-	for i := 1; i <= 100; i++ {
-		m.lines = append(m.lines, runner.Line{Number: i, Content: "line content"})
-	}
-
-	// Set initial state with offset
-	m.filter = ""
-	m.updateFiltered()
-	m.offset = 50
-	m.cursor = 55
-
-	// Simulate streaming update - add more lines without changing filter
-	m.lines = append(m.lines, runner.Line{Number: 101, Content: "new line"})
-	m.updateFiltered()
-
-	// Offset should be preserved (or clamped if necessary)
-	if m.offset < 50 {
-		t.Errorf("expected offset to be preserved (>= 50), got %d", m.offset)
-	}
-
-	// Cursor should be preserved
-	if m.cursor != 55 {
-		t.Errorf("expected cursor to be preserved at 55, got %d", m.cursor)
-	}
-}
-
-func TestUpdateFilteredClampsOffsetWhenNeeded(t *testing.T) {
-	cfg := Config{
-		Command: "echo test",
-		Shell:   "sh",
-	}
-
-	m := initialModel(cfg)
-	m.height = 20
-
-	// Add test lines
-	for i := 1; i <= 100; i++ {
-		m.lines = append(m.lines, runner.Line{Number: i, Content: "line content"})
-	}
-
-	m.filter = ""
-	m.updateFiltered()
-	m.offset = 90
-	m.cursor = 95
-
-	// Now filter to fewer lines
-	m.filter = "xyz" // No matches
-	m.updateFiltered()
-
-	// Offset should be clamped to valid range
-	if m.offset != 0 {
-		t.Errorf("expected offset to be clamped to 0, got %d", m.offset)
-	}
-
-	// Cursor should be clamped
-	if m.cursor != 0 {
-		t.Errorf("expected cursor to be clamped to 0, got %d", m.cursor)
-	}
-}
-
-func TestConfigRefreshFromStart(t *testing.T) {
-	// Test with RefreshFromStart false (default)
-	cfg := Config{
-		Command:          "echo test",
-		Shell:            "sh",
-		RefreshInterval:  5 * time.Second,
-		RefreshFromStart: false,
-	}
-
-	if cfg.RefreshFromStart {
-		t.Error("expected RefreshFromStart to be false by default")
-	}
-
-	// Test with RefreshFromStart true
-	cfg.RefreshFromStart = true
-	if !cfg.RefreshFromStart {
-		t.Error("expected RefreshFromStart to be true after setting")
-	}
-}
-
-func TestModelUserScrolled(t *testing.T) {
-	cfg := Config{
-		Command: "echo test",
-		Shell:   "sh",
-	}
-
-	m := initialModel(cfg)
-
-	// Initially should be false
-	if m.userScrolled {
-		t.Error("expected userScrolled to be false initially")
-	}
-
-	// After setting, should be true
-	m.userScrolled = true
-	if !m.userScrolled {
-		t.Error("expected userScrolled to be true after setting")
-	}
-}
-
-func TestModelRefreshGeneration(t *testing.T) {
-	cfg := Config{
-		Command: "echo test",
-		Shell:   "sh",
-	}
-
-	m := initialModel(cfg)
-
-	// Initially should be 0
-	if m.refreshGeneration != 0 {
-		t.Errorf("expected refreshGeneration to be 0 initially, got %d", m.refreshGeneration)
-	}
-
-	// After incrementing
-	m.refreshGeneration++
-	if m.refreshGeneration != 1 {
-		t.Errorf("expected refreshGeneration to be 1 after increment, got %d", m.refreshGeneration)
-	}
-}
-
-func testModel(cfg Config) *model {
-	m := initialModel(cfg)
-	return &m
-}
-
-func TestFilterCursorMovement(t *testing.T) {
-	cfg := Config{Command: "echo test", Shell: "sh"}
-	m := testModel(cfg)
-	m.filterMode = true
-	m.filter = "hello"
-	m.filterCursor = 5
-
-	// Left arrow moves cursor left
-	keyMsg := tea.KeyMsg{Type: tea.KeyLeft}
-	result, _ := m.handleKeyPress(keyMsg)
-	m = result.(*model)
-	if m.filterCursor != 4 {
-		t.Errorf("expected filterCursor 4 after left, got %d", m.filterCursor)
-	}
-
-	// Left again
-	result, _ = m.handleKeyPress(keyMsg)
-	m = result.(*model)
-	if m.filterCursor != 3 {
-		t.Errorf("expected filterCursor 3 after second left, got %d", m.filterCursor)
-	}
-
-	// Left doesn't go below 0
-	m.filterCursor = 0
-	result, _ = m.handleKeyPress(keyMsg)
-	m = result.(*model)
-	if m.filterCursor != 0 {
-		t.Errorf("expected filterCursor 0 (clamped), got %d", m.filterCursor)
-	}
-
-	// Right arrow moves cursor right
-	m.filterCursor = 2
-	keyMsg = tea.KeyMsg{Type: tea.KeyRight}
-	result, _ = m.handleKeyPress(keyMsg)
-	m = result.(*model)
-	if m.filterCursor != 3 {
-		t.Errorf("expected filterCursor 3 after right, got %d", m.filterCursor)
-	}
-
-	// Right doesn't go past end
-	m.filterCursor = 5
-	result, _ = m.handleKeyPress(keyMsg)
-	m = result.(*model)
-	if m.filterCursor != 5 {
-		t.Errorf("expected filterCursor 5 (clamped), got %d", m.filterCursor)
-	}
-}
-
-func TestFilterAltLeftRight(t *testing.T) {
-	cfg := Config{Command: "echo test", Shell: "sh"}
-
-	t.Run("alt+left jumps to previous word boundary", func(t *testing.T) {
-		m := testModel(cfg)
-		m.filterMode = true
-		m.filter = "foo bar baz"
-		m.filterCursor = 11 // end
-
-		keyMsg := tea.KeyMsg{Type: tea.KeyLeft, Alt: true}
-		result, _ := m.handleKeyPress(keyMsg)
-		m = result.(*model)
-		if m.filterCursor != 8 {
-			t.Errorf("expected filterCursor 8, got %d", m.filterCursor)
-		}
-
-		result, _ = m.handleKeyPress(keyMsg)
-		m = result.(*model)
-		if m.filterCursor != 4 {
-			t.Errorf("expected filterCursor 4, got %d", m.filterCursor)
-		}
-
-		result, _ = m.handleKeyPress(keyMsg)
-		m = result.(*model)
-		if m.filterCursor != 0 {
-			t.Errorf("expected filterCursor 0, got %d", m.filterCursor)
-		}
-
-		// Already at start, stays at 0
-		result, _ = m.handleKeyPress(keyMsg)
-		m = result.(*model)
-		if m.filterCursor != 0 {
-			t.Errorf("expected filterCursor 0 (clamped), got %d", m.filterCursor)
-		}
-	})
-
-	t.Run("alt+right jumps to next word boundary", func(t *testing.T) {
-		m := testModel(cfg)
-		m.filterMode = true
-		m.filter = "foo bar baz"
-		m.filterCursor = 0
-
-		keyMsg := tea.KeyMsg{Type: tea.KeyRight, Alt: true}
-		result, _ := m.handleKeyPress(keyMsg)
-		m = result.(*model)
-		if m.filterCursor != 4 {
-			t.Errorf("expected filterCursor 4, got %d", m.filterCursor)
-		}
-
-		result, _ = m.handleKeyPress(keyMsg)
-		m = result.(*model)
-		if m.filterCursor != 8 {
-			t.Errorf("expected filterCursor 8, got %d", m.filterCursor)
-		}
-
-		result, _ = m.handleKeyPress(keyMsg)
-		m = result.(*model)
-		if m.filterCursor != 11 {
-			t.Errorf("expected filterCursor 11, got %d", m.filterCursor)
-		}
-
-		// Already at end, stays at 11
-		result, _ = m.handleKeyPress(keyMsg)
-		m = result.(*model)
-		if m.filterCursor != 11 {
-			t.Errorf("expected filterCursor 11 (clamped), got %d", m.filterCursor)
-		}
-	})
-
-	t.Run("alt+left skips trailing spaces", func(t *testing.T) {
-		m := testModel(cfg)
-		m.filterMode = true
-		m.filter = "foo   bar"
-		m.filterCursor = 6 // middle of spaces, before "bar"
-
-		keyMsg := tea.KeyMsg{Type: tea.KeyLeft, Alt: true}
-		result, _ := m.handleKeyPress(keyMsg)
-		m = result.(*model)
-		if m.filterCursor != 0 {
-			t.Errorf("expected filterCursor 0, got %d", m.filterCursor)
-		}
-	})
-
-	t.Run("alt+right skips trailing spaces", func(t *testing.T) {
-		m := testModel(cfg)
-		m.filterMode = true
-		m.filter = "foo   bar"
-		m.filterCursor = 3 // end of "foo"
-
-		keyMsg := tea.KeyMsg{Type: tea.KeyRight, Alt: true}
-		result, _ := m.handleKeyPress(keyMsg)
-		m = result.(*model)
-		if m.filterCursor != 6 {
-			t.Errorf("expected filterCursor 6, got %d", m.filterCursor)
-		}
-	})
-}
-
-func TestFilterInsertAtCursor(t *testing.T) {
-	cfg := Config{Command: "echo test", Shell: "sh"}
-	m := testModel(cfg)
-	m.filterMode = true
-	m.filter = "helo"
-	m.filterCursor = 3
-
-	// Insert 'l' at position 3 -> "hello"
-	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'l'}}
-	result, _ := m.handleKeyPress(keyMsg)
-	m = result.(*model)
-	if m.filter != "hello" {
-		t.Errorf("expected filter 'hello', got %q", m.filter)
-	}
-	if m.filterCursor != 4 {
-		t.Errorf("expected filterCursor 4, got %d", m.filterCursor)
-	}
-}
-
-func TestFilterBackspaceAtCursor(t *testing.T) {
-	cfg := Config{Command: "echo test", Shell: "sh"}
-	m := testModel(cfg)
-	m.filterMode = true
-	m.filter = "hello"
-	m.filterCursor = 3
-
-	// Backspace at position 3 -> "helo"
-	keyMsg := tea.KeyMsg{Type: tea.KeyBackspace}
-	result, _ := m.handleKeyPress(keyMsg)
-	m = result.(*model)
-	if m.filter != "helo" {
-		t.Errorf("expected filter 'helo', got %q", m.filter)
-	}
-	if m.filterCursor != 2 {
-		t.Errorf("expected filterCursor 2, got %d", m.filterCursor)
-	}
-
-	// Backspace at position 0 does nothing
-	m.filterCursor = 0
-	result, _ = m.handleKeyPress(keyMsg)
-	m = result.(*model)
-	if m.filter != "helo" {
-		t.Errorf("expected filter 'helo' (unchanged), got %q", m.filter)
-	}
-	if m.filterCursor != 0 {
-		t.Errorf("expected filterCursor 0, got %d", m.filterCursor)
-	}
-}
-
-func TestFilterAltBackspace(t *testing.T) {
-	cfg := Config{Command: "echo test", Shell: "sh"}
-
-	tests := []struct {
-		name           string
-		filter         string
-		cursor         int
-		expectedFilter string
-		expectedCursor int
-	}{
-		{"delete last word", "hello world", 11, "hello ", 6},
-		{"delete middle word", "foo bar baz", 7, "foo  baz", 4},
-		{"delete first word", "hello world", 5, " world", 0},
-		{"delete with trailing spaces", "hello   ", 8, "", 0},
-		{"cursor at start", "hello", 0, "hello", 0},
-		{"single word", "hello", 5, "", 0},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			m := testModel(cfg)
-			m.filterMode = true
-			m.filter = tt.filter
-			m.filterCursor = tt.cursor
-
-			keyMsg := tea.KeyMsg{Type: tea.KeyBackspace, Alt: true}
-			result, _ := m.handleKeyPress(keyMsg)
-			newModel := result.(*model)
-
-			if newModel.filter != tt.expectedFilter {
-				t.Errorf("expected filter %q, got %q", tt.expectedFilter, newModel.filter)
-			}
-			if newModel.filterCursor != tt.expectedCursor {
-				t.Errorf("expected filterCursor %d, got %d", tt.expectedCursor, newModel.filterCursor)
-			}
-		})
-	}
-}
-
-func TestFilterRegexToggle(t *testing.T) {
-	cfg := Config{Command: "echo test", Shell: "sh"}
-	m := testModel(cfg)
-	m.filterMode = true
-	m.filter = ""
-	m.filterCursor = 0
-
-	// Type '/' on empty filter toggles regex mode on
-	keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'/'}}
-	result, _ := m.handleKeyPress(keyMsg)
-	m = result.(*model)
-	if !m.filterRegex {
-		t.Error("expected filterRegex to be true after typing /")
-	}
-	if m.filter != "" {
-		t.Errorf("expected empty filter, got %q", m.filter)
-	}
-
-	// Type '/' again on empty filter toggles regex mode off
-	result, _ = m.handleKeyPress(keyMsg)
-	m = result.(*model)
-	if m.filterRegex {
-		t.Error("expected filterRegex to be false after second /")
-	}
-
-	// Type '/' when filter is non-empty adds it to filter
-	m.filterRegex = true
-	m.filter = "abc"
-	m.filterCursor = 3
-	result, _ = m.handleKeyPress(keyMsg)
-	m = result.(*model)
-	if m.filter != "abc/" {
-		t.Errorf("expected filter 'abc/', got %q", m.filter)
-	}
-	if !m.filterRegex {
-		t.Error("expected filterRegex to remain true")
-	}
-}
-
-func TestFilterRegexMatching(t *testing.T) {
-	cfg := Config{Command: "echo test", Shell: "sh"}
-	m := initialModel(cfg)
-	m.lines = []runner.Line{
-		{Number: 1, Content: "hello world"},
-		{Number: 2, Content: "foo bar"},
-		{Number: 3, Content: "hello foo"},
-		{Number: 4, Content: "baz 123 qux"},
-	}
-
-	// Regex filter matching
-	m.filterRegex = true
-	m.filter = "hello.*foo"
-	m.updateFiltered()
-	if len(m.filtered) != 1 {
-		t.Errorf("expected 1 match for regex 'hello.*foo', got %d", len(m.filtered))
-	}
-	if len(m.filtered) > 0 && m.filtered[0] != 2 {
-		t.Errorf("expected match at index 2, got %d", m.filtered[0])
-	}
-
-	// Regex with character class
-	m.filter = "\\d+"
-	m.updateFiltered()
-	if len(m.filtered) != 1 {
-		t.Errorf("expected 1 match for regex '\\d+', got %d", len(m.filtered))
-	}
-
-	// Regex is case insensitive
-	m.filter = "HELLO"
-	m.updateFiltered()
-	if len(m.filtered) != 2 {
-		t.Errorf("expected 2 matches for case-insensitive regex 'HELLO', got %d", len(m.filtered))
-	}
-}
-
-func TestFilterRegexInvalid(t *testing.T) {
-	cfg := Config{Command: "echo test", Shell: "sh"}
-	m := initialModel(cfg)
-	m.lines = []runner.Line{
-		{Number: 1, Content: "hello world"},
-		{Number: 2, Content: "foo bar"},
-	}
-
-	m.filterRegex = true
-	m.filter = "[invalid"
-	m.updateFiltered()
-
-	// Should have an error
-	if m.filterRegexErr == nil {
-		t.Error("expected filterRegexErr to be non-nil for invalid regex")
-	}
-
-	// Should show all lines when regex is invalid
-	if len(m.filtered) != 2 {
-		t.Errorf("expected all 2 lines shown for invalid regex, got %d", len(m.filtered))
-	}
-
-	// Valid regex clears the error
-	m.filter = "hello"
-	m.updateFiltered()
-	if m.filterRegexErr != nil {
-		t.Errorf("expected filterRegexErr to be nil for valid regex, got %v", m.filterRegexErr)
-	}
-}
-
-func TestFilterEscClearsRegex(t *testing.T) {
-	cfg := Config{Command: "echo test", Shell: "sh"}
-	m := testModel(cfg)
-	m.filterMode = true
-	m.filter = "test"
-	m.filterCursor = 4
-	m.filterRegex = true
-
-	// Esc in filter mode clears everything
-	keyMsg := tea.KeyMsg{Type: tea.KeyEsc}
-	result, _ := m.handleKeyPress(keyMsg)
-	m = result.(*model)
-
-	if m.filterMode {
-		t.Error("expected filterMode to be false")
-	}
-	if m.filter != "" {
-		t.Errorf("expected empty filter, got %q", m.filter)
-	}
-	if m.filterCursor != 0 {
-		t.Errorf("expected filterCursor 0, got %d", m.filterCursor)
-	}
-	if m.filterRegex {
-		t.Error("expected filterRegex to be false")
-	}
-}
-
-func TestStopCommandKeybinding(t *testing.T) {
-	cfg := Config{
-		Command: "echo test",
-		Shell:   "sh",
-	}
-
-	t.Run("stops running command when streaming", func(t *testing.T) {
-		m := initialModel(cfg)
-		// Set up a cancellable context to track if cancel was called
-		ctx, cancel := context.WithCancel(context.Background())
-		m.ctx = ctx
-		m.cancel = cancel
-		m.streaming = true
-		m.statusMsg = ""
-
-		// Simulate pressing 'c'
-		keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'c'}}
-		result, cmd := m.handleKeyPress(keyMsg)
-		newModel := result.(*model)
-
-		// Should set status message
-		if newModel.statusMsg != "Command stopped" {
-			t.Errorf("expected statusMsg 'Command stopped', got %q", newModel.statusMsg)
-		}
-
-		// Should return a command (the tick for clearing status)
-		if cmd == nil {
-			t.Error("expected a command to be returned for status message timeout")
-		}
-
-		// Context should be cancelled
-		select {
-		case <-ctx.Done():
-			// Good, context was cancelled
-		default:
-			t.Error("expected context to be cancelled")
-		}
-	})
-
-	t.Run("does nothing when not streaming", func(t *testing.T) {
-		m := initialModel(cfg)
-		ctx, cancel := context.WithCancel(context.Background())
-		m.ctx = ctx
-		m.cancel = cancel
-		m.streaming = false
-		m.statusMsg = ""
-
-		// Simulate pressing 'c'
-		keyMsg := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'c'}}
-		result, cmd := m.handleKeyPress(keyMsg)
-		newModel := result.(*model)
-
-		// Should not set status message
-		if newModel.statusMsg != "" {
-			t.Errorf("expected empty statusMsg, got %q", newModel.statusMsg)
-		}
-
-		// Should not return a command
-		if cmd != nil {
-			t.Error("expected no command to be returned when not streaming")
-		}
-
-		// Context should NOT be cancelled
-		select {
-		case <-ctx.Done():
-			t.Error("expected context to NOT be cancelled when not streaming")
-		default:
-			// Good, context is still active
-		}
-	})
-}

internal/ui/update.go

@@ -0,0 +1,223 @@
+package ui
+
+import (
+	"context"
+	"time"
+
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/chenasraf/watchr/internal/runner"
+)
+
+func initialModel(cfg Config) model {
+	ctx, cancel := context.WithCancel(context.Background())
+
+	var r *runner.Runner
+	if cfg.Interactive {
+		r = runner.NewInteractiveRunner(cfg.Shell, cfg.Command)
+	} else {
+		r = runner.NewRunner(cfg.Shell, cfg.Command)
+	}
+
+	return model{
+		config:      cfg,
+		lines:       []runner.Line{},
+		filtered:    []int{},
+		cursor:      0,
+		offset:      0,
+		filter:      "",
+		filterMode:  false,
+		showPreview: false,
+		runner:      r,
+		ctx:         ctx,
+		cancel:      cancel,
+		loading:     true,
+	}
+}
+
+func (m *model) Init() tea.Cmd {
+	// Send a message to start streaming (handled in Update with pointer receiver)
+	return func() tea.Msg {
+		return startStreamMsg{}
+	}
+}
+
+func (m model) spinnerTickCmd() tea.Cmd {
+	return tea.Tick(80*time.Millisecond, func(t time.Time) tea.Msg {
+		return spinnerTickMsg(t)
+	})
+}
+
+func (m model) streamTickCmd() tea.Cmd {
+	return tea.Tick(50*time.Millisecond, func(t time.Time) tea.Msg {
+		return streamTickMsg(t)
+	})
+}
+
+func (m model) countdownTickCmd() tea.Cmd {
+	gen := m.refreshGeneration
+	return tea.Tick(time.Second, func(t time.Time) tea.Msg {
+		return countdownTickMsg{generation: gen}
+	})
+}
+
+func (m *model) startStreaming() tea.Cmd {
+	// Cancel any existing context and create a new one
+	if m.cancel != nil {
+		m.cancel()
+	}
+	m.ctx, m.cancel = context.WithCancel(context.Background())
+
+	// Pass previous lines for in-place updates
+	m.streamResult = m.runner.RunStreaming(m.ctx, m.lines)
+	m.streaming = true
+	m.loading = true
+	m.lastLineCount = len(m.lines)
+	m.exitCode = -1
+	m.errorMsg = ""
+	m.userScrolled = false
+
+	cmds := []tea.Cmd{m.streamTickCmd()}
+
+	// Start refresh timer from command start if configured
+	if m.config.RefreshFromStart && m.config.RefreshInterval > 0 {
+		m.refreshStartTime = time.Now()
+		cmds = append(cmds, m.tickCmd())
+		if m.config.RefreshInterval > time.Second {
+			cmds = append(cmds, m.countdownTickCmd())
+		}
+	}
+
+	return tea.Batch(cmds...)
+}
+
+func (m *model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		return m.handleKeyPress(msg)
+
+	case tea.WindowSizeMsg:
+		m.width = msg.Width
+		m.height = msg.Height
+		return m, nil
+
+	case startStreamMsg:
+		cmd := m.startStreaming()
+		return m, tea.Batch(cmd, m.spinnerTickCmd())
+
+	case resultMsg:
+		m.lines = msg.lines
+		m.exitCode = msg.exitCode
+		m.loading = false
+		m.streaming = false
+		m.updateFiltered()
+		return m, nil
+
+	case streamTickMsg:
+		if m.streamResult == nil {
+			return m, nil
+		}
+
+		// Check for new lines
+		newLines := m.streamResult.GetLines()
+		newCount := len(newLines)
+
+		if newCount != m.lastLineCount {
+			m.lines = newLines
+			m.lastLineCount = newCount
+			m.updateFiltered()
+
+			// Auto-scroll to bottom if user hasn't manually scrolled
+			if !m.userScrolled {
+				visible := m.visibleLines()
+				if visible > 0 {
+					m.cursor = max(len(m.filtered)-1, 0)
+					m.offset = max(len(m.filtered)-visible, 0)
+				}
+			}
+		}
+
+		// Check if command completed
+		if m.streamResult.IsDone() {
+			m.streaming = false
+			m.loading = false
+			m.exitCode = m.streamResult.ExitCode
+			if m.streamResult.Error != nil {
+				m.errorMsg = m.streamResult.Error.Error()
+			}
+
+			// Trim excess lines from previous run
+			currentCount := m.streamResult.GetCurrentLineCount()
+			if currentCount < len(m.lines) {
+				m.lines = m.lines[:currentCount]
+				m.updateFiltered()
+			}
+
+			// If auto-refresh is enabled and timer starts from end, schedule the next run
+			if m.config.RefreshInterval > 0 && !m.config.RefreshFromStart {
+				m.refreshStartTime = time.Now()
+				cmds := []tea.Cmd{m.tickCmd()}
+				// Start countdown display updates if interval > 1s
+				if m.config.RefreshInterval > time.Second {
+					cmds = append(cmds, m.countdownTickCmd())
+				}
+				return m, tea.Batch(cmds...)
+			}
+			return m, nil
+		}
+
+		// Continue streaming
+		return m, m.streamTickCmd()
+
+	case tickMsg:
+		// Ignore ticks from before a manual refresh
+		if msg.generation != m.refreshGeneration {
+			return m, nil
+		}
+		if m.config.RefreshInterval > 0 && !m.streaming {
+			// Restart streaming for refresh
+			cmd := m.startStreaming()
+			return m, tea.Batch(cmd, m.spinnerTickCmd())
+		}
+		return m, nil
+
+	case errMsg:
+		m.errorMsg = msg.Error()
+		m.loading = false
+		m.streaming = false
+		return m, nil
+
+	case clearStatusMsg:
+		m.statusMsg = ""
+		return m, nil
+
+	case spinnerTickMsg:
+		if m.loading || m.streaming {
+			m.spinnerFrame = (m.spinnerFrame + 1) % len(spinnerFrames)
+			return m, m.spinnerTickCmd()
+		}
+		return m, nil
+
+	case countdownTickMsg:
+		// Ignore ticks from before a manual refresh
+		if msg.generation != m.refreshGeneration {
+			return m, nil
+		}
+		// Continue ticking if waiting for auto-refresh
+		if m.config.RefreshInterval > time.Second && !m.streaming && !m.refreshStartTime.IsZero() {
+			elapsed := time.Since(m.refreshStartTime)
+			if elapsed < m.config.RefreshInterval {
+				return m, m.countdownTickCmd()
+			}
+		}
+		return m, nil
+	}
+
+	return m, nil
+}
+
+func (m model) tickCmd() tea.Cmd {
+	gen := m.refreshGeneration
+	return tea.Tick(m.config.RefreshInterval, func(t time.Time) tea.Msg {
+		return tickMsg{generation: gen}
+	})
+}

internal/ui/update_test.go

@@ -0,0 +1,87 @@
+package ui
+
+import (
+	"fmt"
+	"testing"
+
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+func TestUpdateWindowSize(t *testing.T) {
+	m := testModelWithLines()
+	msg := tea.WindowSizeMsg{Width: 120, Height: 40}
+	result, _ := m.Update(msg)
+	newModel := result.(*model)
+
+	if newModel.width != 120 {
+		t.Errorf("expected width 120, got %d", newModel.width)
+	}
+	if newModel.height != 40 {
+		t.Errorf("expected height 40, got %d", newModel.height)
+	}
+}
+
+func TestUpdateClearStatusMsg(t *testing.T) {
+	m := testModelWithLines()
+	m.statusMsg = "some status"
+
+	result, _ := m.Update(clearStatusMsg{})
+	newModel := result.(*model)
+
+	if newModel.statusMsg != "" {
+		t.Errorf("expected empty statusMsg, got %q", newModel.statusMsg)
+	}
+}
+
+func TestUpdateSpinnerTick(t *testing.T) {
+	m := testModelWithLines()
+	m.loading = true
+	m.spinnerFrame = 0
+
+	result, cmd := m.Update(spinnerTickMsg{})
+	newModel := result.(*model)
+
+	if newModel.spinnerFrame != 1 {
+		t.Errorf("expected spinnerFrame 1, got %d", newModel.spinnerFrame)
+	}
+	if cmd == nil {
+		t.Error("expected a command for next spinner tick")
+	}
+}
+
+func TestUpdateSpinnerTickNotLoading(t *testing.T) {
+	m := testModelWithLines()
+	m.loading = false
+	m.streaming = false
+	m.spinnerFrame = 3
+
+	result, cmd := m.Update(spinnerTickMsg{})
+	newModel := result.(*model)
+
+	// Frame should not advance
+	if newModel.spinnerFrame != 3 {
+		t.Errorf("expected spinnerFrame 3 (unchanged), got %d", newModel.spinnerFrame)
+	}
+	if cmd != nil {
+		t.Error("expected no command when not loading/streaming")
+	}
+}
+
+func TestUpdateErrMsg(t *testing.T) {
+	m := testModelWithLines()
+	m.loading = true
+	m.streaming = true
+
+	result, _ := m.Update(errMsg{err: fmt.Errorf("test error")})
+	newModel := result.(*model)
+
+	if newModel.errorMsg != "test error" {
+		t.Errorf("expected errorMsg 'test error', got %q", newModel.errorMsg)
+	}
+	if newModel.loading {
+		t.Error("expected loading false after error")
+	}
+	if newModel.streaming {
+		t.Error("expected streaming false after error")
+	}
+}

internal/ui/view.go

@@ -0,0 +1,585 @@
+package ui
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/charmbracelet/lipgloss"
+)
+
+// renderCmdPaletteOverlay creates the command palette overlay box
+func (m model) renderCmdPaletteOverlay() (box string, boxWidth, boxHeight int) {
+	keyStyle := lipgloss.NewStyle().
+		Foreground(lipgloss.Color("241")) // dim
+
+	nameStyle := lipgloss.NewStyle().
+		Foreground(lipgloss.Color("252"))
+
+	selectedNameStyle := lipgloss.NewStyle().
+		Background(lipgloss.Color("15")).
+		Foreground(lipgloss.Color("#000000")).
+		Bold(true)
+
+	selectedKeyStyle := lipgloss.NewStyle().
+		Background(lipgloss.Color("15")).
+		Foreground(lipgloss.Color("241"))
+
+	filterStyle := lipgloss.NewStyle().
+		Foreground(lipgloss.Color("11"))
+
+	borderColor := lipgloss.Color("12")
+
+	allCommands := commands()
+	filtered := m.filteredCommands()
+
+	// Compute column width
+	const paletteWidth = 40
+	totalSlots := len(allCommands) // fixed height so box doesn't move
+
+	var content strings.Builder
+
+	// Filter input with bottom border
+	before := m.cmdPaletteFilter[:m.cmdPaletteCursor]
+	after := m.cmdPaletteFilter[m.cmdPaletteCursor:]
+	filterLine := filterStyle.Render(":"+before) + "█" + filterStyle.Render(after)
+	// Pad filter line to full width
+	filterVisual := lipgloss.Width(filterLine)
+	if filterVisual < paletteWidth {
+		filterLine += strings.Repeat(" ", paletteWidth-filterVisual)
+	}
+	content.WriteString(filterLine + "\n")
+	content.WriteString(lipgloss.NewStyle().Foreground(borderColor).Render(strings.Repeat("─", paletteWidth)) + "\n")
+
+	// Command list (fixed number of rows)
+	for i := range totalSlots {
+		if i < len(filtered) {
+			cmd := filtered[i]
+			gap := max(paletteWidth-lipgloss.Width(cmd.name)-lipgloss.Width(cmd.shortcut), 2)
+			if i == m.cmdPaletteSelected {
+				line := selectedNameStyle.Render(cmd.name+strings.Repeat(" ", gap)) + selectedKeyStyle.Render(cmd.shortcut)
+				content.WriteString(line + "\n")
+			} else {
+				content.WriteString(nameStyle.Render(cmd.name) + strings.Repeat(" ", gap) + keyStyle.Render(cmd.shortcut) + "\n")
+			}
+		} else {
+			content.WriteString(strings.Repeat(" ", paletteWidth) + "\n")
+		}
+	}
+
+	boxStyle := lipgloss.NewStyle().
+		Border(lipgloss.RoundedBorder()).
+		BorderForeground(borderColor)
+
+	box = boxStyle.Render(content.String())
+	boxWidth = lipgloss.Width(box)
+	boxHeight = lipgloss.Height(box)
+
+	return box, boxWidth, boxHeight
+}
+
+// renderHelpOverlay creates the help box content (without positioning)
+func (m model) renderHelpOverlay() (box string, boxWidth, boxHeight int) {
+	keyStyle := lipgloss.NewStyle().
+		Bold(true).
+		Foreground(lipgloss.Color("10")) // green
+
+	descStyle := lipgloss.NewStyle().
+		Foreground(lipgloss.Color("252")) // light gray
+
+	titleStyle := lipgloss.NewStyle().
+		Bold(true).
+		Foreground(lipgloss.Color("12")) // blue
+
+	// Define keybindings
+	bindings := []struct {
+		key  string
+		desc string
+	}{
+		{"j / k", "Move down / up"},
+		{"g / G", "Go to first / last line"},
+		{"Ctrl+d / Ctrl+u", "Half page down / up"},
+		{"PgDn / PgUp", "Full page down / up"},
+		{"Ctrl+f / Ctrl+b", "Full page down / up"},
+		{"", ""},
+		{"p", "Toggle preview pane"},
+		{"+/-", "Resize preview pane"},
+		{"J / K", "Scroll preview down / up"},
+		{"/", "Enter filter mode"},
+		{"//", "Toggle regex filter mode"},
+		{"Esc", "Exit filter / clear"},
+		{"", ""},
+		{"r / Ctrl+r", "Reload command"},
+		{"R", "Reload & clear lines"},
+		{"d / Del", "Delete selected line"},
+		{"D", "Clear all lines"},
+		{"c", "Stop running command"},
+		{"y", "Copy line to clipboard"},
+		{"Y", "Copy line (plain text)"},
+		{":", "Open command palette"},
+		{"q / Esc", "Quit"},
+		{"?", "Toggle this help"},
+	}
+
+	// Build content
+	var content strings.Builder
+	content.WriteString(titleStyle.Render("Keybindings"))
+	content.WriteString("\n\n")
+
+	for _, b := range bindings {
+		if b.key == "" {
+			content.WriteString("\n")
+			continue
+		}
+		key := keyStyle.Render(fmt.Sprintf("%-18s", b.key))
+		desc := descStyle.Render(b.desc)
+		fmt.Fprintf(&content, "  %s  %s\n", key, desc)
+	}
+
+	content.WriteString("\n")
+	content.WriteString(descStyle.Render("Press any key to close"))
+
+	// Create box style
+	boxStyle := lipgloss.NewStyle().
+		Border(lipgloss.RoundedBorder()).
+		BorderForeground(lipgloss.Color("12")).
+		Padding(1, 2)
+
+	box = boxStyle.Render(content.String())
+	boxWidth = lipgloss.Width(box)
+	boxHeight = lipgloss.Height(box)
+
+	return box, boxWidth, boxHeight
+}
+
+// renderConfirmOverlay creates a confirmation dialog overlay
+func (m model) renderConfirmOverlay() (box string, boxWidth, boxHeight int) {
+	msgStyle := lipgloss.NewStyle().
+		Foreground(lipgloss.Color("252"))
+
+	boxStyle := lipgloss.NewStyle().
+		Border(lipgloss.RoundedBorder()).
+		BorderForeground(lipgloss.Color("11")).
+		Padding(1, 2)
+
+	content := msgStyle.Render(m.confirmMessage)
+	box = boxStyle.Render(content)
+	boxWidth = lipgloss.Width(box)
+	boxHeight = lipgloss.Height(box)
+
+	return box, boxWidth, boxHeight
+}
+
+func (m *model) View() string {
+	if m.width == 0 || m.height == 0 {
+		return spinnerFrames[m.spinnerFrame] + " Running command…"
+	}
+
+	// Render the main UI
+	mainView := m.renderMainView()
+
+	// Overlay help if active
+	if m.showHelp {
+		box, boxWidth, boxHeight := m.renderHelpOverlay()
+		return overlayBox(mainView, box, boxWidth, boxHeight, m.width, m.height)
+	}
+
+	// Overlay command palette if active
+	if m.cmdPaletteMode {
+		box, boxWidth, boxHeight := m.renderCmdPaletteOverlay()
+		return overlayBox(mainView, box, boxWidth, boxHeight, m.width, m.height)
+	}
+
+	// Overlay confirmation dialog if active
+	if m.confirmMode {
+		box, boxWidth, boxHeight := m.renderConfirmOverlay()
+		return overlayBox(mainView, box, boxWidth, boxHeight, m.width, m.height)
+	}
+
+	return mainView
+}
+
+// Box drawing characters (rounded)
+const (
+	boxTopLeft     = "╭"
+	boxTopRight    = "╮"
+	boxBottomLeft  = "╰"
+	boxBottomRight = "╯"
+	boxHorizontal  = "─"
+	boxVertical    = "│"
+	boxLeftT       = "├"
+	boxRightT      = "┤"
+	boxTopT        = "┬"
+	boxBottomT     = "┴"
+)
+
+// viewContext holds shared rendering state for a single View() call.
+type viewContext struct {
+	innerWidth  int
+	borderStyle lipgloss.Style
+}
+
+func (vc viewContext) hLine(left, right string, splitPos int, junction string) string {
+	if splitPos > 0 && splitPos < vc.innerWidth {
+		return vc.borderStyle.Render(left + strings.Repeat(boxHorizontal, splitPos) + junction + strings.Repeat(boxHorizontal, vc.innerWidth-splitPos-1) + right)
+	}
+	return vc.borderStyle.Render(left + strings.Repeat(boxHorizontal, vc.innerWidth) + right)
+}
+
+func (vc viewContext) padLine(content string) string {
+	contentWidth := lipgloss.Width(content)
+	if contentWidth < vc.innerWidth {
+		content += strings.Repeat(" ", vc.innerWidth-contentWidth)
+	} else if contentWidth > vc.innerWidth {
+		content = lipgloss.NewStyle().MaxWidth(vc.innerWidth-1).Render(content) + ellipsis
+	}
+	return vc.borderStyle.Render(boxVertical) + content + vc.borderStyle.Render(boxVertical)
+}
+
+func (m model) renderMainView() string {
+	borderColor := lipgloss.Color("240")
+	vc := viewContext{
+		innerWidth:  m.width - 2,
+		borderStyle: lipgloss.NewStyle().Foreground(borderColor),
+	}
+
+	commandLine := m.renderHeaderLine(vc.innerWidth)
+	promptLine := m.renderPromptLine()
+	listHeight, listWidth := m.listDimensions(vc.innerWidth)
+	listLines := m.renderListLines(listHeight, listWidth)
+
+	// Preview content
+	var previewContent string
+	if m.showPreview && len(m.filtered) > 0 && m.cursor >= 0 && m.cursor < len(m.filtered) {
+		idx := m.filtered[m.cursor]
+		if idx < len(m.lines) {
+			previewContent = highlightJSON(m.lines[idx].Content)
+		}
+	}
+
+	// Error message
+	if m.errorMsg != "" {
+		listLines = append(listLines, lipgloss.NewStyle().Foreground(lipgloss.Color("9")).Render("Error: "+m.errorMsg))
+	}
+
+	// Vertical split position for left/right preview
+	var vSplitPos int
+	if m.showPreview {
+		switch m.config.PreviewPosition {
+		case PreviewLeft:
+			vSplitPos = m.previewSize()
+		case PreviewRight:
+			vSplitPos = vc.innerWidth - m.previewSize() - 1
+		}
+	}
+
+	// Build the unified box
+	var lines []string
+	lines = append(lines, vc.hLine(boxTopLeft, boxTopRight, 0, boxTopT))
+	lines = append(lines, vc.padLine(commandLine))
+	lines = append(lines, vc.hLine(boxLeftT, boxRightT, vSplitPos, boxTopT))
+
+	// Content area
+	if !m.showPreview {
+		lines = append(lines, m.renderContentNoPreview(vc, listLines, listHeight)...)
+	} else {
+		lines = append(lines, m.renderContentWithPreview(vc, listLines, listHeight, previewContent)...)
+	}
+
+	lines = append(lines, vc.hLine(boxBottomLeft, boxBottomRight, vSplitPos, boxBottomT))
+
+	return strings.Join(lines, "\n") + "\n" + promptLine
+}
+
+func (m model) renderHeaderLine(innerWidth int) string {
+	titleStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("12")).Bold(true)
+	prefix := titleStyle.Render("watchr") + " • "
+
+	var commandLine string
+	switch {
+	case m.streaming:
+		streamStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("14"))
+		commandLine = prefix + streamStyle.Render("◉ "+m.config.Command)
+	case m.loading:
+		commandLine = prefix + m.config.Command
+	case m.exitCode == 0:
+		successStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("10"))
+		commandLine = prefix + successStyle.Render("✓ "+m.config.Command)
+	default:
+		failStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("9"))
+		commandLine = prefix + failStyle.Render(fmt.Sprintf("✗ [%d] %s", m.exitCode, m.config.Command))
+	}
+
+	if m.config.RefreshInterval > time.Second && !m.streaming && !m.refreshStartTime.IsZero() {
+		elapsed := time.Since(m.refreshStartTime)
+		remaining := m.config.RefreshInterval - elapsed
+		if remaining > 0 {
+			countdownStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("241"))
+			countdown := countdownStyle.Render(fmt.Sprintf("(%ds)", int(remaining.Seconds())+1))
+			cmdWidth := lipgloss.Width(commandLine)
+			countdownWidth := lipgloss.Width(countdown)
+			gap := innerWidth - cmdWidth - countdownWidth
+			if gap > 0 {
+				commandLine += strings.Repeat(" ", gap) + countdown
+			}
+		}
+	}
+
+	return commandLine
+}
+
+func (m model) renderPromptLine() string {
+	promptStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("14"))
+	filterStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("11"))
+	filterRegexStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("13"))
+	filterErrStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("9"))
+
+	var promptLine string
+	switch {
+	case m.filterMode && m.filterRegex:
+		label := filterRegexStyle.Render("regex/")
+		before := m.filter[:m.filterCursor]
+		after := m.filter[m.filterCursor:]
+		input := filterStyle.Render(before) + "█" + filterStyle.Render(after)
+		promptLine = label + input
+		if m.filterRegexErr != nil {
+			promptLine += " " + filterErrStyle.Render("(invalid regex)")
+		}
+	case m.filterMode:
+		before := m.filter[:m.filterCursor]
+		after := m.filter[m.filterCursor:]
+		promptLine = filterStyle.Render("/"+before) + "█" + filterStyle.Render(after)
+	case m.filter != "" && m.filterRegex:
+		promptLine = promptStyle.Render(fmt.Sprintf("%s (regex: %s)", m.config.Prompt, m.filter))
+	case m.filter != "":
+		promptLine = promptStyle.Render(fmt.Sprintf("%s (filter: %s)", m.config.Prompt, m.filter))
+	default:
+		promptLine = promptStyle.Render(m.config.Prompt)
+	}
+
+	if m.streaming {
+		promptLine += " " + spinnerFrames[m.spinnerFrame] + " Streaming…"
+	} else if m.loading {
+		promptLine += " " + spinnerFrames[m.spinnerFrame] + " Running command…"
+	}
+	if m.statusMsg != "" {
+		statusStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("10"))
+		promptLine += " " + statusStyle.Render(m.statusMsg)
+	}
+
+	helpHint := lipgloss.NewStyle().Foreground(lipgloss.Color("241")).Render("? for help")
+	promptWidth := lipgloss.Width(promptLine)
+	hintWidth := lipgloss.Width(helpHint)
+	gap := m.width - promptWidth - hintWidth
+	if gap > 0 {
+		promptLine += strings.Repeat(" ", gap) + helpHint
+	}
+
+	return promptLine
+}
+
+func (m model) listDimensions(innerWidth int) (height, width int) {
+	height = m.visibleLines()
+	width = innerWidth - 1
+	if m.showPreview && (m.config.PreviewPosition == PreviewLeft || m.config.PreviewPosition == PreviewRight) {
+		width = innerWidth - m.previewSize() - 2
+	}
+	return height, width
+}
+
+func (m model) renderListLines(listHeight, listWidth int) []string {
+	selectedStyle := lipgloss.NewStyle().
+		Background(lipgloss.Color("15")).
+		Foreground(lipgloss.Color("#000000")).
+		Bold(true)
+	lineNumStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("241"))
+
+	var listLines []string
+	for i := range listHeight {
+		lineIdx := m.offset + i
+		if lineIdx >= len(m.filtered) {
+			listLines = append(listLines, "")
+			continue
+		}
+
+		idx := m.filtered[lineIdx]
+		if idx >= len(m.lines) {
+			listLines = append(listLines, "")
+			continue
+		}
+		line := m.lines[idx]
+		isSelected := lineIdx == m.cursor
+		fullWidth := listWidth + 1
+
+		var lineText string
+		if m.config.ShowLineNums {
+			lineNumStr := fmt.Sprintf("%*d  ", m.config.LineNumWidth, line.Number)
+			lineNumWidth := len(lineNumStr)
+			contentWidth := listWidth - lineNumWidth
+			content := truncateToWidth(line.Content, contentWidth)
+
+			if isSelected {
+				plainContent := stripANSI(content)
+				selectedLineNumStyle := lipgloss.NewStyle().
+					Background(lipgloss.Color("15")).
+					Foreground(lipgloss.Color("241"))
+				selectedContentStyle := lipgloss.NewStyle().
+					Background(lipgloss.Color("15")).
+					Foreground(lipgloss.Color("#000000")).
+					Bold(true)
+				contentPadded := plainContent
+				padding := fullWidth - lineNumWidth - len(plainContent)
+				if padding > 0 {
+					contentPadded = plainContent + strings.Repeat(" ", padding)
+				}
+				lineText = selectedLineNumStyle.Render(lineNumStr) + selectedContentStyle.Render(contentPadded)
+			} else {
+				lineText = lineNumStyle.Render(lineNumStr) + content
+			}
+		} else {
+			lineText = truncateToWidth(line.Content, listWidth)
+			if isSelected {
+				lineText = stripANSI(lineText)
+				padding := fullWidth - len(lineText)
+				if padding > 0 {
+					lineText += strings.Repeat(" ", padding)
+				}
+				lineText = selectedStyle.Render(lineText)
+			}
+		}
+
+		listLines = append(listLines, lineText)
+	}
+	return listLines
+}
+
+func (m model) renderContentNoPreview(vc viewContext, listLines []string, listHeight int) []string {
+	var lines []string
+	for i := range listHeight {
+		if i < len(listLines) {
+			lines = append(lines, vc.padLine(listLines[i]))
+		} else {
+			lines = append(lines, vc.padLine(""))
+		}
+	}
+	return lines
+}
+
+func (m model) renderContentWithPreview(vc viewContext, listLines []string, listHeight int, previewContent string) []string {
+	switch m.config.PreviewPosition {
+	case PreviewTop, PreviewBottom:
+		return m.renderVerticalPreview(vc, listLines, listHeight, previewContent)
+	case PreviewLeft, PreviewRight:
+		return m.renderHorizontalPreview(vc, listLines, listHeight, previewContent)
+	}
+	return nil
+}
+
+func (m *model) renderVerticalPreview(vc viewContext, listLines []string, listHeight int, previewContent string) []string {
+	previewH := m.previewSize()
+
+	var previewLines []string
+	if previewContent != "" {
+		previewLines = wrapPreviewContent(previewContent, vc.innerWidth)
+	}
+	previewLines = m.applyPreviewOffset(previewLines, previewH)
+	for len(previewLines) < previewH {
+		previewLines = append(previewLines, "")
+	}
+
+	paddedList := m.renderContentNoPreview(vc, listLines, listHeight)
+	var paddedPreview []string
+	for _, line := range previewLines[:previewH] {
+		paddedPreview = append(paddedPreview, vc.padLine(line))
+	}
+
+	separator := vc.hLine(boxLeftT, boxRightT, 0, boxTopT)
+
+	if m.config.PreviewPosition == PreviewTop {
+		result := paddedPreview
+		result = append(result, separator)
+		result = append(result, paddedList...)
+		return result
+	}
+	// PreviewBottom
+	result := paddedList
+	result = append(result, separator)
+	result = append(result, paddedPreview...)
+	return result
+}
+
+func (m *model) renderHorizontalPreview(vc viewContext, listLines []string, listHeight int, previewContent string) []string {
+	var leftW, rightW int
+	if m.config.PreviewPosition == PreviewLeft {
+		leftW = m.previewSize()
+		rightW = vc.innerWidth - leftW - 1
+	} else {
+		rightW = m.previewSize()
+		leftW = vc.innerWidth - rightW - 1
+	}
+
+	var previewLines []string
+	if previewContent != "" {
+		previewW := leftW
+		if m.config.PreviewPosition == PreviewRight {
+			previewW = rightW
+		}
+		previewLines = wrapPreviewContent(previewContent, previewW)
+	}
+	previewLines = m.applyPreviewOffset(previewLines, listHeight)
+	for len(previewLines) < listHeight {
+		previewLines = append(previewLines, "")
+	}
+
+	fitToWidth := func(s string, w int, isPreview bool) string {
+		sw := lipgloss.Width(s)
+		if sw > w {
+			if isPreview {
+				return s + strings.Repeat(" ", w-sw)
+			}
+			return lipgloss.NewStyle().MaxWidth(w-1).Render(s) + ellipsis
+		}
+		return s + strings.Repeat(" ", w-sw)
+	}
+
+	var lines []string
+	for i := range listHeight {
+		var leftContent, rightContent string
+		var leftIsPreview, rightIsPreview bool
+
+		if m.config.PreviewPosition == PreviewLeft {
+			leftContent = previewLines[i]
+			leftIsPreview = true
+			if i < len(listLines) {
+				rightContent = listLines[i]
+			}
+		} else {
+			if i < len(listLines) {
+				leftContent = listLines[i]
+			}
+			rightContent = previewLines[i]
+			rightIsPreview = true
+		}
+
+		leftContent = fitToWidth(leftContent, leftW, leftIsPreview)
+		rightContent = fitToWidth(rightContent, rightW, rightIsPreview)
+
+		line := vc.borderStyle.Render(boxVertical) + leftContent + vc.borderStyle.Render(boxVertical) + rightContent + vc.borderStyle.Render(boxVertical)
+		lines = append(lines, line)
+	}
+	return lines
+}
+
+// Run starts the UI
+func Run(cfg Config) error {
+	if cfg.PreviewPosition == "" {
+		cfg.PreviewPosition = PreviewBottom
+	}
+
+	m := initialModel(cfg)
+	p := tea.NewProgram(&m, tea.WithAltScreen())
+
+	_, err := p.Run()
+	return err
+}

internal/ui/view_test.go

@@ -0,0 +1,104 @@
+package ui
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestRenderHelpOverlay(t *testing.T) {
+	m := testModelWithLines()
+	box, boxWidth, boxHeight := m.renderHelpOverlay()
+
+	if boxWidth == 0 || boxHeight == 0 {
+		t.Error("expected non-zero overlay dimensions")
+	}
+
+	// Should contain some keybinding text
+	if !strings.Contains(box, "Keybindings") {
+		t.Error("expected help overlay to contain 'Keybindings'")
+	}
+	if !strings.Contains(box, "Reload command") {
+		t.Error("expected help overlay to contain 'Reload command'")
+	}
+}
+
+func TestRenderConfirmOverlay(t *testing.T) {
+	m := testModelWithLines()
+	m.confirmMessage = "Delete everything?"
+
+	box, boxWidth, boxHeight := m.renderConfirmOverlay()
+
+	if boxWidth == 0 || boxHeight == 0 {
+		t.Error("expected non-zero overlay dimensions")
+	}
+
+	if !strings.Contains(box, "Delete everything?") {
+		t.Error("expected confirm overlay to contain the message")
+	}
+}
+
+func TestRenderCmdPaletteOverlay(t *testing.T) {
+	m := testModelWithLines()
+	m.cmdPaletteMode = true
+	m.cmdPaletteFilter = ""
+	m.cmdPaletteCursor = 0
+	m.cmdPaletteSelected = 0
+
+	box, boxWidth, boxHeight := m.renderCmdPaletteOverlay()
+
+	if boxWidth == 0 || boxHeight == 0 {
+		t.Error("expected non-zero overlay dimensions")
+	}
+
+	// Should contain command names
+	if !strings.Contains(box, "Reload command") {
+		t.Error("expected palette to contain 'Reload command'")
+	}
+	if !strings.Contains(box, "Quit") {
+		t.Error("expected palette to contain 'Quit'")
+	}
+}
+
+func TestViewInitialLoading(t *testing.T) {
+	m := testModelWithLines()
+	m.width = 0
+	m.height = 0
+
+	view := m.View()
+	if !strings.Contains(view, "Running command") {
+		t.Errorf("expected loading view, got %q", view)
+	}
+}
+
+func TestViewWithHelpOverlay(t *testing.T) {
+	m := testModelWithLines()
+	m.showHelp = true
+
+	view := m.View()
+	if !strings.Contains(view, "Keybindings") {
+		t.Error("expected help overlay in view")
+	}
+}
+
+func TestViewWithConfirmOverlay(t *testing.T) {
+	m := testModelWithLines()
+	m.confirmMode = true
+	m.confirmMessage = "Are you sure?"
+
+	view := m.View()
+	if !strings.Contains(view, "Are you sure?") {
+		t.Error("expected confirm overlay in view")
+	}
+}
+
+func TestViewWithCmdPalette(t *testing.T) {
+	m := testModelWithLines()
+	m.cmdPaletteMode = true
+	m.cmdPaletteFilter = ""
+	m.cmdPaletteCursor = 0
+
+	view := m.View()
+	if !strings.Contains(view, "Reload command") {
+		t.Error("expected command palette in view")
+	}
+}

main.go

@@ -48,8 +48,8 @@ func main() {
 		_, _ = fmt.Fprintf(w, "\nKeybindings:\n")
 		_, _ = fmt.Fprintf(w, "  r, Ctrl-r      Reload (re-run command)\n")
 		_, _ = fmt.Fprintf(w, "  R              Reload & clear all lines\n")
-		_, _ = fmt.Fprintf(w, "  Del            Delete selected line\n")
+		_, _ = fmt.Fprintf(w, "  d, Del         Delete selected line\n")
-		_, _ = fmt.Fprintf(w, "  Ctrl-Del       Clear all lines (with confirm)\n")
+		_, _ = fmt.Fprintf(w, "  D              Clear all lines\n")
 		_, _ = fmt.Fprintf(w, "  c              Stop running command\n")
 		_, _ = fmt.Fprintf(w, "  q, Esc         Quit\n")
 		_, _ = fmt.Fprintf(w, "  j, k           Move down/up\n")