fix(taints): keep the effect field visible in the add-row

internal/app/taint_editor_addrow_test.go

@@ -0,0 +1,101 @@
+package app
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// addRowBlock returns the add-row portion of the rendered editor. Assertions
+// must target this, not the whole overlay: the taint list above it also
+// contains effect names. Anchored on the blank line the renderer joins the
+// block with, not on the "add:" label — at narrow widths the label is itself
+// truncated away.
+func addRowBlock(t *testing.T, m Model) (block string, width int) {
+	t.Helper()
+	content, w, _ := m.renderOverlayTaintEditor()
+	plain := stripANSI(content)
+	sep := strings.LastIndex(plain, "\n\n")
+	require.Positive(t, sep, "add-row must render while an input is focused")
+	return plain[sep+2:], w
+}
+
+// The effect selector is a cycling control with no scroll of its own, so it
+// must render in full no matter how long the key is. Before the fix the
+// add-row was joined onto one line and truncated to a box sized from the taint
+// LIST alone, so a realistic key pushed the effect off the edge as "eff~" —
+// leaving the user unable to see which effect they were about to stage.
+func TestRenderTaintEditorAddRow_LongKeyKeepsEffectVisible(t *testing.T) {
+	m := openTaintEditorLoaded(t, taintEditorTestModel())
+	m = taintKey(t, m, "a")
+	m = taintKey(t, m, "node.kubernetes.io/very-long-taint", "tab", "true")
+
+	block, _ := addRowBlock(t, m)
+
+	assert.Contains(t, block, "effect <NoSchedule>", "effect must render in full")
+	assert.NotContains(t, block, "eff~", "effect must never be the truncated field")
+}
+
+// A key too long for even a widened box truncates inside its own field, and
+// the effect still renders — the row wraps rather than dropping fields.
+func TestRenderTaintEditorAddRow_ExtremeKeyStillShowsEffect(t *testing.T) {
+	m := openTaintEditorLoaded(t, taintEditorTestModel())
+	m = taintKey(t, m, "a")
+	m = taintKey(t, m, "example.com/"+strings.Repeat("x", 200))
+
+	block, w := addRowBlock(t, m)
+
+	assert.Contains(t, block, "effect <NoSchedule>", "effect must survive an unrenderable key")
+	assert.LessOrEqual(t, w, m.width, "box must stay on screen")
+	for line := range strings.SplitSeq(block, "\n") {
+		assert.LessOrEqual(t, len([]rune(line)), w, "no line may overflow the box: %q", line)
+	}
+}
+
+// The typing caret sits at the end of the focused field, so an over-long value
+// truncates from the front — the user must see what they are typing.
+func TestRenderTaintEditorAddRow_FocusedFieldKeepsCaretVisible(t *testing.T) {
+	m := openTaintEditorLoaded(t, taintEditorTestModel())
+	m = taintKey(t, m, "a")
+	m = taintKey(t, m, "k", "tab", "prefix-"+strings.Repeat("y", 120)+"-tail")
+
+	block, _ := addRowBlock(t, m)
+
+	assert.Contains(t, block, "-tail", "focused field must keep its tail (the caret end) visible")
+	assert.Contains(t, block, "effect <NoSchedule>")
+}
+
+// The box grows to fit the add-row instead of sizing itself from the taint
+// list alone, so a moderately long key needs no wrapping at all.
+func TestRenderOverlayTaintEditor_BoxWidensForAddRow(t *testing.T) {
+	m := openTaintEditorLoaded(t, taintEditorTestModel())
+	_, listOnlyW, _ := m.renderOverlayTaintEditor()
+
+	m = taintKey(t, m, "a")
+	m = taintKey(t, m, "node-role.kubernetes.io/control-plane")
+	block, addRowW := addRowBlock(t, m)
+
+	require.Greater(t, addRowW, listOnlyW, "box must widen to fit the add-row")
+	assert.LessOrEqual(t, addRowW, m.width, "box must stay on screen")
+	assert.Contains(t, block, "node-role.kubernetes.io/control-plane", "key fits without truncation")
+	assert.Equal(t, 1, strings.Count(strings.TrimSpace(block), "\n")+1,
+		"a fitting add-row stays on one line")
+}
+
+// At a terminal narrow enough that a field's label alone exceeds the line
+// budget, taintAddRowFields returns a field wider than innerW and the final
+// safety-net truncation runs. That last cut must respect focus too: cutting the
+// focused field from the right strips exactly the caret the per-field
+// front-truncation just preserved.
+func TestRenderTaintEditorAddRow_NarrowOverlayKeepsCaret(t *testing.T) {
+	m := openTaintEditorLoaded(t, taintEditorTestModel())
+	m.width = 20 // innerW lands well below the "add: key [" label width
+	m = taintKey(t, m, "a")
+	m = taintKey(t, m, "node.kubernetes.io/some-taint")
+
+	block, _ := addRowBlock(t, m)
+
+	assert.Contains(t, block, "█", "the caret must survive the safety-net truncation")
+}

internal/app/view_overlay_taint_editor.go

@@ -51,8 +51,14 @@ func (m Model) renderOverlayTaintEditor() (string, int, int) {
 	}
 
 	// Fit the box to the widest row (70-col floor, screen-capped), then
-	// truncate names against the width that actually won.
-	overlayW := ui.OverlayListWidth(items, cfg, max(m.width-10, 1))
+	// truncate names against the width that actually won. While the add-row
+	// is up it joins the measurement: sizing the box from the list alone
+	// pushed a long key's effect selector off the right edge.
+	capW := max(m.width-10, 1)
+	overlayW := ui.OverlayListWidth(items, cfg, capW)
+	if p.focus != taintFocusList {
+		overlayW = max(overlayW, ui.OverlayContentWidth(taintAddRowNaturalWidth(p), capW))
+	}
 	innerW := max(overlayW-4, 1)
 	for i := range items {
 		items[i].Name = ui.Truncate(items[i].Name, innerW)
@@ -86,35 +92,90 @@ func taintEditorEmptyMessage(p taintEditorState) string {
 	return "No taints on this node"
 }
 
-// renderTaintEditorAddRow paints the staged-input line: the three
-// fields with the focused one highlighted and a cursor marker on the
-// text inputs. Rendered only while an input field is focused.
-func (m Model) renderTaintEditorAddRow(innerW int) string {
-	p := m.taintEditor
-	field := func(label, val string, focused bool) string {
-		text := label + " [" + val
+// taintAddRowSep separates the add-row's fields when they share a line.
+const taintAddRowSep = "  "
+
+// taintAddRowFocus maps each add-row field to the focus value that owns it.
+var taintAddRowFocus = []taintEditorFocus{taintFocusKey, taintFocusValue, taintFocusEffect}
+
+// taintAddRowFields returns the add-row's three field texts, unstyled. Each
+// input's value is fitted to valW visual columns (the focused one carries a
+// block cursor, matching the kv-editor / secret-editor inputs); pass a
+// negative valW for the untruncated natural text used to size the box.
+//
+// The focused value truncates from the front so the caret end — what the user
+// is typing right now — stays visible, while an unfocused one keeps its
+// recognizable head.
+func taintAddRowFields(p taintEditorState, valW int) []string {
+	input := func(label, val string, focused bool) string {
+		suffix := "]"
 		if focused {
-			// Block cursor, matching the kv-editor / secret-editor inputs.
-			text += "█"
+			suffix = "\u2588]"
 		}
-		text += "]"
-		if focused {
-			return ui.OverlayFilterStyle.Render(text)
+		prefix := label + " ["
+		if valW >= 0 {
+			budget := max(valW-lipgloss.Width(prefix)-lipgloss.Width(suffix), 1)
+			if focused {
+				val = ui.TruncateStart(val, budget)
+			} else {
+				val = ui.Truncate(val, budget)
+			}
+		}
+		return prefix + val + suffix
+	}
+	return []string{
+		input("add: key", p.addKey, p.focus == taintFocusKey),
+		input("value", p.addVal, p.focus == taintFocusValue),
+		"effect <" + model.ValidTaintEffects[p.addEff] + ">",
+	}
+}
+
+// taintAddRowNaturalWidth is the width the add-row wants on one line, used to
+// size the overlay box before anything is truncated.
+func taintAddRowNaturalWidth(p taintEditorState) int {
+	fields := taintAddRowFields(p, -1)
+	w := len(taintAddRowSep) * (len(fields) - 1)
+	for _, f := range fields {
+		w += lipgloss.Width(f)
+	}
+	return w
+}
+
+// renderTaintEditorAddRow paints the staged-input line: the three fields with
+// the focused one highlighted and the rest dimmed. Rendered only while an
+// input field is focused.
+//
+// The fields stack onto separate lines when they cannot share one, rather than
+// the row truncating as a unit — that dropped the effect selector off the right
+// edge on a long key, hiding a choice that reshapes scheduling for the whole
+// node.
+func (m Model) renderTaintEditorAddRow(innerW int) string {
+	p := m.taintEditor
+	style := func(i int) lipgloss.Style {
+		if p.focus == taintAddRowFocus[i] {
+			return ui.OverlayFilterStyle
 		}
-		return ui.OverlayDimStyle.Render(text)
+		return ui.OverlayDimStyle
 	}
-	effect := "effect <" + model.ValidTaintEffects[p.addEff] + ">"
-	if p.focus == taintFocusEffect {
-		effect = ui.OverlayFilterStyle.Render(effect)
-	} else {
-		effect = ui.OverlayDimStyle.Render(effect)
+
+	fields := taintAddRowFields(p, -1)
+	sep := taintAddRowSep
+	if taintAddRowNaturalWidth(p) > innerW {
+		fields = taintAddRowFields(p, innerW)
+		sep = "\n"
+	}
+	for i, f := range fields {
+		// Safety net for a field whose label alone outgrows innerW (the
+		// per-field budget floors at one column). It has to respect focus for
+		// the same reason the budget does: cutting the focused field from the
+		// right strips the caret the front-truncation just preserved.
+		trunc := ui.Truncate
+		if p.focus == taintAddRowFocus[i] {
+			trunc = ui.TruncateStart
+		}
+		fields[i] = style(i).Render(trunc(f, innerW))
 	}
-	row := strings.Join([]string{
-		field("add: key", p.addKey, p.focus == taintFocusKey),
-		field("value", p.addVal, p.focus == taintFocusValue),
-		effect,
-	}, "  ")
-	return ui.Truncate(row, innerW)
+	return strings.Join(fields, sep)
 }
 
 // taintDisplayString renders a taint for the overlay row with control

internal/ui/explorer_format.go

@@ -560,6 +560,24 @@ func Truncate(s string, maxW int) string {
 	return ansi.Truncate(s, maxW-1, "") + "~"
 }
 
+// TruncateStart truncates a string from the left to maxW visual columns,
+// prefixing "~" when it was cut. The mirror of Truncate, for text whose end
+// matters more than its start: a text input's caret sits after the last
+// character, so the tail is the part the user needs to see while typing.
+func TruncateStart(s string, maxW int) string {
+	if maxW <= 0 {
+		return ""
+	}
+	w := lipgloss.Width(s)
+	if w <= maxW {
+		return s
+	}
+	if maxW <= 1 {
+		return "~"
+	}
+	return ansi.TruncateLeft(s, w-maxW+1, "~")
+}
+
 // TruncateWithSuffix truncates body so that body + suffix fits within maxW
 // visual columns, then right-pads with spaces so the suffix lands flush
 // against the right edge. Empty suffix degrades to plain Truncate.

internal/ui/explorer_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/charmbracelet/lipgloss"
 	"github.com/stretchr/testify/assert"
 
 	"github.com/janosmiko/lfk/internal/model"
@@ -243,6 +244,33 @@ func TestTruncate(t *testing.T) {
 	}
 }
 
+// TruncateStart is Truncate's mirror: it keeps the tail, which is where a
+// text input's caret sits, so the user can see what they are typing.
+func TestTruncateStart(t *testing.T) {
+	tests := []struct {
+		name     string
+		s        string
+		maxW     int
+		expected string
+	}{
+		{"zero maxW", "hello", 0, ""},
+		{"negative maxW", "hello", -1, ""},
+		{"fits exactly", "hello", 5, "hello"},
+		{"fits with room", "hi", 5, "hi"},
+		{"needs truncation", "hello world", 6, "~world"},
+		{"maxW 1", "hello", 1, "~"},
+		{"empty string", "", 5, ""},
+		{"unicode", "héllo", 4, "~llo"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := TruncateStart(tt.s, tt.maxW)
+			assert.Equal(t, tt.expected, got)
+			assert.LessOrEqual(t, lipgloss.Width(got), max(tt.maxW, 0), "never exceeds maxW")
+		})
+	}
+}
+
 // --- FormatCPU ---
 
 func TestFormatCPU(t *testing.T) {

internal/ui/overlay_list.go

@@ -117,6 +117,15 @@ func OverlayListWidth(items []OverlayListItem, cfg OverlayListConfig, maxWidth i
 			contentW = w
 		}
 	}
+	return OverlayContentWidth(contentW, maxWidth)
+}
+
+// OverlayContentWidth returns the overlay box width that shows contentW
+// columns of content, applying the same chrome, floor and cap as
+// OverlayListWidth. Overlays that render their own content below the list
+// (the taint editor's add-row) size themselves against this so the box grows
+// to fit them instead of truncating them against a list-derived width.
+func OverlayContentWidth(contentW, maxWidth int) int {
 	w := max(contentW+overlayListChrome, OverlayListFloor)
 	if maxWidth > 0 && w > maxWidth {
 		w = maxWidth