Fix lint findings from first real golangci-lint run

errcheck: wrap deferred Close calls; staticcheck: De Morgan
simplifications, tagged switch, Fprintf over WriteString(Sprintf),
drop redundant nil check; remove unused newConfirmModal and
renderSparkline.

Author: luthermonson

audit/audit.go

@@ -61,7 +61,7 @@ func Append(e Entry) {
 	if err != nil {
 		return
 	}
-	defer f.Close()
+	defer func() { _ = f.Close() }()
 	data, err := json.Marshal(e)
 	if err != nil {
 		return

tools/archive.go

@@ -30,7 +30,7 @@ func extractFromTarGz(archive []byte, binName string) ([]byte, error) {
 	if err != nil {
 		return nil, fmt.Errorf("gzip: %w", err)
 	}
-	defer gz.Close()
+	defer func() { _ = gz.Close() }()
 	tr := tar.NewReader(gz)
 	for {
 		h, err := tr.Next()

tools/release.go

@@ -66,7 +66,7 @@ func k9sReleaser(goos, goarch string) (Releaser, error) {
 	if !ok {
 		return Releaser{}, fmt.Errorf("k9s: unsupported OS %s", goos)
 	}
-	if !(goarch == "amd64" || goarch == "arm64") {
+	if goarch != "amd64" && goarch != "arm64" {
 		return Releaser{}, fmt.Errorf("k9s: unsupported arch %s", goarch)
 	}
 	ext := "tar.gz"

tui/app.go

@@ -1567,8 +1567,8 @@ func (m model) headerView() string {
 	// LINODE_TOKEN with no named account). Falls back to the account
 	// name otherwise.
 	label := ""
-	switch acct := m.cfg.DefaultAccount; {
-	case acct == "__cli__" || acct == "":
+	switch acct := m.cfg.DefaultAccount; acct {
+	case "__cli__", "":
 		if m.username != "" {
 			label = m.username
 		}
@@ -1726,7 +1726,7 @@ func (m model) dispatch(input string) (tea.Model, tea.Cmd) {
 					b.WriteString(line + "\n")
 				}
 			}
-			b.WriteString(fmt.Sprintf("\nactive (global): %s\n", m.cfg.ActiveTheme))
+			fmt.Fprintf(&b, "\nactive (global): %s\n", m.cfg.ActiveTheme)
 			if len(m.cfg.Accounts) > 0 {
 				b.WriteString("\nper-account overrides:\n")
 				names := make([]string, 0, len(m.cfg.Accounts))
@@ -1744,9 +1744,9 @@ func (m model) dispatch(input string) (tea.Model, tea.Cmd) {
 						marker = " (active)"
 					}
 					if override == "" {
-						b.WriteString(fmt.Sprintf("  %s%s: (inherits global)\n", n, marker))
+						fmt.Fprintf(&b, "  %s%s: (inherits global)\n", n, marker)
 					} else {
-						b.WriteString(fmt.Sprintf("  %s%s: %s\n", n, marker, override))
+						fmt.Fprintf(&b, "  %s%s: %s\n", n, marker, override)
 					}
 				}
 			}

tui/confirm.go

@@ -21,10 +21,6 @@ type confirmModal struct {
 	destructive bool
 }
 
-func newConfirmModal(prompt string, onYes tea.Cmd) *confirmModal {
-	return newConfirmModalWithTheme(prompt, onYes, theme.Theme{})
-}
-
 func newConfirmModalWithTheme(prompt string, onYes tea.Cmd, th theme.Theme) *confirmModal {
 	m := &confirmModal{
 		onYes:       onYes,

tui/create_linode.go

@@ -195,7 +195,7 @@ func (m *createLinode) Update(msg tea.Msg) tea.Cmd {
 }
 
 func (m *createLinode) maybeBuildForm() tea.Cmd {
-	if !(m.gotReg && m.gotTyp && m.gotImg && m.gotSSH) {
+	if !m.gotReg || !m.gotTyp || !m.gotImg || !m.gotSSH {
 		return nil
 	}
 	regionOpts := make([]huh.Option[string], 0, len(m.regions))

tui/create_lke.go

@@ -139,7 +139,7 @@ func (m *createLKE) Update(msg tea.Msg) tea.Cmd {
 }
 
 func (m *createLKE) maybeBuildForm() tea.Cmd {
-	if !(m.gotReg && m.gotTyp && m.gotVer) {
+	if !m.gotReg || !m.gotTyp || !m.gotVer {
 		return nil
 	}
 	regionOpts := make([]huh.Option[string], 0, len(m.regions))

tui/views/instance_detail.go

@@ -489,7 +489,7 @@ func (m *instanceDetail) renderBackups() string {
 		return "  (no backup data — check `backups:read_only` scope)\n"
 	}
 	var b strings.Builder
-	if bks.Automatic != nil && len(bks.Automatic) > 0 {
+	if len(bks.Automatic) > 0 {
 		b.WriteString("  Automatic Backups\n  " + strings.Repeat("─", 40) + "\n")
 		for _, bk := range bks.Automatic {
 			created := ""
@@ -809,68 +809,6 @@ func bucketValues(values []float64, width int) []float64 {
 	return out
 }
 
-// renderSparkline turns a series of values into a single line of unicode
-// block characters. Width controls how many cells to render — values are
-// bucketed if there are more samples than cells. Baseline is 0 so the
-// height of each bar corresponds to the absolute value (not min-max scale).
-func renderSparkline(values []float64, width int) string {
-	if len(values) == 0 || width <= 0 {
-		return ""
-	}
-	// Bucket to width cells. Each cell is the mean of its bucket.
-	buckets := make([]float64, width)
-	if len(values) <= width {
-		// Stretch: pad the left with zeros so the recent samples land on
-		// the right edge (most readable).
-		offset := width - len(values)
-		for i, v := range values {
-			buckets[offset+i] = v
-		}
-	} else {
-		samplesPerCell := float64(len(values)) / float64(width)
-		for cell := 0; cell < width; cell++ {
-			lo := int(float64(cell) * samplesPerCell)
-			hi := int(float64(cell+1) * samplesPerCell)
-			if hi > len(values) {
-				hi = len(values)
-			}
-			if lo >= hi {
-				buckets[cell] = values[lo]
-				continue
-			}
-			var sum float64
-			for _, v := range values[lo:hi] {
-				sum += v
-			}
-			buckets[cell] = sum / float64(hi-lo)
-		}
-	}
-	var maxV float64
-	for _, v := range buckets {
-		if v > maxV {
-			maxV = v
-		}
-	}
-	if maxV == 0 {
-		// All zeros — render a flat baseline.
-		return strings.Repeat("▁", width)
-	}
-	// 8-level unicode block ramp.
-	levels := []rune{'▁', '▂', '▃', '▄', '▅', '▆', '▇', '█'}
-	var b strings.Builder
-	for _, v := range buckets {
-		idx := int((v / maxV) * float64(len(levels)-1))
-		if idx < 0 {
-			idx = 0
-		}
-		if idx >= len(levels) {
-			idx = len(levels) - 1
-		}
-		b.WriteRune(levels[idx])
-	}
-	return b.String()
-}
-
 func stats(values []float64) (minV, maxV, cur, avg float64) {
 	if len(values) == 0 {
 		return 0, 0, 0, 0