resolve perf issues highlighted by golangci-lint

Author: Stanislav (Stas) Katkov

cmd/jsonrepair.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"errors"
 	"fmt"
 	"io"
 
@@ -42,7 +43,7 @@ This tool can fix various JSON issues including:
 		}
 
 		if len(data) == 0 {
-			return fmt.Errorf("no input provided. Pipe JSON input to this command")
+			return errors.New("no input provided. Pipe JSON input to this command")
 		}
 
 		result, err := jsonrepair.RepairJSON(string(data))

docs/tui-docs.go

@@ -258,7 +258,9 @@ Most TUI tools share these common key bindings:
 }
 
 func generateModuleFile(sitePath string, module TUIModule) error {
-	content := fmt.Sprintf(`---
+	var builder strings.Builder
+
+	fmt.Fprintf(&builder, `---
 title: %s
 parent: TUI
 ---
@@ -277,23 +279,18 @@ parent: TUI
 `, module.Title, module.Title)
 
 	if len(module.KeyBindings) > 0 {
-		content += "| Key | Action |\n|-----|--------|\n"
-		var builder strings.Builder
+		builder.WriteString("| Key | Action |\n|-----|--------|\n")
 		for _, binding := range module.KeyBindings {
-			builder.WriteString(fmt.Sprintf("| `%s` | %s |\n", binding.Key, binding.Description))
+			fmt.Fprintf(&builder, "| `%s` | %s |\n", binding.Key, binding.Description)
 		}
-		content += builder.String()
 	} else {
-		content += "Standard key bindings apply (see main TUI documentation).\n"
+		builder.WriteString("Standard key bindings apply (see main TUI documentation).\n")
 	}
 
-	content += `
-
-
-`
+	builder.WriteString("\n\n")
 
 	filename := module.Name + ".md"
-	return os.WriteFile(filepath.Join(sitePath, filename), []byte(content), 0o644)
+	return os.WriteFile(filepath.Join(sitePath, filename), []byte(builder.String()), 0o644)
 }
 
 func GenerateTUIDocumentation() error {

internal/csv2md/main.go

@@ -39,16 +39,16 @@ func Convert(header string, records [][]string, aligned bool) []string {
 	// build markdown table
 	for row_idx, row := range records {
 		// table content
-		var sb strings.Builder
-		sb.WriteString("| ")
+		var builder strings.Builder
+		builder.WriteString("| ")
 		for col_idx, col := range row {
 			if aligned {
-				sb.WriteString(fmt.Sprintf("%-*s | ", widths[col_idx], col))
+				fmt.Fprintf(&builder, "%-*s | ", widths[col_idx], col)
 			} else {
-				sb.WriteString(col + " | ")
+				builder.WriteString(col + " | ")
 			}
 		}
-		result = append(result, sb.String())
+		result = append(result, builder.String())
 
 		// content separator only after first row (header)
 		if row_idx == 0 {