From 0efa67908c1c28ef6f24bc85df019ef4e233a477 Mon Sep 17 00:00:00 2001
From: Copilot <copilot@github.com>
Date: Thu, 19 Feb 2026 19:04:34 +0000
Subject: [PATCH] refactor: remove duplicate CSI helper functions from parser
 package

The refactoring in #16892 moved the ANSI stripping implementation to
pkg/stringutil/ansi.go and created a thin wrapper in pkg/parser/ansi_strip.go.
However, the private helper functions isFinalCSIChar and isCSIParameterChar
were accidentally left in pkg/parser/ansi_strip.go as duplicates.

These helpers are already defined in pkg/stringutil/ansi.go (their canonical
location) and are only used internally by stringutil.StripANSI. The parser
package never uses them directly - it delegates to stringutil.StripANSI via
the wrapper.

Remove the duplicate helper functions and their associated tests from the
parser package to eliminate the code duplication.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 pkg/parser/ansi_strip.go             | 13 -----
 pkg/parser/frontmatter_utils_test.go | 79 ----------------------------
 2 files changed, 92 deletions(-)

diff --git a/pkg/parser/ansi_strip.go b/pkg/parser/ansi_strip.go
index ad905765621..a8d911ca9fa 100644
--- a/pkg/parser/ansi_strip.go
+++ b/pkg/parser/ansi_strip.go
@@ -10,16 +10,3 @@ import (
 func StripANSI(s string) string {
 	return stringutil.StripANSI(s)
 }
-
-// isFinalCSIChar checks if a character is a valid CSI final character
-// Final characters are in range 0x40-0x7E (@-~)
-func isFinalCSIChar(b byte) bool {
-	return b >= 0x40 && b <= 0x7E
-}
-
-// isCSIParameterChar checks if a character is a valid CSI parameter or intermediate character
-// Parameter characters are in range 0x30-0x3F (0-?)
-// Intermediate characters are in range 0x20-0x2F (space-/)
-func isCSIParameterChar(b byte) bool {
-	return (b >= 0x20 && b <= 0x2F) || (b >= 0x30 && b <= 0x3F)
-}
diff --git a/pkg/parser/frontmatter_utils_test.go b/pkg/parser/frontmatter_utils_test.go
index 2cd814a4edb..2a18f9c1880 100644
--- a/pkg/parser/frontmatter_utils_test.go
+++ b/pkg/parser/frontmatter_utils_test.go
@@ -563,85 +563,6 @@ func TestStripANSI(t *testing.T) {
 	}
 }
 
-// Test isCSIParameterChar function
-func TestIsCSIParameterChar(t *testing.T) {
-	tests := []struct {
-		name     string
-		char     byte
-		expected bool
-	}{
-		// Valid parameter characters (0x30-0x3F, 0-?)
-		{name: "0 (0x30)", char: '0', expected: true},
-		{name: "9 (0x39)", char: '9', expected: true},
-		{name: "; (0x3B)", char: ';', expected: true},
-		{name: "? (0x3F)", char: '?', expected: true},
-
-		// Valid intermediate characters (0x20-0x2F, space-/)
-		{name: "space (0x20)", char: ' ', expected: true},
-		{name: "! (0x21)", char: '!', expected: true},
-		{name: "/ (0x2F)", char: '/', expected: true},
-
-		// Invalid characters (below 0x20)
-		{name: "tab (0x09)", char: '\t', expected: false},
-		{name: "newline (0x0A)", char: '\n', expected: false},
-		{name: "null (0x00)", char: 0x00, expected: false},
-
-		// Invalid characters (above 0x3F)
-		{name: "@ (0x40)", char: '@', expected: false},
-		{name: "A (0x41)", char: 'A', expected: false},
-		{name: "m (0x6D)", char: 'm', expected: false},
-		{name: "~ (0x7E)", char: '~', expected: false},
-		{name: "DEL (0x7F)", char: 0x7F, expected: false},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			result := isCSIParameterChar(tt.char)
-			if result != tt.expected {
-				t.Errorf("isCSIParameterChar(%q/0x%02X) = %v, want %v", tt.char, tt.char, result, tt.expected)
-			}
-		})
-	}
-}
-
-// Test isFinalCSIChar function
-func TestIsFinalCSIChar(t *testing.T) {
-	tests := []struct {
-		name     string
-		char     byte
-		expected bool
-	}{
-		// Valid final characters (0x40-0x7E, @-~)
-		{name: "@ (0x40)", char: '@', expected: true},
-		{name: "A (0x41)", char: 'A', expected: true},
-		{name: "Z (0x5A)", char: 'Z', expected: true},
-		{name: "a (0x61)", char: 'a', expected: true},
-		{name: "m (0x6D)", char: 'm', expected: true}, // Common color final char
-		{name: "~ (0x7E)", char: '~', expected: true},
-
-		// Invalid characters (below 0x40)
-		{name: "space (0x20)", char: ' ', expected: false},
-		{name: "0 (0x30)", char: '0', expected: false},
-		{name: "9 (0x39)", char: '9', expected: false},
-		{name: "; (0x3B)", char: ';', expected: false},
-		{name: "? (0x3F)", char: '?', expected: false},
-
-		// Invalid characters (above 0x7E)
-		{name: "DEL (0x7F)", char: 0x7F, expected: false},
-		{name: "high byte (0x80)", char: 0x80, expected: false},
-		{name: "high byte (0xFF)", char: 0xFF, expected: false},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			result := isFinalCSIChar(tt.char)
-			if result != tt.expected {
-				t.Errorf("isFinalCSIChar(%q/0x%02X) = %v, want %v", tt.char, tt.char, result, tt.expected)
-			}
-		})
-	}
-}
-
 // Benchmark StripANSI function for performance
 func BenchmarkStripANSI(b *testing.B) {
 	testCases := []struct {