문자열 유틸리티 함수 추가 (Claude Code Review 테스트)

golang/strings/string_utils.go

@@ -0,0 +1,81 @@
+package go_strings
+
+import (
+	"strings"
+	"unicode"
+)
+
+// ReverseString reverses the given string, handling Unicode correctly.
+func ReverseString(s string) string {
+	runes := []rune(s)
+	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
+		runes[i], runes[j] = runes[j], runes[i]
+	}
+	return string(runes)
+}
+
+// CamelToSnake converts a camelCase or PascalCase string to snake_case.
+func CamelToSnake(s string) string {
+	var result strings.Builder
+	for i, r := range s {
+		if unicode.IsUpper(r) {
+			if i > 0 {
+				result.WriteRune('_')
+			}
+			result.WriteRune(unicode.ToLower(r))
+		} else {
+			result.WriteRune(r)
+		}
+	}
+	return result.String()
+}
+
+// SnakeToCamel converts a snake_case string to camelCase.
+func SnakeToCamel(s string) string {
+	parts := strings.Split(s, "_")
+	var result strings.Builder
+	for i, part := range parts {
+		if part == "" {
+			continue
+		}
+		if i == 0 {
+			result.WriteString(strings.ToLower(part))
+		} else {
+			result.WriteString(strings.ToUpper(part[:1]) + strings.ToLower(part[1:]))
+		}
+	}
+	return result.String()
+}
+
+// TruncateWithEllipsis truncates a string to maxLen and appends "..." if truncated.
+func TruncateWithEllipsis(s string, maxLen int) string {
+	runes := []rune(s)
+	if len(runes) <= maxLen {
+		return s
+	}
+	if maxLen <= 3 {
+		return string(runes[:maxLen])
+	}
+	return string(runes[:maxLen-3]) + "..."
+}
+
+// CountWords counts the number of words in a string.
+func CountWords(s string) int {
+	return len(strings.Fields(s))
+}
+
+// IsPalindrome checks if a string is a palindrome, ignoring case and non-alphanumeric characters.
+func IsPalindrome(s string) bool {
+	var cleaned []rune
+	for _, r := range strings.ToLower(s) {
+		if unicode.IsLetter(r) || unicode.IsDigit(r) {
+			cleaned = append(cleaned, r)
+		}
+	}
+	for i, j := 0, len(cleaned)-1; i < j; i, j = i+1, j-1 {
+		if cleaned[i] != cleaned[j] {
+			return false
+		}
+	}
+	return true
+}

golang/strings/string_utils_test.go

@@ -0,0 +1,129 @@
+package go_strings
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestReverseString_다양한입력(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{"영문", "hello", "olleh"},
+		{"한글", "안녕하세요", "요세하녕안"},
+		{"빈문자열", "", ""},
+		{"한글자", "a", "a"},
+		{"회문", "racecar", "racecar"},
+		{"이모지", "hello🌍", "🌍olleh"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.expected, ReverseString(tt.input))
+		})
+	}
+}
+
+func TestCamelToSnake_변환(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{"camelCase", "camelCase", "camel_case"},
+		{"PascalCase", "PascalCase", "pascal_case"},
+		{"단일소문자", "hello", "hello"},
+		{"여러대문자", "HTTPServer", "h_t_t_p_server"},
+		{"빈문자열", "", ""},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.expected, CamelToSnake(tt.input))
+		})
+	}
+}
+
+func TestSnakeToCamel_변환(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{"기본", "snake_case", "snakeCase"},
+		{"세단어", "hello_world_go", "helloWorldGo"},
+		{"단일단어", "hello", "hello"},
+		{"빈문자열", "", ""},
+		{"앞뒤언더스코어", "_hello_world_", "helloWorld"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.expected, SnakeToCamel(tt.input))
+		})
+	}
+}
+
+func TestTruncateWithEllipsis_잘라내기(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		maxLen   int
+		expected string
+	}{
+		{"짧은문자열", "hi", 10, "hi"},
+		{"정확히같은길이", "hello", 5, "hello"},
+		{"잘라내기", "hello world", 8, "hello..."},
+		{"매우짧은최대길이", "hello", 3, "hel"},
+		{"한글잘라내기", "안녕하세요 세계입니다", 7, "안녕하세..."},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.expected, TruncateWithEllipsis(tt.input, tt.maxLen))
+		})
+	}
+}
+
+func TestCountWords_단어수세기(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected int
+	}{
+		{"일반문장", "hello world", 2},
+		{"여러공백", "  hello   world  ", 2},
+		{"빈문자열", "", 0},
+		{"탭포함", "hello\tworld\ngo", 3},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.expected, CountWords(tt.input))
+		})
+	}
+}
+
+func TestIsPalindrome_회문검사(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected bool
+	}{
+		{"영문회문", "racecar", true},
+		{"대소문자무시", "RaceCar", true},
+		{"공백과특수문자무시", "A man, a plan, a canal: Panama", true},
+		{"회문아님", "hello", false},
+		{"빈문자열", "", true},
+		{"숫자포함회문", "12321", true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.expected, IsPalindrome(tt.input))
+		})
+	}
+}