tocamel_test.go

package main

import (
	"bytes"
	"regexp"
	"strings"
	"testing"
	"unicode"
)

func BenchmarkSplitJoin(b *testing.B) {
	b.StopTimer()
	s := "hoge_foo_bar"
	b.StartTimer()
	for i := 0; i < b.N; i++ {
		ss := strings.Split(s, "_")
		var buf bytes.Buffer
		for _, v := range ss {
			buf.WriteString(strings.Title(v))
			buf.String()
		}
	}
}

func BenchmarkReplace(b *testing.B) {
	b.StopTimer()
	s := "hoge_foo_bar"
	b.StartTimer()
	for i := 0; i < b.N; i++ {
		strings.Replace(strings.Title(strings.Replace(s, "_", " ", -1)), " ", "", -1)
	}
}

func BenchmarkRegexp(b *testing.B) {
	b.StopTimer()
	s := "hoge_foo_bar"
	r := regexp.MustCompile(`_([a-z])`)
	fn := func(m string) string {
		return strings.ToUpper(string(m[1]))
	}
	b.StartTimer()
	for i := 0; i < b.N; i++ {
		strings.Title(r.ReplaceAllStringFunc(s, fn))
	}
}

func BenchmarkForLoop(b *testing.B) {
	b.StopTimer()
	s := "hoge_foo_bar"
	b.StartTimer()
	for i := 0; i < b.N; i++ {
		buf := make([]rune, 0, len(s))
		conv := false
		for _, v := range s {
			if v == '_' {
				conv = true
				continue
			}
			if conv {
				buf = append(buf, unicode.ToUpper(v))
				conv = false
				continue
			}
			buf = append(buf, v)
		}
		buf[0] = unicode.ToUpper(buf[0])
		_ = string(buf)
	}
}