Benchmark yozishda ba'zi nozik jihatlarni bilish, natijani noto'g'ri o'lchashning oldini oladi.

package main

import (
	"strings"
	"testing"
)

func BuildString(n int) string {
	var b strings.Builder
	for i := 0; i < n; i++ {
		b.WriteString("x")
	}
	return b.String()
}

func BenchmarkBuildString(b *testing.B) {
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		BuildString(1000)
	}
}

func BenchmarkBuildStringSizes(b *testing.B) {
	sizes := []int{10, 100, 1000}
	for _, size := range sizes {
		b.Run(strings.Repeat("x", 1), func(b *testing.B) {
			for i := 0; i < b.N; i++ {
				BuildString(size)
			}
		})
	}
}

b.ResetTimer() — agar benchmark boshida sikldan tashqarida sekin "tayyorgarlik" kodi bo'lsa (masalan katta test ma'lumotini yaratish), soatni shu tayyorgarlikdan keyin qaytadan nolga tashlaydi — aks holda tayyorgarlik vaqti ham "benchmark natijasi"ga noto'g'ri qo'shilib ketadi. b.Run esa xuddi t.Run kabi, benchmark'ni turli parametrlar (masalan turli hajmlar) bilan alohida-alohida o'lchash imkonini beradi — masalan "kichik kirish tezmi yoki katta kirish tezmi?" degan savolga javob berish uchun.

Yana bir muhim maslahat: b.ReportAllocs() chaqirilsa, benchmark har bir chaqiruvda nechta xotira ajratish (allocation) bo'lganini ham hisoblab beradi — bu ko'pincha vaqtning o'zidan ham muhimroq, chunki ortiqcha xotira ajratish garbage collectorga ortiqcha yuk beradi.