benchmark_test.go

package slogx

import (
	"io"
	"testing"
)

// BenchmarkNew measures the cost of building a default logger with env loading
// disabled — representative of a cold start without environment interaction.
func BenchmarkNew(b *testing.B) {
	for b.Loop() {
		_ = New(
			WithWriter(io.Discard),
			WithLoadFromEnv(false),
			WithSetDefault(false),
		)
	}
}

// BenchmarkNew_WithHandler measures the [WithHandler] short-circuit path where
// format, writer, level, and add-source resolution are skipped.
func BenchmarkNew_WithHandler(b *testing.B) {
	h := stubHandler{}
	b.ResetTimer()
	for b.Loop() {
		_ = New(
			WithHandler(h),
			WithLoadFromEnv(false),
			WithSetDefault(false),
		)
	}
}

// BenchmarkLoadFromEnv measures the cost of parsing all four LOG_* overrides.
func BenchmarkLoadFromEnv(b *testing.B) {
	b.Setenv("LOG_FORMAT", "text")
	b.Setenv("LOG_LEVEL", "debug")
	b.Setenv("LOG_ADD_SOURCE", "true")
	b.Setenv("LOG_OUTPUT", "stderr")

	b.ResetTimer()
	for b.Loop() {
		loadFromEnv(defaultConfig())
	}
}

// BenchmarkLogger_Info measures end-to-end emit cost for a single info record
// through the default JSON handler to [io.Discard].
func BenchmarkLogger_Info(b *testing.B) {
	lg := New(
		WithWriter(io.Discard),
		WithLoadFromEnv(false),
		WithSetDefault(false),
	)

	b.ResetTimer()
	for b.Loop() {
		lg.Info("benchmark", "k", "v")
	}
}

// BenchmarkNewWithLevelVar measures the cost of building a logger and
// allocating the returned [*slog.LevelVar].
func BenchmarkNewWithLevelVar(b *testing.B) {
	for b.Loop() {
		_, _ = NewWithLevelVar(
			WithWriter(io.Discard),
			WithLoadFromEnv(false),
			WithSetDefault(false),
		)
	}
}