package main

import (
	"context"
	"testing"
)

type Breaker interface {
	Done() <-chan struct{}
	Err() error
}

type breaker struct{}

func (*breaker) Done() <-chan struct{} { return nil }
func (*breaker) Err() error            { return nil }

func withCast(breaker Breaker) {
	ctx, is := breaker.(context.Context)
	if !is {
		ctx = context.Background()
	}
	ctx, cancel := context.WithCancel(ctx)
	defer cancel()
}

func withoutCast(breaker Breaker) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	_, _ = breaker, ctx
}

func Benchmark(b *testing.B) {
	ctx := context.WithValue(context.Background(), "test", "test")

	b.Run("ctx, with cast", func(b *testing.B) {
		b.ReportAllocs()
		for i := 0; i < b.N; i++ {
			withCast(ctx)
		}
	})

	b.Run("ctx, without cast", func(b *testing.B) {
		b.ReportAllocs()
		for i := 0; i < b.N; i++ {
			withoutCast(ctx)
		}
	})

	br := new(breaker)

	b.Run("breaker, with cast", func(b *testing.B) {
		b.ReportAllocs()
		for i := 0; i < b.N; i++ {
			withCast(br)
		}
	})

	b.Run("breaker, without cast", func(b *testing.B) {
		b.ReportAllocs()
		for i := 0; i < b.N; i++ {
			withoutCast(br)
		}
	})
}