Example_httpServerContext.go

package main

import (
	"errors"
	"fmt"
	"io"
	"net"
	"net/http"
	"net/http/httptest"
)

func Example_httpServerContext() {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if tcpAddr, ok := r.Context().Value(http.LocalAddrContextKey).(*net.TCPAddr); ok {
			fmt.Println("network:", tcpAddr.Network())
		}
		if server, ok := r.Context().Value(http.ServerContextKey).(*http.Server); ok {
			fmt.Println("halt the server")
			_ = server.Close()
		}
		w.WriteHeader(http.StatusOK)
		w.Write([]byte(`Писать уже некуда: сервер остановлен, соединения разорваны`))
	}))
	defer srv.Close()

	req := httptest.NewRequest(http.MethodGet, srv.URL, nil)
	res, err := http.DefaultClient.Do(req)
	fmt.Println("request is interrupted:", errors.Is(err, io.EOF))
	fmt.Println("response is nil:", res == nil)
	// Output:
	// network: tcp
	// halt the server
	// request is interrupted: true
	// response is nil: true
}