net.errClosing use case

output.txt

erik$ go version
go version go1.4.1 darwin/amd64
erik$ go test -v usecase_test.go 
=== RUN TestUseOfClosedNetworkConnection
--- PASS: TestUseOfClosedNetworkConnection (0.01s)
	usecase_test.go:15: request start
	usecase_test.go:34: timeout
	usecase_test.go:17: request end
PASS
ok  	command-line-arguments	0.019s

usecase_test.go

package testcase

import (
        "net"
        "net/http"
        "strings"
        "testing"
        "time"
)

func TestUseOfClosedNetworkConnection(t *testing.T) {
        requestDone := make(chan int)

        http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
                t.Log("request start")
                time.Sleep(time.Millisecond * 10)
                t.Log("request end")
                close(requestDone)
        })

        l, err := net.Listen("tcp", ":12345")
        if err != nil {
                t.Fatal(err)
        }

        go http.Serve(l, nil)

        client := &http.Client{
                Timeout: time.Millisecond,
        }

        if res, err := client.Get("http://127.0.0.1:12345/"); err != nil {
                if strings.HasSuffix(err.Error(), "use of closed network connection") {
                        t.Log("timeout")
                } else {
                        t.Fatal(err)
                }
        } else {
                t.Logf("status: %s", res.Status)
        }

        l.Close()

        <-requestDone
}

working_go1.5_test.go

package testcase

import (
        "net"
        "net/http"
        "testing"
        "time"
)

func TestUseOfClosedNetworkConnection(t *testing.T) {
        requestDone := make(chan int)

        http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
                t.Log("request start")
                time.Sleep(time.Millisecond * 10)
                t.Log("request end")
                close(requestDone)
        })

        l, err := net.Listen("tcp", ":12345")
        if err != nil {
                t.Fatal(err)
        }

        go http.Serve(l, nil)

        client := &http.Client{
                Timeout: time.Millisecond,
        }

        if res, err := client.Get("http://127.0.0.1:12345/"); err != nil {
                if err.(net.Error).Timeout() {
                        t.Log("timeout")
                } else {
                        t.Fatal(err.Error())
                }
        } else {
                t.Logf("status: %s", res.Status)
        }

        l.Close()

        <-requestDone
}