HW11 is completed

hw11_telnet_client/go.mod

@@ -1,5 +1,8 @@
-module github.com/fixme_my_friend/hw11_telnet_client
+module github.com/tiburon-777/HW_OTUS/hw11_telnet_client
 
 go 1.14
 
-require github.com/stretchr/testify v1.5.1
+require (
+	github.com/spf13/pflag v1.0.5
+	github.com/stretchr/testify v1.5.1
+)

hw11_telnet_client/go.sum

@@ -2,6 +2,8 @@ github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=

hw11_telnet_client/main.go

@@ -1,6 +1,53 @@
 package main
 
+import (
+	"flag"
+	"log"
+	"net"
+	"os"
+	"sync"
+	"time"
+)
+
 func main() {
-	// Place your code here
-	// P.S. Do not rush to throw context down, think think if it is useful with blocking operation?
+	var timeout time.Duration
+	var wg sync.WaitGroup
+	flag.DurationVar(&timeout, "timeout", time.Second*10, "Set connection timeout. Default = 10s")
+	flag.Parse()
+	args := flag.Args()
+	if len(args) < 2 {
+		log.Fatal("incorrect host/port")
+	}
+	addr := net.JoinHostPort(args[0], args[1])
+	client := NewTelnetClient(addr, timeout, os.Stdin, os.Stdout)
+	if err := client.Connect(); err != nil {
+		log.Fatal("Can't connect: ", err.Error())
+	}
+	log.Println("...connected to", addr)
+	defer client.Close()
+
+	wg.Add(2)
+	go readRoutine(&wg, client)
+	go writeRoutine(&wg, client)
+	wg.Wait()
+}
+
+func readRoutine(wg *sync.WaitGroup, client TelnetClient) {
+	defer wg.Done()
+	for {
+		if err := client.Receive(); err != nil {
+			log.Fatal(err)
+			return
+		}
+	}
+}
+
+func writeRoutine(wg *sync.WaitGroup, client TelnetClient) {
+	defer wg.Done()
+	for {
+		if err := client.Send(); err != nil {
+			log.Fatal(err)
+			return
+		}
+	}
 }

hw11_telnet_client/telnet.go

@@ -1,18 +1,58 @@
 package main
 
 import (
+	"bufio"
+	"errors"
 	"io"
+	"net"
 	"time"
 )
 
 type TelnetClient interface {
-	// Place your code here
+	Connect() error
+	Send() error
+	Receive() error
+	Close() error
+}
+
+type Client struct {
+	address     string
+	timeout     time.Duration
+	in          io.ReadCloser
+	inScanner   *bufio.Scanner
+	out         io.Writer
+	conn        net.Conn
+	connScanner *bufio.Scanner
 }
 
 func NewTelnetClient(address string, timeout time.Duration, in io.ReadCloser, out io.Writer) TelnetClient {
-	// Place your code here
-	return nil
+	return &Client{address: address, timeout: timeout, in: in, out: out}
 }
 
-// Place your code here
-// P.S. Author's solution takes no more than 50 lines
+func (t *Client) Connect() error {
+	var err error
+	t.conn, err = net.DialTimeout("tcp", t.address, t.timeout)
+	t.inScanner = bufio.NewScanner(t.in)
+	t.connScanner = bufio.NewScanner(t.conn)
+	return err
+}
+
+func (t *Client) Send() error {
+	if !t.inScanner.Scan() {
+		return errors.New("...EOF")
+	}
+	_, err := t.conn.Write(append(t.inScanner.Bytes(), '\n'))
+	return err
+}
+
+func (t *Client) Receive() error {
+	if !t.connScanner.Scan() {
+		return errors.New("...connection closed by peer")
+	}
+	_, err := t.out.Write(append(t.connScanner.Bytes(), '\n'))
+	return err
+}
+
+func (t *Client) Close() error {
+	return t.conn.Close()
+}

hw11_telnet_client/telnet_test.go

@@ -62,4 +62,61 @@ func TestTelnetClient(t *testing.T) {
 
 		wg.Wait()
 	})
+
+	t.Run("bad host with timeout", func(t *testing.T) {
+		timeout := time.Second * 5
+		client := NewTelnetClient("mail.ru:25", timeout, nil, nil)
+		start := time.Now()
+		err := client.Connect()
+		require.Error(t, err, "Can't connect: dial tcp 94.100.180.201:25: i/o timeout")
+		require.GreaterOrEqual(t, time.Since(start).Milliseconds(), timeout.Milliseconds()-time.Second.Milliseconds())
+		require.LessOrEqual(t, time.Since(start).Milliseconds(), timeout.Milliseconds()+time.Second.Milliseconds())
+	})
+
+	t.Run("close by peer", func(t *testing.T) {
+		l, err := net.Listen("tcp", "127.0.0.1:")
+		require.NoError(t, err)
+		defer func() { require.NoError(t, l.Close()) }()
+
+		var wg sync.WaitGroup
+		wg.Add(2)
+
+		go func() {
+			defer wg.Done()
+
+			in := &bytes.Buffer{}
+			out := &bytes.Buffer{}
+
+			timeout, err := time.ParseDuration("10s")
+			require.NoError(t, err)
+
+			client := NewTelnetClient(l.Addr().String(), timeout, ioutil.NopCloser(in), out)
+			require.NoError(t, client.Connect())
+			defer func() { require.NoError(t, client.Close()) }()
+
+			in.WriteString("hello\n")
+			err = client.Send()
+			require.NoError(t, err)
+			err = client.Receive()
+			require.Error(t, err, "...connection closed by peer")
+		}()
+
+		go func() {
+			defer wg.Done()
+
+			conn, err := l.Accept()
+			require.NoError(t, err)
+			require.NotNil(t, conn)
+
+			request := make([]byte, 1024)
+			n, err := conn.Read(request)
+			require.NoError(t, err)
+			require.Equal(t, "hello\n", string(request)[:n])
+			require.NoError(t, conn.Close())
+
+		}()
+
+		wg.Wait()
+	})
+
 }