Go WebSocket server











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I have task assigment to implement HTTP server on Go and there are guidelines:




  • Server should listen for WebSocket connections on /ws path.

  • Server should accept only text type messages.

  • Incoming messages should be transformed and sent back to the sender.

  • End connection on client command or when non text message is received.


Task must be tested as much as possible. I thought only one test case. What kind of tests I should prepare to assure reliability?



server.go



package main

import (
"bytes"
"flag"
"fmt"
"log"
"net/http"

"github.com/gorilla/websocket"
)

var upgrader = websocket.Upgrader{}

func serveWs(w http.ResponseWriter, r *http.Request) {
// Upgrade HTTP connection to WebSocket connection
conn, err := upgrader.Upgrade(w, r, nil)
if err != nil {
log.Println(err)
return
}
defer conn.Close()

for {
mt, message, err := conn.ReadMessage()
if err != nil {
log.Println(err)
break
}

// End connection if client message type is not acceptable
if mt != websocket.TextMessage {
break
}

log.Printf("Received: %s", message)

// Transform message and send back to client
message = bytes.ToUpper(message)
err = conn.WriteMessage(websocket.TextMessage, message)
if err != nil {
log.Println(err)
break
}

log.Printf("Sent: %s", message)
}
}

func main() {
flag.Parse()

if len(flag.Args()) < 1 {
log.Fatal("Must specify port")
}

var port = flag.Args()[0]

http.HandleFunc("/ws", serveWs)

err := http.ListenAndServe(fmt.Sprintf(":%s", port), nil)
if err != nil {
log.Fatal(err)
}
}


client.go



package main

import (
"bufio"
"bytes"
"flag"
"fmt"
"log"
"os"

"github.com/gorilla/websocket"
)

func main() {
flag.Parse()

// Check if server URL is specified
if len(flag.Args()) < 1 {
log.Fatal("Must specify url")
}

var url = flag.Args()[0]

// Connect to the server
conn, _, err := websocket.DefaultDialer.Dial(url, nil)
if err != nil {
log.Fatal(err)
}
defer conn.Close()

// Create input reader
reader := bufio.NewReader(os.Stdin)

// Wait for first user input and send it to the server
fmt.Print("Message: ")
input, _ := reader.ReadBytes('n')
conn.WriteMessage(websocket.TextMessage, bytes.TrimRight(input, "n"))

// Websocket read loop
for {
_, msg, err := conn.ReadMessage()
if err != nil {
log.Println(err)
return
}

fmt.Printf("Received: %sn", msg)

fmt.Print("Message: ")
input, _ := reader.ReadBytes('n')
conn.WriteMessage(websocket.TextMessage, bytes.TrimRight(input, "n"))
}
}


server_test.go



package main

import (
"net/http"
"net/http/httptest"
"strings"
"testing"

"github.com/gorilla/websocket"
)

func TestExample(t *testing.T) {
// Create test server
s := httptest.NewServer(http.HandlerFunc(serveWs))
defer s.Close()

// Convert http URL to ws
url := "ws" + strings.TrimPrefix(s.URL, "http")

// Connect to the server
conn, _, err := websocket.DefaultDialer.Dial(url, nil)
if err != nil {
t.Fatalf("%v", err)
}
defer conn.Close()

// Send message to server and check response
testResponse("hello", "HELLO", conn, t)
testResponse("heLLo", "HELLO", conn, t)
testResponse("HeLLo", "HELLO", conn, t)
}

func testResponse(send string, expect string, conn *websocket.Conn, t *testing.T) {
err := conn.WriteMessage(websocket.TextMessage, byte(send))
if err != nil {
t.Errorf("Read: %v", err)
}

_, msg, err := conn.ReadMessage()
if err != nil {
t.Errorf("Read: %v", err)
}

if string(msg) != expect {
t.Errorf("message transformation failed: got %v want %v", send, expect)
}
}









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    up vote
    0
    down vote

    favorite












    I have task assigment to implement HTTP server on Go and there are guidelines:




    • Server should listen for WebSocket connections on /ws path.

    • Server should accept only text type messages.

    • Incoming messages should be transformed and sent back to the sender.

    • End connection on client command or when non text message is received.


    Task must be tested as much as possible. I thought only one test case. What kind of tests I should prepare to assure reliability?



    server.go



    package main

    import (
    "bytes"
    "flag"
    "fmt"
    "log"
    "net/http"

    "github.com/gorilla/websocket"
    )

    var upgrader = websocket.Upgrader{}

    func serveWs(w http.ResponseWriter, r *http.Request) {
    // Upgrade HTTP connection to WebSocket connection
    conn, err := upgrader.Upgrade(w, r, nil)
    if err != nil {
    log.Println(err)
    return
    }
    defer conn.Close()

    for {
    mt, message, err := conn.ReadMessage()
    if err != nil {
    log.Println(err)
    break
    }

    // End connection if client message type is not acceptable
    if mt != websocket.TextMessage {
    break
    }

    log.Printf("Received: %s", message)

    // Transform message and send back to client
    message = bytes.ToUpper(message)
    err = conn.WriteMessage(websocket.TextMessage, message)
    if err != nil {
    log.Println(err)
    break
    }

    log.Printf("Sent: %s", message)
    }
    }

    func main() {
    flag.Parse()

    if len(flag.Args()) < 1 {
    log.Fatal("Must specify port")
    }

    var port = flag.Args()[0]

    http.HandleFunc("/ws", serveWs)

    err := http.ListenAndServe(fmt.Sprintf(":%s", port), nil)
    if err != nil {
    log.Fatal(err)
    }
    }


    client.go



    package main

    import (
    "bufio"
    "bytes"
    "flag"
    "fmt"
    "log"
    "os"

    "github.com/gorilla/websocket"
    )

    func main() {
    flag.Parse()

    // Check if server URL is specified
    if len(flag.Args()) < 1 {
    log.Fatal("Must specify url")
    }

    var url = flag.Args()[0]

    // Connect to the server
    conn, _, err := websocket.DefaultDialer.Dial(url, nil)
    if err != nil {
    log.Fatal(err)
    }
    defer conn.Close()

    // Create input reader
    reader := bufio.NewReader(os.Stdin)

    // Wait for first user input and send it to the server
    fmt.Print("Message: ")
    input, _ := reader.ReadBytes('n')
    conn.WriteMessage(websocket.TextMessage, bytes.TrimRight(input, "n"))

    // Websocket read loop
    for {
    _, msg, err := conn.ReadMessage()
    if err != nil {
    log.Println(err)
    return
    }

    fmt.Printf("Received: %sn", msg)

    fmt.Print("Message: ")
    input, _ := reader.ReadBytes('n')
    conn.WriteMessage(websocket.TextMessage, bytes.TrimRight(input, "n"))
    }
    }


    server_test.go



    package main

    import (
    "net/http"
    "net/http/httptest"
    "strings"
    "testing"

    "github.com/gorilla/websocket"
    )

    func TestExample(t *testing.T) {
    // Create test server
    s := httptest.NewServer(http.HandlerFunc(serveWs))
    defer s.Close()

    // Convert http URL to ws
    url := "ws" + strings.TrimPrefix(s.URL, "http")

    // Connect to the server
    conn, _, err := websocket.DefaultDialer.Dial(url, nil)
    if err != nil {
    t.Fatalf("%v", err)
    }
    defer conn.Close()

    // Send message to server and check response
    testResponse("hello", "HELLO", conn, t)
    testResponse("heLLo", "HELLO", conn, t)
    testResponse("HeLLo", "HELLO", conn, t)
    }

    func testResponse(send string, expect string, conn *websocket.Conn, t *testing.T) {
    err := conn.WriteMessage(websocket.TextMessage, byte(send))
    if err != nil {
    t.Errorf("Read: %v", err)
    }

    _, msg, err := conn.ReadMessage()
    if err != nil {
    t.Errorf("Read: %v", err)
    }

    if string(msg) != expect {
    t.Errorf("message transformation failed: got %v want %v", send, expect)
    }
    }









    share|improve this question







    New contributor




    Gugis is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.






















      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      I have task assigment to implement HTTP server on Go and there are guidelines:




      • Server should listen for WebSocket connections on /ws path.

      • Server should accept only text type messages.

      • Incoming messages should be transformed and sent back to the sender.

      • End connection on client command or when non text message is received.


      Task must be tested as much as possible. I thought only one test case. What kind of tests I should prepare to assure reliability?



      server.go



      package main

      import (
      "bytes"
      "flag"
      "fmt"
      "log"
      "net/http"

      "github.com/gorilla/websocket"
      )

      var upgrader = websocket.Upgrader{}

      func serveWs(w http.ResponseWriter, r *http.Request) {
      // Upgrade HTTP connection to WebSocket connection
      conn, err := upgrader.Upgrade(w, r, nil)
      if err != nil {
      log.Println(err)
      return
      }
      defer conn.Close()

      for {
      mt, message, err := conn.ReadMessage()
      if err != nil {
      log.Println(err)
      break
      }

      // End connection if client message type is not acceptable
      if mt != websocket.TextMessage {
      break
      }

      log.Printf("Received: %s", message)

      // Transform message and send back to client
      message = bytes.ToUpper(message)
      err = conn.WriteMessage(websocket.TextMessage, message)
      if err != nil {
      log.Println(err)
      break
      }

      log.Printf("Sent: %s", message)
      }
      }

      func main() {
      flag.Parse()

      if len(flag.Args()) < 1 {
      log.Fatal("Must specify port")
      }

      var port = flag.Args()[0]

      http.HandleFunc("/ws", serveWs)

      err := http.ListenAndServe(fmt.Sprintf(":%s", port), nil)
      if err != nil {
      log.Fatal(err)
      }
      }


      client.go



      package main

      import (
      "bufio"
      "bytes"
      "flag"
      "fmt"
      "log"
      "os"

      "github.com/gorilla/websocket"
      )

      func main() {
      flag.Parse()

      // Check if server URL is specified
      if len(flag.Args()) < 1 {
      log.Fatal("Must specify url")
      }

      var url = flag.Args()[0]

      // Connect to the server
      conn, _, err := websocket.DefaultDialer.Dial(url, nil)
      if err != nil {
      log.Fatal(err)
      }
      defer conn.Close()

      // Create input reader
      reader := bufio.NewReader(os.Stdin)

      // Wait for first user input and send it to the server
      fmt.Print("Message: ")
      input, _ := reader.ReadBytes('n')
      conn.WriteMessage(websocket.TextMessage, bytes.TrimRight(input, "n"))

      // Websocket read loop
      for {
      _, msg, err := conn.ReadMessage()
      if err != nil {
      log.Println(err)
      return
      }

      fmt.Printf("Received: %sn", msg)

      fmt.Print("Message: ")
      input, _ := reader.ReadBytes('n')
      conn.WriteMessage(websocket.TextMessage, bytes.TrimRight(input, "n"))
      }
      }


      server_test.go



      package main

      import (
      "net/http"
      "net/http/httptest"
      "strings"
      "testing"

      "github.com/gorilla/websocket"
      )

      func TestExample(t *testing.T) {
      // Create test server
      s := httptest.NewServer(http.HandlerFunc(serveWs))
      defer s.Close()

      // Convert http URL to ws
      url := "ws" + strings.TrimPrefix(s.URL, "http")

      // Connect to the server
      conn, _, err := websocket.DefaultDialer.Dial(url, nil)
      if err != nil {
      t.Fatalf("%v", err)
      }
      defer conn.Close()

      // Send message to server and check response
      testResponse("hello", "HELLO", conn, t)
      testResponse("heLLo", "HELLO", conn, t)
      testResponse("HeLLo", "HELLO", conn, t)
      }

      func testResponse(send string, expect string, conn *websocket.Conn, t *testing.T) {
      err := conn.WriteMessage(websocket.TextMessage, byte(send))
      if err != nil {
      t.Errorf("Read: %v", err)
      }

      _, msg, err := conn.ReadMessage()
      if err != nil {
      t.Errorf("Read: %v", err)
      }

      if string(msg) != expect {
      t.Errorf("message transformation failed: got %v want %v", send, expect)
      }
      }









      share|improve this question







      New contributor




      Gugis is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      I have task assigment to implement HTTP server on Go and there are guidelines:




      • Server should listen for WebSocket connections on /ws path.

      • Server should accept only text type messages.

      • Incoming messages should be transformed and sent back to the sender.

      • End connection on client command or when non text message is received.


      Task must be tested as much as possible. I thought only one test case. What kind of tests I should prepare to assure reliability?



      server.go



      package main

      import (
      "bytes"
      "flag"
      "fmt"
      "log"
      "net/http"

      "github.com/gorilla/websocket"
      )

      var upgrader = websocket.Upgrader{}

      func serveWs(w http.ResponseWriter, r *http.Request) {
      // Upgrade HTTP connection to WebSocket connection
      conn, err := upgrader.Upgrade(w, r, nil)
      if err != nil {
      log.Println(err)
      return
      }
      defer conn.Close()

      for {
      mt, message, err := conn.ReadMessage()
      if err != nil {
      log.Println(err)
      break
      }

      // End connection if client message type is not acceptable
      if mt != websocket.TextMessage {
      break
      }

      log.Printf("Received: %s", message)

      // Transform message and send back to client
      message = bytes.ToUpper(message)
      err = conn.WriteMessage(websocket.TextMessage, message)
      if err != nil {
      log.Println(err)
      break
      }

      log.Printf("Sent: %s", message)
      }
      }

      func main() {
      flag.Parse()

      if len(flag.Args()) < 1 {
      log.Fatal("Must specify port")
      }

      var port = flag.Args()[0]

      http.HandleFunc("/ws", serveWs)

      err := http.ListenAndServe(fmt.Sprintf(":%s", port), nil)
      if err != nil {
      log.Fatal(err)
      }
      }


      client.go



      package main

      import (
      "bufio"
      "bytes"
      "flag"
      "fmt"
      "log"
      "os"

      "github.com/gorilla/websocket"
      )

      func main() {
      flag.Parse()

      // Check if server URL is specified
      if len(flag.Args()) < 1 {
      log.Fatal("Must specify url")
      }

      var url = flag.Args()[0]

      // Connect to the server
      conn, _, err := websocket.DefaultDialer.Dial(url, nil)
      if err != nil {
      log.Fatal(err)
      }
      defer conn.Close()

      // Create input reader
      reader := bufio.NewReader(os.Stdin)

      // Wait for first user input and send it to the server
      fmt.Print("Message: ")
      input, _ := reader.ReadBytes('n')
      conn.WriteMessage(websocket.TextMessage, bytes.TrimRight(input, "n"))

      // Websocket read loop
      for {
      _, msg, err := conn.ReadMessage()
      if err != nil {
      log.Println(err)
      return
      }

      fmt.Printf("Received: %sn", msg)

      fmt.Print("Message: ")
      input, _ := reader.ReadBytes('n')
      conn.WriteMessage(websocket.TextMessage, bytes.TrimRight(input, "n"))
      }
      }


      server_test.go



      package main

      import (
      "net/http"
      "net/http/httptest"
      "strings"
      "testing"

      "github.com/gorilla/websocket"
      )

      func TestExample(t *testing.T) {
      // Create test server
      s := httptest.NewServer(http.HandlerFunc(serveWs))
      defer s.Close()

      // Convert http URL to ws
      url := "ws" + strings.TrimPrefix(s.URL, "http")

      // Connect to the server
      conn, _, err := websocket.DefaultDialer.Dial(url, nil)
      if err != nil {
      t.Fatalf("%v", err)
      }
      defer conn.Close()

      // Send message to server and check response
      testResponse("hello", "HELLO", conn, t)
      testResponse("heLLo", "HELLO", conn, t)
      testResponse("HeLLo", "HELLO", conn, t)
      }

      func testResponse(send string, expect string, conn *websocket.Conn, t *testing.T) {
      err := conn.WriteMessage(websocket.TextMessage, byte(send))
      if err != nil {
      t.Errorf("Read: %v", err)
      }

      _, msg, err := conn.ReadMessage()
      if err != nil {
      t.Errorf("Read: %v", err)
      }

      if string(msg) != expect {
      t.Errorf("message transformation failed: got %v want %v", send, expect)
      }
      }






      go websocket






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      Gugis is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.









      share|improve this question




      share|improve this question






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      asked 18 mins ago









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      Gugis is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






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      Check out our Code of Conduct.



























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