Testing Go TCP Connections

foo.go

package foo

import (
    "fmt"
    "log"
    "net"
)
var connection net.Conn = nil
func close() {
    if connection != nil  {
        connection.Close()
        connection = nil
    }
}

func connect(loc string) {
    if connection != nil {
        close()
    }
    
    
    log.Print("Client Started")
    connection, err := net.Dial("tcp", loc)
    if err != nil {
        log.Print("Cannot connect to server")
    }
}

func sendMessage(message string) {

    log.Print("SENT FROM CLIENT")
    fmt.Fprintf(connection, "[prefix]" + message+ "\n")

}

foo_test.go

package foo
import (
    "fmt"
    "log"
    "net"
    "log"
    "sync"
)
func server(recvMsg func(conn net.Conn), loc string) {
    log.Print("Server")
    server, err := net.Listen("tcp", loc)
    if server == nil {
        panic("couldn't start listening: " + err.Error())
    }

    go func() {

        log.Print("PING .. waiting for connections:")
        c, err := server.Accept()

        if err != nil {
            log.Print("ERROR IS: ", err)
        }

        log.Print("Accepted Connection")

        recvMsg(c)
    }()

}

func TestClient() {
    log.Print("Start")

    h, _ := os.Hostname()

    log.Print("HOSTNAME: ", h)
    var wg sync.WaitGroup

    wg.Add(1)
    recvMsg := func(conn net.Conn) {
        defer wg.Done()
        log.Print("RECV")
        buf := make([]byte, 1024)
        // Read the incoming connection into the buffer.
        reqLen, err := conn.Read(buf)
        log.Print("ReqLen is: ", reqLen)
        if err != nil {
            log.Print("Error reading:", err.Error())
        }

        // DO YOUR TEST HERE!

        log.Print(buf)
        // Send a response back to person contacting us.
        conn.Write([]byte("Message received."))
        // Close the connection when you're done with it.
        conn.Close()

    }
    
    //Can randomize too!
    loc = "127.0.0.1:1234" 
    go server(recvMsg, loc)

    go client(loc)

    wg.Wait()
    // Clean up
    
    close()
}