refactor sendPingReply and added first unit test for login

sending_test.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"net"
+	"testing"
+)
+
+// Test scafolding
+func TestSendLogin(t *testing.T) {
+	testTable := []struct {
+		name         string
+		pass         string
+		resultBuffer []byte
+		resultLenght int
+		// input, output
+	}{
+		{
+			name:         "happy",
+			pass:         "happy2",
+			resultBuffer: []byte{140, 15, 0, 104, 97, 112, 112, 121, 32, 104, 97, 112, 112, 121, 50, 0, 0},
+			resultLenght: 17,
+		},
+	}
+
+	for _, tt := range testTable {
+		t.Run(tt.name, func(t *testing.T) {
+			// call function or method under test
+			// ....
+			// check respose
+			server, client := net.Pipe()
+
+			go func() {
+				sendLogin(client, tt.name, tt.pass)
+			}()
+
+			reply := make([]byte, 4096)
+			length, _ := server.Read(reply)
+			if length != tt.resultLenght {
+				t.Errorf("Expected length %v, got %v buffer: %v for %s / %s", tt.resultLenght, length, reply[0:length], tt.name, tt.pass)
+			}
+		})
+	}
+}