add IPv4 packet addr encoding test

common/net/packetaddr/packetaddr_test.go

@@ -0,0 +1,21 @@
+package packetaddr
+
+import (
+	"github.com/stretchr/testify/assert"
+	sysnet "net"
+	"testing"
+)
+
+func TestPacketEncodingIPv4(t *testing.T) {
+	packetAddress := &sysnet.UDPAddr{
+		IP:   sysnet.IPv4(1, 2, 3, 4).To4(),
+		Port: 1234,
+	}
+	var packetData [256]byte
+	wrapped := AttachAddressToPacket(packetData[:], packetAddress)
+
+	packetPayload, decodedAddress := ExtractAddressFromPacket(wrapped)
+
+	assert.Equal(t, packetPayload, packetData[:])
+	assert.Equal(t, packetAddress, decodedAddress)
+}