rename TestPacket -> TestPacketEncodeDecode

also, verify encoded bytes to a sample

internal/protocol/packet.go

@@ -61,10 +61,9 @@ func (pkt Packet) encodeStructField(field reflect.StructField, value reflect.Val
 	// write padding bytes
 	pad, err := strconv.Atoi(field.Tag.Get("pad"))
 	if err == nil {
-		for i := 0; i < pad; i++ {
-			if _, err := pkt.readWriter.Write([]byte{0}); err != nil {
-				return err
-			}
+		dummy := make([]byte, pad)
+		if _, err := pkt.readWriter.Write(dummy); err != nil {
+			return err
 		}
 	}
 
@@ -126,10 +125,9 @@ func (pkt Packet) decodeStructField(field reflect.StructField, value reflect.Val
 	// consume padding bytes
 	pad, err := strconv.Atoi(field.Tag.Get("pad"))
 	if err == nil {
-		for i := 0; i < pad; i++ {
-			if _, err := pkt.readWriter.Read([]byte{0}); err != nil {
-				return err
-			}
+		dummy := make([]byte, pad)
+		if _, err := pkt.readWriter.Read(dummy); err != nil {
+			return err
 		}
 	}
 

internal/protocol/packet_test.go

@@ -0,0 +1,49 @@
+package protocol
+
+import (
+	"bytes"
+	"testing"
+)
+
+type TestPacketData struct {
+	A        int32
+	B        int32
+	UTF16Str string `size:"32"`
+	Pad      int16  `pad:"2"`
+	C        int32
+}
+
+// this is the data we expect to get from encoding the above struct with:
+//
+//	Encode(TestPacketData{
+//		A:        1,
+//		B:        2,
+//		UTF16Str: "hello world",
+//		C:        3,
+//	})
+var testData = [...]byte{0x01, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x68, 0x00, 0x65, 0x00, 0x6c, 0x00, 0x6c, 0x00, 0x6f, 0x00, 0x20, 0x00, 0x77, 0x00, 0x6f, 0x00, 0x72, 0x00, 0x6c, 0x00, 0x64, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00}
+
+func TestPacketEncodeDecode(t *testing.T) {
+	pkt := NewPacket(&bytes.Buffer{})
+	if err := pkt.Encode(TestPacketData{
+		A:        1,
+		B:        2,
+		UTF16Str: "hello world",
+		C:        3,
+	}); err != nil {
+		t.Error(err)
+	}
+
+	if !bytes.Equal(pkt.readWriter.(*bytes.Buffer).Bytes(), testData[:]) {
+		t.Error("packet data does not match!")
+	}
+
+	var test TestPacketData
+	if err := pkt.Decode(&test); err != nil {
+		t.Error(err)
+	}
+
+	if test.A != 1 || test.B != 2 || test.C != 3 || test.UTF16Str != "hello world" {
+		t.Error("decoded packet data does not match!")
+	}
+}