Fix bugs with pk.Ary. Add tests and examples.

net/packet/util_test.go

@@ -0,0 +1,72 @@
+package packet_test
+
+import (
+	"bytes"
+	"testing"
+
+	pk "github.com/Tnze/go-mc/net/packet"
+)
+
+func ExampleAry_WriteTo() {
+	data := []pk.Int{0, 1, 2, 3, 4, 5, 6}
+	// Len is completely ignored by WriteTo method.
+	// The length is inferred from the length of Ary.
+	pk.Marshal(
+		0x00,
+		// It's important to remember that
+		// typically the responsibility of
+		// sending the length field
+		// is on you.
+		pk.VarInt(len(data)),
+		pk.Ary{
+			Len: len(data), // this line can be removed
+			Ary: data,
+		},
+	)
+}
+
+func ExampleAry_ReadFrom() {
+	var length pk.VarInt
+	var data []pk.String
+
+	var p pk.Packet // = conn.ReadPacket()
+	if err := p.Scan(
+
+		&length, // decode length first
+		pk.Ary{ // then decode Ary according to length
+			Len: &length,
+			Ary: &data,
+		},
+	); err != nil {
+		panic(err)
+	}
+}
+
+func TestAry_WriteTo(t *testing.T) {
+	var buf bytes.Buffer
+	want := []byte{
+		0x00, 0x00, 0x00, 0x01,
+		0x00, 0x00, 0x00, 0x02,
+		0x00, 0x00, 0x00, 0x03,
+	}
+	int3, long3, varint3, varlong3 := pk.Int(3), pk.Long(3), pk.VarInt(3), pk.VarLong(3)
+	for _, item := range [...]pk.Ary{
+		{Len: int3, Ary: []pk.Int{1, 2, 3}},
+		{Len: long3, Ary: []pk.Int{1, 2, 3}},
+		{Len: varint3, Ary: []pk.Int{1, 2, 3}},
+		{Len: varlong3, Ary: []pk.Int{1, 2, 3}},
+		{Len: &int3, Ary: []pk.Int{1, 2, 3}},
+		{Len: &long3, Ary: []pk.Int{1, 2, 3}},
+		{Len: &varint3, Ary: []pk.Int{1, 2, 3}},
+		{Len: &varlong3, Ary: []pk.Int{1, 2, 3}},
+	} {
+		_, err := item.WriteTo(&buf)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !bytes.Equal(buf.Bytes(), want) {
+			t.Fatalf("Ary encoding error: got %#v, want %#v", buf.Bytes(), want)
+		}
+		buf.Reset()
+	}
+}