From 94c6798e8bf776f6c68d9eb2c9c06fcfb7a6ae54 Mon Sep 17 00:00:00 2001
From: ChillerDragon <ChillerDragon@gmail.com>
Date: Tue, 25 Jun 2024 12:19:51 +0800
Subject: [PATCH] Refactor unpacker and add some more snap tests

---
 chunk7/chunk.go                               |  44 ++-
 chunk7/chunk_test.go                          |   6 +-
 chunk7/splitter.go                            |   3 +-
 messages7/cl_say.go                           |   2 +-
 messages7/cl_start_info.go                    |  16 +-
 messages7/ctrl_close.go                       |   2 +-
 messages7/info.go                             |   4 +-
 messages7/map_change.go                       |   2 +-
 messages7/maplist_entry_add.go                |   2 +-
 messages7/maplist_entry_rem.go                |   2 +-
 messages7/rcon_auth.go                        |   2 +-
 messages7/rcon_cmd.go                         |   2 +-
 messages7/rcon_cmd_add.go                     |   6 +-
 messages7/rcon_cmd_rem.go                     |   2 +-
 messages7/rcon_line.go                        |   2 +-
 messages7/server_info.go                      |  10 +-
 messages7/sv_broadcast.go                     |   2 +-
 messages7/sv_chat.go                          |   2 +-
 messages7/sv_client_info.go                   |  16 +-
 messages7/sv_emoticon.go                      |   3 +
 messages7/sv_emoticon_test.go                 |  88 ++++++
 messages7/sv_motd.go                          |   2 +-
 messages7/sv_vote_option_add.go               |   2 +-
 messages7/sv_vote_option_list_add.go          |   2 +-
 messages7/sv_vote_option_list_add_test.go     |  37 +++
 messages7/sv_vote_option_remove.go            |   2 +-
 messages7/sv_vote_set.go                      |   4 +-
 object7/laser_test.go                         |  79 ++++++
 object7/snap_object.go                        |   6 +-
 packer/packer.go                              |  47 +++-
 packer/packer_state_test.go                   |  16 +-
 snapshot7/full_ddnet_server_test.go           | 266 ++++++++++++++++++
 ...pshot_test.go => simple_localhost_test.go} |   2 +-
 33 files changed, 616 insertions(+), 67 deletions(-)
 create mode 100644 messages7/sv_emoticon_test.go
 create mode 100644 messages7/sv_vote_option_list_add_test.go
 create mode 100644 object7/laser_test.go
 create mode 100644 snapshot7/full_ddnet_server_test.go
 rename snapshot7/{snapshot_test.go => simple_localhost_test.go} (96%)

diff --git a/chunk7/chunk.go b/chunk7/chunk.go
index 3b67372..7fc87dc 100644
--- a/chunk7/chunk.go
+++ b/chunk7/chunk.go
@@ -1,5 +1,11 @@
 package chunk7
 
+import (
+	"fmt"
+
+	"github.com/teeworlds-go/go-teeworlds-protocol/packer"
+)
+
 const (
 	chunkFlagVital  = 1
 	chunkFlagResend = 2
@@ -49,13 +55,49 @@ func (header *ChunkHeader) Pack() []byte {
 	return data
 }
 
-func (header *ChunkHeader) Unpack(data []byte) {
+func (header *ChunkHeader) Unpack(u *packer.Unpacker) error {
+	data, err := u.GetRaw(2)
+	if err != nil {
+		return err
+	}
 	flagBits := (data[0] >> 6) & 0x03
 	header.Flags.Vital = (flagBits & chunkFlagVital) != 0
 	header.Flags.Resend = (flagBits & chunkFlagResend) != 0
 	header.Size = (int(data[0]&0x3F) << 6) | (int(data[1]) & 0x3F)
 
 	if header.Flags.Vital {
+		thirdByte, err := u.GetByte()
+		if err != nil {
+			return err
+		}
+		header.Seq = int((data[1]&0xC0)<<2) | int(thirdByte)
+	}
+	return nil
+}
+
+// TODO: give this a better name
+//
+//	but it would be nice to have two unpack methods for all structs
+//
+//	Unpack(u *packer.Unpacker)
+//	UnpackTodoFindAGoodName(data []byte)
+//
+//	See https://github.com/teeworlds-go/go-teeworlds-protocol/issues/5
+func (header *ChunkHeader) UnpackRaw(data []byte) error {
+	if len(data) < 2 {
+		return fmt.Errorf("size=%d not enough data to read chunk header", len(data))
+	}
+
+	flagBits := (data[0] >> 6) & 0x03
+	header.Flags.Vital = (flagBits & chunkFlagVital) != 0
+	header.Flags.Resend = (flagBits & chunkFlagResend) != 0
+	header.Size = (int(data[0]&0x3F) << 6) | (int(data[1]) & 0x3F)
+
+	if header.Flags.Vital {
+		if len(data) < 3 {
+			return fmt.Errorf("size=%d not enough data to read vital chunk header", len(data))
+		}
 		header.Seq = int((data[1]&0xC0)<<2) | int(data[2])
 	}
+	return nil
 }
diff --git a/chunk7/chunk_test.go b/chunk7/chunk_test.go
index e15fa30..6904f0f 100644
--- a/chunk7/chunk_test.go
+++ b/chunk7/chunk_test.go
@@ -12,7 +12,7 @@ func TestBrokenNonVitalHeader(t *testing.T) {
 
 	header := ChunkHeader{}
 	//            {0x40, 0x3a, 0x01}
-	header.Unpack([]byte{0x3a, 0x01})
+	header.UnpackRaw([]byte{0x3a, 0x01})
 
 	want := ChunkHeader{
 		Flags: ChunkFlags{
@@ -33,7 +33,7 @@ func TestVitalHeaderMapChange(t *testing.T) {
 	// verified with libtw2 wireshark dissector
 
 	header := ChunkHeader{}
-	header.Unpack([]byte{0x40, 0x3a, 0x01})
+	header.UnpackRaw([]byte{0x40, 0x3a, 0x01})
 
 	want := ChunkHeader{
 		Flags: ChunkFlags{
@@ -51,7 +51,7 @@ func TestVitalHeaderMapChange(t *testing.T) {
 
 func TestVitalHeader(t *testing.T) {
 	header := ChunkHeader{}
-	header.Unpack([]byte{0x40, 0x10, 0x0a})
+	header.UnpackRaw([]byte{0x40, 0x10, 0x0a})
 	want := ChunkHeader{
 		Flags: ChunkFlags{
 			Vital:  true,
diff --git a/chunk7/splitter.go b/chunk7/splitter.go
index 6e51edb..f21cb53 100644
--- a/chunk7/splitter.go
+++ b/chunk7/splitter.go
@@ -11,7 +11,8 @@ func UnpackChunks(data []byte) []Chunk {
 
 	for i < payloadSize {
 		chunk := Chunk{}
-		chunk.Header.Unpack(data[i:])
+		// TODO: can we use ChunkHeader.Unpack(u) here to simplify the code?
+		chunk.Header.UnpackRaw(data[i:])
 		i += 2 // header
 		if chunk.Header.Flags.Vital {
 			i++
diff --git a/messages7/cl_say.go b/messages7/cl_say.go
index 42f7e2b..f5131df 100644
--- a/messages7/cl_say.go
+++ b/messages7/cl_say.go
@@ -43,7 +43,7 @@ func (msg *ClSay) Pack() []byte {
 func (msg *ClSay) Unpack(u *packer.Unpacker) error {
 	msg.Mode = network7.ChatMode(u.GetInt())
 	msg.TargetId = u.GetInt()
-	msg.Message = u.GetString()
+	msg.Message, _ = u.GetString()
 
 	return nil
 }
diff --git a/messages7/cl_start_info.go b/messages7/cl_start_info.go
index 6044b4d..097e5c2 100644
--- a/messages7/cl_start_info.go
+++ b/messages7/cl_start_info.go
@@ -77,15 +77,15 @@ func (msg *ClStartInfo) Pack() []byte {
 }
 
 func (msg *ClStartInfo) Unpack(u *packer.Unpacker) error {
-	msg.Name = u.GetString()
-	msg.Clan = u.GetString()
+	msg.Name, _ = u.GetString()
+	msg.Clan, _ = u.GetString()
 	msg.Country = u.GetInt()
-	msg.Body = u.GetString()
-	msg.Marking = u.GetString()
-	msg.Decoration = u.GetString()
-	msg.Hands = u.GetString()
-	msg.Feet = u.GetString()
-	msg.Eyes = u.GetString()
+	msg.Body, _ = u.GetString()
+	msg.Marking, _ = u.GetString()
+	msg.Decoration, _ = u.GetString()
+	msg.Hands, _ = u.GetString()
+	msg.Feet, _ = u.GetString()
+	msg.Eyes, _ = u.GetString()
 	msg.CustomColorBody = u.GetInt() != 0
 	msg.CustomColorMarking = u.GetInt() != 0
 	msg.CustomColorDecoration = u.GetInt() != 0
diff --git a/messages7/ctrl_close.go b/messages7/ctrl_close.go
index 9f7fe52..4ba8192 100644
--- a/messages7/ctrl_close.go
+++ b/messages7/ctrl_close.go
@@ -37,7 +37,7 @@ func (msg *CtrlClose) Pack() []byte {
 
 func (msg *CtrlClose) Unpack(u *packer.Unpacker) error {
 	// TODO: sanitize
-	msg.Reason = u.GetString()
+	msg.Reason, _ = u.GetString()
 	return nil
 }
 
diff --git a/messages7/info.go b/messages7/info.go
index 5abe827..c879e88 100644
--- a/messages7/info.go
+++ b/messages7/info.go
@@ -59,8 +59,8 @@ func (msg *Info) Pack() []byte {
 }
 
 func (msg *Info) Unpack(u *packer.Unpacker) error {
-	msg.Version = u.GetString()
-	msg.Password = u.GetString()
+	msg.Version, _ = u.GetString()
+	msg.Password, _ = u.GetString()
 	msg.ClientVersion = u.GetInt()
 	return nil
 }
diff --git a/messages7/map_change.go b/messages7/map_change.go
index 21caecb..90ad8ce 100644
--- a/messages7/map_change.go
+++ b/messages7/map_change.go
@@ -47,7 +47,7 @@ func (msg *MapChange) Pack() []byte {
 }
 
 func (msg *MapChange) Unpack(u *packer.Unpacker) error {
-	msg.Name = u.GetString()
+	msg.Name, _ = u.GetString()
 	msg.Crc = u.GetInt()
 	msg.Size = u.GetInt()
 	msg.NumResponseChunksPerRequest = u.GetInt()
diff --git a/messages7/maplist_entry_add.go b/messages7/maplist_entry_add.go
index 03a57e8..41c1f1a 100644
--- a/messages7/maplist_entry_add.go
+++ b/messages7/maplist_entry_add.go
@@ -37,7 +37,7 @@ func (msg *MaplistEntryAdd) Pack() []byte {
 }
 
 func (msg *MaplistEntryAdd) Unpack(u *packer.Unpacker) error {
-	msg.MapName = u.GetString()
+	msg.MapName, _ = u.GetString()
 	return nil
 }
 
diff --git a/messages7/maplist_entry_rem.go b/messages7/maplist_entry_rem.go
index bd12ff7..cd6cfc2 100644
--- a/messages7/maplist_entry_rem.go
+++ b/messages7/maplist_entry_rem.go
@@ -37,7 +37,7 @@ func (msg *MaplistEntryRem) Pack() []byte {
 }
 
 func (msg *MaplistEntryRem) Unpack(u *packer.Unpacker) error {
-	msg.MapName = u.GetString()
+	msg.MapName, _ = u.GetString()
 	return nil
 }
 
diff --git a/messages7/rcon_auth.go b/messages7/rcon_auth.go
index c95cc93..5f8da2e 100644
--- a/messages7/rcon_auth.go
+++ b/messages7/rcon_auth.go
@@ -37,7 +37,7 @@ func (msg *RconAuth) Pack() []byte {
 }
 
 func (msg *RconAuth) Unpack(u *packer.Unpacker) error {
-	msg.Password = u.GetString()
+	msg.Password, _ = u.GetString()
 	return nil
 }
 
diff --git a/messages7/rcon_cmd.go b/messages7/rcon_cmd.go
index c142e90..15978b4 100644
--- a/messages7/rcon_cmd.go
+++ b/messages7/rcon_cmd.go
@@ -37,7 +37,7 @@ func (msg *RconCmd) Pack() []byte {
 }
 
 func (msg *RconCmd) Unpack(u *packer.Unpacker) error {
-	msg.Command = u.GetString()
+	msg.Command, _ = u.GetString()
 	return nil
 }
 
diff --git a/messages7/rcon_cmd_add.go b/messages7/rcon_cmd_add.go
index 1c45012..358ad1b 100644
--- a/messages7/rcon_cmd_add.go
+++ b/messages7/rcon_cmd_add.go
@@ -41,9 +41,9 @@ func (msg *RconCmdAdd) Pack() []byte {
 }
 
 func (msg *RconCmdAdd) Unpack(u *packer.Unpacker) error {
-	msg.Name = u.GetString()
-	msg.Help = u.GetString()
-	msg.Params = u.GetString()
+	msg.Name, _ = u.GetString()
+	msg.Help, _ = u.GetString()
+	msg.Params, _ = u.GetString()
 	return nil
 }
 
diff --git a/messages7/rcon_cmd_rem.go b/messages7/rcon_cmd_rem.go
index 99f657c..e24a99e 100644
--- a/messages7/rcon_cmd_rem.go
+++ b/messages7/rcon_cmd_rem.go
@@ -37,7 +37,7 @@ func (msg *RconCmdRem) Pack() []byte {
 }
 
 func (msg *RconCmdRem) Unpack(u *packer.Unpacker) error {
-	msg.Name = u.GetString()
+	msg.Name, _ = u.GetString()
 	return nil
 }
 
diff --git a/messages7/rcon_line.go b/messages7/rcon_line.go
index 60d1954..ff353b3 100644
--- a/messages7/rcon_line.go
+++ b/messages7/rcon_line.go
@@ -37,7 +37,7 @@ func (msg *RconLine) Pack() []byte {
 }
 
 func (msg *RconLine) Unpack(u *packer.Unpacker) error {
-	msg.Line = u.GetString()
+	msg.Line, _ = u.GetString()
 	return nil
 }
 
diff --git a/messages7/server_info.go b/messages7/server_info.go
index 58b747c..80c1c3a 100644
--- a/messages7/server_info.go
+++ b/messages7/server_info.go
@@ -57,11 +57,11 @@ func (msg *ServerInfo) Pack() []byte {
 }
 
 func (msg *ServerInfo) Unpack(u *packer.Unpacker) error {
-	msg.Version = u.GetString()
-	msg.Name = u.GetString()
-	msg.Hostname = u.GetString()
-	msg.MapName = u.GetString()
-	msg.GameType = u.GetString()
+	msg.Version, _ = u.GetString()
+	msg.Name, _ = u.GetString()
+	msg.Hostname, _ = u.GetString()
+	msg.MapName, _ = u.GetString()
+	msg.GameType, _ = u.GetString()
 	msg.Flags = u.GetInt()
 	msg.SkillLevel = u.GetInt()
 	msg.PlayerCount = u.GetInt()
diff --git a/messages7/sv_broadcast.go b/messages7/sv_broadcast.go
index 2912cff..36e208c 100644
--- a/messages7/sv_broadcast.go
+++ b/messages7/sv_broadcast.go
@@ -33,7 +33,7 @@ func (msg *SvBroadcast) Pack() []byte {
 }
 
 func (msg *SvBroadcast) Unpack(u *packer.Unpacker) error {
-	msg.Message = u.GetString()
+	msg.Message, _ = u.GetString()
 	return nil
 }
 
diff --git a/messages7/sv_chat.go b/messages7/sv_chat.go
index 4fc4831..a07423c 100644
--- a/messages7/sv_chat.go
+++ b/messages7/sv_chat.go
@@ -46,7 +46,7 @@ func (msg *SvChat) Unpack(u *packer.Unpacker) error {
 	msg.Mode = network7.ChatMode(u.GetInt())
 	msg.ClientId = u.GetInt()
 	msg.TargetId = u.GetInt()
-	msg.Message = u.GetString()
+	msg.Message, _ = u.GetString()
 
 	return nil
 }
diff --git a/messages7/sv_client_info.go b/messages7/sv_client_info.go
index dc609ca..20241c9 100644
--- a/messages7/sv_client_info.go
+++ b/messages7/sv_client_info.go
@@ -86,15 +86,15 @@ func (info *SvClientInfo) Unpack(u *packer.Unpacker) error {
 	info.ClientId = u.GetInt()
 	info.Local = u.GetInt() != 0
 	info.Team = u.GetInt()
-	info.Name = u.GetString()
-	info.Clan = u.GetString()
+	info.Name, _ = u.GetString()
+	info.Clan, _ = u.GetString()
 	info.Country = u.GetInt()
-	info.Body = u.GetString()
-	info.Marking = u.GetString()
-	info.Decoration = u.GetString()
-	info.Hands = u.GetString()
-	info.Feet = u.GetString()
-	info.Eyes = u.GetString()
+	info.Body, _ = u.GetString()
+	info.Marking, _ = u.GetString()
+	info.Decoration, _ = u.GetString()
+	info.Hands, _ = u.GetString()
+	info.Feet, _ = u.GetString()
+	info.Eyes, _ = u.GetString()
 	info.CustomColorBody = u.GetInt() != 0
 	info.CustomColorMarking = u.GetInt() != 0
 	info.CustomColorDecoration = u.GetInt() != 0
diff --git a/messages7/sv_emoticon.go b/messages7/sv_emoticon.go
index 0212f15..3a6fa15 100644
--- a/messages7/sv_emoticon.go
+++ b/messages7/sv_emoticon.go
@@ -11,6 +11,7 @@ import (
 type SvEmoticon struct {
 	ChunkHeader *chunk7.ChunkHeader
 
+	ClientId int
 	Emoticon network7.Emote
 }
 
@@ -32,11 +33,13 @@ func (msg *SvEmoticon) Vital() bool {
 
 func (msg *SvEmoticon) Pack() []byte {
 	return slices.Concat(
+		packer.PackInt(msg.ClientId),
 		packer.PackInt(int(msg.Emoticon)),
 	)
 }
 
 func (msg *SvEmoticon) Unpack(u *packer.Unpacker) error {
+	msg.ClientId = u.GetInt()
 	msg.Emoticon = network7.Emote(u.GetInt())
 
 	return nil
diff --git a/messages7/sv_emoticon_test.go b/messages7/sv_emoticon_test.go
new file mode 100644
index 0000000..5a12586
--- /dev/null
+++ b/messages7/sv_emoticon_test.go
@@ -0,0 +1,88 @@
+package messages7_test
+
+import (
+	"testing"
+
+	"github.com/teeworlds-go/go-teeworlds-protocol/internal/testutils/require"
+	"github.com/teeworlds-go/go-teeworlds-protocol/messages7"
+	"github.com/teeworlds-go/go-teeworlds-protocol/network7"
+	"github.com/teeworlds-go/go-teeworlds-protocol/packer"
+	"github.com/teeworlds-go/go-teeworlds-protocol/protocol7"
+)
+
+func TestFullPacket(t *testing.T) {
+	packet := protocol7.Packet{}
+	packet.Messages = append(
+		packet.Messages,
+		&messages7.SvEmoticon{
+			ClientId: 0,
+			Emoticon: network7.EmoteGhost,
+		},
+	)
+
+	{
+		// if this test breaks because the session tokens are actually used
+		// this is not necessarily a bad thing
+		session := &protocol7.Session{
+			ServerToken: [4]byte{0x55, 0x55, 0x55, 0x55},
+			ClientToken: [4]byte{0xfa, 0xfa, 0xfa, 0xfa},
+		}
+
+		want := []byte{0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x40, 0x03, 0x01, 0x14, 0x00, 0x07}
+		got := packet.Pack(session)
+
+		require.Equal(t, want, got)
+	}
+}
+
+func TestSvEmoticonStandalone(t *testing.T) {
+	// simple pack
+	emoticon := &messages7.SvEmoticon{
+		ClientId: 0,
+		Emoticon: network7.EmoteExclamation,
+	}
+
+	{
+		want := []byte{0x00, 0x01}
+		got := emoticon.Pack()
+
+		require.Equal(t, want, got)
+	}
+
+	// repack
+	u := &packer.Unpacker{}
+	u.Reset(emoticon.Pack())
+	emoticon.Unpack(u)
+
+	{
+		want := network7.EmoteExclamation
+		got := emoticon.Emoticon
+		require.Equal(t, want, got)
+	}
+}
+
+func TestSvEmoticonStandaloneCrazyGirlEdition(t *testing.T) {
+	// simple pack
+	emoticon := &messages7.SvEmoticon{
+		ClientId: -99999,
+		Emoticon: 999,
+	}
+
+	{
+		want := []byte{222, 154, 12, 167, 15}
+		got := emoticon.Pack()
+
+		require.Equal(t, want, got)
+	}
+
+	// repack
+	u := &packer.Unpacker{}
+	u.Reset(emoticon.Pack())
+	emoticon.Unpack(u)
+
+	{
+		want := network7.Emote(999)
+		got := emoticon.Emoticon
+		require.Equal(t, want, got)
+	}
+}
diff --git a/messages7/sv_motd.go b/messages7/sv_motd.go
index 44fafdb..b657152 100644
--- a/messages7/sv_motd.go
+++ b/messages7/sv_motd.go
@@ -33,7 +33,7 @@ func (msg *SvMotd) Pack() []byte {
 }
 
 func (msg *SvMotd) Unpack(u *packer.Unpacker) error {
-	msg.Message = u.GetString()
+	msg.Message, _ = u.GetString()
 	return nil
 }
 
diff --git a/messages7/sv_vote_option_add.go b/messages7/sv_vote_option_add.go
index 505ad8f..53796fa 100644
--- a/messages7/sv_vote_option_add.go
+++ b/messages7/sv_vote_option_add.go
@@ -37,7 +37,7 @@ func (msg *SvVoteOptionAdd) Pack() []byte {
 }
 
 func (msg *SvVoteOptionAdd) Unpack(u *packer.Unpacker) error {
-	msg.Description = u.GetString()
+	msg.Description, _ = u.GetString()
 	return nil
 }
 
diff --git a/messages7/sv_vote_option_list_add.go b/messages7/sv_vote_option_list_add.go
index 51340cf..7cf06c1 100644
--- a/messages7/sv_vote_option_list_add.go
+++ b/messages7/sv_vote_option_list_add.go
@@ -52,7 +52,7 @@ func (msg *SvVoteOptionListAdd) Unpack(u *packer.Unpacker) error {
 	msg.NumOptions = u.GetInt()
 	msg.Descriptions = make([]string, msg.NumOptions)
 	for i := 0; i < msg.NumOptions; i++ {
-		msg.Descriptions[i] = u.GetString()
+		msg.Descriptions[i], _ = u.GetString()
 	}
 
 	return nil
diff --git a/messages7/sv_vote_option_list_add_test.go b/messages7/sv_vote_option_list_add_test.go
new file mode 100644
index 0000000..c9f4e34
--- /dev/null
+++ b/messages7/sv_vote_option_list_add_test.go
@@ -0,0 +1,37 @@
+package messages7_test
+
+import (
+	"testing"
+
+	"github.com/teeworlds-go/go-teeworlds-protocol/chunk7"
+	"github.com/teeworlds-go/go-teeworlds-protocol/internal/testutils/require"
+	"github.com/teeworlds-go/go-teeworlds-protocol/messages7"
+	"github.com/teeworlds-go/go-teeworlds-protocol/network7"
+	"github.com/teeworlds-go/go-teeworlds-protocol/packer"
+)
+
+func TestVoteListAdd(t *testing.T) {
+	// unpack
+	fullChunk := []byte{0x40, 0x06, 0x06, 0x18, 0x01, 0x66, 0x6f, 0x6f, 0x00}
+	u := &packer.Unpacker{}
+	u.Reset(fullChunk)
+
+	header := &chunk7.ChunkHeader{}
+	header.Unpack(u)
+
+	msg, sys, err := u.GetMsgAndSys()
+	require.NoError(t, err)
+	require.Equal(t, network7.MsgGameSvVoteOptionListAdd, msg)
+	require.Equal(t, false, sys)
+
+	listAdd := &messages7.SvVoteOptionListAdd{ChunkHeader: header}
+	listAdd.Unpack(u)
+
+	require.Equal(t, 1, listAdd.NumOptions)
+	require.Equal(t, 1, len(listAdd.Descriptions))
+	require.Equal(t, "foo", listAdd.Descriptions[0])
+	require.Equal(t, 0, u.RemainingSize())
+
+	// pack
+	require.Equal(t, []byte{1, 'f', 'o', 'o', 0x00}, listAdd.Pack())
+}
diff --git a/messages7/sv_vote_option_remove.go b/messages7/sv_vote_option_remove.go
index ba6c88d..acfeb23 100644
--- a/messages7/sv_vote_option_remove.go
+++ b/messages7/sv_vote_option_remove.go
@@ -37,7 +37,7 @@ func (msg *SvVoteOptionRemove) Pack() []byte {
 }
 
 func (msg *SvVoteOptionRemove) Unpack(u *packer.Unpacker) error {
-	msg.Description = u.GetString()
+	msg.Description, _ = u.GetString()
 	return nil
 }
 
diff --git a/messages7/sv_vote_set.go b/messages7/sv_vote_set.go
index 8e05325..d22e39c 100644
--- a/messages7/sv_vote_set.go
+++ b/messages7/sv_vote_set.go
@@ -48,8 +48,8 @@ func (msg *SvVoteSet) Unpack(u *packer.Unpacker) error {
 	msg.ClientId = u.GetInt()
 	msg.Type = network7.Vote(u.GetInt())
 	msg.Timeout = u.GetInt()
-	msg.Description = u.GetString()
-	msg.Reason = u.GetString()
+	msg.Description, _ = u.GetString()
+	msg.Reason, _ = u.GetString()
 	return nil
 }
 
diff --git a/object7/laser_test.go b/object7/laser_test.go
new file mode 100644
index 0000000..61e4e15
--- /dev/null
+++ b/object7/laser_test.go
@@ -0,0 +1,79 @@
+package object7_test
+
+import (
+	"testing"
+
+	"github.com/teeworlds-go/go-teeworlds-protocol/internal/testutils/require"
+	"github.com/teeworlds-go/go-teeworlds-protocol/network7"
+	"github.com/teeworlds-go/go-teeworlds-protocol/object7"
+	"github.com/teeworlds-go/go-teeworlds-protocol/packer"
+)
+
+func TestLaserStandalone(t *testing.T) {
+	// simple pack
+	laser := &object7.Laser{
+		ItemId:    1,
+		X:         200,
+		Y:         301,
+		FromX:     20,
+		FromY:     40,
+		StartTick: 7812,
+	}
+
+	{
+		// this is not verified against anything
+		want := []byte{3, 1, 136, 3, 173, 4, 20, 40, 132, 122}
+		got := laser.Pack()
+
+		require.Equal(t, want, got)
+	}
+
+	// repack
+	u := &packer.Unpacker{}
+	u.Reset(laser.Pack())
+	typeId := u.GetInt()
+	require.Equal(t, network7.ObjLaser, typeId)
+	itemId := u.GetInt()
+	require.Equal(t, 1, itemId)
+	laser.Unpack(u)
+
+	require.Equal(t, 200, laser.X)
+	require.Equal(t, 301, laser.Y)
+	require.Equal(t, 20, laser.FromX)
+	require.Equal(t, 40, laser.FromY)
+	require.Equal(t, 7812, laser.StartTick)
+}
+
+func TestLaserStandaloneAllZeros(t *testing.T) {
+	// simple pack
+	laser := &object7.Laser{
+		ItemId:    0,
+		X:         0,
+		Y:         0,
+		FromX:     0,
+		FromY:     0,
+		StartTick: 0,
+	}
+
+	{
+		want := []byte{0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
+		got := laser.Pack()
+
+		require.Equal(t, want, got)
+	}
+
+	// repack
+	u := &packer.Unpacker{}
+	u.Reset(laser.Pack())
+	typeId := u.GetInt()
+	require.Equal(t, network7.ObjLaser, typeId)
+	itemId := u.GetInt()
+	require.Equal(t, 0, itemId)
+	laser.Unpack(u)
+
+	{
+		want := 0
+		got := laser.X
+		require.Equal(t, want, got)
+	}
+}
diff --git a/object7/snap_object.go b/object7/snap_object.go
index 72645db..dbbd03a 100644
--- a/object7/snap_object.go
+++ b/object7/snap_object.go
@@ -1,8 +1,6 @@
 package object7
 
 import (
-	"log"
-
 	"github.com/teeworlds-go/go-teeworlds-protocol/network7"
 	"github.com/teeworlds-go/go-teeworlds-protocol/packer"
 )
@@ -61,8 +59,8 @@ func NewObject(typeId int, itemId int) SnapObject {
 		return &Damage{ItemId: itemId}
 	}
 
-	// TODO: remove this is just for debugging
-	log.Fatalf("unknown item type %d\n", typeId)
+	// TODO: add this panic and remove it again once all tests pass
+	// log.Panicf("unknown item type %d\n", typeId)
 
 	unknown := &Unknown{
 		ItemId:   itemId,
diff --git a/packer/packer.go b/packer/packer.go
index ffd254d..36a2e44 100644
--- a/packer/packer.go
+++ b/packer/packer.go
@@ -1,6 +1,8 @@
 package packer
 
 import (
+	"errors"
+	"fmt"
 	"slices"
 )
 
@@ -20,10 +22,33 @@ func (u *Unpacker) byte() byte {
 }
 
 // consume one byte
-func (u *Unpacker) getByte() byte {
+func (u *Unpacker) GetByte() (byte, error) {
+	if u.RemainingSize() < 1 {
+		return 0x00, errors.New("GetByte not enough data")
+	}
 	b := u.data[u.idx]
 	u.idx++
-	return b
+	return b, nil
+}
+
+func (u *Unpacker) GetMsgAndSys() (msgId int, system bool, err error) {
+	msg := u.GetInt()
+	sys := msg&1 != 0
+	msg >>= 1
+	return msg, sys, nil
+}
+
+func (u *Unpacker) GetRaw(size int) ([]byte, error) {
+	if size < 0 {
+		return nil, fmt.Errorf("GetRaw called with negative size %d", size)
+	}
+	end := u.idx + size
+	if end > u.Size() {
+		return nil, fmt.Errorf("GetRaw can not read size %d not enough data", size)
+	}
+	b := u.data[u.idx:end]
+	u.idx += size
+	return b, nil
 }
 
 func (u *Unpacker) Data() []byte {
@@ -50,13 +75,16 @@ const (
 	SanitizeSkipWhitespaces = 4
 )
 
-func (u *Unpacker) GetStringSanitized(sanitizeType int) string {
+func (u *Unpacker) GetStringSanitized(sanitizeType int) (string, error) {
 	bytes := []byte{}
 
 	skipping := sanitizeType&SanitizeSkipWhitespaces != 0
 
 	for {
-		b := u.getByte()
+		b, err := u.GetByte()
+		if err != nil {
+			return "", err
+		}
 		if b == 0x00 {
 			break
 		}
@@ -81,10 +109,10 @@ func (u *Unpacker) GetStringSanitized(sanitizeType int) string {
 		bytes = append(bytes, b)
 	}
 
-	return string(bytes)
+	return string(bytes), nil
 }
 
-func (u *Unpacker) GetString() string {
+func (u *Unpacker) GetString() (string, error) {
 	return u.GetStringSanitized(Sanitize)
 }
 
@@ -197,3 +225,10 @@ func UnpackInt(data []byte) int {
 	res ^= -sign
 	return res
 }
+
+func UnpackMsgAndSys(data []byte) (msgId int, system bool) {
+	msg := UnpackInt(data)
+	sys := msg&1 != 0
+	msg >>= 1
+	return msg, sys
+}
diff --git a/packer/packer_state_test.go b/packer/packer_state_test.go
index 08a1be3..c1bdb9a 100644
--- a/packer/packer_state_test.go
+++ b/packer/packer_state_test.go
@@ -68,12 +68,12 @@ func TestUnpackClientInfo(t *testing.T) {
 	{
 		// name
 		want := "gopher"
-		got := u.GetString()
+		got, _ := u.GetString()
 		require.Equal(t, want, got)
 
 		// clan
 		want = ""
-		got = u.GetString()
+		got, _ = u.GetString()
 		require.Equal(t, want, got)
 	}
 
@@ -87,7 +87,7 @@ func TestUnpackClientInfo(t *testing.T) {
 	{
 		// body
 		want := "greensward"
-		got := u.GetString()
+		got, _ := u.GetString()
 		require.Equal(t, want, got)
 	}
 }
@@ -120,7 +120,7 @@ func TestUnpackString(t *testing.T) {
 	u.Reset([]byte{'f', 'o', 'o', 0x00})
 
 	want := "foo"
-	got := u.GetString()
+	got, _ := u.GetString()
 	require.Equal(t, want, got)
 }
 
@@ -129,11 +129,11 @@ func TestUnpackTwoStrings(t *testing.T) {
 	u.Reset([]byte{'f', 'o', 'o', 0x00, 'b', 'a', 'r', 0x00})
 
 	want := "foo"
-	got := u.GetString()
+	got, _ := u.GetString()
 	require.Equal(t, want, got)
 
 	want = "bar"
-	got = u.GetString()
+	got, _ = u.GetString()
 	require.Equal(t, want, got)
 
 }
@@ -156,11 +156,11 @@ func TestUnpackMixed(t *testing.T) {
 	// strings
 	{
 		want := "foo"
-		got := u.GetString()
+		got, _ := u.GetString()
 		require.Equal(t, want, got)
 
 		want = "bar"
-		got = u.GetString()
+		got, _ = u.GetString()
 		require.Equal(t, want, got)
 	}
 
diff --git a/snapshot7/full_ddnet_server_test.go b/snapshot7/full_ddnet_server_test.go
new file mode 100644
index 0000000..1acc53f
--- /dev/null
+++ b/snapshot7/full_ddnet_server_test.go
@@ -0,0 +1,266 @@
+package snapshot7_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/teeworlds-go/go-teeworlds-protocol/internal/testutils/require"
+	"github.com/teeworlds-go/go-teeworlds-protocol/protocol7"
+)
+
+// --------------------------------
+// snap single
+// --------------------------------
+
+func TestDDNetFullServerSnapSingle(t *testing.T) {
+	// vanilla client connected to almost full ddnet rus server
+	// dumped with tcpdump
+	// libtw2 dissector details
+	// this is the n-th snapshot that is a snap single the prior snapshots were partials snaps
+	//
+	// User Datagram Protocol, Src Port: 8316, Dst Port: 51479
+	// Teeworlds 0.7 Protocol packet
+	// Teeworlds 0.7 Protocol chunk: sys.snap_single
+	//     Header (non-vital)
+	//     Message: sys.snap_single
+	//     Tick: 11271652
+	//     Delta tick: 22
+	//     Crc: 1032529567
+	//     Data (114 bytes)
+	dump := []byte{
+		0x10, 0x04, 0x01, 0x1f, 0x5a, 0x5e, 0xd8,
+		0x28, 0x15, 0xa6, 0x6c, 0xfb, 0x4a, 0xd3, 0xd6, 0xd3, 0xe0, 0x54, 0x85, 0x09, 0x72, 0xc4,
+		0x0d, 0x2e, 0xb6, 0xe9, 0x2f, 0xbc, 0xfd, 0xb9, 0x5d, 0xd0, 0x35, 0x5d, 0x5e, 0xcf, 0xb5, 0x35,
+		0xeb, 0x92, 0xe8, 0xbe, 0xbb, 0x9f, 0xd1, 0x7f, 0x17, 0x24, 0x2d, 0xb8, 0xfa, 0x7f, 0x5f, 0xf5,
+		0x38, 0x7b, 0x7a, 0xc1, 0x47, 0x73, 0xeb, 0x4a, 0xd0, 0x62, 0x02, 0x17, 0x6d, 0xd9, 0xe2, 0x58,
+		0x57, 0x68, 0xc9, 0xe6, 0x35, 0xf9, 0x0a, 0xd3, 0xd6, 0x7b, 0xf6, 0x5d, 0x90, 0xb4, 0x10, 0xfa,
+		0x9a, 0x7c, 0x85, 0x69, 0xeb, 0xbf, 0xe1, 0x2b, 0x4d, 0x5b, 0xef, 0x1e, 0x4f, 0xea, 0x85, 0xe2,
+		0x06,
+	}
+
+	conn := protocol7.Session{}
+
+	packet := protocol7.Packet{}
+	err := packet.Unpack(dump)
+	require.NoError(t, err)
+
+	conn.Ack = packet.Header.Ack
+	repack := packet.Pack(&conn)
+	require.Equal(t, dump, repack)
+}
+
+func TestSvEmoticonAndSnapSingle(t *testing.T) {
+	// Teeworlds 0.7 Protocol packet
+	// Teeworlds 0.7 Protocol chunk: game.sv_emoticon
+	//     Header (vital: 234)
+	//     Message: game.sv_emoticon
+	//     Client id: 39
+	//     Emoticon: exclamation
+	// Teeworlds 0.7 Protocol chunk: sys.snap_single
+	//     Header (non-vital)
+	//     Message: sys.snap_single
+	//     Tick: 11271828
+	//     Delta tick: 24
+	//     Crc: 1021386082
+	//     Data (190 bytes)
+	dump := []byte{
+		0x10, 0x05, 0x02, 0x1f, 0x5a, 0x5e,
+		0xd8, 0x4a, 0x16, 0xd4, 0x0d, 0x2f, 0x0b, 0x2d, 0xfc, 0x4d, 0x19, 0xae, 0xd4, 0xb4, 0xf5, 0x10,
+		0x9f, 0xa1, 0x48, 0x8b, 0x2b, 0xbb, 0xd1, 0x15, 0x48, 0x5a, 0xce, 0x52, 0xed, 0xef, 0x97, 0x58,
+		0xef, 0xa2, 0x29, 0x6d, 0x82, 0xb7, 0x6b, 0xb6, 0x91, 0x1a, 0x1b, 0x4e, 0x72, 0xbb, 0x1d, 0x7d,
+		0xcf, 0x71, 0x04, 0x55, 0x09, 0x5f, 0x21, 0xfe, 0x2e, 0x48, 0x5a, 0xb8, 0xa8, 0xff, 0x87, 0x42,
+		0x26, 0x55, 0xa2, 0x9e, 0xeb, 0x22, 0x2d, 0x37, 0xc6, 0xb0, 0xa4, 0x33, 0x9e, 0x96, 0x1b, 0x0b,
+		0xfc, 0xab, 0xaa, 0x87, 0x37, 0x5c, 0xa9, 0x69, 0xeb, 0x19, 0x92, 0xe8, 0x3b, 0x56, 0x3e, 0x0b,
+		0x5b, 0x80, 0x73, 0xea, 0xb4, 0x50, 0xaa, 0x54, 0x6f, 0x49, 0xa2, 0x0b, 0xac, 0x38, 0x15, 0x3c,
+		0x66, 0x71, 0xc4, 0x5d, 0x90, 0xb4, 0x80, 0xd7, 0x03, 0x60, 0x53, 0x14, 0xa7, 0x5e, 0xf8, 0x90,
+		0xa7, 0x17, 0x3c, 0xa1, 0x17, 0xbe, 0x2e, 0x54, 0xa0, 0xde, 0x0f, 0xe4, 0x2d, 0xe8, 0xcc, 0x44,
+		0xc2, 0x2f, 0x85, 0x36, 0x7f, 0x17, 0x24, 0x2d, 0x84, 0xfe, 0x9f, 0x25, 0x52, 0xaf, 0x57, 0xdc,
+		0x00,
+	}
+
+	conn := protocol7.Session{}
+
+	packet := protocol7.Packet{}
+	err := packet.Unpack(dump)
+	require.NoError(t, err)
+
+	conn.Ack = packet.Header.Ack
+	repack := packet.Pack(&conn)
+
+	fmt.Printf("repack: %x\n", repack)
+	fmt.Printf("dump:   %x\n", dump)
+
+	require.Equal(t, dump, repack)
+}
+
+// --------------------------------
+// multi part snaps
+// --------------------------------
+
+func TestVoteOptionListAddPlusTwoSnaps(t *testing.T) {
+	// vanilla client connected to almost full ddnet rus server
+	// dumped with tcpdump
+	//
+	// these are two consecutive packets
+	// - packet1: vote_list, snap (part 1/2)
+	// - packet2: snap (part 2/2)
+
+	// Teeworlds 0.7 Protocol packet
+	// Teeworlds 0.7 Protocol chunk: game.sv_vote_option_list_add
+	// Teeworlds 0.7 Protocol chunk: sys.snap
+	//     Header (non-vital)
+	//     Message: sys.snap
+	//     Tick: 11271610
+	//     Delta tick: 11271611
+	//     Num parts: 2
+	//     Part: 0
+	//     Crc: 986678629
+	//     Data (900 bytes)
+	dumpVoteListAndPart1 := []byte{
+		0x10, 0x04, 0x02, 0x1f, 0x5a, 0x5e,
+		0xd8, 0x5a, 0xd9, 0x55, 0x86, 0xd8, 0xb5, 0xf6, 0x35, 0x1c, 0x0d, 0xe7, 0x8a, 0xc3, 0xda, 0x35,
+		0xab, 0xf0, 0x03, 0x6b, 0x5b, 0xc2, 0xda, 0x75, 0x8e, 0x86, 0x52, 0x5f, 0x7c, 0x0d, 0x6b, 0xd7,
+		0x6c, 0x62, 0x97, 0x87, 0x83, 0x13, 0x5c, 0x3b, 0x27, 0xc0, 0x99, 0x2d, 0xe5, 0x04, 0xd6, 0xb6,
+		0x18, 0xca, 0x59, 0x53, 0xe8, 0x5a, 0x39, 0x81, 0x8e, 0x5c, 0x8b, 0x6b, 0x63, 0x6d, 0x4b, 0x58,
+		0xf3, 0xc8, 0x32, 0x8e, 0x66, 0xed, 0x9a, 0x69, 0xba, 0x27, 0x47, 0xfb, 0xa4, 0x38, 0xd4, 0xe5,
+		0x6b, 0x58, 0xbb, 0x66, 0x15, 0x7e, 0x60, 0x6d, 0x4b, 0x58, 0xfb, 0xe2, 0x6b, 0xa0, 0x54, 0x6b,
+		0x9f, 0x58, 0xbb, 0x66, 0x13, 0xbb, 0x3c, 0x1c, 0x9c, 0xe0, 0x03, 0x5b, 0xe4, 0x4a, 0xb8, 0x12,
+		0xbc, 0x59, 0xdb, 0x62, 0x28, 0x67, 0x2d, 0x9b, 0xaf, 0x65, 0x8b, 0x5c, 0x09, 0xd7, 0xc2, 0xda,
+		0x96, 0xb0, 0xd6, 0xda, 0x32, 0x8e, 0x66, 0xed, 0x9a, 0x69, 0xba, 0xa7, 0xd6, 0xae, 0xc3, 0xb9,
+		0x2f, 0x3e, 0xb1, 0x76, 0xcd, 0x2a, 0xfc, 0xc0, 0xda, 0x96, 0xb0, 0xf6, 0x85, 0xa3, 0xa1, 0xd4,
+		0x75, 0x5f, 0x58, 0xbb, 0x66, 0x13, 0xbb, 0xfc, 0xff, 0xf4, 0x34, 0x1c, 0x0e, 0x1c, 0x63, 0xda,
+		0x7a, 0xf7, 0x72, 0x8c, 0x69, 0xeb, 0x45, 0x06, 0x8a, 0x99, 0x56, 0x69, 0x6e, 0x1a, 0xe9, 0x43,
+		0x2f, 0x56, 0x59, 0xd2, 0xc2, 0x33, 0x0d, 0xc5, 0x33, 0xa9, 0xf8, 0x8e, 0x69, 0xf0, 0x52, 0xc8,
+		0x11, 0x4f, 0x6a, 0xa0, 0xd0, 0x6f, 0x1a, 0x44, 0xef, 0x1e, 0x06, 0x7c, 0x4b, 0x15, 0x36, 0xe9,
+		0x4a, 0x5a, 0x78, 0x7e, 0x74, 0x65, 0x28, 0x94, 0xe6, 0x51, 0xaf, 0xb8, 0xfb, 0x49, 0x51, 0x50,
+		0xb7, 0x42, 0x0d, 0x69, 0xca, 0xa1, 0xd8, 0xd5, 0x9c, 0xa4, 0x18, 0x7d, 0x17, 0x24, 0x2d, 0x3c,
+		0x5d, 0x29, 0xa6, 0xf9, 0x3e, 0x8c, 0xde, 0x57, 0xca, 0xb0, 0xc4, 0x51, 0x52, 0xa9, 0xc1, 0xba,
+		0xee, 0xb3, 0x9e, 0x4e, 0xa0, 0xd8, 0xc4, 0x74, 0x9d, 0xbc, 0x24, 0x2d, 0x3c, 0xfe, 0x54, 0xe5,
+		0x6a, 0xd3, 0x90, 0xbb, 0x32, 0x4c, 0x3e, 0xe4, 0xca, 0xa8, 0xf8, 0x26, 0xf2, 0x11, 0xa0, 0xe7,
+		0x2f, 0xf5, 0xa6, 0x21, 0x75, 0xee, 0xba, 0x57, 0xd2, 0xc2, 0xf3, 0xd9, 0x67, 0xa9, 0xf3, 0xb1,
+		0x9d, 0xa2, 0x0f, 0x49, 0x2d, 0x0b, 0x47, 0x6a, 0x7c, 0xa5, 0x2b, 0xb5, 0x05, 0x77, 0x8c, 0xf9,
+		0xc1, 0x87, 0x71, 0xac, 0xbb, 0x1c, 0x24, 0x2d, 0x3c, 0x28, 0x56, 0x3c, 0x3f, 0xba, 0x06, 0xa1,
+		0xd1, 0x35, 0x98, 0x20, 0x63, 0xfe, 0x26, 0x60, 0x5a, 0x39, 0xe2, 0x07, 0x87, 0x81, 0xe5, 0x96,
+		0x24, 0xe5, 0x5d, 0x26, 0x69, 0xe1, 0x29, 0x9e, 0xaf, 0x4b, 0x3d, 0x5d, 0xc1, 0x11, 0xb8, 0x1c,
+		0xc3, 0xd9, 0x86, 0xe3, 0xe8, 0x4a, 0xa6, 0x89, 0xf5, 0x8a, 0x69, 0x10, 0x17, 0xe0, 0xfa, 0xa7,
+		0x28, 0x69, 0xe1, 0xb9, 0xcc, 0xb6, 0x69, 0xa5, 0xc0, 0xe1, 0x31, 0xce, 0x8a, 0x27, 0x53, 0x98,
+		0x00, 0x5c, 0xaa, 0xf2, 0x95, 0x8e, 0x89, 0x65, 0xb8, 0x87, 0xaa, 0xdd, 0x75, 0xb9, 0xa4, 0x85,
+		0x27, 0x9d, 0x2a, 0x4d, 0xc0, 0xd7, 0xd1, 0x77, 0x54, 0xe9, 0x23, 0x85, 0x76, 0xaa, 0xe2, 0xe5,
+		0x9a, 0x74, 0x9d, 0xc0, 0xb5, 0x05, 0x0d, 0xca, 0x71, 0x88, 0xca, 0x92, 0x16, 0x2d, 0x5c, 0x05,
+		0xab, 0xb2, 0x0f, 0x43, 0x26, 0x40, 0x9b, 0x87, 0xb4, 0xe0, 0x67, 0x39, 0x34, 0xe1, 0xf9, 0x0f,
+		0xab, 0x91, 0x9d, 0xae, 0xa4, 0x45, 0xb1, 0x3f, 0x36, 0x7c, 0xc8, 0x15, 0xe9, 0x4a, 0x5a, 0xa0,
+		0x98, 0x0f, 0x22, 0x63, 0x52, 0xa3, 0x41, 0xf5, 0xfe, 0x22, 0x54, 0x69, 0xd4, 0x95, 0xae, 0xa4,
+		0x85, 0x10, 0xfb, 0x5b, 0xb4, 0xcd, 0x11, 0xcd, 0x4b, 0x57, 0xd2, 0xc2, 0x42, 0xcc, 0xc7, 0x02,
+		0x35, 0x6a, 0x68, 0xda, 0x7a, 0x7f, 0xaf, 0x61, 0xf8, 0xf0, 0x74, 0x25, 0x2d, 0x3c, 0x81, 0xfd,
+		0xed, 0x29, 0x1a, 0x3e, 0xc6, 0x74, 0x25, 0x2d, 0xec, 0x62, 0x3e, 0x76, 0x94, 0xe1, 0x6a, 0x8e,
+		0xe8, 0xfd, 0x6d, 0x2a, 0xa5, 0x2b, 0x69, 0x61, 0x23, 0xe6, 0x63, 0x83, 0x96, 0xf8, 0xc6, 0xb4,
+		0xf5, 0xfe, 0x6e, 0x61, 0xf9, 0xd6, 0x67, 0x4c, 0x57, 0xd2, 0xc2, 0x4d, 0xec, 0x4f, 0x02, 0x9f,
+		0x6d, 0x69, 0xba, 0x92, 0x16, 0x44, 0xcc, 0x87, 0x20, 0x3f, 0xfe, 0xa6, 0xad, 0xf7, 0x67, 0x36,
+		0x58, 0xa8, 0x94, 0xae, 0xa4, 0x05, 0x53, 0xcc, 0x87, 0x89, 0x9a, 0x5c, 0xd9, 0xb4, 0xf5, 0xfe,
+		0xfa, 0x4a, 0xe9, 0x4a, 0x5a, 0xe8, 0xc5, 0x7c, 0xf4, 0xa8, 0xd0, 0x95, 0x39, 0x49, 0xef, 0xef,
+		0x1f, 0xb8, 0x66, 0x95, 0xd2, 0x95, 0xb4, 0xf0, 0x17, 0xf3, 0xf1, 0x47, 0x3f, 0xd0, 0xa4, 0x7a,
+		0xbd, 0xbf, 0xbc, 0x52, 0xba, 0x92, 0x16, 0x72, 0x81, 0xf9, 0xc8, 0x51, 0x57, 0x7c, 0xd7, 0x35,
+		0xe8, 0xfd, 0x9d, 0x50, 0xa5, 0xce, 0xd7, 0xa4, 0x2b, 0x69, 0xe1, 0x88, 0xf9, 0x38, 0x68, 0x22,
+		0xbe, 0x37, 0x6d, 0xbd, 0x3f, 0x7d, 0xa5, 0x74, 0x25, 0x2d, 0xe8, 0xc5, 0x7c, 0xe8, 0x51, 0xa3,
+		0xe5, 0x54, 0xaf, 0xf7, 0x77, 0x57, 0xa3, 0x0a, 0x95, 0x31, 0x5d, 0x49, 0x0b, 0x77, 0x62, 0x7f,
+		0x75, 0x9a, 0xd2, 0xa9, 0x43, 0xba, 0x92, 0x16, 0x6a, 0x31, 0x1f, 0x35, 0xaa, 0xb0, 0xc4, 0xf7,
+		0x7a, 0x7f, 0x53, 0x29, 0xba, 0xdc, 0x07, 0xe9, 0x4a, 0x5a, 0x98, 0x12, 0xf3, 0x31, 0x85, 0x74,
+		0x39, 0x9b, 0xb6, 0xde, 0x9f, 0x5b, 0x29, 0x5d, 0x49, 0x0b, 0xae, 0xc0, 0xfe, 0xaa, 0x2a, 0xa5,
+		0x2b, 0x69, 0xa1, 0x4a, 0xcc, 0x47, 0x15, 0xba, 0x5c, 0xf1, 0x4d, 0x5b, 0xef, 0x0f, 0x5f, 0x29,
+		0x5d, 0x49, 0x0b, 0x78, 0xb1, 0xbf, 0x6f, 0x79, 0xc9, 0xd4, 0x35, 0x91, 0xae, 0xa4, 0x85, 0x6f,
+		0x62, 0x3e, 0xbe, 0x21, 0x80, 0x4b, 0xf5, 0x7a, 0x7f, 0x1a, 0xa5, 0xb3, 0xb0, 0xa6, 0x2b, 0x69,
+		0x41, 0x43, 0xcc, 0x87, 0x06, 0xfa, 0xc8, 0xd5, 0x54, 0xa7, 0xf7, 0xe7, 0x53, 0x9a, 0x69, 0x43,
+		0x69, 0xba, 0x92, 0x16, 0x7c, 0xc4, 0x7c, 0xf8, 0x20, 0x3f, 0xa9, 0xa4, 0x7a, 0xbd, 0x3f, 0xa4,
+		0x16, 0x0a, 0x64, 0x4b, 0x57, 0xd2, 0x02, 0x22, 0xb0, 0x3f, 0xcf, 0x86, 0x62, 0x06, 0xa6, 0x2b,
+		0x69, 0xc1, 0x53, 0xcc, 0x87, 0x27, 0xda, 0xf6, 0x21, 0xd3, 0xd6, 0xfb, 0x4b, 0xa8, 0x94, 0xae,
+		0xa4, 0x85, 0x04, 0x31, 0x1f, 0x09, 0xc8, 0xa9, 0x1f, 0x35, 0xa8, 0xde, 0x1f, 0x5a, 0xa5, 0x74,
+		0x25, 0x2d, 0xa0, 0x89, 0xf9, 0x40, 0x43, 0x9a, 0x92, 0x54, 0xaf, 0xf7, 0x57, 0x50, 0x29, 0x5d,
+		0x49, 0x0b, 0x05, 0x62, 0x3e, 0x0a, 0x90, 0x03, 0xc7, 0xbb, 0x06, 0xbd, 0xbf, 0xb9, 0x52, 0xba,
+		0x92, 0x16, 0x66, 0x31, 0x1f, 0x33, 0x6a, 0x72, 0x65, 0xd3, 0xd6, 0xfb, 0x2b, 0xd7, 0xc2, 0x5f,
+		0x2a, 0xd2, 0x95, 0xb4, 0x50, 0x16, 0xf3, 0x51, 0x46, 0xb8, 0xae, 0x6c, 0xda, 0x7a, 0x7f, 0x97,
+		0xda, 0x86, 0x9e, 0x47, 0xe9, 0x4a, 0x5a, 0xb8, 0x24, 0x30, 0x1f, 0x97, 0xd0, 0xc7, 0xd2, 0xf9,
+		0x5e, 0xef, 0xcf, 0xba, 0x52, 0xba, 0x92, 0x16, 0xac, 0xc5, 0x7c, 0x58, 0xa3, 0x14, 0x8e, 0xb8,
+		0x06, 0xbd, 0x3f, 0xa3, 0x4a, 0xe9, 0x4a, 0x5a, 0x30, 0x12, 0xd8, 0x5f, 0x77, 0x2d, 0xbe, 0xb6,
+		0x8f, 0x31, 0x5d, 0x49, 0x0b, 0xdd, 0x62, 0x3e, 0x8a, 0x1b,
+	}
+
+	// User Datagram Protocol, Src Port: 8316, Dst Port: 51479
+	// Teeworlds 0.7 Protocol packet
+	// Teeworlds 0.7 Protocol chunk: sys.snap
+	//     Header (non-vital)
+	//     Message: sys.snap
+	//     Tick: 11271610
+	//     Delta tick: 11271611
+	//     Num parts: 2
+	//     Part: 1
+	//     Crc: 986678629
+	//     Data (556 bytes)
+	dumpPart2 := []byte{
+
+		0x10, 0x04, 0x01, 0x1f, 0x5a, 0x5e,
+		0xd8, 0xc4, 0xb4, 0x38, 0x1c, 0x38, 0xc6, 0xb4, 0xf5, 0xee, 0xe5, 0x18, 0xd3, 0xd6, 0x0b, 0x64,
+		0xa0, 0x98, 0x69, 0x95, 0xe6, 0x26, 0x8d, 0xe8, 0x46, 0x97, 0x9b, 0x98, 0xea, 0xf5, 0xfe, 0xa6,
+		0x57, 0x4a, 0x57, 0xd2, 0xc2, 0x74, 0x31, 0x1f, 0xd3, 0x91, 0x1f, 0xc7, 0x98, 0xb6, 0xde, 0x1f,
+		0x46, 0xa5, 0x74, 0x25, 0x2d, 0x60, 0x88, 0xf9, 0xc0, 0x40, 0x96, 0xb4, 0xf8, 0x5e, 0xef, 0xaf,
+		0xa8, 0x52, 0xba, 0x92, 0x16, 0x8a, 0xc4, 0x7c, 0x14, 0xa1, 0x42, 0x5f, 0x9b, 0xea, 0xf5, 0xfe,
+		0xda, 0x4b, 0xa7, 0x7a, 0x57, 0xa4, 0x2b, 0x69, 0xa1, 0x5d, 0xcc, 0x47, 0x3b, 0xfa, 0x4e, 0xea,
+		0xa8, 0x5e, 0xef, 0x2f, 0xab, 0x52, 0xba, 0x92, 0x16, 0xb2, 0xc4, 0x7c, 0x64, 0xa1, 0x14, 0xbe,
+		0x31, 0x6d, 0xbd, 0xbf, 0x35, 0x54, 0x5f, 0x75, 0x2d, 0xe9, 0x4a, 0x5a, 0x58, 0xc5, 0x7c, 0xac,
+		0x68, 0xdb, 0x87, 0x4c, 0x5b, 0xef, 0xaf, 0xd3, 0xb6, 0x25, 0x28, 0x4f, 0x57, 0xd2, 0x42, 0x47,
+		0xcc, 0x47, 0x07, 0xfd, 0xe0, 0x2b, 0xa8, 0x5e, 0xef, 0x2f, 0x31, 0x2d, 0xdf, 0xb1, 0x4a, 0x57,
+		0xd2, 0x42, 0xa2, 0x98, 0x8f, 0x44, 0xd4, 0xc4, 0x9f, 0xef, 0xf5, 0xfe, 0x7e, 0x55, 0x4a, 0x57,
+		0xd2, 0xc2, 0x2f, 0x31, 0x1f, 0xbf, 0x90, 0xa6, 0x24, 0xd5, 0xeb, 0xfd, 0x69, 0xa7, 0x45, 0xd5,
+		0xaa, 0xd3, 0x95, 0xb4, 0xa0, 0x2d, 0xe6, 0x43, 0x1b, 0x5d, 0xd0, 0x35, 0xbe, 0xd7, 0xfb, 0xdb,
+		0x9a, 0xa6, 0x2b, 0xa5, 0x00, 0xd3, 0x95, 0xb4, 0xb0, 0x55, 0xcc, 0xc7, 0x56, 0xa4, 0x6b, 0xb9,
+		0x06, 0xd5, 0xfb, 0xbb, 0x58, 0x1b, 0x55, 0xd8, 0xd2, 0x74, 0x25, 0x2d, 0x5c, 0x14, 0xf3, 0x71,
+		0x11, 0xa9, 0x70, 0x8c, 0x69, 0xeb, 0xfd, 0x2d, 0x0b, 0x0b, 0x45, 0xba, 0x2c, 0x5d, 0x49, 0x0b,
+		0xcb, 0x04, 0xe6, 0x63, 0x19, 0x6a, 0xf1, 0x15, 0x7c, 0xaf, 0xf7, 0x77, 0xbd, 0x52, 0xba, 0x92,
+		0x16, 0xae, 0x8b, 0xf9, 0xb8, 0x8e, 0x50, 0x4d, 0xd3, 0xb4, 0xf5, 0xfe, 0x3e, 0x55, 0x4a, 0x57,
+		0xd2, 0xc2, 0x27, 0x31, 0x1f, 0x9f, 0xd0, 0x44, 0xbe, 0xce, 0xf7, 0x7a, 0x7f, 0xad, 0x2b, 0xa5,
+		0x2b, 0x69, 0xa1, 0xb5, 0x98, 0x8f, 0xd6, 0xe8, 0x82, 0xdf, 0xa8, 0x5e, 0xef, 0xef, 0x6b, 0x2a,
+		0xa5, 0x2b, 0x69, 0xe1, 0x6b, 0xc4, 0x7c, 0x7c, 0x0d, 0xca, 0xa0, 0x46, 0x75, 0x7a, 0x7f, 0xea,
+		0xaa, 0x94, 0xae, 0xa4, 0x05, 0x75, 0x89, 0xf9, 0x50, 0x17, 0xda, 0xa6, 0x0a, 0xaa, 0xd3, 0xfb,
+		0xd3, 0xa1, 0x6d, 0x28, 0xb3, 0x2c, 0x5d, 0x49, 0x0b, 0x3a, 0x08, 0xd1, 0xdf, 0xb4, 0x84, 0x95,
+		0x4a, 0xa5, 0x74, 0x25, 0x2d, 0x4c, 0x8b, 0x98, 0x8f, 0x69, 0x41, 0x5d, 0xb9, 0x5a, 0x83, 0xea,
+		0xf5, 0x5c, 0x57, 0x71, 0x8c, 0x69, 0xeb, 0x4d, 0x3a, 0x7e, 0xd0, 0xe5, 0x81, 0xe0, 0x1b, 0x9b,
+		0x95, 0x36, 0xe9, 0x98, 0xd4, 0xe5, 0xeb, 0xf5, 0xd1, 0xbe, 0x0b, 0x92, 0x16, 0x5c, 0x3d, 0x00,
+		0x36, 0xc5, 0xaf, 0xa4, 0x17, 0x2e, 0xe3, 0x18, 0xd3, 0xd6, 0x53, 0x51, 0xa5, 0xd0, 0xf7, 0x39,
+		0x8e, 0xe9, 0xd2, 0x99, 0x2b, 0xd5, 0x53, 0x53, 0xa5, 0xb2, 0xef, 0x5d, 0x40, 0xaa, 0xb3, 0x38,
+		0xde, 0x05, 0x49, 0x0b, 0xa1, 0x07, 0xc0, 0xa6, 0x28, 0xee, 0x1a, 0x3c, 0xd9, 0x3d, 0x3d, 0x1d,
+		0x68, 0x72, 0x8c, 0x69, 0xeb, 0x7d, 0x86, 0xf8, 0x41, 0xaa, 0x4a, 0x19, 0xe8, 0x57, 0x4a, 0xef,
+		0x33, 0xc4, 0x0f, 0x52, 0x75, 0x01, 0xa9, 0xce, 0xe2, 0xed, 0xbb, 0x20, 0x69, 0x41, 0x07, 0x3d,
+		0x00, 0x36, 0x45, 0x68, 0xa7, 0x4a, 0xe4, 0x68, 0xc5, 0x0d,
+	}
+
+	// packet 1
+	{
+		conn := protocol7.Session{}
+
+		packet := protocol7.Packet{}
+		err := packet.Unpack(dumpVoteListAndPart1)
+		require.NoError(t, err)
+
+		conn.Ack = packet.Header.Ack
+		repack := packet.Pack(&conn)
+
+		fmt.Printf("  want: %x\n", dumpVoteListAndPart1)
+		fmt.Printf("repack: %x\n", repack)
+
+		require.Equal(t, dumpVoteListAndPart1, repack)
+	}
+
+	// packet 2
+	{
+		conn := protocol7.Session{}
+
+		packet := protocol7.Packet{}
+		err := packet.Unpack(dumpPart2)
+		require.NoError(t, err)
+
+		conn.Ack = packet.Header.Ack
+		repack := packet.Pack(&conn)
+		require.Equal(t, dumpPart2, repack)
+	}
+
+	// TODO: combine the snap parts together into one full snap
+}
diff --git a/snapshot7/snapshot_test.go b/snapshot7/simple_localhost_test.go
similarity index 96%
rename from snapshot7/snapshot_test.go
rename to snapshot7/simple_localhost_test.go
index 312cd89..9eb47ac 100644
--- a/snapshot7/snapshot_test.go
+++ b/snapshot7/simple_localhost_test.go
@@ -7,7 +7,7 @@ import (
 	"github.com/teeworlds-go/go-teeworlds-protocol/protocol7"
 )
 
-func TestRepackSnapshot(t *testing.T) {
+func TestSmallVanillaServerSnapSingle(t *testing.T) {
 	// snapshot captured with tcpdump
 	// generated by a vanilla teeworlds 0.7.5 server
 	// used the go-teeworlds-protocol sample client to connect to the server