will return ErrMesgNotSupport if mesg hasn't defined

.github/workflows/go.yml

@@ -19,4 +19,4 @@ jobs:
         go-version: "1.20"
 
     - name: Test
-      run: go test -v ./...
+      run: go test ./...

decoder_test.go

@@ -38,7 +38,7 @@ func Test_Unmarshal(t *testing.T) {
 			},
 		},
 		{
-			name:     "mesg 0200 -2",
+			name:     "mesg 0200 - 1",
 			mesgPack: new(message.MessagePack[message.MesgBody]),
 			data:     []byte{0x7e, 0x02, 0x00, 0x00, 0x26, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x22, 0xb8, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x02, 0x00, 0xba, 0x7f, 0x0e, 0x07, 0xe4, 0xf1, 0x1c, 0x00, 0x28, 0x00, 0x3c, 0x00, 0x00, 0x18, 0x07, 0x15, 0x10, 0x10, 0x10, 0x01, 0x04, 0x00, 0x00, 0x00, 0x64, 0x02, 0x02, 0x00, 0x37, 0x57, 0x7e},
 			assertFunc: func(t *testing.T, mesgPack *message.MessagePack[message.MesgBody]) {
@@ -77,13 +77,20 @@ func Test_Unmarshal(t *testing.T) {
 				assert.IsType(t, new(message.Body0200), mesgPack.PackBody)
 			},
 		},
+		{
+			name:     "unknown mesg",
+			mesgPack: new(message.MessagePack[message.MesgBody]),
+			data:     []byte{0x7e, 0x00, 0x00, 0x00, 0x05, 0x01, 0x86, 0x57, 0x40, 0x59, 0x79, 0x00, 0x8f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x2f, 0x7e},
+			wantErr:  true,
+		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			err := Unmarshal(tt.data, tt.mesgPack)
 
 			if tt.wantErr {
+				t.Log(err)
 				assert.Error(t, err)
 			} else if assert.NoError(t, err) {
 				tt.assertFunc(t, tt.mesgPack)

message/const.go

@@ -1,5 +1,7 @@
 package message
 
+import "errors"
+
 const (
 	AckType_0001_Succeed byte = iota
 	AckType_0001_Failed
@@ -27,3 +29,5 @@ const (
 	Version2013 byte = iota
 	Version2019
 )
+
+var ErrMesgNotSupport = errors.New("unsupported message")

message/mesg_pack.go

@@ -119,6 +119,15 @@ func (p *MessagePack[T]) UnmarshalBinary(buf []byte) error {
 		_ = reader.UnreadFixedBytes(4)
 	}
 
+	checksumActually, err = bytes.CalcChecksum(buf[0 : len(buf)-1])
+
+	if err != nil {
+		return err
+	}
+
+	p.Checksum = buf[len(buf)-1]
+	p.checksumActually = checksumActually
+
 	// update PackBody field from readed bytes to struct
 	packBody, err := p.NewPackBodyFromMesgId()
 
@@ -145,15 +154,7 @@ func (p *MessagePack[T]) UnmarshalBinary(buf []byte) error {
 		return fmt.Errorf("can't convert mesgBody %T as %T", packBody, p.PackBody)
 	}
 
-	checksumActually, err = bytes.CalcChecksum(buf[0 : len(buf)-1])
-
-	if err != nil {
-		return err
-	}
-
 	p.PackBody = typedPackBody
-	p.Checksum = buf[len(buf)-1]
-	p.checksumActually = checksumActually
 
 	return nil
 }

tools/generator/decoder/gen_newpkg_body_from_mesgid.go

@@ -50,10 +50,7 @@ func genNewPkgBodyFromMesgId(f *File, mesgDecls []*generator.MesgDecl) {
 
 					g.Default().Return(
 						Nil(),
-						Qual("fmt", "Errorf").Call(
-							Lit("unsupported messageId: 0x%.4X"),
-							Id("m").Dot("PackHeader").Dot("MessageID"),
-						),
+						Id("ErrMesgNotSupport"),
 					)
 				}),
 			),