Add more tests for snbt parser

nbt/snbt_decode.go

@@ -21,8 +21,6 @@ func writeValue(e *Encoder, d *decodeState, ifWriteTag bool, tagName string) err
 	switch d.opcode {
 	case scanError:
 		return d.error(d.scan.errContext)
-	default:
-		panic(phasePanicMsg)
 
 	case scanBeginLiteral:
 		start := d.readIndex()
@@ -52,30 +50,32 @@ func writeValue(e *Encoder, d *decodeState, ifWriteTag bool, tagName string) err
 	case scanBeginList:
 		_, err := writeListOrArray(e, d, ifWriteTag, tagName)
 		return err
+
+	default:
+		panic(phasePanicMsg)
 	}
 }
 
 func writeLiteralPayload(e *Encoder, v any) (err error) {
-	switch v.(type) {
+	switch v := v.(type) {
 	case string:
-		str := v.(string)
+		err = writeInt16(e.w, int16(len(v)))
-		err = writeInt16(e.w, int16(len(str)))
 		if err != nil {
 			return
 		}
-		_, err = e.w.Write([]byte(str))
+		_, err = e.w.Write([]byte(v))
 	case int8:
-		_, err = e.w.Write([]byte{byte(v.(int8))})
+		_, err = e.w.Write([]byte{byte(v)})
 	case int16:
-		err = writeInt16(e.w, v.(int16))
+		err = writeInt16(e.w, v)
 	case int32:
-		err = writeInt32(e.w, v.(int32))
+		err = writeInt32(e.w, v)
 	case int64:
-		err = writeInt64(e.w, v.(int64))
+		err = writeInt64(e.w, v)
 	case float32:
-		err = writeInt32(e.w, int32(math.Float32bits(v.(float32))))
+		err = writeInt32(e.w, int32(math.Float32bits(v)))
 	case float64:
-		err = writeInt64(e.w, int64(math.Float64bits(v.(float64))))
+		err = writeInt64(e.w, int64(math.Float64bits(v)))
 	}
 	return
 }
@@ -508,7 +508,7 @@ func parseLiteral(literal []byte) (byte, any, error) {
 			case 'S', 's':
 				num, err := strconv.ParseInt(string(literal[:strlen]), 10, 16)
 				return TagShort, int16(num), err
-			default:
+			case 'I', 'i', 0:
 				num, err := strconv.ParseInt(string(literal[:strlen]), 10, 32)
 				return TagInt, int32(num), err
 			case 'L', 'l':

nbt/snbt_decode_test.go

@@ -2,6 +2,7 @@ package nbt
 
 import (
 	"bytes"
+	"io"
 	"strings"
 	"testing"
 )
@@ -41,7 +42,7 @@ var testCases = []testCase{
 	{`[B; ]`, TagByteArray, []byte{7, 0, 0, 0, 0, 0, 0}},
 	{`[B; 1b ,2B,3B]`, TagByteArray, []byte{7, 0, 0, 0, 0, 0, 3, 1, 2, 3}},
 	{`[I;]`, TagIntArray, []byte{11, 0, 0, 0, 0, 0, 0}},
-	{`[I; 1, 2 ,3]`, TagIntArray, []byte{11, 0, 0, 0, 0, 0, 3, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3}},
+	{`[I; -1, 0, 1, 2 ,3]`, TagIntArray, []byte{11, 0, 0, 0, 0, 0, 5, 255, 255, 255, 255, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3}},
 	{`[L;]`, TagLongArray, []byte{12, 0, 0, 0, 0, 0, 0}},
 	{`[ L; 1L,2L,3L]`, TagLongArray, []byte{12, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 3}},
 	{`{a:[B;]}`, TagCompound, []byte{10, 0, 0, 7, 0, 1, 'a', 0, 0, 0, 0, 0}},
@@ -82,6 +83,20 @@ func TestEncoder_writeSNBT(t *testing.T) {
 	}
 }
 
+func TestEncoder_ErrorInput(t *testing.T) {
+	for _, s := range []string{
+		"][",
+		"[I; 1, b, 3]",
+		"[I; 1, -2a, 3]",
+		"[I; 1, -2/I, 3]",
+	} {
+		err := NewEncoder(io.Discard).Encode(StringifiedMessage(s), "")
+		if err == nil {
+			t.Errorf("String %q is not valid SNBT, expeted to got a error", s)
+		}
+	}
+}
+
 func TestEncoder_WriteSNBT_bigTest(t *testing.T) {
 	var buf bytes.Buffer
 	e := NewEncoder(&buf)

nbt/snbt_scanner_test.go

@@ -74,7 +74,9 @@ func TestSNBT_list(t *testing.T) {
 		`[B,C,D]`, `[L, "abc"]`,  // List of string (like array)
 		`[B; 01B, 02B, 3B, 10B, 127B]`, // Array
 		`[I;]`, `[B;   ]`,              // Empty array
-		`{a:[],b:[B;]}`, // List or Array in TagCompound
+		`[I; 1, 2, 3, -1, -2, -3]`, // Int array with negtive numbers
+		`[L; 123L, -123L]`,         // Long array with negtive numbers
+		`{a:[],b:[B;]}`,            // List or Array in TagCompound
 	}
 	var s scanner
 	scan := func(str string) bool {