Add new transaction type for NFT token transfer (#86)

* Add new transaction type for NFT token transfer

* Update tests

types/marshal.go

@@ -30,6 +30,8 @@ func (t *Tx) UnmarshalJSON(data []byte) error {
 		t.Metadata = new(ContractCall)
 	case TxSwap:
 		t.Metadata = new(Swap)
+	case TxTransferNFT:
+		t.Metadata = new(TransferNFT)
 	default:
 		return fmt.Errorf("unsupported tx type: %s, hash: %s, metadata: %+v", t.Type, t.ID, t.Metadata)
 	}
@@ -56,7 +58,7 @@ func (t Tx) MarshalJSON() ([]byte, error) {
 
 	// validate metadata type
 	switch t.Metadata.(type) {
-	case *Transfer, *ContractCall, *Swap:
+	case *Transfer, *ContractCall, *Swap, *TransferNFT:
 		break
 	default:
 		return nil, errors.New("unsupported tx metadata")

types/tx.go

@@ -30,11 +30,13 @@ const (
 	TxStakeUndelegate   TransactionType = "stake_undelegate"
 	TxStakeRedelegate   TransactionType = "stake_redelegate"
 	TxStakeCompound     TransactionType = "stake_compound"
+	TxTransferNFT       TransactionType = "transfer_nft"
 )
 
 var SupportedTypes = []TransactionType{
 	TxTransfer, TxSwap, TxContractCall, TxStakeClaimRewards, TxStakeDelegate, TxStakeUndelegate, TxStakeRedelegate,
 	TxStakeCompound,
+	TxTransferNFT,
 }
 
 // Transaction fields
@@ -263,7 +265,7 @@ func cleanMemo(memo string) string {
 func (t *Tx) GetAddresses() []string {
 	addresses := make([]string, 0)
 	switch t.Type {
-	case TxTransfer:
+	case TxTransfer, TxTransferNFT:
 		if len(t.Inputs) > 0 || len(t.Outputs) > 0 {
 			uniqueAddresses := make(map[string]struct{})
 			for _, input := range t.Inputs {

types/tx_test.go

@@ -137,6 +137,16 @@ func TestTx_GetAddresses(t *testing.T) {
 			},
 			expected: []string{"from", "to"},
 		},
+		{
+			name: "transfer_nft",
+			tx: Tx{
+				Type:     TxTransferNFT,
+				From:     "from",
+				To:       "to",
+				Metadata: &TransferNFT{},
+			},
+			expected: []string{"from", "to"},
+		},
 		{
 			name: "delegation",
 			tx: Tx{