feat: support for parsing transaction output from CBOR

Fixes #467

Author: agaffney

ledger/alonzo.go

@@ -276,3 +276,11 @@ func NewAlonzoTransactionFromCbor(data []byte) (*AlonzoTransaction, error) {
 	}
 	return &alonzoTx, nil
 }
+
+func NewAlonzoTransactionOutputFromCbor(data []byte) (*AlonzoTransactionOutput, error) {
+	var alonzoTxOutput AlonzoTransactionOutput
+	if _, err := cbor.Decode(data, &alonzoTxOutput); err != nil {
+		return nil, fmt.Errorf("Alonzo transaction output decode error: %s", err)
+	}
+	return &alonzoTxOutput, nil
+}

ledger/babbage.go

@@ -406,3 +406,11 @@ func NewBabbageTransactionFromCbor(data []byte) (*BabbageTransaction, error) {
 	}
 	return &babbageTx, nil
 }
+
+func NewBabbageTransactionOutputFromCbor(data []byte) (*BabbageTransactionOutput, error) {
+	var babbageTxOutput BabbageTransactionOutput
+	if _, err := cbor.Decode(data, &babbageTxOutput); err != nil {
+		return nil, fmt.Errorf("Babbage transaction output decode error: %s", err)
+	}
+	return &babbageTxOutput, nil
+}

ledger/mary.go

@@ -254,3 +254,11 @@ func NewMaryTransactionFromCbor(data []byte) (*MaryTransaction, error) {
 	}
 	return &maryTx, nil
 }
+
+func NewMaryTransactionOutputFromCbor(data []byte) (*MaryTransactionOutput, error) {
+	var maryTxOutput MaryTransactionOutput
+	if _, err := cbor.Decode(data, &maryTxOutput); err != nil {
+		return nil, fmt.Errorf("Mary transaction output decode error: %s", err)
+	}
+	return &maryTxOutput, nil
+}

ledger/shelley.go

@@ -344,3 +344,11 @@ func NewShelleyTransactionFromCbor(data []byte) (*ShelleyTransaction, error) {
 	}
 	return &shelleyTx, nil
 }
+
+func NewShelleyTransactionOutputFromCbor(data []byte) (*ShelleyTransactionOutput, error) {
+	var shelleyTxOutput ShelleyTransactionOutput
+	if _, err := cbor.Decode(data, &shelleyTxOutput); err != nil {
+		return nil, fmt.Errorf("Shelley transaction output decode error: %s", err)
+	}
+	return &shelleyTxOutput, nil
+}

ledger/tx.go

@@ -93,6 +93,25 @@ func NewTransactionBodyFromCbor(
 	return nil, fmt.Errorf("unknown transaction type: %d", txType)
 }
 
+// NewTransactionOutputFromCbor attempts to parse the provided arbitrary CBOR data as a transaction output from
+// each of the eras, returning the first one that we can successfully decode
+func NewTransactionOutputFromCbor(data []byte) (TransactionOutput, error) {
+	// TODO: add Byron transaction output support
+	if txOut, err := NewShelleyTransactionOutputFromCbor(data); err == nil {
+		return txOut, nil
+	}
+	if txOut, err := NewMaryTransactionOutputFromCbor(data); err == nil {
+		return txOut, nil
+	}
+	if txOut, err := NewAlonzoTransactionOutputFromCbor(data); err == nil {
+		return txOut, nil
+	}
+	if txOut, err := NewBabbageTransactionOutputFromCbor(data); err == nil {
+		return txOut, nil
+	}
+	return nil, fmt.Errorf("unknown transaction output type")
+}
+
 func DetermineTransactionType(data []byte) (uint, error) {
 	// TODO: uncomment this once the following issue is resolved:
 	// https://github.com/blinklabs-io/gouroboros/issues/206