feat(ledger): Add friendly string representation of TX outputs (#1174)

Signed-off-by: Akhil Repala <[email protected]>

Author: arepala-uml

ledger/alonzo/alonzo.go

@@ -445,6 +445,21 @@ func (o AlonzoTransactionOutput) Utxorpc() (*utxorpc.TxOutput, error) {
 		nil
 }
 
+func (o AlonzoTransactionOutput) String() string {
+	assets := ""
+	if o.OutputAmount.Assets != nil {
+		if as := o.OutputAmount.Assets.String(); as != "[]" {
+			assets = " assets=" + as
+		}
+	}
+	return fmt.Sprintf(
+		"(AlonzoTransactionOutput address=%s amount=%d%s)",
+		o.OutputAddress.String(),
+		o.OutputAmount.Amount,
+		assets,
+	)
+}
+
 type AlonzoRedeemer struct {
 	cbor.StructAsArray
 	Tag     common.RedeemerTag

ledger/alonzo/alonzo_test.go

@@ -15,6 +15,7 @@
 package alonzo
 
 import (
+	"encoding/hex"
 	"math/big"
 	"reflect"
 	"testing"
@@ -277,3 +278,24 @@ func TestAlonzoRedeemersIter(t *testing.T) {
 		iterIdx++
 	}
 }
+
+func TestAlonzoTransactionOutputString(t *testing.T) {
+	addrStr := "addr1qytna5k2fq9ler0fuk45j7zfwv7t2zwhp777nvdjqqfr5tz8ztpwnk8zq5ngetcz5k5mckgkajnygtsra9aej2h3ek5seupmvd"
+	addr, _ := common.NewAddress(addrStr)
+	ma := common.NewMultiAsset[common.MultiAssetTypeOutput](
+		map[common.Blake2b224]map[cbor.ByteString]uint64{
+			common.NewBlake2b224(make([]byte, 28)): {cbor.NewByteString([]byte("t")): 2},
+		},
+	)
+	out := AlonzoTransactionOutput{
+		OutputAddress: addr,
+		OutputAmount:  mary.MaryTransactionOutputValue{Amount: 456, Assets: &ma},
+	}
+	s := out.String()
+	policyStr := common.NewBlake2b224(make([]byte, 28)).String()
+	assetsStr := "[" + policyStr + "." + hex.EncodeToString([]byte("t")) + "=2]"
+	expected := "(AlonzoTransactionOutput address=" + addrStr + " amount=456 assets=" + assetsStr + ")"
+	if s != expected {
+		t.Fatalf("unexpected string: %s", s)
+	}
+}

ledger/babbage/babbage.go

@@ -647,6 +647,21 @@ func (o BabbageTransactionOutput) Utxorpc() (*utxorpc.TxOutput, error) {
 		nil
 }
 
+func (o BabbageTransactionOutput) String() string {
+	assets := ""
+	if o.OutputAmount.Assets != nil {
+		if as := o.OutputAmount.Assets.String(); as != "[]" {
+			assets = " assets=" + as
+		}
+	}
+	return fmt.Sprintf(
+		"(BabbageTransactionOutput address=%s amount=%d%s)",
+		o.OutputAddress.String(),
+		o.OutputAmount.Amount,
+		assets,
+	)
+}
+
 type BabbageTransactionWitnessSet struct {
 	cbor.DecodeStoreCbor
 	VkeyWitnesses      []common.VkeyWitness      `cbor:"0,keyasint,omitempty"`

ledger/babbage/babbage_test.go

@@ -2970,3 +2970,22 @@ func TestBabbageTransactionOutputToPlutusDataCoinAssets(t *testing.T) {
 		)
 	}
 }
+
+func TestBabbageTransactionOutputString(t *testing.T) {
+	addrStr := "addr1qytna5k2fq9ler0fuk45j7zfwv7t2zwhp777nvdjqqfr5tz8ztpwnk8zq5ngetcz5k5mckgkajnygtsra9aej2h3ek5seupmvd"
+	addr, _ := common.NewAddress(addrStr)
+	ma := common.NewMultiAsset[common.MultiAssetTypeOutput](
+		map[common.Blake2b224]map[cbor.ByteString]uint64{
+			common.NewBlake2b224(make([]byte, 28)): {cbor.NewByteString([]byte("x")): 2},
+		},
+	)
+	out := BabbageTransactionOutput{
+		OutputAddress: addr,
+		OutputAmount:  mary.MaryTransactionOutputValue{Amount: 456, Assets: &ma},
+	}
+	s := out.String()
+	expected := "(BabbageTransactionOutput address=" + addrStr + " amount=456 assets=" + ma.String() + ")"
+	if s != expected {
+		t.Fatalf("unexpected string: %s", s)
+	}
+}

ledger/byron/byron.go

@@ -489,6 +489,14 @@ func (o ByronTransactionOutput) Utxorpc() (*utxorpc.TxOutput, error) {
 		nil
 }
 
+func (o ByronTransactionOutput) String() string {
+	return fmt.Sprintf(
+		"(ByronTransactionOutput address=%s amount=%d)",
+		o.OutputAddress.String(),
+		o.OutputAmount,
+	)
+}
+
 type ByronBlockVersion struct {
 	cbor.StructAsArray
 	Major   uint16

ledger/byron/byron_test.go

@@ -104,3 +104,24 @@ func TestByronTransaction_Utxorpc_Empty(t *testing.T) {
 		t.Errorf("Expected fee = 0, got %d", result.Fee)
 	}
 }
+
+func TestByronTransactionOutputString(t *testing.T) {
+	addr, err := common.NewByronAddressFromParts(
+		0,
+		make([]byte, common.AddressHashSize),
+		common.ByronAddressAttributes{},
+	)
+	if err != nil {
+		t.Fatalf("address: %v", err)
+	}
+	addrStr := addr.String()
+	out := byron.ByronTransactionOutput{
+		OutputAddress: addr,
+		OutputAmount:  456,
+	}
+	s := out.String()
+	expected := "(ByronTransactionOutput address=" + addrStr + " amount=456)"
+	if s != expected {
+		t.Fatalf("unexpected string: %s", s)
+	}
+}

ledger/common/common.go

@@ -22,6 +22,7 @@ import (
 	"maps"
 	"math/big"
 	"slices"
+	"strings"
 
 	"github.com/blinklabs-io/gouroboros/cbor"
 	"github.com/blinklabs-io/plutigo/data"
@@ -325,6 +326,44 @@ func (m *MultiAsset[T]) normalize() map[Blake2b224]map[cbor.ByteString]T {
 	return ret
 }
 
+// String returns a stable, human-friendly representation of the MultiAsset.
+// Output format: [<policyId>.<assetNameHex>=<amount>, ...] sorted by policyId, then asset name
+func (m *MultiAsset[T]) String() string {
+	if m == nil {
+		return "[]"
+	}
+	norm := m.normalize()
+	if len(norm) == 0 {
+		return "[]"
+	}
+
+	policies := slices.Collect(maps.Keys(norm))
+	slices.SortFunc(policies, func(a, b Blake2b224) int { return bytes.Compare(a.Bytes(), b.Bytes()) })
+
+	var b strings.Builder
+	b.WriteByte('[')
+	first := true
+	for _, pid := range policies {
+		assets := norm[pid]
+		names := slices.Collect(maps.Keys(assets))
+		slices.SortFunc(names, func(a, b cbor.ByteString) int { return bytes.Compare(a.Bytes(), b.Bytes()) })
+
+		for _, name := range names {
+			if !first {
+				b.WriteString(", ")
+			}
+			first = false
+			b.WriteString(pid.String())
+			b.WriteByte('.')
+			b.WriteString(hex.EncodeToString(name.Bytes()))
+			b.WriteByte('=')
+			fmt.Fprintf(&b, "%d", assets[name])
+		}
+	}
+	b.WriteByte(']')
+	return b.String()
+}
+
 type AssetFingerprint struct {
 	policyId  []byte
 	assetName []byte

ledger/common/tx.go

@@ -77,6 +77,7 @@ type TransactionOutput interface {
 	Utxorpc() (*utxorpc.TxOutput, error)
 	ScriptRef() Script
 	ToPlutusData() data.PlutusData
+	String() string
 }
 
 type TransactionWitnessSet interface {

ledger/mary/errors.go

@@ -15,7 +15,6 @@
 package mary
 
 import (
-	"fmt"
 	"strings"
 
 	"github.com/blinklabs-io/gouroboros/ledger/common"
@@ -28,7 +27,7 @@ type OutputTooBigUtxoError struct {
 func (e OutputTooBigUtxoError) Error() string {
 	tmpOutputs := make([]string, len(e.Outputs))
 	for idx, tmpOutput := range e.Outputs {
-		tmpOutputs[idx] = fmt.Sprintf("%#v", tmpOutput)
+		tmpOutputs[idx] = tmpOutput.String()
 	}
 	return "output value too large: " + strings.Join(tmpOutputs, ", ")
 }

ledger/mary/mary.go

@@ -529,6 +529,21 @@ func (o MaryTransactionOutput) Utxorpc() (*utxorpc.TxOutput, error) {
 		err
 }
 
+func (o MaryTransactionOutput) String() string {
+	assets := ""
+	if o.OutputAmount.Assets != nil {
+		if as := o.OutputAmount.Assets.String(); as != "[]" {
+			assets = " assets=" + as
+		}
+	}
+	return fmt.Sprintf(
+		"(MaryTransactionOutput address=%s amount=%d%s)",
+		o.OutputAddress.String(),
+		o.OutputAmount.Amount,
+		assets,
+	)
+}
+
 type MaryTransactionOutputValue struct {
 	cbor.StructAsArray
 	Amount uint64