feat: TX current treasury value attribute (#641)

This adds a method for retrieving the current treasury value attribute from a TX

Fixes #626

README.md

@@ -134,7 +134,7 @@ This is not an exhaustive list of existing and planned features, but it covers t
     - [X] Reference inputs
     - [X] Voting procedures
     - [X] Proposal procedures
-    - [ ] Current treasury value
+    - [X] Current treasury value
     - [ ] Donation
 - [ ] Testing
   - [X] Test framework for mocking Ouroboros conversations

ledger/allegra.go

@@ -210,6 +210,10 @@ func (t AllegraTransaction) ProposalProcedures() []ProposalProcedure {
 	return t.Body.ProposalProcedures()
 }
 
+func (t AllegraTransaction) CurrentTreasuryValue() int64 {
+	return t.Body.CurrentTreasuryValue()
+}
+
 func (t AllegraTransaction) Metadata() *cbor.LazyValue {
 	return t.TxMetadata
 }

ledger/alonzo.go

@@ -324,6 +324,10 @@ func (t AlonzoTransaction) ProposalProcedures() []ProposalProcedure {
 	return t.Body.ProposalProcedures()
 }
 
+func (t AlonzoTransaction) CurrentTreasuryValue() int64 {
+	return t.Body.CurrentTreasuryValue()
+}
+
 func (t AlonzoTransaction) Metadata() *cbor.LazyValue {
 	return t.TxMetadata
 }

ledger/babbage.go

@@ -492,6 +492,10 @@ func (t BabbageTransaction) ProposalProcedures() []ProposalProcedure {
 	return t.Body.ProposalProcedures()
 }
 
+func (t BabbageTransaction) CurrentTreasuryValue() int64 {
+	return t.Body.CurrentTreasuryValue()
+}
+
 func (t BabbageTransaction) Metadata() *cbor.LazyValue {
 	return t.TxMetadata
 }

ledger/byron.go

@@ -235,6 +235,11 @@ func (t *ByronTransaction) ProposalProcedures() []ProposalProcedure {
 	return nil
 }
 
+func (t *ByronTransaction) CurrentTreasuryValue() int64 {
+	// No current treasury value in Byron
+	return 0
+}
+
 func (t *ByronTransaction) Metadata() *cbor.LazyValue {
 	return t.Attributes
 }

ledger/conway.go

@@ -121,10 +121,10 @@ func (h *ConwayBlockHeader) Era() Era {
 
 type ConwayTransactionBody struct {
 	BabbageTransactionBody
-	TxVotingProcedures   VotingProcedures    `cbor:"19,keyasint,omitempty"`
-	TxProposalProcedures []ProposalProcedure `cbor:"20,keyasint,omitempty"`
-	CurrentTreasuryValue int64               `cbor:"21,keyasint,omitempty"`
-	Donation             uint64              `cbor:"22,keyasint,omitempty"`
+	TxVotingProcedures     VotingProcedures    `cbor:"19,keyasint,omitempty"`
+	TxProposalProcedures   []ProposalProcedure `cbor:"20,keyasint,omitempty"`
+	TxCurrentTreasuryValue int64               `cbor:"21,keyasint,omitempty"`
+	Donation               uint64              `cbor:"22,keyasint,omitempty"`
 }
 
 func (b *ConwayTransactionBody) UnmarshalCBOR(cborData []byte) error {
@@ -139,6 +139,10 @@ func (b *ConwayTransactionBody) ProposalProcedures() []ProposalProcedure {
 	return b.TxProposalProcedures
 }
 
+func (b *ConwayTransactionBody) CurrentTreasuryValue() int64 {
+	return b.TxCurrentTreasuryValue
+}
+
 // VotingProcedures is a convenience type to avoid needing to duplicate the full type definition everywhere
 type VotingProcedures map[*Voter]map[*GovActionId]VotingProcedure
 
@@ -397,6 +401,10 @@ func (t ConwayTransaction) ProposalProcedures() []ProposalProcedure {
 	return t.Body.ProposalProcedures()
 }
 
+func (t ConwayTransaction) CurrentTreasuryValue() int64 {
+	return t.Body.CurrentTreasuryValue()
+}
+
 func (t ConwayTransaction) Metadata() *cbor.LazyValue {
 	return t.TxMetadata
 }

ledger/mary.go

@@ -227,6 +227,10 @@ func (t MaryTransaction) ProposalProcedures() []ProposalProcedure {
 	return t.Body.ProposalProcedures()
 }
 
+func (t MaryTransaction) CurrentTreasuryValue() int64 {
+	return t.Body.CurrentTreasuryValue()
+}
+
 func (t MaryTransaction) Metadata() *cbor.LazyValue {
 	return t.TxMetadata
 }

ledger/shelley.go

@@ -278,6 +278,11 @@ func (b *ShelleyTransactionBody) ProposalProcedures() []ProposalProcedure {
 	return nil
 }
 
+func (b *ShelleyTransactionBody) CurrentTreasuryValue() int64 {
+	// No current treasury value in Shelley
+	return 0
+}
+
 func (b *ShelleyTransactionBody) Utxorpc() *utxorpc.Tx {
 	var txi []*utxorpc.TxInput
 	var txo []*utxorpc.TxOutput
@@ -464,6 +469,10 @@ func (t ShelleyTransaction) ProposalProcedures() []ProposalProcedure {
 	return t.Body.ProposalProcedures()
 }
 
+func (t ShelleyTransaction) CurrentTreasuryValue() int64 {
+	return t.Body.CurrentTreasuryValue()
+}
+
 func (t ShelleyTransaction) Metadata() *cbor.LazyValue {
 	return t.TxMetadata
 }

ledger/tx.go

@@ -53,6 +53,7 @@ type TransactionBody interface {
 	ScriptDataHash() *Blake2b256
 	VotingProcedures() VotingProcedures
 	ProposalProcedures() []ProposalProcedure
+	CurrentTreasuryValue() int64
 	Utxorpc() *utxorpc.Tx
 }