fix: use errors instead of fmt

cbor/decode.go

@@ -16,6 +16,7 @@ package cbor
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"math"
 	"reflect"
@@ -53,7 +54,7 @@ func DecodeIdFromList(cborData []byte) (int, error) {
 		return 0, err
 	}
 	if listLen == 0 {
-		return 0, fmt.Errorf("cannot return first item from empty list")
+		return 0, errors.New("cannot return first item from empty list")
 	}
 	if listLen < int(CborMaxUintSimple) {
 		if cborData[1] <= CborMaxUintSimple {
@@ -70,7 +71,7 @@ func DecodeIdFromList(cborData []byte) (int, error) {
 	// The upstream CBOR library uses uint64 by default for numeric values
 	case uint64:
 		if v > uint64(math.MaxInt) {
-			return 0, fmt.Errorf("decoded numeric value too large: uint64 > int")
+			return 0, errors.New("decoded numeric value too large: uint64 > int")
 		}
 		return int(v), nil
 	default:
@@ -133,7 +134,7 @@ func DecodeGeneric(cborData []byte, dest interface{}) error {
 		// destination object
 		if valueDest.Kind() != reflect.Pointer ||
 			valueDest.Elem().Kind() != reflect.Struct {
-			return fmt.Errorf("destination must be a pointer to a struct")
+			return errors.New("destination must be a pointer to a struct")
 		}
 		destTypeFields := []reflect.StructField{}
 		for i := 0; i < typeDest.NumField(); i++ {

cbor/encode.go

@@ -1,4 +1,4 @@
-// Copyright 2024 Blink Labs Software
+// Copyright 2025 Blink Labs Software
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@ package cbor
 
 import (
 	"bytes"
-	"fmt"
+	"errors"
 	"reflect"
 	"sync"
 
@@ -58,7 +58,7 @@ func EncodeGeneric(src interface{}) ([]byte, error) {
 		// source object
 		if valueSrc.Kind() != reflect.Pointer ||
 			valueSrc.Elem().Kind() != reflect.Struct {
-			return nil, fmt.Errorf("source must be a pointer to a struct")
+			return nil, errors.New("source must be a pointer to a struct")
 		}
 		srcTypeFields := []reflect.StructField{}
 		for i := 0; i < typeSrc.NumField(); i++ {

cbor/tags.go

@@ -1,4 +1,4 @@
-// Copyright 2024 Blink Labs Software
+// Copyright 2025 Blink Labs Software
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -15,6 +15,7 @@
 package cbor
 
 import (
+	"errors"
 	"fmt"
 	"math/big"
 	"reflect"
@@ -132,15 +133,15 @@ func (r *Rat) MarshalCBOR() ([]byte, error) {
 	} else if r.Num().IsInt64() {
 		tmpContent[0] = r.Num().Int64()
 	} else {
-		return nil, fmt.Errorf("numerator cannot be represented at int64/uint64")
+		return nil, errors.New("numerator cannot be represented at int64/uint64")
 	}
 	// Denominator
 	if r.Denom().IsUint64() {
 		tmpContent[1] = r.Denom().Uint64()
 	} else if r.Denom().IsInt64() {
 		tmpContent[1] = r.Denom().Int64()
 	} else {
-		return nil, fmt.Errorf("numerator cannot be represented at int64/uint64")
+		return nil, errors.New("numerator cannot be represented at int64/uint64")
 	}
 	tmpData := _cbor.Tag{
 		Number:  CborTagRational,

cmd/gouroboros/chainsync.go

@@ -16,6 +16,7 @@ package main
 
 import (
 	"encoding/hex"
+	"errors"
 	"flag"
 	"fmt"
 	"os"
@@ -266,7 +267,7 @@ func chainSyncRollForwardHandler(
 		blockHash, _ := hex.DecodeString(v.Hash())
 		var err error
 		if oConn == nil {
-			return fmt.Errorf("empty ouroboros connection, aborting!")
+			return errors.New("empty ouroboros connection, aborting!")
 		}
 		block, err = oConn.BlockFetch().Client.GetBlock(common.NewPoint(blockSlot, blockHash))
 		if err != nil {
@@ -293,7 +294,7 @@ func chainSyncRollForwardHandler(
 		)
 	default:
 		if block == nil {
-			return fmt.Errorf("block is nil")
+			return errors.New("block is nil")
 		}
 		fmt.Printf(
 			"era = %s, slot = %d, block_no = %d, id = %s\n",

cmd/gouroboros/server.go

@@ -1,4 +1,4 @@
-// Copyright 2023 Blink Labs Software
+// Copyright 2025 Blink Labs Software
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -15,6 +15,7 @@
 package main
 
 import (
+	"errors"
 	"flag"
 	"fmt"
 	"net"
@@ -55,7 +56,7 @@ func createListenerSocket(f *globalFlags) (net.Listener, error) {
 			return nil, fmt.Errorf("failed to open listening socket: %w", err)
 		}
 	default:
-		return nil, fmt.Errorf("no listening address or socket specified")
+		return nil, errors.New("no listening address or socket specified")
 	}
 
 	return listen, nil

connection.go

@@ -1,4 +1,4 @@
-// Copyright 2024 Blink Labs Software
+// Copyright 2025 Blink Labs Software
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -158,7 +158,7 @@ func (c *Connection) DialTimeout(
 	timeout time.Duration,
 ) error {
 	if c.conn != nil {
-		return fmt.Errorf("a connection was already established")
+		return errors.New("a connection was already established")
 	}
 	conn, err := net.DialTimeout(proto, address, timeout)
 	if err != nil {

ledger/allegra/rules.go

@@ -15,7 +15,7 @@
 package allegra
 
 import (
-	"fmt"
+	"errors"
 
 	"github.com/blinklabs-io/gouroboros/ledger/common"
 	"github.com/blinklabs-io/gouroboros/ledger/shelley"
@@ -68,7 +68,7 @@ func UtxoValidateFeeTooSmallUtxo(
 ) error {
 	tmpPparams, ok := pp.(*AllegraProtocolParameters)
 	if !ok {
-		return fmt.Errorf("pparams are not expected type")
+		return errors.New("pparams are not expected type")
 	}
 	return shelley.UtxoValidateFeeTooSmallUtxo(
 		tx,
@@ -113,7 +113,7 @@ func UtxoValidateValueNotConservedUtxo(
 ) error {
 	tmpPparams, ok := pp.(*AllegraProtocolParameters)
 	if !ok {
-		return fmt.Errorf("pparams are not expected type")
+		return errors.New("pparams are not expected type")
 	}
 	return shelley.UtxoValidateValueNotConservedUtxo(
 		tx,
@@ -131,7 +131,7 @@ func UtxoValidateOutputTooSmallUtxo(
 ) error {
 	tmpPparams, ok := pp.(*AllegraProtocolParameters)
 	if !ok {
-		return fmt.Errorf("pparams are not expected type")
+		return errors.New("pparams are not expected type")
 	}
 	return shelley.UtxoValidateOutputTooSmallUtxo(
 		tx,
@@ -158,7 +158,7 @@ func UtxoValidateMaxTxSizeUtxo(
 ) error {
 	tmpPparams, ok := pp.(*AllegraProtocolParameters)
 	if !ok {
-		return fmt.Errorf("pparams are not expected type")
+		return errors.New("pparams are not expected type")
 	}
 	return shelley.UtxoValidateMaxTxSizeUtxo(
 		tx,

ledger/babbage/babbage.go

@@ -17,6 +17,7 @@ package babbage
 import (
 	"encoding/hex"
 	"encoding/json"
+	"errors"
 	"fmt"
 
 	"github.com/blinklabs-io/gouroboros/cbor"
@@ -355,7 +356,7 @@ func (d *BabbageTransactionOutputDatumOption) MarshalCBOR() ([]byte, error) {
 	} else if d.data != nil {
 		tmpObj = []interface{}{DatumOptionTypeData, cbor.Tag{Number: 24, Content: d.data.Cbor()}}
 	} else {
-		return nil, fmt.Errorf("unknown datum option type")
+		return nil, errors.New("unknown datum option type")
 	}
 	return cbor.Encode(&tmpObj)
 }

ledger/block.go

@@ -1,4 +1,4 @@
-// Copyright 2024 Blink Labs Software
+// Copyright 2025 Blink Labs Software
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -15,6 +15,7 @@
 package ledger
 
 import (
+	"errors"
 	"fmt"
 
 	"github.com/blinklabs-io/gouroboros/ledger/common"
@@ -86,5 +87,5 @@ func DetermineBlockType(data []byte) (uint, error) {
 	if _, err := NewConwayBlockFromCbor(data); err == nil {
 		return BlockTypeConway, nil
 	}
-	return 0, fmt.Errorf("unknown block type")
+	return 0, errors.New("unknown block type")
 }

ledger/byron/byron.go

@@ -16,6 +16,7 @@ package byron
 
 import (
 	"encoding/hex"
+	"errors"
 	"fmt"
 	"math"
 
@@ -342,7 +343,7 @@ func (i *ByronTransactionInput) UnmarshalCBOR(data []byte) error {
 		}
 	default:
 		// [u8 .ne 0, encoded-cbor]
-		return fmt.Errorf("can't parse yet")
+		return errors.New("can't parse yet")
 	}
 	return nil
 }

ledger/common/address.go

@@ -1,4 +1,4 @@
-// Copyright 2024 Blink Labs Software
+// Copyright 2025 Blink Labs Software
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -15,6 +15,7 @@
 package common
 
 import (
+	"errors"
 	"fmt"
 	"hash/crc32"
 	"strings"
@@ -182,24 +183,18 @@ func (a *Address) populateFromBytes(data []byte) error {
 		}
 		payloadBytes, ok := rawAddr.Payload.Content.([]byte)
 		if !ok || rawAddr.Payload.Number != 24 {
-			return fmt.Errorf(
-				"invalid Byron address data: unexpected payload content",
-			)
+			return errors.New("invalid Byron address data: unexpected payload content")
 		}
 		payloadChecksum := crc32.ChecksumIEEE(payloadBytes)
 		if rawAddr.Checksum != payloadChecksum {
-			return fmt.Errorf(
-				"invalid Byron address data: checksum does not match",
-			)
+			return errors.New("invalid Byron address data: checksum does not match")
 		}
 		var byronAddr byronAddressPayload
 		if _, err := cbor.Decode(payloadBytes, &byronAddr); err != nil {
 			return err
 		}
 		if len(byronAddr.Hash) != AddressHashSize {
-			return fmt.Errorf(
-				"invalid Byron address data: hash is not expected length",
-			)
+			return errors.New("invalid Byron address data: hash is not expected length")
 		}
 		a.byronAddressType = byronAddr.AddrType
 		a.byronAddressAttr = byronAddr.Attr

ledger/common/certs.go

@@ -15,6 +15,7 @@
 package common
 
 import (
+	"errors"
 	"fmt"
 	"net"
 
@@ -461,7 +462,7 @@ func (r *MoveInstantaneousRewardsCertificateReward) UnmarshalCBOR(
 		r.Source = tmpMapData.Source
 		return nil
 	}
-	return fmt.Errorf("failed to decode as known types")
+	return errors.New("failed to decode as known types")
 }
 
 type MoveInstantaneousRewardsCertificate struct {

ledger/common/nonce.go

@@ -1,4 +1,4 @@
-// Copyright 2024 Blink Labs Software
+// Copyright 2025 Blink Labs Software
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,6 +16,7 @@ package common
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"slices"
 
@@ -60,7 +61,7 @@ func (n *Nonce) UnmarshalJSON(data []byte) error {
 	}
 	tag, ok := tmpData["tag"]
 	if !ok {
-		return fmt.Errorf("did not find expected key 'tag' for nonce")
+		return errors.New("did not find expected key 'tag' for nonce")
 	}
 	switch tag {
 	case "NeutralNonce":