ethclient,event: replace noarg fmt.Errorf with errors.New

ethclient/ethclient.go

@@ -138,16 +138,16 @@ func (ec *Client) getBlock(ctx context.Context, method string, args ...interface
 	}
 	// Quick-verify transaction and uncle lists. This mostly helps with debugging the server.
 	if head.UncleHash == types.EmptyUncleHash && len(body.UncleHashes) > 0 {
-		return nil, fmt.Errorf("server returned non-empty uncle list but block header indicates no uncles")
+		return nil, errors.New("server returned non-empty uncle list but block header indicates no uncles")
 	}
 	if head.UncleHash != types.EmptyUncleHash && len(body.UncleHashes) == 0 {
-		return nil, fmt.Errorf("server returned empty uncle list but block header indicates uncles")
+		return nil, errors.New("server returned empty uncle list but block header indicates uncles")
 	}
 	if head.TxHash == types.EmptyTxsHash && len(body.Transactions) > 0 {
-		return nil, fmt.Errorf("server returned non-empty transaction list but block header indicates no transactions")
+		return nil, errors.New("server returned non-empty transaction list but block header indicates no transactions")
 	}
 	if head.TxHash != types.EmptyTxsHash && len(body.Transactions) == 0 {
-		return nil, fmt.Errorf("server returned empty transaction list but block header indicates transactions")
+		return nil, errors.New("server returned empty transaction list but block header indicates transactions")
 	}
 	// Load uncles because they are not included in the block response.
 	var uncles []*types.Header
@@ -232,7 +232,7 @@ func (ec *Client) TransactionByHash(ctx context.Context, hash common.Hash) (tx *
 	} else if json == nil {
 		return nil, false, ethereum.NotFound
 	} else if _, r, _ := json.tx.RawSignatureValues(); r == nil {
-		return nil, false, fmt.Errorf("server returned transaction without signature")
+		return nil, false, errors.New("server returned transaction without signature")
 	}
 	if json.From != nil && json.BlockHash != nil {
 		setSenderFromServer(json.tx, *json.From, *json.BlockHash)
@@ -284,7 +284,7 @@ func (ec *Client) TransactionInBlock(ctx context.Context, blockHash common.Hash,
 	if json == nil {
 		return nil, ethereum.NotFound
 	} else if _, r, _ := json.tx.RawSignatureValues(); r == nil {
-		return nil, fmt.Errorf("server returned transaction without signature")
+		return nil, errors.New("server returned transaction without signature")
 	}
 	if json.From != nil && json.BlockHash != nil {
 		setSenderFromServer(json.tx, *json.From, *json.BlockHash)
@@ -421,7 +421,7 @@ func toFilterArg(q ethereum.FilterQuery) (interface{}, error) {
 	if q.BlockHash != nil {
 		arg["blockHash"] = *q.BlockHash
 		if q.FromBlock != nil || q.ToBlock != nil {
-			return nil, fmt.Errorf("cannot specify both BlockHash and FromBlock/ToBlock")
+			return nil, errors.New("cannot specify both BlockHash and FromBlock/ToBlock")
 		}
 	} else {
 		if q.FromBlock == nil {

ethclient/ethclient_test.go

@@ -20,7 +20,6 @@ import (
 	"bytes"
 	"context"
 	"errors"
-	"fmt"
 	"math/big"
 	"reflect"
 	"testing"
@@ -55,7 +54,7 @@ var (
 )
 
 func TestToFilterArg(t *testing.T) {
-	blockHashErr := fmt.Errorf("cannot specify both BlockHash and FromBlock/ToBlock")
+	blockHashErr := errors.New("cannot specify both BlockHash and FromBlock/ToBlock")
 	addresses := []common.Address{
 		common.HexToAddress("0xD36722ADeC3EdCB29c8e7b5a47f352D701393462"),
 	}

event/feed_test.go

@@ -17,6 +17,7 @@
 package event
 
 import (
+	"errors"
 	"fmt"
 	"reflect"
 	"sync"
@@ -68,7 +69,7 @@ func checkPanic(want error, fn func()) (err error) {
 	defer func() {
 		panic := recover()
 		if panic == nil {
-			err = fmt.Errorf("didn't panic")
+			err = errors.New("didn't panic")
 		} else if !reflect.DeepEqual(panic, want) {
 			err = fmt.Errorf("panicked with wrong error: got %q, want %q", panic, want)
 		}