all: fix issues found by linters

.golangci.yml

@@ -21,7 +21,7 @@ linters:
     - staticcheck
     - bidichk
     - durationcheck
-    - exportloopref
+    - copyloopvar
     - whitespace
     - revive # only certain checks enabled
 

accounts/abi/unpack_test.go

@@ -947,7 +947,7 @@ func TestOOMMaliciousInput(t *testing.T) {
 		}
 		encb, err := hex.DecodeString(test.enc)
 		if err != nil {
-			t.Fatalf("invalid hex: %s" + test.enc)
+			t.Fatalf("invalid hex: %s", test.enc)
 		}
 		_, err = abi.Methods["method"].Outputs.UnpackValues(encb)
 		if err == nil {

cmd/evm/t8n_test.go

@@ -524,7 +524,7 @@ func TestT9n(t *testing.T) {
 			ok, err := cmpJson(have, want)
 			switch {
 			case err != nil:
-				t.Logf(string(have))
+				t.Log(string(have))
 				t.Fatalf("test %d, json parsing failed: %v", i, err)
 			case !ok:
 				t.Fatalf("test %d: output wrong, have \n%v\nwant\n%v\n", i, string(have), string(want))
@@ -659,7 +659,7 @@ func TestB11r(t *testing.T) {
 			ok, err := cmpJson(have, want)
 			switch {
 			case err != nil:
-				t.Logf(string(have))
+				t.Log(string(have))
 				t.Fatalf("test %d, json parsing failed: %v", i, err)
 			case !ok:
 				t.Fatalf("test %d: output wrong, have \n%v\nwant\n%v\n", i, string(have), string(want))

cmd/rlpdump/main.go

@@ -142,7 +142,7 @@ func dump(in *inStream, s *rlp.Stream, depth int, out io.Writer) error {
 		s.List()
 		defer s.ListEnd()
 		if size == 0 {
-			fmt.Fprintf(out, ws(depth)+"[]")
+			fmt.Fprint(out, ws(depth)+"[]")
 		} else {
 			fmt.Fprintln(out, ws(depth)+"[")
 			for i := 0; ; i++ {

core/rawdb/accessors_chain_test.go

@@ -388,10 +388,10 @@ func TestBlockReceiptStorage(t *testing.T) {
 	// Insert the receipt slice into the database and check presence
 	WriteReceipts(db, hash, 0, receipts)
 	if rs := ReadReceipts(db, hash, 0, 0, params.TestChainConfig); len(rs) == 0 {
-		t.Fatalf("no receipts returned")
+		t.Fatal("no receipts returned")
 	} else {
 		if err := checkReceiptsRLP(rs, receipts); err != nil {
-			t.Fatalf(err.Error())
+			t.Fatal(err)
 		}
 	}
 	// Delete the body and ensure that the receipts are no longer returned (metadata can't be recomputed)
@@ -401,7 +401,7 @@ func TestBlockReceiptStorage(t *testing.T) {
 	}
 	// Ensure that receipts without metadata can be returned without the block body too
 	if err := checkReceiptsRLP(ReadRawReceipts(db, hash, 0), receipts); err != nil {
-		t.Fatalf(err.Error())
+		t.Fatal(err)
 	}
 	// Sanity check that body alone without the receipt is a full purge
 	WriteBody(db, hash, 0, body)

eth/tracers/logger/logger.go

@@ -458,7 +458,7 @@ func formatLogs(logs []StructLog) []StructLogRes {
 			}
 			formatted[index].Stack = &stack
 		}
-		if trace.ReturnData != nil && len(trace.ReturnData) > 0 {
+		if len(trace.ReturnData) > 0 {
 			formatted[index].ReturnData = hexutil.Bytes(trace.ReturnData).String()
 		}
 		if trace.Memory != nil {

metrics/json_test.go

@@ -13,7 +13,7 @@ func TestRegistryMarshallJSON(t *testing.T) {
 	r.Register("counter", NewCounter())
 	enc.Encode(r)
 	if s := b.String(); s != "{\"counter\":{\"count\":0}}\n" {
-		t.Fatalf(s)
+		t.Fatal(s)
 	}
 }