From cfc067dd24c79dd472fe4a3f97109d321b348d26 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 18:13:14 +0300
Subject: [PATCH 01/34] *: remove dead code

Found by deadcode via golangci-lint.
---
 pkg/compiler/analysis.go               |  4 ---
 pkg/consensus/recovery_message_test.go | 14 --------
 pkg/core/helper_test.go                | 47 --------------------------
 pkg/core/interop_system_test.go        | 22 ------------
 pkg/core/native/ledger.go              |  9 +----
 pkg/core/native/util.go                | 30 ----------------
 pkg/core/util.go                       | 11 ------
 pkg/encoding/fixedn/fixed8.go          |  3 --
 pkg/io/size.go                         | 12 -------
 pkg/network/payload/extensible.go      |  6 +---
 pkg/network/server.go                  |  2 --
 pkg/rpc/client/client.go               |  1 -
 pkg/rpc/server/server_test.go          |  6 ----
 pkg/services/oracle/neofs/neofs.go     |  5 ---
 pkg/util/bitfield/bitfield.go          |  1 -
 pkg/wallet/account.go                  | 12 -------
 16 files changed, 2 insertions(+), 183 deletions(-)

diff --git a/pkg/compiler/analysis.go b/pkg/compiler/analysis.go
index b95139510..112c6945d 100644
--- a/pkg/compiler/analysis.go
+++ b/pkg/compiler/analysis.go
@@ -302,10 +302,6 @@ func isInteropPath(s string) bool {
 	return strings.HasPrefix(s, interopPrefix)
 }
 
-func isNativeHelpersPath(s string) bool {
-	return strings.HasPrefix(s, interopPrefix+"/native")
-}
-
 // canConvert returns true if type doesn't need to be converted on type assertion.
 func canConvert(s string) bool {
 	if len(s) != 0 && s[0] == '*' {
diff --git a/pkg/consensus/recovery_message_test.go b/pkg/consensus/recovery_message_test.go
index 3af23db91..9fe19e263 100644
--- a/pkg/consensus/recovery_message_test.go
+++ b/pkg/consensus/recovery_message_test.go
@@ -7,7 +7,6 @@ import (
 	"github.com/nspcc-dev/dbft/payload"
 	"github.com/nspcc-dev/neo-go/internal/testchain"
 	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
-	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/stretchr/testify/require"
 )
@@ -157,16 +156,3 @@ func TestRecoveryMessage_Decode(t *testing.T) {
 	require.Equal(t, gio.EOF, buf.Err)
 }
 */
-
-func getKeys(t *testing.T, n int) []*privateKey {
-	privs := make([]*privateKey, 0, n)
-	for i := 0; i < n; i++ {
-		priv, err := keys.NewPrivateKey()
-		require.NoError(t, err)
-		require.NotNil(t, priv)
-
-		privs = append(privs, &privateKey{PrivateKey: priv})
-	}
-
-	return privs
-}
diff --git a/pkg/core/helper_test.go b/pkg/core/helper_test.go
index 41b0da005..32a470175 100644
--- a/pkg/core/helper_test.go
+++ b/pkg/core/helper_test.go
@@ -15,7 +15,6 @@ import (
 	"time"
 
 	"github.com/nspcc-dev/neo-go/internal/testchain"
-	"github.com/nspcc-dev/neo-go/internal/testserdes"
 	"github.com/nspcc-dev/neo-go/pkg/compiler"
 	"github.com/nspcc-dev/neo-go/pkg/config"
 	"github.com/nspcc-dev/neo-go/pkg/core/block"
@@ -28,7 +27,6 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/core/storage"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
-	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/encoding/fixedn"
 	"github.com/nspcc-dev/neo-go/pkg/io"
@@ -180,51 +178,6 @@ func TestBug1728(t *testing.T) {
 	require.Equal(t, aer.VMState, vm.HaltState)
 }
 
-func getDecodedBlock(t *testing.T, i int) *block.Block {
-	data, err := getBlockData(i)
-	require.NoError(t, err)
-
-	b, err := hex.DecodeString(data["raw"].(string))
-	require.NoError(t, err)
-
-	block := block.New(false)
-	require.NoError(t, testserdes.DecodeBinary(b, block))
-
-	return block
-}
-
-func getBlockData(i int) (map[string]interface{}, error) {
-	b, err := ioutil.ReadFile(fmt.Sprintf("test_data/block_%d.json", i))
-	if err != nil {
-		return nil, err
-	}
-	var data map[string]interface{}
-	if err := json.Unmarshal(b, &data); err != nil {
-		return nil, err
-	}
-	return data, err
-}
-
-func newDumbBlock() *block.Block {
-	return &block.Block{
-		Header: block.Header{
-			Version:       0,
-			PrevHash:      hash.Sha256([]byte("a")),
-			MerkleRoot:    hash.Sha256([]byte("b")),
-			Timestamp:     100500,
-			Index:         1,
-			NextConsensus: hash.Hash160([]byte("a")),
-			Script: transaction.Witness{
-				VerificationScript: []byte{0x51}, // PUSH1
-				InvocationScript:   []byte{0x61}, // NOP
-			},
-		},
-		Transactions: []*transaction.Transaction{
-			transaction.New([]byte{byte(opcode.PUSH1)}, 0),
-		},
-	}
-}
-
 // This function generates "../rpc/testdata/testblocks.acc" file which contains data
 // for RPC unit tests. It also is a nice integration test.
 // To generate new "../rpc/testdata/testblocks.acc", follow the steps:
diff --git a/pkg/core/interop_system_test.go b/pkg/core/interop_system_test.go
index 7c6f714ef..298bf29e9 100644
--- a/pkg/core/interop_system_test.go
+++ b/pkg/core/interop_system_test.go
@@ -7,7 +7,6 @@ import (
 	"testing"
 
 	"github.com/nspcc-dev/neo-go/internal/random"
-	"github.com/nspcc-dev/neo-go/pkg/core/block"
 	"github.com/nspcc-dev/neo-go/pkg/core/dao"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop/contract"
@@ -451,27 +450,6 @@ func createVM(t *testing.T) (*vm.VM, *interop.Context, *Blockchain) {
 	return v, context, chain
 }
 
-func createVMAndPushBlock(t *testing.T) (*vm.VM, *block.Block, *interop.Context, *Blockchain) {
-	v, block, context, chain := createVMAndBlock(t)
-	v.Estack().PushVal(stackitem.NewInterop(block))
-	return v, block, context, chain
-}
-
-func createVMAndBlock(t *testing.T) (*vm.VM, *block.Block, *interop.Context, *Blockchain) {
-	block := newDumbBlock()
-	chain := newTestChain(t)
-	d := dao.NewSimple(storage.NewMemoryStore(), chain.GetConfig().StateRootInHeader)
-	context := chain.newInteropContext(trigger.Application, d, block, nil)
-	v := context.SpawnVM()
-	return v, block, context, chain
-}
-
-func createVMAndPushTX(t *testing.T) (*vm.VM, *transaction.Transaction, *interop.Context, *Blockchain) {
-	v, tx, context, chain := createVMAndTX(t)
-	v.Estack().PushVal(stackitem.NewInterop(tx))
-	return v, tx, context, chain
-}
-
 func createVMAndContractState(t *testing.T) (*vm.VM, *state.Contract, *interop.Context, *Blockchain) {
 	script := []byte("testscript")
 	m := manifest.NewManifest("Test")
diff --git a/pkg/core/native/ledger.go b/pkg/core/native/ledger.go
index 88e86f87e..4dfd6b313 100644
--- a/pkg/core/native/ledger.go
+++ b/pkg/core/native/ledger.go
@@ -25,14 +25,7 @@ type Ledger struct {
 	interop.ContractMD
 }
 
-const (
-	ledgerContractID = -4
-
-	prefixBlockHash    = 9
-	prefixCurrentBlock = 12
-	prefixBlock        = 5
-	prefixTransaction  = 11
-)
+const ledgerContractID = -4
 
 // newLedger creates new Ledger native contract.
 func newLedger() *Ledger {
diff --git a/pkg/core/native/util.go b/pkg/core/native/util.go
index af7ffd6e7..73ac7f316 100644
--- a/pkg/core/native/util.go
+++ b/pkg/core/native/util.go
@@ -1,13 +1,11 @@
 package native
 
 import (
-	"encoding/binary"
 	"encoding/hex"
 	"fmt"
 	"math/big"
 
 	"github.com/nspcc-dev/neo-go/pkg/core/dao"
-	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/core/storage"
 	"github.com/nspcc-dev/neo-go/pkg/encoding/bigint"
 	"github.com/nspcc-dev/neo-go/pkg/io"
@@ -36,34 +34,6 @@ func putSerializableToDAO(id int32, d dao.DAO, key []byte, item io.Serializable)
 	return d.PutStorageItem(id, key, w.Bytes())
 }
 
-func getInt64WithKey(id int32, d dao.DAO, key []byte, defaultValue int64) int64 {
-	si := d.GetStorageItem(id, key)
-	if si == nil {
-		return defaultValue
-	}
-	return int64(binary.LittleEndian.Uint64(si))
-}
-
-func setInt64WithKey(id int32, dao dao.DAO, key []byte, value int64) error {
-	si := make(state.StorageItem, 8)
-	binary.LittleEndian.PutUint64(si, uint64(value))
-	return dao.PutStorageItem(id, key, si)
-}
-
-func getUint32WithKey(id int32, dao dao.DAO, key []byte, defaultValue uint32) uint32 {
-	si := dao.GetStorageItem(id, key)
-	if si == nil {
-		return defaultValue
-	}
-	return binary.LittleEndian.Uint32(si)
-}
-
-func setUint32WithKey(id int32, dao dao.DAO, key []byte, value uint32) error {
-	si := make(state.StorageItem, 4)
-	binary.LittleEndian.PutUint32(si, value)
-	return dao.PutStorageItem(id, key, si)
-}
-
 func setIntWithKey(id int32, dao dao.DAO, key []byte, value int64) error {
 	return dao.PutStorageItem(id, key, bigint.ToBytes(big.NewInt(value)))
 }
diff --git a/pkg/core/util.go b/pkg/core/util.go
index 2c1750ab8..325bac560 100644
--- a/pkg/core/util.go
+++ b/pkg/core/util.go
@@ -14,17 +14,6 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
 )
 
-var (
-	// governingTokenTX represents transaction that is used to create
-	// governing (NEO) token. It's a part of the genesis block.
-	governingTokenTX transaction.Transaction
-
-	// utilityTokenTX represents transaction that is used to create
-	// utility (GAS) token. It's a part of the genesis block. It's mostly
-	// useful for its hash that represents GAS asset ID.
-	utilityTokenTX transaction.Transaction
-)
-
 // createGenesisBlock creates a genesis block based on the given configuration.
 func createGenesisBlock(cfg config.ProtocolConfiguration) (*block.Block, error) {
 	validators, err := validatorsFromConfig(cfg)
diff --git a/pkg/encoding/fixedn/fixed8.go b/pkg/encoding/fixedn/fixed8.go
index ff92e6b6d..01abc8720 100644
--- a/pkg/encoding/fixedn/fixed8.go
+++ b/pkg/encoding/fixedn/fixed8.go
@@ -1,7 +1,6 @@
 package fixedn
 
 import (
-	"errors"
 	"strconv"
 	"strings"
 
@@ -13,8 +12,6 @@ const (
 	decimals  = 100000000
 )
 
-var errInvalidString = errors.New("fixed8 must satisfy following regex \\d+(\\.\\d{1,8})?")
-
 // Fixed8 represents a fixed-point number with precision 10^-8.
 type Fixed8 int64
 
diff --git a/pkg/io/size.go b/pkg/io/size.go
index 93f7021f8..3075a77db 100644
--- a/pkg/io/size.go
+++ b/pkg/io/size.go
@@ -5,18 +5,6 @@ import (
 	"reflect"
 )
 
-var (
-	bit8 byte
-	ui8  uint8
-	ui16 uint16
-	ui32 uint32
-	ui64 uint64
-	i8   int8
-	i16  int16
-	i32  int32
-	i64  int64
-)
-
 // This structure is used to calculate the wire size of the serializable
 // structure. It's an io.Writer that doesn't do any real writes, but instead
 // just counts the number of bytes to be written.
diff --git a/pkg/network/payload/extensible.go b/pkg/network/payload/extensible.go
index 529a8dc37..66891e7e7 100644
--- a/pkg/network/payload/extensible.go
+++ b/pkg/network/payload/extensible.go
@@ -2,7 +2,6 @@ package payload
 
 import (
 	"errors"
-	"math"
 
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
@@ -10,10 +9,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/util"
 )
 
-const (
-	maxExtensibleCategorySize = 32
-	maxExtensibleDataSize     = math.MaxUint16
-)
+const maxExtensibleCategorySize = 32
 
 // Extensible represents payload containing arbitrary data.
 type Extensible struct {
diff --git a/pkg/network/server.go b/pkg/network/server.go
index e5f9f8e96..3e5d00808 100644
--- a/pkg/network/server.go
+++ b/pkg/network/server.go
@@ -41,12 +41,10 @@ const (
 var (
 	errAlreadyConnected = errors.New("already connected")
 	errIdenticalID      = errors.New("identical node id")
-	errInvalidHandshake = errors.New("invalid handshake")
 	errInvalidNetwork   = errors.New("invalid network")
 	errMaxPeers         = errors.New("max peers reached")
 	errServerShutdown   = errors.New("server shutdown")
 	errInvalidInvType   = errors.New("invalid inventory type")
-	errInvalidHashStart = errors.New("invalid requested HashStart")
 )
 
 type (
diff --git a/pkg/rpc/client/client.go b/pkg/rpc/client/client.go
index bccd0d4a5..d112ef33c 100644
--- a/pkg/rpc/client/client.go
+++ b/pkg/rpc/client/client.go
@@ -21,7 +21,6 @@ import (
 const (
 	defaultDialTimeout    = 4 * time.Second
 	defaultRequestTimeout = 4 * time.Second
-	defaultClientVersion  = "2.0"
 	// number of blocks after which cache is expired
 	cacheTimeout = 100
 )
diff --git a/pkg/rpc/server/server_test.go b/pkg/rpc/server/server_test.go
index 526c54f2a..bd9df957b 100644
--- a/pkg/rpc/server/server_test.go
+++ b/pkg/rpc/server/server_test.go
@@ -46,11 +46,6 @@ type executor struct {
 	httpSrv *httptest.Server
 }
 
-const (
-	defaultJSONRPC = "2.0"
-	defaultID      = 1
-)
-
 type rpcTestCase struct {
 	name   string
 	params string
@@ -66,7 +61,6 @@ const genesisBlockHash = "73fe50b5564d57118296cbab0a78fe7cb11c97b7699d07a9a21fab
 const verifyContractHash = "c50082e0d8364d61ce6933bd24027a3363474dce"
 const verifyContractAVM = "VwMAQS1RCDAhcAwU7p6iLCfjS9AUj8QQjgj3To9QSLLbMHFoE87bKGnbKJdA"
 const verifyWithArgsContractHash = "8744ffdd07af8e9f18ab90685c8c2ebfd37c6415"
-const verifyWithArgsContractAVM = "VwIDeAwLZ29vZF9zdHJpbmeXJA15FSgJehHbIJciBRHbIHBoQA=="
 const invokescriptContractAVM = "VwcADBQBDAMOBQYMDQIODw0DDgcJAAAAANswcGhB+CfsjCGqJgQRQAwUDQ8DAgkAAgEDBwMEBQIBAA4GDAnbMHFpQfgn7IwhqiYEEkATQA=="
 
 var rpcTestCases = map[string][]rpcTestCase{
diff --git a/pkg/services/oracle/neofs/neofs.go b/pkg/services/oracle/neofs/neofs.go
index ee09ae424..199310569 100644
--- a/pkg/services/oracle/neofs/neofs.go
+++ b/pkg/services/oracle/neofs/neofs.go
@@ -3,7 +3,6 @@ package neofs
 import (
 	"bytes"
 	"context"
-	"crypto/sha256"
 	"errors"
 	"fmt"
 	"net/url"
@@ -24,10 +23,6 @@ const (
 	// URIScheme is the name of neofs URI scheme.
 	URIScheme = "neofs"
 
-	// containerIDSize is the size of container id in bytes.
-	containerIDSize = sha256.Size
-	// objectIDSize is the size of container id in bytes.
-	objectIDSize = sha256.Size
 	// rangeSep is a separator between offset and length.
 	rangeSep = '|'
 
diff --git a/pkg/util/bitfield/bitfield.go b/pkg/util/bitfield/bitfield.go
index 8766c8d60..c2de953b4 100644
--- a/pkg/util/bitfield/bitfield.go
+++ b/pkg/util/bitfield/bitfield.go
@@ -10,7 +10,6 @@ type Field []uint64
 
 // Bits and bytes count in a basic element of Field.
 const elemBits = 64
-const elemBytes = 8
 
 // New creates a new bit field of specified length. Actual field length
 // can be rounded to the next multiple of 64, so it's a responsibility
diff --git a/pkg/wallet/account.go b/pkg/wallet/account.go
index 93f0c983f..f67a4fc17 100644
--- a/pkg/wallet/account.go
+++ b/pkg/wallet/account.go
@@ -61,18 +61,6 @@ type Contract struct {
 	Deployed bool `json:"deployed"`
 }
 
-// contract is an intermediate struct used for json unmarshalling.
-type contract struct {
-	// Script is a hex-encoded script of the contract.
-	Script string `json:"script"`
-
-	// A list of parameters used deploying this contract.
-	Parameters []ContractParam `json:"parameters"`
-
-	// Indicates whether the contract has been deployed to the blockchain.
-	Deployed bool `json:"deployed"`
-}
-
 // ContractParam is a descriptor of a contract parameter
 // containing type and optional name.
 type ContractParam struct {

From 73ecbbb7c6c0c2d9f5c482855824094dedb080ba Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 18:18:49 +0300
Subject: [PATCH 02/34] compiler: remove unused testPrintHash from test code

---
 pkg/compiler/native_test.go | 31 +++++++++++--------------------
 1 file changed, 11 insertions(+), 20 deletions(-)

diff --git a/pkg/compiler/native_test.go b/pkg/compiler/native_test.go
index 03c3fc77b..08012b03f 100644
--- a/pkg/compiler/native_test.go
+++ b/pkg/compiler/native_test.go
@@ -33,26 +33,17 @@ import (
 
 func TestContractHashes(t *testing.T) {
 	cs := native.NewContracts(true, map[string][]uint32{})
-	require.Equal(t, []byte(neo.Hash), cs.NEO.Hash.BytesBE())
-	require.Equal(t, []byte(gas.Hash), cs.GAS.Hash.BytesBE())
-	require.Equal(t, []byte(oracle.Hash), cs.Oracle.Hash.BytesBE())
-	require.Equal(t, []byte(roles.Hash), cs.Designate.Hash.BytesBE())
-	require.Equal(t, []byte(policy.Hash), cs.Policy.Hash.BytesBE())
-	require.Equal(t, []byte(nameservice.Hash), cs.NameService.Hash.BytesBE())
-	require.Equal(t, []byte(ledger.Hash), cs.Ledger.Hash.BytesBE())
-	require.Equal(t, []byte(management.Hash), cs.Management.Hash.BytesBE())
-	require.Equal(t, []byte(notary.Hash), cs.Notary.Hash.BytesBE())
-	require.Equal(t, []byte(crypto.Hash), cs.Crypto.Hash.BytesBE())
-	require.Equal(t, []byte(std.Hash), cs.Std.Hash.BytesBE())
-}
-
-// testPrintHash is a helper for updating contract hashes.
-func testPrintHash(u util.Uint160) {
-	fmt.Print(`"`)
-	for _, b := range u.BytesBE() {
-		fmt.Printf("\\x%02x", b)
-	}
-	fmt.Println(`"`)
+	require.Equalf(t, []byte(neo.Hash), cs.NEO.Hash.BytesBE(), "%q", string(cs.NEO.Hash.BytesBE()))
+	require.Equalf(t, []byte(gas.Hash), cs.GAS.Hash.BytesBE(), "%q", string(cs.GAS.Hash.BytesBE()))
+	require.Equalf(t, []byte(oracle.Hash), cs.Oracle.Hash.BytesBE(), "%q", string(cs.Oracle.Hash.BytesBE()))
+	require.Equalf(t, []byte(roles.Hash), cs.Designate.Hash.BytesBE(), "%q", string(cs.Designate.Hash.BytesBE()))
+	require.Equalf(t, []byte(policy.Hash), cs.Policy.Hash.BytesBE(), "%q", string(cs.Policy.Hash.BytesBE()))
+	require.Equalf(t, []byte(nameservice.Hash), cs.NameService.Hash.BytesBE(), "%q", string(cs.NameService.Hash.BytesBE()))
+	require.Equalf(t, []byte(ledger.Hash), cs.Ledger.Hash.BytesBE(), "%q", string(cs.Ledger.Hash.BytesBE()))
+	require.Equalf(t, []byte(management.Hash), cs.Management.Hash.BytesBE(), "%q", string(cs.Management.Hash.BytesBE()))
+	require.Equalf(t, []byte(notary.Hash), cs.Notary.Hash.BytesBE(), "%q", string(cs.Notary.Hash.BytesBE()))
+	require.Equalf(t, []byte(crypto.Hash), cs.Crypto.Hash.BytesBE(), "%q", string(cs.Crypto.Hash.BytesBE()))
+	require.Equalf(t, []byte(std.Hash), cs.Std.Hash.BytesBE(), "%q", string(cs.Std.Hash.BytesBE()))
 }
 
 func TestContractParameterTypes(t *testing.T) {

From 8322607fd2e4ea50b1340742a7291b639b599e25 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 18:20:48 +0300
Subject: [PATCH 03/34] rpc/server: silence deadcode warning

---
 pkg/rpc/server/subscription_test.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/pkg/rpc/server/subscription_test.go b/pkg/rpc/server/subscription_test.go
index 58f4dc6d3..7f8872eed 100644
--- a/pkg/rpc/server/subscription_test.go
+++ b/pkg/rpc/server/subscription_test.go
@@ -16,6 +16,8 @@ import (
 	"go.uber.org/atomic"
 )
 
+const testOverflow = false
+
 func wsReader(t *testing.T, ws *websocket.Conn, msgCh chan<- []byte, isFinished *atomic.Bool) {
 	for {
 		ws.SetReadDeadline(time.Now().Add(time.Second))
@@ -428,7 +430,10 @@ func TestWSClientsLimit(t *testing.T) {
 // that's going to happen because of network-level buffering, typical
 // number seen in tests is around ~3500 events, but it's not reliable enough,
 // thus this test is disabled.
-func testSubscriptionOverflow(t *testing.T) {
+func TestSubscriptionOverflow(t *testing.T) {
+	if !testOverflow {
+		return
+	}
 	const blockCnt = notificationBufSize * 5
 	var receivedMiss bool
 

From ad8ffee0ab8d1ffe492cf7a5d528845daf0cf915 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 18:24:16 +0300
Subject: [PATCH 04/34] *: remove redundant `return` statements

Found by gosimple via golangci-lint.
---
 cli/nep17_test.go                | 1 -
 pkg/compiler/binary_expr_test.go | 1 -
 2 files changed, 2 deletions(-)

diff --git a/cli/nep17_test.go b/cli/nep17_test.go
index cc85497ee..5f94c344f 100644
--- a/cli/nep17_test.go
+++ b/cli/nep17_test.go
@@ -99,7 +99,6 @@ func TestNEP17Balance(t *testing.T) {
 	t.Run("Bad wallet", func(t *testing.T) {
 		e.RunWithError(t, append(cmdbalance, "--wallet", "/dev/null")...)
 	})
-	return
 }
 
 func TestNEP17Transfer(t *testing.T) {
diff --git a/pkg/compiler/binary_expr_test.go b/pkg/compiler/binary_expr_test.go
index 0afb2bcc2..899beaf89 100644
--- a/pkg/compiler/binary_expr_test.go
+++ b/pkg/compiler/binary_expr_test.go
@@ -339,7 +339,6 @@ func TestBooleanExprs(t *testing.T) {
 			t.Run(triple[i].s, getBoolExprTestFunc(triple[i].val, triple[i].s))
 		}
 	})
-	return
 }
 
 func TestShortCircuit(t *testing.T) {

From 07cdbb815c1c8007a6de3df1726021c8109ff8ad Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 18:29:39 +0300
Subject: [PATCH 05/34] *: drop unnecessary fmt.Sprintf uses

gosimple: S1039: unnecessary use of fmt.Sprintf
---
 pkg/io/size.go         |  2 +-
 pkg/vm/cli/cli_test.go | 10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/pkg/io/size.go b/pkg/io/size.go
index 3075a77db..9ee40eeba 100644
--- a/pkg/io/size.go
+++ b/pkg/io/size.go
@@ -59,7 +59,7 @@ func GetVarSize(value interface{}) int {
 	case reflect.Ptr:
 		vser, ok := v.Interface().(Serializable)
 		if !ok {
-			panic(fmt.Sprintf("unable to calculate GetVarSize for a non-Serializable pointer"))
+			panic("unable to calculate GetVarSize for a non-Serializable pointer")
 		}
 		cw := counterWriter{}
 		w := NewBinWriterFromIO(&cw)
diff --git a/pkg/vm/cli/cli_test.go b/pkg/vm/cli/cli_test.go
index 477e996ec..7eb4a2abd 100644
--- a/pkg/vm/cli/cli_test.go
+++ b/pkg/vm/cli/cli_test.go
@@ -324,7 +324,7 @@ func TestLoadAbort(t *testing.T) {
 		"run",
 	)
 
-	e.checkNextLine(t, fmt.Sprintf("READY: loaded 2 instructions"))
+	e.checkNextLine(t, "READY: loaded 2 instructions")
 	e.checkNextLine(t, "Error:.*at instruction 1.*ABORT")
 }
 
@@ -349,7 +349,7 @@ func TestBreakpoint(t *testing.T) {
 	e.checkNextLine(t, "no program loaded")
 	e.checkNextLine(t, "no program loaded")
 	e.checkNextLine(t, "no program loaded")
-	e.checkNextLine(t, fmt.Sprintf("READY: loaded 5 instructions"))
+	e.checkNextLine(t, "READY: loaded 5 instructions")
 	e.checkError(t, ErrMissingParameter)
 	e.checkError(t, ErrInvalidParameter)
 	e.checkNextLine(t, "breakpoint added at instruction 2")
@@ -415,19 +415,19 @@ func TestStepIntoOverOut(t *testing.T) {
 		"loadhex "+script,
 		"step", "stepinto", "stepout", "run")
 
-	e.checkNextLine(t, fmt.Sprintf("READY: loaded \\d+ instructions"))
+	e.checkNextLine(t, "READY: loaded 8 instructions")
 	e.checkNextLine(t, "at breakpoint 1.*CALL")
 	e.checkNextLine(t, "instruction pointer at.*NOP")
 	e.checkStack(t, 5)
 
-	e.checkNextLine(t, fmt.Sprintf("READY: loaded \\d+ instructions"))
+	e.checkNextLine(t, "READY: loaded 8 instructions")
 	e.checkNextLine(t, "at breakpoint.*CALL")
 	e.checkNextLine(t, "instruction pointer at.*PUSH3")
 	e.checkNextLine(t, "at breakpoint.*ADD")
 	e.checkStack(t, 2, 3)
 	e.checkStack(t, 5)
 
-	e.checkNextLine(t, fmt.Sprintf("READY: loaded \\d+ instructions"))
+	e.checkNextLine(t, "READY: loaded 8 instructions")
 	e.checkNextLine(t, "at breakpoint 1.*CALL")
 	e.checkNextLine(t, "instruction pointer at.*PUSH3")
 	e.checkNextLine(t, "instruction pointer at.*NOP")

From 017859485048df586d403ba7301346739b7f998c Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 18:32:11 +0300
Subject: [PATCH 06/34] *: simpilfy make() invocations

gosimple: S1019: should use make([]byte, 64) instead
---
 pkg/core/blockchain_test.go                |  4 ++--
 pkg/network/payload/notary_request_test.go | 20 ++++++++++----------
 pkg/network/server_test.go                 |  2 +-
 pkg/rpc/server/server_test.go              |  4 ++--
 4 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/pkg/core/blockchain_test.go b/pkg/core/blockchain_test.go
index bec2d4a47..848c8e54d 100644
--- a/pkg/core/blockchain_test.go
+++ b/pkg/core/blockchain_test.go
@@ -1024,7 +1024,7 @@ func TestVerifyTx(t *testing.T) {
 				nativeprices.NotaryVerificationPrice*bc.GetBaseExecFee() // Notary witness verification price
 			tx.Scripts = []transaction.Witness{
 				{
-					InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64, 64)...),
+					InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...),
 					VerificationScript: []byte{},
 				},
 				{
@@ -1051,7 +1051,7 @@ func TestVerifyTx(t *testing.T) {
 			tx.NetworkFee-- // to check that NetworkFee was set correctly in getPartiallyFilledTx
 			tx.Scripts = []transaction.Witness{
 				{
-					InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64, 64)...),
+					InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...),
 					VerificationScript: []byte{},
 				},
 				{
diff --git a/pkg/network/payload/notary_request_test.go b/pkg/network/payload/notary_request_test.go
index e148ab9ba..8e0bc6ea0 100644
--- a/pkg/network/payload/notary_request_test.go
+++ b/pkg/network/payload/notary_request_test.go
@@ -45,21 +45,21 @@ func TestNotaryRequestIsValid(t *testing.T) {
 			MainTransaction: mainTx,
 			FallbackTransaction: &transaction.Transaction{
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 65}, make([]byte, 64, 64)...)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 65}, make([]byte, 64)...)}, {}},
 			},
 		},
 		"fallback tx: invalid dummy Notary witness (non-empty verification script))": {
 			MainTransaction: mainTx,
 			FallbackTransaction: &transaction.Transaction{
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64, 64)...), VerificationScript: make([]byte, 1, 1)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 1)}, {}},
 			},
 		},
 		"fallback tx: missing NotValidBefore attribute": {
 			MainTransaction: mainTx,
 			FallbackTransaction: &transaction.Transaction{
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64, 64)...), VerificationScript: make([]byte, 0)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {}},
 			},
 		},
 		"fallback tx: invalid number of Conflicts attributes": {
@@ -67,7 +67,7 @@ func TestNotaryRequestIsValid(t *testing.T) {
 			FallbackTransaction: &transaction.Transaction{
 				Attributes: []transaction.Attribute{{Type: transaction.NotValidBeforeT, Value: &transaction.NotValidBefore{Height: 123}}},
 				Signers:    []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts:    []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64, 64)...), VerificationScript: make([]byte, 0)}, {}},
+				Scripts:    []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {}},
 			},
 		},
 		"fallback tx: does not conflicts with main tx": {
@@ -78,7 +78,7 @@ func TestNotaryRequestIsValid(t *testing.T) {
 					{Type: transaction.ConflictsT, Value: &transaction.Conflicts{Hash: util.Uint256{}}},
 				},
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64, 64)...), VerificationScript: make([]byte, 0)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {}},
 			},
 		},
 		"fallback tx: missing NotaryAssisted attribute": {
@@ -89,7 +89,7 @@ func TestNotaryRequestIsValid(t *testing.T) {
 					{Type: transaction.ConflictsT, Value: &transaction.Conflicts{Hash: mainTx.Hash()}},
 				},
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64, 64)...), VerificationScript: make([]byte, 0)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {}},
 			},
 		},
 		"fallback tx: non-zero NKeys": {
@@ -101,7 +101,7 @@ func TestNotaryRequestIsValid(t *testing.T) {
 					{Type: transaction.NotaryAssistedT, Value: &transaction.NotaryAssisted{NKeys: 1}},
 				},
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64, 64)...), VerificationScript: make([]byte, 0)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {}},
 			},
 		},
 		"fallback tx: ValidUntilBlock mismatch": {
@@ -114,7 +114,7 @@ func TestNotaryRequestIsValid(t *testing.T) {
 					{Type: transaction.NotaryAssistedT, Value: &transaction.NotaryAssisted{NKeys: 0}},
 				},
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64, 64)...), VerificationScript: make([]byte, 0)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {}},
 			},
 		},
 	}
@@ -134,7 +134,7 @@ func TestNotaryRequestIsValid(t *testing.T) {
 					{Type: transaction.NotaryAssistedT, Value: &transaction.NotaryAssisted{NKeys: 0}},
 				},
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64, 64)...), VerificationScript: make([]byte, 0)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {}},
 			},
 		}
 		require.NoError(t, p.isValid())
@@ -164,7 +164,7 @@ func TestNotaryRequestBytesFromBytes(t *testing.T) {
 		},
 		Signers: []transaction.Signer{{Account: util.Uint160{1, 4, 7}}, {Account: util.Uint160{9, 8, 7}}},
 		Scripts: []transaction.Witness{
-			{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64, 64)...), VerificationScript: make([]byte, 0)},
+			{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)},
 			{InvocationScript: []byte{1, 2, 3}, VerificationScript: []byte{1, 2, 3}}},
 	}
 	_ = fallbackTx.Hash()
diff --git a/pkg/network/server_test.go b/pkg/network/server_test.go
index cf20c9a09..da1385430 100644
--- a/pkg/network/server_test.go
+++ b/pkg/network/server_test.go
@@ -535,7 +535,7 @@ func TestGetData(t *testing.T) {
 				{Type: transaction.NotaryAssistedT, Value: &transaction.NotaryAssisted{NKeys: 0}},
 			},
 			Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-			Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64, 64)...), VerificationScript: make([]byte, 0)}, {InvocationScript: []byte{}, VerificationScript: []byte{}}},
+			Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {InvocationScript: []byte{}, VerificationScript: []byte{}}},
 		}
 		fallbackTx.Size()
 		fallbackTx.Hash()
diff --git a/pkg/rpc/server/server_test.go b/pkg/rpc/server/server_test.go
index bd9df957b..fc06ebcc3 100644
--- a/pkg/rpc/server/server_test.go
+++ b/pkg/rpc/server/server_test.go
@@ -1088,7 +1088,7 @@ func TestSubmitNotaryRequest(t *testing.T) {
 			},
 			Signers: []transaction.Signer{{Account: util.Uint160{1, 4, 7}}, {Account: util.Uint160{9, 8, 7}}},
 			Scripts: []transaction.Witness{
-				{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64, 64)...), VerificationScript: make([]byte, 0)},
+				{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)},
 				{InvocationScript: []byte{1, 2, 3}, VerificationScript: []byte{1, 2, 3}}},
 		}
 		p := &payload.P2PNotaryRequest{
@@ -1126,7 +1126,7 @@ func TestSubmitNotaryRequest(t *testing.T) {
 			},
 			Signers: []transaction.Signer{{Account: chain.GetNotaryContractScriptHash()}, {Account: sender.GetScriptHash()}},
 			Scripts: []transaction.Witness{
-				{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64, 64)...), VerificationScript: []byte{}},
+				{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: []byte{}},
 			},
 			NetworkFee: 2_0000_0000,
 		}

From cf59bd878df0eabcfbfe1c091bd5556289d7fdf7 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 18:38:24 +0300
Subject: [PATCH 07/34] native: simplify escaping in regexp.MustCompile()

gosimple: S1007: should use raw string (`...`) with regexp.MustCompile to avoid having to escape twice
---
 pkg/core/native/name_service.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkg/core/native/name_service.go b/pkg/core/native/name_service.go
index d39d8e3c4..b2a950699 100644
--- a/pkg/core/native/name_service.go
+++ b/pkg/core/native/name_service.go
@@ -64,8 +64,8 @@ const (
 var (
 	// Lookahead is not supported by Go, but it is simple `(?=.{3,255}$)`,
 	// so we check name length explicitly.
-	nameRegex = regexp.MustCompile("^([a-z0-9]{1,62}\\.)+[a-z][a-z0-9]{0,15}$")
-	ipv4Regex = regexp.MustCompile("^(?:(?:25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\\.){3}(?:25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])$")
+	nameRegex = regexp.MustCompile(`^([a-z0-9]{1,62}\.)+[a-z][a-z0-9]{0,15}$`)
+	ipv4Regex = regexp.MustCompile(`^(?:(?:25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.){3}(?:25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])$`)
 	ipv6Regex = regexp.MustCompile("(?:^)(([0-9a-f]{1,4}:){7,7}[0-9a-f]{1,4}|([0-9a-f]{1,4}:){1,7}:|([0-9a-f]{1,4}:){1,6}:[0-9a-f]{1,4}|([0-9a-f]{1,4}:){1,5}(:[0-9a-f]{1,4}){1,2}|([0-9a-f]{1,4}:){1,4}(:[0-9a-f]{1,4}){1,3}|([0-9a-f]{1,4}:){1,3}(:[0-9a-f]{1,4}){1,4}|([0-9a-f]{1,4}:){1,2}(:[0-9a-f]{1,4}){1,5}|[0-9a-f]{1,4}:((:[0-9a-f]{1,4}){1,6})|:((:[0-9a-f]{1,4}){1,7}|:))$")
 	rootRegex = regexp.MustCompile("^[a-z][a-z0-9]{0,15}$")
 )

From bd48454c72ba350617770b76e6c919ab3155c277 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 18:40:41 +0300
Subject: [PATCH 08/34] mempool: simpilfy boolean comparisons in test code

gosimple: S1008: should use 'return t == tx2' instead of 'if t == tx2 { return true }; return false'
---
 pkg/core/mempool/mem_pool_test.go      | 10 ++--------
 pkg/core/mempool/subscriptions_test.go |  5 +----
 2 files changed, 3 insertions(+), 12 deletions(-)

diff --git a/pkg/core/mempool/mem_pool_test.go b/pkg/core/mempool/mem_pool_test.go
index 694ce8960..a7e73839e 100644
--- a/pkg/core/mempool/mem_pool_test.go
+++ b/pkg/core/mempool/mem_pool_test.go
@@ -298,10 +298,7 @@ func TestMemPoolFees(t *testing.T) {
 
 	// check whether sender's fee updates correctly
 	mp.RemoveStale(func(t *transaction.Transaction) bool {
-		if t == tx2 {
-			return true
-		}
-		return false
+		return t == tx2
 	}, fs)
 	require.Equal(t, 1, len(mp.fees))
 	require.Equal(t, utilityBalanceAndFees{
@@ -311,10 +308,7 @@ func TestMemPoolFees(t *testing.T) {
 
 	// there should be nothing left
 	mp.RemoveStale(func(t *transaction.Transaction) bool {
-		if t == tx3 {
-			return true
-		}
-		return false
+		return t == tx3
 	}, fs)
 	require.Equal(t, 0, len(mp.fees))
 }
diff --git a/pkg/core/mempool/subscriptions_test.go b/pkg/core/mempool/subscriptions_test.go
index 67557455f..a2fb3a91f 100644
--- a/pkg/core/mempool/subscriptions_test.go
+++ b/pkg/core/mempool/subscriptions_test.go
@@ -75,10 +75,7 @@ func TestSubscriptions(t *testing.T) {
 
 		// remove stale
 		mp.RemoveStale(func(tx *transaction.Transaction) bool {
-			if tx.Hash().Equals(txs[2].Hash()) {
-				return false
-			}
-			return true
+			return !tx.Hash().Equals(txs[2].Hash())
 		}, fs)
 		require.Eventually(t, func() bool { return len(subChan1) == 1 && len(subChan2) == 1 }, time.Second, time.Millisecond*100)
 		event1 = <-subChan1

From 7af67d2a3cbe9bed7a6b109bebe2a26ea069c25b Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 18:42:50 +0300
Subject: [PATCH 09/34] vm/cli: simplify buffer-related code

gosimple: S1030: should use buf.String() instead of string(buf.Bytes())
---
 pkg/vm/cli/cli.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkg/vm/cli/cli.go b/pkg/vm/cli/cli.go
index 3e3495dd1..99988f280 100644
--- a/pkg/vm/cli/cli.go
+++ b/pkg/vm/cli/cli.go
@@ -589,7 +589,7 @@ func Parse(args []string) (string, error) {
 	if err := w.Flush(); err != nil {
 		return "", err
 	}
-	return string(buf.Bytes()), nil
+	return buf.String(), nil
 }
 
 func parseArgs(args []string) ([]stackitem.Item, error) {

From de5e61588d1206cfd65f2473dd7a35275112182b Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 18:44:35 +0300
Subject: [PATCH 10/34] vm: simplify some test code

gosimple: S1017: should replace this `if` statement with an unconditional `strings.TrimPrefix`
---
 pkg/vm/json_test.go | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/pkg/vm/json_test.go b/pkg/vm/json_test.go
index f5f85695c..fd3f87860 100644
--- a/pkg/vm/json_test.go
+++ b/pkg/vm/json_test.go
@@ -454,8 +454,6 @@ func decodeBytes(data []byte) ([]byte, error) {
 }
 
 func decodeHex(s string) ([]byte, error) {
-	if strings.HasPrefix(s, "0x") {
-		s = s[2:]
-	}
+	s = strings.TrimPrefix(s, "0x")
 	return hex.DecodeString(s)
 }

From 92dbb3c4b97431d8a1a3a00f308a2a71129d20d7 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 18:53:12 +0300
Subject: [PATCH 11/34] *: fix all `unused` warnings

From golangci-lint.
---
 pkg/compiler/codegen.go            | 27 ---------------------------
 pkg/core/mpt/batch_test.go         |  2 ++
 pkg/core/native/name_service.go    | 11 -----------
 pkg/core/native/nonfungible.go     |  2 ++
 pkg/services/oracle/transaction.go | 12 ------------
 5 files changed, 4 insertions(+), 50 deletions(-)

diff --git a/pkg/compiler/codegen.go b/pkg/compiler/codegen.go
index 6bb8b2c62..f80311da5 100644
--- a/pkg/compiler/codegen.go
+++ b/pkg/compiler/codegen.go
@@ -1521,33 +1521,6 @@ func getJumpForToken(tok token.Token, typ types.Type) (opcode.Opcode, bool) {
 	return 0, false
 }
 
-// getByteArray returns byte array value from constant expr.
-// Only literals are supported.
-func (c *codegen) getByteArray(expr ast.Expr) []byte {
-	switch t := expr.(type) {
-	case *ast.CompositeLit:
-		if !isByteSlice(c.typeOf(t.Type)) {
-			return nil
-		}
-		buf := make([]byte, len(t.Elts))
-		for i := 0; i < len(t.Elts); i++ {
-			t := c.typeAndValueOf(t.Elts[i])
-			val, _ := constant.Int64Val(t.Value)
-			buf[i] = byte(val)
-		}
-		return buf
-	case *ast.CallExpr:
-		if tv := c.typeAndValueOf(t.Args[0]); tv.Value != nil {
-			val := constant.StringVal(tv.Value)
-			return []byte(val)
-		}
-
-		return nil
-	default:
-		return nil
-	}
-}
-
 func (c *codegen) convertSyscall(f *funcScope, expr *ast.CallExpr) {
 	for _, arg := range expr.Args[1:] {
 		ast.Walk(c, arg)
diff --git a/pkg/core/mpt/batch_test.go b/pkg/core/mpt/batch_test.go
index eebc21caa..dffb4b9ae 100644
--- a/pkg/core/mpt/batch_test.go
+++ b/pkg/core/mpt/batch_test.go
@@ -277,6 +277,8 @@ func TestTrie_PutBatch(t *testing.T) {
 	testPut(t, ps, tr1, tr2)
 }
 
+var _ = printNode
+
 // This function is unused, but is helpful for debugging
 // as it provides more readable Trie representation compared to
 // `spew.Dump()`
diff --git a/pkg/core/native/name_service.go b/pkg/core/native/name_service.go
index b2a950699..0044624d3 100644
--- a/pkg/core/native/name_service.go
+++ b/pkg/core/native/name_service.go
@@ -711,17 +711,6 @@ func (sl stringList) index(s string) (int, bool) {
 	return index, index < len(sl) && sl[index] == s
 }
 
-func (sl *stringList) remove(s string) bool {
-	index, has := sl.index(s)
-	if !has {
-		return false
-	}
-
-	copy((*sl)[index:], (*sl)[index+1:])
-	*sl = (*sl)[:len(*sl)-1]
-	return true
-}
-
 func (sl *stringList) add(s string) bool {
 	index, has := sl.index(s)
 	if has {
diff --git a/pkg/core/native/nonfungible.go b/pkg/core/native/nonfungible.go
index 03cd67ef7..4288824f7 100644
--- a/pkg/core/native/nonfungible.go
+++ b/pkg/core/native/nonfungible.go
@@ -305,6 +305,8 @@ func (n *nonfungible) postTransfer(ic *interop.Context, from, to *util.Uint160,
 	}
 }
 
+var _ = (*nonfungible).burn // fix unused warning
+
 func (n *nonfungible) burn(ic *interop.Context, tokenID []byte) {
 	key := n.getTokenKey(tokenID)
 	n.burnByKey(ic, key)
diff --git a/pkg/services/oracle/transaction.go b/pkg/services/oracle/transaction.go
index 6e38b8416..b76552f28 100644
--- a/pkg/services/oracle/transaction.go
+++ b/pkg/services/oracle/transaction.go
@@ -117,15 +117,3 @@ func finalizeTx(oracleNodes keys.PublicKeys, tx *transaction.Transaction, txSigs
 	tx.Scripts[1].InvocationScript = w.Bytes()
 	return true
 }
-
-func (t *incompleteTx) getRequest() *state.OracleRequest {
-	t.RLock()
-	defer t.RUnlock()
-	return t.request
-}
-
-func (t *incompleteTx) getTime() time.Time {
-	t.RLock()
-	defer t.RUnlock()
-	return t.time
-}

From 333f778aa623e437098e1e5fb768be242a9a2582 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 19:10:31 +0300
Subject: [PATCH 12/34] *: drop empty branches

Fix this warning from staticcheck: SA9003: empty branch
---
 pkg/core/fee/calculate.go | 4 ++--
 pkg/rpc/client/client.go  | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/pkg/core/fee/calculate.go b/pkg/core/fee/calculate.go
index 7a64caa2a..c15874932 100644
--- a/pkg/core/fee/calculate.go
+++ b/pkg/core/fee/calculate.go
@@ -25,9 +25,9 @@ func Calculate(base int64, script []byte) (int64, int) {
 		size += io.GetVarSize(sizeInv) + sizeInv + io.GetVarSize(script)
 		netFee += calculateMultisig(base, m) + calculateMultisig(base, n)
 		netFee += base * ECDSAVerifyPrice * int64(n)
-	} else {
+	} /*else {
 		// We can support more contract types in the future.
-	}
+	}*/
 	return netFee, size
 }
 
diff --git a/pkg/rpc/client/client.go b/pkg/rpc/client/client.go
index d112ef33c..4623a9070 100644
--- a/pkg/rpc/client/client.go
+++ b/pkg/rpc/client/client.go
@@ -91,8 +91,8 @@ func New(ctx context.Context, endpoint string, opts Options) (*Client, error) {
 	}
 
 	// TODO(@antdm): Enable SSL.
-	if opts.Cert != "" && opts.Key != "" {
-	}
+	//	if opts.Cert != "" && opts.Key != "" {
+	//	}
 
 	cl := &Client{
 		ctx:      ctx,

From b8ba923874736f3df8dee82f356300c64cf6a538 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 19:12:09 +0300
Subject: [PATCH 13/34] standard: improve testing code

staticcheck: SA4021: x = append(y) is equivalent to x = y
---
 pkg/smartcontract/manifest/standard/comply_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkg/smartcontract/manifest/standard/comply_test.go b/pkg/smartcontract/manifest/standard/comply_test.go
index 159815cc0..0d218c536 100644
--- a/pkg/smartcontract/manifest/standard/comply_test.go
+++ b/pkg/smartcontract/manifest/standard/comply_test.go
@@ -60,7 +60,7 @@ func TestComplyMethodParameterCount(t *testing.T) {
 	t.Run("Event", func(t *testing.T) {
 		m := fooMethodBarEvent()
 		ev := m.ABI.GetEvent("bar")
-		ev.Parameters = append(ev.Parameters[:0])
+		ev.Parameters = ev.Parameters[:0]
 		err := Comply(m, &Standard{Manifest: *fooMethodBarEvent()})
 		require.True(t, errors.Is(err, ErrInvalidParameterCount))
 	})

From d15cacc1baba50f27c4ab2a0d7c394a1a8bafa1f Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 19:15:21 +0300
Subject: [PATCH 14/34] rpc/client: fix broken test code

SA1024: cutset contains duplicate characters (staticcheck)
---
 pkg/rpc/client/wsclient_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkg/rpc/client/wsclient_test.go b/pkg/rpc/client/wsclient_test.go
index 84ba6602a..61b1cd9c7 100644
--- a/pkg/rpc/client/wsclient_test.go
+++ b/pkg/rpc/client/wsclient_test.go
@@ -344,7 +344,7 @@ func TestNewWS(t *testing.T) {
 		require.NoError(t, c.Init())
 	})
 	t.Run("bad URL", func(t *testing.T) {
-		_, err := NewWS(context.TODO(), strings.Trim(srv.URL, "http://"), Options{})
+		_, err := NewWS(context.TODO(), strings.TrimPrefix(srv.URL, "http://"), Options{})
 		require.Error(t, err)
 	})
 }

From b5ff87c2bdf5807a3e66703a9483ef16dd5644fb Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 19:27:02 +0300
Subject: [PATCH 15/34] native: fix minimum deployment fee setting

SA4003: no value of type uint32 is less than 0 (staticcheck)

But it's more involved than that, we should allow any positive big.Int here.
---
 pkg/core/native/management.go | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/pkg/core/native/management.go b/pkg/core/native/management.go
index 6b73c2528..2a1bc77d5 100644
--- a/pkg/core/native/management.go
+++ b/pkg/core/native/management.go
@@ -409,14 +409,14 @@ func (m *Management) GetMinimumDeploymentFee(dao dao.DAO) int64 {
 }
 
 func (m *Management) setMinimumDeploymentFee(ic *interop.Context, args []stackitem.Item) stackitem.Item {
-	value := toUint32(args[0])
-	if value < 0 {
-		panic(fmt.Errorf("MinimumDeploymentFee cannot be negative"))
+	value := toBigInt(args[0])
+	if value.Sign() < 0 {
+		panic("MinimumDeploymentFee cannot be negative")
 	}
 	if !m.NEO.checkCommittee(ic) {
 		panic("invalid committee signature")
 	}
-	err := setIntWithKey(m.ID, ic.DAO, keyMinimumDeploymentFee, int64(value))
+	err := ic.DAO.PutStorageItem(m.ID, keyMinimumDeploymentFee, bigint.ToBytes(value))
 	if err != nil {
 		panic(err)
 	}

From 78bf1721084800cd17813272ac06606f3bd04761 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 19:29:45 +0300
Subject: [PATCH 16/34] network: drop some not really useful test code

SA4010: this result of append is never used, except maybe in other appends (staticcheck)
---
 pkg/network/discovery_test.go | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/pkg/network/discovery_test.go b/pkg/network/discovery_test.go
index 9c8fb1aad..83464a26f 100644
--- a/pkg/network/discovery_test.go
+++ b/pkg/network/discovery_test.go
@@ -197,12 +197,10 @@ func TestSeedDiscovery(t *testing.T) {
 	d := NewDefaultDiscovery(seeds, time.Second/10, ts)
 
 	d.RequestRemote(len(seeds))
-	dialled := make([]string, 0)
 	for i := 0; i < connRetries*2; i++ {
 		for range seeds {
 			select {
-			case a := <-ts.dialCh:
-				dialled = append(dialled, a)
+			case <-ts.dialCh:
 			case <-time.After(time.Second):
 				t.Fatalf("timeout expecting for transport dial")
 			}

From ec50bb4041bfa4f4400e4af778595884e4b72b23 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 19:33:27 +0300
Subject: [PATCH 17/34] cli/wallet: fix error handling

ineffectual assignment to err (ineffassign)

`err` is shadowed at `tx, err = c.CreateNEP11TransferTx()` line.
---
 cli/wallet/nep11.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/cli/wallet/nep11.go b/cli/wallet/nep11.go
index 322cbc6d0..fe92ce857 100644
--- a/cli/wallet/nep11.go
+++ b/cli/wallet/nep11.go
@@ -243,7 +243,9 @@ func signAndSendNEP11Transfer(ctx *cli.Context, c *client.Client, acc *wallet.Ac
 		err error
 	)
 	if amount != nil {
-		from, err := address.StringToUint160(acc.Address)
+		var from util.Uint160
+
+		from, err = address.StringToUint160(acc.Address)
 		if err != nil {
 			return cli.NewExitError(fmt.Errorf("bad account address: %w", err), 1)
 		}

From 4cd3da99b429f66845ac35312e4170bda8b5d1c1 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 19:37:14 +0300
Subject: [PATCH 18/34] core: fix ineffassign warning in test code

ineffectual assignment to err (ineffassign)
---
 pkg/core/blockchain_test.go       | 1 +
 pkg/core/native_designate_test.go | 4 ++--
 pkg/core/stateroot_test.go        | 2 ++
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/pkg/core/blockchain_test.go b/pkg/core/blockchain_test.go
index 848c8e54d..3bbf4b043 100644
--- a/pkg/core/blockchain_test.go
+++ b/pkg/core/blockchain_test.go
@@ -238,6 +238,7 @@ func TestGetBlock(t *testing.T) {
 		t.Run("non-empty block", func(t *testing.T) {
 			tx, err := testchain.NewTransferFromOwner(bc, bc.contracts.NEO.Hash,
 				random.Uint160(), 1, 1, 1000)
+			require.NoError(t, err)
 			b := bc.newBlock(tx)
 			require.NoError(t, bc.AddHeaders(&b.Header))
 
diff --git a/pkg/core/native_designate_test.go b/pkg/core/native_designate_test.go
index f66d464fc..6f8bacb7f 100644
--- a/pkg/core/native_designate_test.go
+++ b/pkg/core/native_designate_test.go
@@ -130,10 +130,10 @@ func TestDesignate_DesignateAsRole(t *testing.T) {
 	ic.SpawnVM()
 	ic.VM.LoadScript([]byte{byte(opcode.RET)})
 
-	pubs, index, err := des.GetDesignatedByRole(bc.dao, 0xFF, 255)
+	_, _, err := des.GetDesignatedByRole(bc.dao, 0xFF, 255)
 	require.True(t, errors.Is(err, native.ErrInvalidRole), "got: %v", err)
 
-	pubs, index, err = des.GetDesignatedByRole(bc.dao, noderoles.Oracle, 255)
+	pubs, index, err := des.GetDesignatedByRole(bc.dao, noderoles.Oracle, 255)
 	require.NoError(t, err)
 	require.Equal(t, 0, len(pubs))
 	require.Equal(t, uint32(0), index)
diff --git a/pkg/core/stateroot_test.go b/pkg/core/stateroot_test.go
index fafdc0c82..39df0e959 100644
--- a/pkg/core/stateroot_test.go
+++ b/pkg/core/stateroot_test.go
@@ -215,6 +215,7 @@ func TestStateRootFull(t *testing.T) {
 	require.Eventually(t, func() bool { return lastHeight.Load() == 2 }, time.Second, time.Millisecond)
 	checkVoteBroadcasted(t, bc, lastValidated.Load().(*payload.Extensible), 2, 1)
 	_, err = persistBlock(bc)
+	require.NoError(t, err)
 	require.Eventually(t, func() bool { return lastHeight.Load() == 3 }, time.Second, time.Millisecond)
 	checkVoteBroadcasted(t, bc, lastValidated.Load().(*payload.Extensible), 3, 1)
 
@@ -257,6 +258,7 @@ func checkVoteBroadcasted(t *testing.T, bc *Blockchain, p *payload.Extensible,
 	require.Equal(t, int32(valIndex), vote.ValidatorIndex)
 
 	pubs, _, err := bc.contracts.Designate.GetDesignatedByRole(bc.dao, noderoles.StateValidator, bc.BlockHeight())
+	require.NoError(t, err)
 	require.True(t, len(pubs) > int(valIndex))
 	require.True(t, pubs[valIndex].VerifyHashable(vote.Signature, uint32(netmode.UnitTestNet), r))
 }

From 601841ef35a395860a8f22534f78a162a6071571 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 19:41:23 +0300
Subject: [PATCH 19/34] *: drop unused structure fields

Found by structcheck:
 `good` is unused (structcheck)
and alike.
---
 pkg/compiler/vars.go       | 1 -
 pkg/network/helper_test.go | 1 -
 pkg/network/tcp_peer.go    | 2 --
 pkg/rpc/server/server.go   | 1 -
 4 files changed, 5 deletions(-)

diff --git a/pkg/compiler/vars.go b/pkg/compiler/vars.go
index 4753d56f8..7b21151a4 100644
--- a/pkg/compiler/vars.go
+++ b/pkg/compiler/vars.go
@@ -6,7 +6,6 @@ import (
 
 type varScope struct {
 	localsCnt int
-	argCnt    int
 	arguments map[string]int
 	locals    []map[string]varInfo
 }
diff --git a/pkg/network/helper_test.go b/pkg/network/helper_test.go
index 0be730bb1..4a1779a78 100644
--- a/pkg/network/helper_test.go
+++ b/pkg/network/helper_test.go
@@ -19,7 +19,6 @@ import (
 type testDiscovery struct {
 	sync.Mutex
 	bad          []string
-	good         []string
 	connected    []string
 	unregistered []string
 	backfill     []string
diff --git a/pkg/network/tcp_peer.go b/pkg/network/tcp_peer.go
index d0ba1c576..85678d297 100644
--- a/pkg/network/tcp_peer.go
+++ b/pkg/network/tcp_peer.go
@@ -58,8 +58,6 @@ type TCPPeer struct {
 	p2pSendQ chan []byte
 	hpSendQ  chan []byte
 
-	wg sync.WaitGroup
-
 	// track outstanding getaddr requests.
 	getAddrSent atomic.Int32
 
diff --git a/pkg/rpc/server/server.go b/pkg/rpc/server/server.go
index 4d65a437e..ab3e5bca7 100644
--- a/pkg/rpc/server/server.go
+++ b/pkg/rpc/server/server.go
@@ -59,7 +59,6 @@ type (
 
 		subsLock         sync.RWMutex
 		subscribers      map[*subscriber]bool
-		subsGroup        sync.WaitGroup
 		blockSubs        int
 		executionSubs    int
 		notificationSubs int

From 99108c620f6838ce14a164331c9b38edeac6c4d7 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 20:14:35 +0300
Subject: [PATCH 20/34] network: fix errcheck warning

---
 pkg/network/server.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkg/network/server.go b/pkg/network/server.go
index 3e5d00808..2303b5be9 100644
--- a/pkg/network/server.go
+++ b/pkg/network/server.go
@@ -862,7 +862,7 @@ func (s *Server) handleP2PNotaryRequestCmd(r *payload.P2PNotaryRequest) error {
 	}
 	// It's OK for it to fail for various reasons like request already existing
 	// in the pool.
-	s.RelayP2PNotaryRequest(r)
+	_ = s.RelayP2PNotaryRequest(r)
 	return nil
 }
 

From 4caff35e73083945a1751b15c95dea35d98f0835 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 20:14:52 +0300
Subject: [PATCH 21/34] consensus: fix error checking in decoders

Spotted by errcheck.
---
 pkg/consensus/consensus.go | 15 ++++++---------
 pkg/consensus/payload.go   |  4 +++-
 2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/pkg/consensus/consensus.go b/pkg/consensus/consensus.go
index b6cb8cc07..9bb26483a 100644
--- a/pkg/consensus/consensus.go
+++ b/pkg/consensus/consensus.go
@@ -373,7 +373,12 @@ func (s *service) payloadFromExtensible(ep *npayload.Extensible) *Payload {
 func (s *service) OnPayload(cp *npayload.Extensible) {
 	log := s.log.With(zap.Stringer("hash", cp.Hash()))
 	p := s.payloadFromExtensible(cp)
-	p.decodeData()
+	// decode payload data into message
+	if err := p.decodeData(); err != nil {
+		log.Info("can't decode payload data", zap.Error(err))
+		return
+	}
+
 	if !s.validatePayload(p) {
 		log.Info("can't validate payload")
 		return
@@ -384,14 +389,6 @@ func (s *service) OnPayload(cp *npayload.Extensible) {
 		return
 	}
 
-	// decode payload data into message
-	if p.message.payload == nil {
-		if err := p.decodeData(); err != nil {
-			log.Info("can't decode payload data")
-			return
-		}
-	}
-
 	s.messages <- *p
 }
 
diff --git a/pkg/consensus/payload.go b/pkg/consensus/payload.go
index f06d0a54c..2d17938ea 100644
--- a/pkg/consensus/payload.go
+++ b/pkg/consensus/payload.go
@@ -151,7 +151,9 @@ func (p *Payload) Hash() util.Uint256 {
 // DecodeBinary implements io.Serializable interface.
 func (p *Payload) DecodeBinary(r *io.BinReader) {
 	p.Extensible.DecodeBinary(r)
-	p.decodeData()
+	if r.Err == nil {
+		r.Err = p.decodeData()
+	}
 }
 
 // EncodeBinary implements io.Serializable interface.

From f1f30fd0c51bb6ec225aca1bdea0d24d8492afc9 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 20:18:11 +0300
Subject: [PATCH 22/34] gendump: fix errcheck warning

scripts/gendump/main.go:95:13: Error return value of `rand.Read` is not checked (errcheck)
                        rand.Read(key)
                                 ^
scripts/gendump/main.go:96:13: Error return value of `rand.Read` is not checked (errcheck)
                        rand.Read(value)
                                 ^
---
 scripts/gendump/main.go | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/scripts/gendump/main.go b/scripts/gendump/main.go
index 879059726..15712d532 100644
--- a/scripts/gendump/main.go
+++ b/scripts/gendump/main.go
@@ -92,8 +92,10 @@ func main() {
 		txs := make([]*transaction.Transaction, txNum)
 		for j := 0; j < txNum; j++ {
 			nonce++
-			rand.Read(key)
-			rand.Read(value)
+			_, err = rand.Read(key)
+			handleError("can't get random data for key", err)
+			_, err = rand.Read(value)
+			handleError("can't get random data for value", err)
 
 			w := io.NewBufBinWriter()
 			emit.AppCall(w.BinWriter, contractHash, "put", callflag.All, key, value)

From 0500c8f9d72d7524ceb47026a46896a02c975ed5 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 20:19:24 +0300
Subject: [PATCH 23/34] cli/wallet: fix error handling

cli/wallet/wallet.go:527:19: Error return value of `cli.NewExitError` is not checked (errcheck)
                cli.NewExitError("valid account address must be provided", 1)
---
 cli/wallet/wallet.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cli/wallet/wallet.go b/cli/wallet/wallet.go
index 82e165925..89df95be0 100644
--- a/cli/wallet/wallet.go
+++ b/cli/wallet/wallet.go
@@ -524,7 +524,7 @@ func removeAccount(ctx *cli.Context) error {
 
 	addr := ctx.Generic("address").(*flags.Address)
 	if !addr.IsSet {
-		cli.NewExitError("valid account address must be provided", 1)
+		return cli.NewExitError("valid account address must be provided", 1)
 	}
 	acc := wall.GetAccount(addr.Uint160())
 	if acc == nil {

From e9cefc4bfc3ce92bb1d724659e339737f645a389 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 21:34:07 +0300
Subject: [PATCH 24/34] *: fix all errcheck warnings in testing code

---
 cli/contract_test.go                     |  3 ++-
 cli/server/server_test.go                | 24 ++++++++++++-------
 cli/smartcontract/smart_contract_test.go |  6 +++--
 pkg/core/native/management_test.go       |  3 ++-
 pkg/core/native_neo_test.go              |  3 ++-
 pkg/core/native_notary_test.go           |  3 ++-
 pkg/core/notary_test.go                  |  3 ++-
 pkg/rpc/client/rpc_test.go               |  6 +++--
 pkg/rpc/client/wsclient_test.go          |  9 ++++---
 pkg/rpc/server/client_test.go            | 30 +++++++++++++-----------
 pkg/rpc/server/server_test.go            | 14 ++++++-----
 pkg/rpc/server/subscription_test.go      | 26 ++++++++++----------
 12 files changed, 78 insertions(+), 52 deletions(-)

diff --git a/cli/contract_test.go b/cli/contract_test.go
index 0dd20b12a..06bcf8551 100644
--- a/cli/contract_test.go
+++ b/cli/contract_test.go
@@ -403,7 +403,8 @@ func TestComlileAndInvokeFunction(t *testing.T) {
 			require.NoError(t, err)
 			pk, err := keys.NewPrivateKey()
 			require.NoError(t, err)
-			acc.ConvertMultisig(2, keys.PublicKeys{acc.PrivateKey().PublicKey(), pk.PublicKey()})
+			err = acc.ConvertMultisig(2, keys.PublicKeys{acc.PrivateKey().PublicKey(), pk.PublicKey()})
+			require.NoError(t, err)
 
 			t.Run("cosigner is multisig account", func(t *testing.T) {
 				t.Run("missing in the wallet", func(t *testing.T) {
diff --git a/cli/server/server_test.go b/cli/server/server_test.go
index 5f0184550..f3bb25fee 100644
--- a/cli/server/server_test.go
+++ b/cli/server/server_test.go
@@ -62,9 +62,11 @@ func TestHandleLoggingParams(t *testing.T) {
 func TestInitBCWithMetrics(t *testing.T) {
 	d, err := ioutil.TempDir("./", "")
 	require.NoError(t, err)
-	os.Chdir(d)
+	err = os.Chdir(d)
+	require.NoError(t, err)
 	t.Cleanup(func() {
-		os.Chdir("..")
+		err = os.Chdir("..")
+		require.NoError(t, err)
 		os.RemoveAll(d)
 	})
 
@@ -91,9 +93,11 @@ func TestDumpDB(t *testing.T) {
 	t.Run("too low chain", func(t *testing.T) {
 		d, err := ioutil.TempDir("./", "")
 		require.NoError(t, err)
-		os.Chdir(d)
+		err = os.Chdir(d)
+		require.NoError(t, err)
 		t.Cleanup(func() {
-			os.Chdir("..")
+			err = os.Chdir("..")
+			require.NoError(t, err)
 			os.RemoveAll(d)
 		})
 		testDump := "file.acc"
@@ -112,9 +116,11 @@ func TestDumpDB(t *testing.T) {
 	t.Run("positive", func(t *testing.T) {
 		d, err := ioutil.TempDir("./", "")
 		require.NoError(t, err)
-		os.Chdir(d)
+		err = os.Chdir(d)
+		require.NoError(t, err)
 		t.Cleanup(func() {
-			os.Chdir("..")
+			err = os.Chdir("..")
+			require.NoError(t, err)
 			os.RemoveAll(d)
 		})
 		testDump := "file.acc"
@@ -136,9 +142,11 @@ func TestRestoreDB(t *testing.T) {
 	require.NoError(t, err)
 	testDump := "file1.acc"
 	saveDump := "file2.acc"
-	os.Chdir(d)
+	err = os.Chdir(d)
+	require.NoError(t, err)
 	t.Cleanup(func() {
-		os.Chdir("..")
+		err = os.Chdir("..")
+		require.NoError(t, err)
 		os.RemoveAll(d)
 	})
 
diff --git a/cli/smartcontract/smart_contract_test.go b/cli/smartcontract/smart_contract_test.go
index 3dfbb298c..a85b8eff2 100644
--- a/cli/smartcontract/smart_contract_test.go
+++ b/cli/smartcontract/smart_contract_test.go
@@ -13,9 +13,11 @@ import (
 func TestInitSmartContract(t *testing.T) {
 	d, err := ioutil.TempDir("./", "")
 	require.NoError(t, err)
-	os.Chdir(d)
+	err = os.Chdir(d)
+	require.NoError(t, err)
 	t.Cleanup(func() {
-		os.Chdir("..")
+		err = os.Chdir("..")
+		require.NoError(t, err)
 		os.RemoveAll(d)
 	})
 	contractName := "testContract"
diff --git a/pkg/core/native/management_test.go b/pkg/core/native/management_test.go
index d8e619fe1..fedb9ed0e 100644
--- a/pkg/core/native/management_test.go
+++ b/pkg/core/native/management_test.go
@@ -18,7 +18,8 @@ import (
 func TestDeployGetUpdateDestroyContract(t *testing.T) {
 	mgmt := newManagement()
 	d := dao.NewCached(dao.NewSimple(storage.NewMemoryStore(), false))
-	mgmt.Initialize(&interop.Context{DAO: d})
+	err := mgmt.Initialize(&interop.Context{DAO: d})
+	require.NoError(t, err)
 	script := []byte{byte(opcode.RET)}
 	sender := util.Uint160{1, 2, 3}
 	ne, err := nef.NewFile(script)
diff --git a/pkg/core/native_neo_test.go b/pkg/core/native_neo_test.go
index b085ba824..19207137b 100644
--- a/pkg/core/native_neo_test.go
+++ b/pkg/core/native_neo_test.go
@@ -122,7 +122,8 @@ func TestNEO_Vote(t *testing.T) {
 	ic.VM.Load(priv.PublicKey().GetVerificationScript())
 	require.NoError(t, neo.VoteInternal(ic, h, candidates[0]))
 
-	ic.DAO.Persist()
+	_, err = ic.DAO.Persist()
+	require.NoError(t, err)
 	advanceChain(t)
 	pubs, err = neo.ComputeNextBlockValidators(bc, ic.DAO)
 	require.NoError(t, err)
diff --git a/pkg/core/native_notary_test.go b/pkg/core/native_notary_test.go
index 1eed3a19c..22d17f1e7 100644
--- a/pkg/core/native_notary_test.go
+++ b/pkg/core/native_notary_test.go
@@ -208,7 +208,8 @@ func TestNotaryContractPipeline(t *testing.T) {
 	checkResult(t, balance, stackitem.Make(3*transaction.NotaryServiceFeePerKey))
 
 	// `withdraw`: unlock deposit and transfer GAS back to owner
-	chain.genBlocks(depositLock)
+	_, err = chain.genBlocks(depositLock)
+	require.NoError(t, err)
 	withdrawRes, err = invokeContractMethod(chain, 100000000, notaryHash, "withdraw", testchain.MultisigScriptHash(), testchain.MultisigScriptHash())
 	require.NoError(t, err)
 	checkResult(t, withdrawRes, stackitem.NewBool(true))
diff --git a/pkg/core/notary_test.go b/pkg/core/notary_test.go
index 35c18fa50..ebdea6f0d 100644
--- a/pkg/core/notary_test.go
+++ b/pkg/core/notary_test.go
@@ -145,7 +145,8 @@ func TestNotary(t *testing.T) {
 				VerificationScript: []byte{},
 			},
 		}
-		requester.SignTx(testchain.Network(), fallback)
+		err = requester.SignTx(testchain.Network(), fallback)
+		require.NoError(t, err)
 		return fallback
 	}
 
diff --git a/pkg/rpc/client/rpc_test.go b/pkg/rpc/client/rpc_test.go
index 3d7cde863..ea74a0276 100644
--- a/pkg/rpc/client/rpc_test.go
+++ b/pkg/rpc/client/rpc_test.go
@@ -1539,7 +1539,8 @@ func initTestServer(t *testing.T, resp string) *httptest.Server {
 			ws, err := upgrader.Upgrade(w, req, nil)
 			require.NoError(t, err)
 			for {
-				ws.SetReadDeadline(time.Now().Add(2 * time.Second))
+				err = ws.SetReadDeadline(time.Now().Add(2 * time.Second))
+				require.NoError(t, err)
 				_, p, err := ws.ReadMessage()
 				if err != nil {
 					break
@@ -1550,7 +1551,8 @@ func initTestServer(t *testing.T, resp string) *httptest.Server {
 					t.Fatalf("Cannot decode request body: %s", req.Body)
 				}
 				response := wrapInitResponse(r, resp)
-				ws.SetWriteDeadline(time.Now().Add(2 * time.Second))
+				err = ws.SetWriteDeadline(time.Now().Add(2 * time.Second))
+				require.NoError(t, err)
 				err = ws.WriteMessage(1, []byte(response))
 				if err != nil {
 					break
diff --git a/pkg/rpc/client/wsclient_test.go b/pkg/rpc/client/wsclient_test.go
index 61b1cd9c7..24b2dc4a8 100644
--- a/pkg/rpc/client/wsclient_test.go
+++ b/pkg/rpc/client/wsclient_test.go
@@ -128,7 +128,8 @@ func TestWSClientEvents(t *testing.T) {
 			ws, err := upgrader.Upgrade(w, req, nil)
 			require.NoError(t, err)
 			for _, event := range events {
-				ws.SetWriteDeadline(time.Now().Add(2 * time.Second))
+				err = ws.SetWriteDeadline(time.Now().Add(2 * time.Second))
+				require.NoError(t, err)
 				err = ws.WriteMessage(1, []byte(event))
 				if err != nil {
 					break
@@ -313,14 +314,16 @@ func TestWSFilteredSubscriptions(t *testing.T) {
 					var upgrader = websocket.Upgrader{}
 					ws, err := upgrader.Upgrade(w, req, nil)
 					require.NoError(t, err)
-					ws.SetReadDeadline(time.Now().Add(2 * time.Second))
+					err = ws.SetReadDeadline(time.Now().Add(2 * time.Second))
+					require.NoError(t, err)
 					req := request.In{}
 					err = ws.ReadJSON(&req)
 					require.NoError(t, err)
 					params, err := req.Params()
 					require.NoError(t, err)
 					c.serverCode(t, params)
-					ws.SetWriteDeadline(time.Now().Add(2 * time.Second))
+					err = ws.SetWriteDeadline(time.Now().Add(2 * time.Second))
+					require.NoError(t, err)
 					err = ws.WriteMessage(1, []byte(`{"jsonrpc": "2.0", "id": 1, "result": "0"}`))
 					require.NoError(t, err)
 					ws.Close()
diff --git a/pkg/rpc/server/client_test.go b/pkg/rpc/server/client_test.go
index fcabd560d..15fd37d37 100644
--- a/pkg/rpc/server/client_test.go
+++ b/pkg/rpc/server/client_test.go
@@ -31,7 +31,7 @@ import (
 func TestClient_NEP17(t *testing.T) {
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChain(t)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	c, err := client.New(context.Background(), httpSrv.URL, client.Options{})
 	require.NoError(t, err)
@@ -74,7 +74,7 @@ func TestClient_NEP17(t *testing.T) {
 func TestAddNetworkFeeCalculateNetworkFee(t *testing.T) {
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChain(t)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 	const extraFee = 10
 	var nonce uint32
 
@@ -156,12 +156,13 @@ func TestAddNetworkFeeCalculateNetworkFee(t *testing.T) {
 	t.Run("Multi", func(t *testing.T) {
 		acc0 := wallet.NewAccountFromPrivateKey(testchain.PrivateKeyByID(0))
 		acc1 := wallet.NewAccountFromPrivateKey(testchain.PrivateKeyByID(0))
-		acc1.ConvertMultisig(3, keys.PublicKeys{
+		err = acc1.ConvertMultisig(3, keys.PublicKeys{
 			testchain.PrivateKeyByID(0).PublicKey(),
 			testchain.PrivateKeyByID(1).PublicKey(),
 			testchain.PrivateKeyByID(2).PublicKey(),
 			testchain.PrivateKeyByID(3).PublicKey(),
 		})
+		require.NoError(t, err)
 		check := func(t *testing.T, extraFee int64) {
 			tx := transaction.New([]byte{byte(opcode.PUSH1)}, 0)
 			tx.ValidUntilBlock = 20
@@ -322,7 +323,7 @@ func TestAddNetworkFeeCalculateNetworkFee(t *testing.T) {
 func TestCalculateNetworkFee(t *testing.T) {
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChain(t)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 	const extraFee = 10
 
 	c, err := client.New(context.Background(), httpSrv.URL, client.Options{})
@@ -392,7 +393,7 @@ func TestCalculateNetworkFee(t *testing.T) {
 func TestSignAndPushInvocationTx(t *testing.T) {
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChain(t)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	c, err := client.New(context.Background(), httpSrv.URL, client.Options{})
 	require.NoError(t, err)
@@ -549,7 +550,7 @@ func TestSignAndPushInvocationTx(t *testing.T) {
 func TestSignAndPushP2PNotaryRequest(t *testing.T) {
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChainAndServices(t, false, true)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	c, err := client.New(context.Background(), httpSrv.URL, client.Options{})
 	require.NoError(t, err)
@@ -620,7 +621,8 @@ func TestSignAndPushP2PNotaryRequest(t *testing.T) {
 		w, err := wallet.NewWalletFromFile(notaryPath)
 		require.NoError(t, err)
 		ntr := w.Accounts[0]
-		ntr.Decrypt(notaryPass)
+		err = ntr.Decrypt(notaryPass)
+		require.NoError(t, err)
 		req.FallbackTransaction.Scripts[0] = transaction.Witness{
 			InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, ntr.PrivateKey().SignHashable(uint32(testchain.Network()), req.FallbackTransaction)...),
 			VerificationScript: []byte{},
@@ -639,7 +641,7 @@ func TestSignAndPushP2PNotaryRequest(t *testing.T) {
 func TestCalculateNotaryFee(t *testing.T) {
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChain(t)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	c, err := client.New(context.Background(), httpSrv.URL, client.Options{})
 	require.NoError(t, err)
@@ -667,7 +669,7 @@ func TestPing(t *testing.T) {
 func TestCreateTxFromScript(t *testing.T) {
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChain(t)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	c, err := client.New(context.Background(), httpSrv.URL, client.Options{})
 	require.NoError(t, err)
@@ -696,7 +698,7 @@ func TestCreateTxFromScript(t *testing.T) {
 func TestCreateNEP17TransferTx(t *testing.T) {
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChain(t)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	c, err := client.New(context.Background(), httpSrv.URL, client.Options{})
 	require.NoError(t, err)
@@ -720,7 +722,7 @@ func TestCreateNEP17TransferTx(t *testing.T) {
 func TestInvokeVerify(t *testing.T) {
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChain(t)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	c, err := client.New(context.Background(), httpSrv.URL, client.Options{})
 	require.NoError(t, err)
@@ -762,7 +764,7 @@ func TestInvokeVerify(t *testing.T) {
 func TestClient_GetNativeContracts(t *testing.T) {
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChain(t)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	c, err := client.New(context.Background(), httpSrv.URL, client.Options{})
 	require.NoError(t, err)
@@ -776,7 +778,7 @@ func TestClient_GetNativeContracts(t *testing.T) {
 func TestClient_NEP11(t *testing.T) {
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChain(t)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	c, err := client.New(context.Background(), httpSrv.URL, client.Options{})
 	require.NoError(t, err)
@@ -842,7 +844,7 @@ func TestClient_NEP11(t *testing.T) {
 func TestClient_NNS(t *testing.T) {
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChain(t)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	c, err := client.New(context.Background(), httpSrv.URL, client.Options{})
 	require.NoError(t, err)
diff --git a/pkg/rpc/server/server_test.go b/pkg/rpc/server/server_test.go
index fc06ebcc3..804426b34 100644
--- a/pkg/rpc/server/server_test.go
+++ b/pkg/rpc/server/server_test.go
@@ -1010,7 +1010,7 @@ func TestRPC(t *testing.T) {
 func TestSubmitOracle(t *testing.T) {
 	chain, rpcSrv, httpSrv := initClearServerWithServices(t, true, false)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	rpc := `{"jsonrpc": "2.0", "id": 1, "method": "submitoracleresponse", "params": %s}`
 	runCase := func(t *testing.T, fail bool, params ...string) func(t *testing.T) {
@@ -1046,7 +1046,7 @@ func TestSubmitNotaryRequest(t *testing.T) {
 	t.Run("disabled P2PSigExtensions", func(t *testing.T) {
 		chain, rpcSrv, httpSrv := initClearServerWithServices(t, false, false)
 		defer chain.Close()
-		defer rpcSrv.Shutdown()
+		defer func() { _ = rpcSrv.Shutdown() }()
 		req := fmt.Sprintf(rpc, "[]")
 		body := doRPCCallOverHTTP(req, httpSrv.URL, t)
 		checkErrGetResult(t, body, true)
@@ -1054,7 +1054,7 @@ func TestSubmitNotaryRequest(t *testing.T) {
 
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChainAndServices(t, false, true)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	runCase := func(t *testing.T, fail bool, params ...string) func(t *testing.T) {
 		return func(t *testing.T) {
@@ -1156,7 +1156,7 @@ func testRPCProtocol(t *testing.T, doRPCCall func(string, string, *testing.T) []
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChain(t)
 
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	e := &executor{chain: chain, httpSrv: httpSrv}
 	t.Run("single request", func(t *testing.T) {
@@ -1595,9 +1595,11 @@ func doRPCCallOverWS(rpcCall string, url string, t *testing.T) []byte {
 	url = "ws" + strings.TrimPrefix(url, "http")
 	c, _, err := dialer.Dial(url+"/ws", nil)
 	require.NoError(t, err)
-	c.SetWriteDeadline(time.Now().Add(time.Second))
+	err = c.SetWriteDeadline(time.Now().Add(time.Second))
+	require.NoError(t, err)
 	require.NoError(t, c.WriteMessage(1, []byte(rpcCall)))
-	c.SetReadDeadline(time.Now().Add(time.Second))
+	err = c.SetReadDeadline(time.Now().Add(time.Second))
+	require.NoError(t, err)
 	_, body, err := c.ReadMessage()
 	require.NoError(t, err)
 	require.NoError(t, c.Close())
diff --git a/pkg/rpc/server/subscription_test.go b/pkg/rpc/server/subscription_test.go
index 7f8872eed..9fe6ceafc 100644
--- a/pkg/rpc/server/subscription_test.go
+++ b/pkg/rpc/server/subscription_test.go
@@ -20,7 +20,8 @@ const testOverflow = false
 
 func wsReader(t *testing.T, ws *websocket.Conn, msgCh chan<- []byte, isFinished *atomic.Bool) {
 	for {
-		ws.SetReadDeadline(time.Now().Add(time.Second))
+		err := ws.SetReadDeadline(time.Now().Add(time.Second))
+		require.NoError(t, err)
 		_, body, err := ws.ReadMessage()
 		if isFinished.Load() {
 			require.Error(t, err)
@@ -34,7 +35,7 @@ func wsReader(t *testing.T, ws *websocket.Conn, msgCh chan<- []byte, isFinished
 func callWSGetRaw(t *testing.T, ws *websocket.Conn, msg string, respCh <-chan []byte) *response.Raw {
 	var resp = new(response.Raw)
 
-	ws.SetWriteDeadline(time.Now().Add(time.Second))
+	require.NoError(t, ws.SetWriteDeadline(time.Now().Add(time.Second)))
 	require.NoError(t, ws.WriteMessage(websocket.TextMessage, []byte(msg)))
 
 	body := <-respCh
@@ -90,7 +91,7 @@ func TestSubscriptions(t *testing.T) {
 	chain, rpcSrv, c, respMsgs, finishedFlag := initCleanServerAndWSClient(t)
 
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	for _, feed := range subFeeds {
 		s := callSubscribe(t, c, respMsgs, fmt.Sprintf(`["%s"]`, feed))
@@ -243,7 +244,7 @@ func TestFilteredSubscriptions(t *testing.T) {
 			chain, rpcSrv, c, respMsgs, finishedFlag := initCleanServerAndWSClient(t)
 
 			defer chain.Close()
-			defer rpcSrv.Shutdown()
+			defer func() { _ = rpcSrv.Shutdown() }()
 
 			// It's used as an end-of-event-stream, so it's always present.
 			blockSubID := callSubscribe(t, c, respMsgs, `["block_added"]`)
@@ -283,7 +284,7 @@ func TestFilteredBlockSubscriptions(t *testing.T) {
 	chain, rpcSrv, c, respMsgs, finishedFlag := initCleanServerAndWSClient(t)
 
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	blockSubID := callSubscribe(t, c, respMsgs, `["block_added", {"primary":3}]`)
 
@@ -322,7 +323,7 @@ func TestMaxSubscriptions(t *testing.T) {
 	chain, rpcSrv, c, respMsgs, finishedFlag := initCleanServerAndWSClient(t)
 
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	for i := 0; i < maxFeeds+1; i++ {
 		var s string
@@ -368,7 +369,7 @@ func TestBadSubUnsub(t *testing.T) {
 	chain, rpcSrv, c, respMsgs, finishedFlag := initCleanServerAndWSClient(t)
 
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	testF := func(t *testing.T, cases map[string]string) func(t *testing.T) {
 		return func(t *testing.T) {
@@ -389,19 +390,20 @@ func TestBadSubUnsub(t *testing.T) {
 }
 
 func doSomeWSRequest(t *testing.T, ws *websocket.Conn) {
-	ws.SetWriteDeadline(time.Now().Add(time.Second))
+	require.NoError(t, ws.SetWriteDeadline(time.Now().Add(time.Second)))
 	// It could be just about anything including invalid request,
 	// we only care about server handling being active.
 	require.NoError(t, ws.WriteMessage(websocket.TextMessage, []byte(`{"jsonrpc": "2.0", "method": "getversion", "params": [], "id": 1}`)))
-	ws.SetReadDeadline(time.Now().Add(time.Second))
-	_, _, err := ws.ReadMessage()
+	err := ws.SetReadDeadline(time.Now().Add(time.Second))
+	require.NoError(t, err)
+	_, _, err = ws.ReadMessage()
 	require.NoError(t, err)
 }
 
 func TestWSClientsLimit(t *testing.T) {
 	chain, rpcSrv, httpSrv := initClearServerWithInMemoryChain(t)
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	dialer := websocket.Dialer{HandshakeTimeout: time.Second}
 	url := "ws" + strings.TrimPrefix(httpSrv.URL, "http") + "/ws"
@@ -440,7 +442,7 @@ func TestSubscriptionOverflow(t *testing.T) {
 	chain, rpcSrv, c, respMsgs, finishedFlag := initCleanServerAndWSClient(t)
 
 	defer chain.Close()
-	defer rpcSrv.Shutdown()
+	defer func() { _ = rpcSrv.Shutdown() }()
 
 	resp := callWSGetRaw(t, c, `{"jsonrpc": "2.0","method": "subscribe","params": ["block_added"],"id": 1}`, respMsgs)
 	require.Nil(t, resp.Error)

From a44376903a46c81b8a13a1929e3927131544ac56 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 21:45:32 +0300
Subject: [PATCH 25/34] rpc: fix errcheck warnings in websocket code

---
 pkg/rpc/client/wsclient.go | 17 ++++++++++++-----
 pkg/rpc/server/server.go   | 18 ++++++++++++------
 2 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/pkg/rpc/client/wsclient.go b/pkg/rpc/client/wsclient.go
index 7ff486246..8a8e4824f 100644
--- a/pkg/rpc/client/wsclient.go
+++ b/pkg/rpc/client/wsclient.go
@@ -114,12 +114,15 @@ func (c *WSClient) Close() {
 
 func (c *WSClient) wsReader() {
 	c.ws.SetReadLimit(wsReadLimit)
-	c.ws.SetPongHandler(func(string) error { c.ws.SetReadDeadline(time.Now().Add(wsPongLimit)); return nil })
+	c.ws.SetPongHandler(func(string) error { return c.ws.SetReadDeadline(time.Now().Add(wsPongLimit)) })
 readloop:
 	for {
 		rr := new(requestResponse)
-		c.ws.SetReadDeadline(time.Now().Add(wsPongLimit))
-		err := c.ws.ReadJSON(rr)
+		err := c.ws.SetReadDeadline(time.Now().Add(wsPongLimit))
+		if err != nil {
+			break
+		}
+		err = c.ws.ReadJSON(rr)
 		if err != nil {
 			// Timeout/connection loss/malformed response.
 			break
@@ -191,12 +194,16 @@ func (c *WSClient) wsWriter() {
 			if !ok {
 				return
 			}
-			c.ws.SetWriteDeadline(time.Now().Add(c.opts.RequestTimeout))
+			if err := c.ws.SetWriteDeadline(time.Now().Add(c.opts.RequestTimeout)); err != nil {
+				return
+			}
 			if err := c.ws.WriteJSON(req); err != nil {
 				return
 			}
 		case <-pingTicker.C:
-			c.ws.SetWriteDeadline(time.Now().Add(wsWriteLimit))
+			if err := c.ws.SetWriteDeadline(time.Now().Add(wsWriteLimit)); err != nil {
+				return
+			}
 			if err := c.ws.WriteMessage(websocket.PingMessage, []byte{}); err != nil {
 				return
 			}
diff --git a/pkg/rpc/server/server.go b/pkg/rpc/server/server.go
index ab3e5bca7..085329474 100644
--- a/pkg/rpc/server/server.go
+++ b/pkg/rpc/server/server.go
@@ -359,7 +359,9 @@ eventloop:
 			if !ok {
 				break eventloop
 			}
-			ws.SetWriteDeadline(time.Now().Add(wsWriteLimit))
+			if err := ws.SetWriteDeadline(time.Now().Add(wsWriteLimit)); err != nil {
+				break eventloop
+			}
 			if err := ws.WritePreparedMessage(event); err != nil {
 				break eventloop
 			}
@@ -367,12 +369,16 @@ eventloop:
 			if !ok {
 				break eventloop
 			}
-			ws.SetWriteDeadline(time.Now().Add(wsWriteLimit))
+			if err := ws.SetWriteDeadline(time.Now().Add(wsWriteLimit)); err != nil {
+				break eventloop
+			}
 			if err := ws.WriteJSON(res); err != nil {
 				break eventloop
 			}
 		case <-pingTicker.C:
-			ws.SetWriteDeadline(time.Now().Add(wsWriteLimit))
+			if err := ws.SetWriteDeadline(time.Now().Add(wsWriteLimit)); err != nil {
+				break eventloop
+			}
 			if err := ws.WriteMessage(websocket.PingMessage, []byte{}); err != nil {
 				break eventloop
 			}
@@ -397,10 +403,10 @@ drainloop:
 
 func (s *Server) handleWsReads(ws *websocket.Conn, resChan chan<- response.AbstractResult, subscr *subscriber) {
 	ws.SetReadLimit(wsReadLimit)
-	ws.SetReadDeadline(time.Now().Add(wsPongLimit))
-	ws.SetPongHandler(func(string) error { ws.SetReadDeadline(time.Now().Add(wsPongLimit)); return nil })
+	err := ws.SetReadDeadline(time.Now().Add(wsPongLimit))
+	ws.SetPongHandler(func(string) error { return ws.SetReadDeadline(time.Now().Add(wsPongLimit)) })
 requestloop:
-	for {
+	for err == nil {
 		req := request.NewRequest()
 		err := ws.ReadJSON(req)
 		if err != nil {

From b1710bebaaba519d8412d0c733cca00f011eab11 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 21:49:42 +0300
Subject: [PATCH 26/34] native: fix errcheck errors in nns contract

---
 pkg/core/native/name_service.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkg/core/native/name_service.go b/pkg/core/native/name_service.go
index 0044624d3..7e3893f90 100644
--- a/pkg/core/native/name_service.go
+++ b/pkg/core/native/name_service.go
@@ -565,7 +565,7 @@ func (s *nameState) EncodeBinary(w *io.BinWriter) {
 func (s *nameState) DecodeBinary(r *io.BinReader) {
 	item := stackitem.DecodeBinaryStackItem(r)
 	if r.Err == nil {
-		s.FromStackItem(item)
+		r.Err = s.FromStackItem(item)
 	}
 }
 
@@ -700,7 +700,7 @@ func (sl stringList) EncodeBinary(w *io.BinWriter) {
 func (sl *stringList) DecodeBinary(r *io.BinReader) {
 	item := stackitem.DecodeBinaryStackItem(r)
 	if r.Err == nil {
-		sl.FromStackItem(item)
+		r.Err = sl.FromStackItem(item)
 	}
 }
 

From 6fea16451a940eacc84b6a4071b4d18ab1c9e54e Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 21:53:41 +0300
Subject: [PATCH 27/34] cli/input: ignore term.Restore errors, fix errcheck
 warnings

I'm not sure we can do anything useful here.
---
 cli/input/input.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/cli/input/input.go b/cli/input/input.go
index fa61dee10..ee62a531a 100644
--- a/cli/input/input.go
+++ b/cli/input/input.go
@@ -25,7 +25,7 @@ func ReadLine(prompt string) (string, error) {
 		if err != nil {
 			panic(err)
 		}
-		defer term.Restore(syscall.Stdin, s)
+		defer func() { _ = term.Restore(syscall.Stdin, s) }()
 		trm = term.NewTerminal(ReadWriter{
 			Reader: os.Stdin,
 			Writer: os.Stdout,
@@ -50,7 +50,7 @@ func ReadPassword(prompt string) (string, error) {
 		if err != nil {
 			panic(err)
 		}
-		defer term.Restore(syscall.Stdin, s)
+		defer func() { _ = term.Restore(syscall.Stdin, s) }()
 		trm = term.NewTerminal(ReadWriter{os.Stdin, os.Stdout}, prompt)
 	}
 	return trm.ReadPassword(prompt)

From c4e084b0d857f7f11e489a55e21ee3065b4bc18a Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 22:51:41 +0300
Subject: [PATCH 28/34] *: fix whitespace errors

leading/trailing newlines
---
 cli/wallet/legacy.go                      | 1 -
 cli/wallet/legacy_test.go                 | 1 -
 cli/wallet/nep11.go                       | 1 -
 internal/testchain/transaction.go         | 1 -
 pkg/compiler/codegen.go                   | 1 -
 pkg/compiler/vm_test.go                   | 1 -
 pkg/consensus/consensus.go                | 1 -
 pkg/core/block/block_test.go              | 1 -
 pkg/core/blockchain.go                    | 1 -
 pkg/core/blockchain_test.go               | 1 -
 pkg/core/mpt/batch.go                     | 1 -
 pkg/core/native/management.go             | 1 -
 pkg/core/native/name_service.go           | 1 -
 pkg/core/native/native_neo.go             | 1 -
 pkg/core/native/util.go                   | 1 -
 pkg/core/native_designate_test.go         | 1 -
 pkg/core/native_management_test.go        | 1 -
 pkg/core/native_name_service_test.go      | 1 -
 pkg/core/native_neo_test.go               | 1 -
 pkg/core/state/notification_event_test.go | 1 -
 pkg/core/state/oracle_test.go             | 1 -
 pkg/crypto/keys/nep2_test.go              | 1 -
 pkg/crypto/keys/publickey.go              | 1 -
 pkg/encoding/fixedn/fixed8_test.go        | 1 -
 pkg/io/binaryWriter.go                    | 1 -
 pkg/network/payload/getblocks.go          | 1 -
 pkg/network/server.go                     | 1 -
 pkg/network/server_test.go                | 1 -
 pkg/rpc/client/wsclient.go                | 1 -
 pkg/rpc/response/errors.go                | 1 -
 pkg/rpc/server/server.go                  | 1 -
 pkg/rpc/server/server_test.go             | 1 -
 pkg/rpc/server/subscription_test.go       | 1 -
 pkg/services/oracle/neofs/neofs_test.go   | 1 -
 pkg/services/oracle/transaction.go        | 1 -
 pkg/vm/vm_test.go                         | 1 -
 36 files changed, 36 deletions(-)

diff --git a/cli/wallet/legacy.go b/cli/wallet/legacy.go
index 3ddbd6e5f..bace1cef9 100644
--- a/cli/wallet/legacy.go
+++ b/cli/wallet/legacy.go
@@ -156,7 +156,6 @@ func parseMultisigContract(script []byte) (int, keys.PublicKeys, bool) {
 			return 0, nil, false
 		}
 		ret[i] = pub
-
 	}
 	return nsigs, ret, true
 }
diff --git a/cli/wallet/legacy_test.go b/cli/wallet/legacy_test.go
index af952fff5..7195bc81a 100644
--- a/cli/wallet/legacy_test.go
+++ b/cli/wallet/legacy_test.go
@@ -94,7 +94,6 @@ func TestParseMultisigContract(t *testing.T) {
 			}
 		})
 	})
-
 }
 
 func fromHex(t *testing.T, s string) []byte {
diff --git a/cli/wallet/nep11.go b/cli/wallet/nep11.go
index fe92ce857..7481fdb6f 100644
--- a/cli/wallet/nep11.go
+++ b/cli/wallet/nep11.go
@@ -226,7 +226,6 @@ func getNEP11Balance(ctx *cli.Context) error {
 		}
 		fmt.Fprintf(ctx.App.Writer, format, formatArgs...)
 		fmt.Fprintf(ctx.App.Writer, "\tAmount : %s\n", amountStr)
-
 	}
 	return nil
 }
diff --git a/internal/testchain/transaction.go b/internal/testchain/transaction.go
index 04363f7cd..bf8cfc685 100644
--- a/internal/testchain/transaction.go
+++ b/internal/testchain/transaction.go
@@ -79,7 +79,6 @@ func NewDeployTx(bc blockchainer.Blockchainer, name string, sender util.Uint160,
 		o.ContractEvents = conf.Events
 		o.ContractSupportedStandards = conf.SupportedStandards
 		o.SafeMethods = conf.SafeMethods
-
 	}
 	m, err := compiler.CreateManifest(di, o)
 	if err != nil {
diff --git a/pkg/compiler/codegen.go b/pkg/compiler/codegen.go
index f80311da5..14a456165 100644
--- a/pkg/compiler/codegen.go
+++ b/pkg/compiler/codegen.go
@@ -473,7 +473,6 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 		return nil
 	}
 	switch n := node.(type) {
-
 	// General declarations.
 	// var (
 	//     x = 2
diff --git a/pkg/compiler/vm_test.go b/pkg/compiler/vm_test.go
index 4752ef708..6545dcf73 100644
--- a/pkg/compiler/vm_test.go
+++ b/pkg/compiler/vm_test.go
@@ -109,7 +109,6 @@ func newStoragePlugin() *storagePlugin {
 	s.interops[interopnames.ToID([]byte(interopnames.SystemRuntimeNotify))] = s.Notify
 	s.interops[interopnames.ToID([]byte(interopnames.SystemRuntimeGetTime))] = s.GetTime
 	return s
-
 }
 
 func (s *storagePlugin) syscallHandler(v *vm.VM, id uint32) error {
diff --git a/pkg/consensus/consensus.go b/pkg/consensus/consensus.go
index 9bb26483a..3321bb8c0 100644
--- a/pkg/consensus/consensus.go
+++ b/pkg/consensus/consensus.go
@@ -309,7 +309,6 @@ events:
 			s.handleChainBlock(b)
 		default:
 		}
-
 	}
 	close(s.finished)
 }
diff --git a/pkg/core/block/block_test.go b/pkg/core/block/block_test.go
index b8042f3ef..834ca0620 100644
--- a/pkg/core/block/block_test.go
+++ b/pkg/core/block/block_test.go
@@ -239,7 +239,6 @@ func TestBlockEncodeDecode(t *testing.T) {
 
 func TestGetExpectedBlockSize(t *testing.T) {
 	check := func(t *testing.T, stateRootEnabled bool) {
-
 		t.Run("without transactions", func(t *testing.T) {
 			b := newDumbBlock()
 			b.StateRootEnabled = stateRootEnabled
diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index 566626c63..9aeb78a93 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -1600,7 +1600,6 @@ func (bc *Blockchain) IsTxStillRelevant(t *transaction.Transaction, txpool *memp
 		return bc.verifyTxWitnesses(t, nil, isPartialTx) == nil
 	}
 	return true
-
 }
 
 // VerifyTx verifies whether transaction is bonafide or not relative to the
diff --git a/pkg/core/blockchain_test.go b/pkg/core/blockchain_test.go
index 3bbf4b043..6393016d1 100644
--- a/pkg/core/blockchain_test.go
+++ b/pkg/core/blockchain_test.go
@@ -1529,7 +1529,6 @@ func testDumpAndRestore(t *testing.T, dumpF, restoreF func(c *config.Config)) {
 			require.Equal(t, bc.BlockHeight()-1, lastIndex)
 		})
 	})
-
 }
 
 func TestDumpAndRestore(t *testing.T) {
diff --git a/pkg/core/mpt/batch.go b/pkg/core/mpt/batch.go
index 7a9409151..5c9287413 100644
--- a/pkg/core/mpt/batch.go
+++ b/pkg/core/mpt/batch.go
@@ -208,7 +208,6 @@ func (t *Trie) newSubTrieMany(prefix []byte, kv []keyValue, value []byte) (Node,
 		if len(kv[0].value) == 0 {
 			if len(kv) == 1 {
 				return new(HashNode), 1, nil
-
 			}
 			node, n, err := t.newSubTrieMany(prefix, kv[1:], nil)
 			return node, n + 1, err
diff --git a/pkg/core/native/management.go b/pkg/core/native/management.go
index 2a1bc77d5..01aeab5b5 100644
--- a/pkg/core/native/management.go
+++ b/pkg/core/native/management.go
@@ -539,7 +539,6 @@ func (m *Management) getNextContractID(d dao.DAO) (int32, error) {
 	si := d.GetStorageItem(m.ID, keyNextAvailableID)
 	if si == nil {
 		return 0, errors.New("nextAvailableID is not initialized")
-
 	}
 	id := bigint.FromBytes(si)
 	ret := int32(id.Int64())
diff --git a/pkg/core/native/name_service.go b/pkg/core/native/name_service.go
index 7e3893f90..4116d1fbc 100644
--- a/pkg/core/native/name_service.go
+++ b/pkg/core/native/name_service.go
@@ -626,7 +626,6 @@ func domainFromString(name string) (string, bool) {
 		return name, true
 	}
 	return name[i+1:], true
-
 }
 
 func toDomain(name string) string {
diff --git a/pkg/core/native/native_neo.go b/pkg/core/native/native_neo.go
index 0580680fa..1a6af1a16 100644
--- a/pkg/core/native/native_neo.go
+++ b/pkg/core/native/native_neo.go
@@ -337,7 +337,6 @@ func (n *NEO) PostPersist(ic *interop.Context) error {
 				}
 			}
 		}
-
 	}
 	if n.gasPerBlockChanged.Load().(bool) {
 		gr, err := n.getSortedGASRecordFromDAO(ic.DAO)
diff --git a/pkg/core/native/util.go b/pkg/core/native/util.go
index 73ac7f316..c882762cb 100644
--- a/pkg/core/native/util.go
+++ b/pkg/core/native/util.go
@@ -42,7 +42,6 @@ func getIntWithKey(id int32, dao dao.DAO, key []byte) int64 {
 	si := dao.GetStorageItem(id, key)
 	if si == nil {
 		panic(fmt.Errorf("item with id = %d and key = %s is not initialized", id, hex.EncodeToString(key)))
-
 	}
 	return bigint.FromBytes(si).Int64()
 }
diff --git a/pkg/core/native_designate_test.go b/pkg/core/native_designate_test.go
index 6f8bacb7f..0846a8a2c 100644
--- a/pkg/core/native_designate_test.go
+++ b/pkg/core/native_designate_test.go
@@ -116,7 +116,6 @@ func TestDesignate_DesignateAsRoleTx(t *testing.T) {
 		bc.setNodesByRole(t, true, noderoles.NeoFSAlphabet, pubs)
 		bc.getNodesByRole(t, true, noderoles.NeoFSAlphabet, bc.BlockHeight()+1, 1)
 	})
-
 }
 
 func TestDesignate_DesignateAsRole(t *testing.T) {
diff --git a/pkg/core/native_management_test.go b/pkg/core/native_management_test.go
index b0f441e68..355a57e37 100644
--- a/pkg/core/native_management_test.go
+++ b/pkg/core/native_management_test.go
@@ -577,7 +577,6 @@ func TestContractDestroy(t *testing.T) {
 		t.Run("check contract", func(t *testing.T) {
 			checkContractState(t, bc, cs1.Hash, nil)
 		})
-
 	})
 }
 
diff --git a/pkg/core/native_name_service_test.go b/pkg/core/native_name_service_test.go
index a428b48dc..8c394f86b 100644
--- a/pkg/core/native_name_service_test.go
+++ b/pkg/core/native_name_service_test.go
@@ -120,7 +120,6 @@ func TestExpiration(t *testing.T) {
 	aer, err = bc.GetAppExecResults(tx.Hash(), trigger.Application)
 	require.NoError(t, err)
 	checkResult(t, &aer[0], stackitem.Null{})
-
 }
 
 const secondsInYear = 365 * 24 * 3600
diff --git a/pkg/core/native_neo_test.go b/pkg/core/native_neo_test.go
index 19207137b..5050681da 100644
--- a/pkg/core/native_neo_test.go
+++ b/pkg/core/native_neo_test.go
@@ -226,7 +226,6 @@ func TestNEO_CalculateBonus(t *testing.T) {
 		res, err := neo.CalculateNEOHolderReward(ic.DAO, big.NewInt(100), 5, 15)
 		require.NoError(t, err)
 		require.EqualValues(t, (100*5*5/10)+(100*5*1/10), res.Int64())
-
 	})
 }
 
diff --git a/pkg/core/state/notification_event_test.go b/pkg/core/state/notification_event_test.go
index 99defd0d9..2429b7c81 100644
--- a/pkg/core/state/notification_event_test.go
+++ b/pkg/core/state/notification_event_test.go
@@ -116,7 +116,6 @@ func TestMarshalUnmarshalJSONNotificationEvent(t *testing.T) {
 			err := json.Unmarshal([]byte(errCase), new(NotificationEvent))
 			require.Error(t, err)
 		}
-
 	})
 }
 
diff --git a/pkg/core/state/oracle_test.go b/pkg/core/state/oracle_test.go
index 3c3a3abe2..dc0a9ed12 100644
--- a/pkg/core/state/oracle_test.go
+++ b/pkg/core/state/oracle_test.go
@@ -76,5 +76,4 @@ func TestOracleRequest_EncodeBinary(t *testing.T) {
 		t.Run("Method", runInvalid(5, stackitem.NewMap()))
 		t.Run("UserData", runInvalid(6, stackitem.NewMap()))
 	})
-
 }
diff --git a/pkg/crypto/keys/nep2_test.go b/pkg/crypto/keys/nep2_test.go
index 218ab050a..78de1f5c6 100644
--- a/pkg/crypto/keys/nep2_test.go
+++ b/pkg/crypto/keys/nep2_test.go
@@ -9,7 +9,6 @@ import (
 
 func TestNEP2Encrypt(t *testing.T) {
 	for _, testCase := range keytestcases.Arr {
-
 		privKey, err := NewPrivateKeyFromHex(testCase.PrivateKey)
 		if testCase.Invalid {
 			assert.Error(t, err)
diff --git a/pkg/crypto/keys/publickey.go b/pkg/crypto/keys/publickey.go
index 9ff009490..a3660d616 100644
--- a/pkg/crypto/keys/publickey.go
+++ b/pkg/crypto/keys/publickey.go
@@ -161,7 +161,6 @@ func (p *PublicKey) getBytes(compressed bool) []byte {
 		prefix = 0x04
 		yBytes := p.Y.Bytes()
 		copy(res[1+coordLen+coordLen-len(yBytes):], yBytes)
-
 	}
 	res[0] = prefix
 
diff --git a/pkg/encoding/fixedn/fixed8_test.go b/pkg/encoding/fixedn/fixed8_test.go
index 99ef0d74e..8498a5793 100644
--- a/pkg/encoding/fixedn/fixed8_test.go
+++ b/pkg/encoding/fixedn/fixed8_test.go
@@ -31,7 +31,6 @@ func TestFixed8Add(t *testing.T) {
 }
 
 func TestFixed8Sub(t *testing.T) {
-
 	a := Fixed8FromInt64(42)
 	b := Fixed8FromInt64(34)
 
diff --git a/pkg/io/binaryWriter.go b/pkg/io/binaryWriter.go
index 9785b0449..5ad499988 100644
--- a/pkg/io/binaryWriter.go
+++ b/pkg/io/binaryWriter.go
@@ -119,7 +119,6 @@ func (w *BinWriter) WriteVarUint(val uint64) {
 		w.WriteB(byte(0xfe))
 		w.WriteU32LE(uint32(val))
 		return
-
 	}
 
 	w.WriteB(byte(0xff))
diff --git a/pkg/network/payload/getblocks.go b/pkg/network/payload/getblocks.go
index 8a0bf0a56..e3434ebce 100644
--- a/pkg/network/payload/getblocks.go
+++ b/pkg/network/payload/getblocks.go
@@ -34,7 +34,6 @@ func (p *GetBlocks) DecodeBinary(br *io.BinReader) {
 	if p.Count < -1 || p.Count == 0 {
 		br.Err = errors.New("invalid count")
 	}
-
 }
 
 // EncodeBinary implements Serializable interface.
diff --git a/pkg/network/server.go b/pkg/network/server.go
index 2303b5be9..560829d5d 100644
--- a/pkg/network/server.go
+++ b/pkg/network/server.go
@@ -409,7 +409,6 @@ func (s *Server) run() {
 				// because we have two goroutines sending signals here
 				s.lock.Unlock()
 			}
-
 		}
 	}
 }
diff --git a/pkg/network/server_test.go b/pkg/network/server_test.go
index da1385430..d70618b54 100644
--- a/pkg/network/server_test.go
+++ b/pkg/network/server_test.go
@@ -178,7 +178,6 @@ func TestServerRegisterPeer(t *testing.T) {
 		}
 		return false
 	}, time.Second, time.Millisecond*50)
-
 }
 
 func TestGetBlocksByIndex(t *testing.T) {
diff --git a/pkg/rpc/client/wsclient.go b/pkg/rpc/client/wsclient.go
index 8a8e4824f..e0b9c7a52 100644
--- a/pkg/rpc/client/wsclient.go
+++ b/pkg/rpc/client/wsclient.go
@@ -209,7 +209,6 @@ func (c *WSClient) wsWriter() {
 			}
 		}
 	}
-
 }
 
 func (c *WSClient) makeWsRequest(r *request.Raw) (*response.Raw, error) {
diff --git a/pkg/rpc/response/errors.go b/pkg/rpc/response/errors.go
index 1e542dbd2..70201403b 100644
--- a/pkg/rpc/response/errors.go
+++ b/pkg/rpc/response/errors.go
@@ -44,7 +44,6 @@ func NewError(code int64, httpCode int, message string, data string, cause error
 		Message:  message,
 		Data:     data,
 	}
-
 }
 
 // NewParseError creates a new error with code
diff --git a/pkg/rpc/server/server.go b/pkg/rpc/server/server.go
index 085329474..5c06eb6b3 100644
--- a/pkg/rpc/server/server.go
+++ b/pkg/rpc/server/server.go
@@ -421,7 +421,6 @@ requestloop:
 			break requestloop
 		case resChan <- res:
 		}
-
 	}
 	s.subsLock.Lock()
 	delete(s.subscribers, subscr)
diff --git a/pkg/rpc/server/server_test.go b/pkg/rpc/server/server_test.go
index 804426b34..d1d6138f8 100644
--- a/pkg/rpc/server/server_test.go
+++ b/pkg/rpc/server/server_test.go
@@ -1261,7 +1261,6 @@ func testRPCProtocol(t *testing.T, doRPCCall func(string, string, *testing.T) []
 						tc.check(t, e, res)
 					}
 				}
-
 			})
 		}
 	})
diff --git a/pkg/rpc/server/subscription_test.go b/pkg/rpc/server/subscription_test.go
index 9fe6ceafc..e2ca27ce4 100644
--- a/pkg/rpc/server/subscription_test.go
+++ b/pkg/rpc/server/subscription_test.go
@@ -311,7 +311,6 @@ func TestFilteredBlockSubscriptions(t *testing.T) {
 		rmap := resp.Payload[0].(map[string]interface{})
 		primary := rmap["primary"].(float64)
 		require.Equal(t, 3, int(primary))
-
 	}
 	callUnsubscribe(t, c, respMsgs, blockSubID)
 	finishedFlag.CAS(false, true)
diff --git a/pkg/services/oracle/neofs/neofs_test.go b/pkg/services/oracle/neofs/neofs_test.go
index 6483875b9..82b25d4be 100644
--- a/pkg/services/oracle/neofs/neofs_test.go
+++ b/pkg/services/oracle/neofs/neofs_test.go
@@ -78,7 +78,6 @@ func TestParseNeoFSURL(t *testing.T) {
 				require.Equal(t, tc.params, ps)
 			}
 		})
-
 	}
 }
 
diff --git a/pkg/services/oracle/transaction.go b/pkg/services/oracle/transaction.go
index b76552f28..5902afe7c 100644
--- a/pkg/services/oracle/transaction.go
+++ b/pkg/services/oracle/transaction.go
@@ -79,7 +79,6 @@ func (t *incompleteTx) addResponse(pub *keys.PublicKey, sig []byte, isBackup boo
 		ok:  tx != nil,
 		sig: sig,
 	}
-
 }
 
 // finalize checks is either main or backup tx has sufficient number of signatures and returns
diff --git a/pkg/vm/vm_test.go b/pkg/vm/vm_test.go
index d6d9a4e8a..2b3e97477 100644
--- a/pkg/vm/vm_test.go
+++ b/pkg/vm/vm_test.go
@@ -753,7 +753,6 @@ func TestArithNullArg(t *testing.T) {
 			runWithArgs(t, prog, false, 0, stackitem.Null{})
 			runWithArgs(t, prog, nil, stackitem.NewInterop(nil), 1) // also has `.Value() == nil`
 		})
-
 	}
 }
 

From 4e651eaf83265d433da632742be3ed0564043a83 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 22:52:07 +0300
Subject: [PATCH 29/34] compiler: simplify increments as suggested by golint

---
 pkg/compiler/native_test.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkg/compiler/native_test.go b/pkg/compiler/native_test.go
index 08012b03f..12e5ab6d0 100644
--- a/pkg/compiler/native_test.go
+++ b/pkg/compiler/native_test.go
@@ -246,12 +246,12 @@ func getMethod(t *testing.T, ctr interop.ContractMD, name string, params []strin
 		name = name[:4]
 	case strings.HasPrefix(name, "memorySearch"):
 		if strings.HasSuffix(name, "LastIndex") {
-			paramLen += 1 // true should be appended inside of an interop
+			paramLen++ // true should be appended inside of an interop
 		}
 		name = "memorySearch"
 	case strings.HasPrefix(name, "stringSplit"):
 		if strings.HasSuffix(name, "NonEmpty") {
-			paramLen += 1 // true should be appended inside of an interop
+			paramLen++ // true should be appended inside of an interop
 		}
 		name = "stringSplit"
 	default:

From d4a2f4d8b9e028686e934fb31f31e2e6cd1e61a0 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 22:52:32 +0300
Subject: [PATCH 30/34] hash: suppress staticcheck warning

---
 pkg/crypto/hash/hash.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkg/crypto/hash/hash.go b/pkg/crypto/hash/hash.go
index 06ce1f421..45f18c7fd 100644
--- a/pkg/crypto/hash/hash.go
+++ b/pkg/crypto/hash/hash.go
@@ -5,7 +5,7 @@ import (
 	"encoding/binary"
 
 	"github.com/nspcc-dev/neo-go/pkg/util"
-	"golang.org/x/crypto/ripemd160"
+	"golang.org/x/crypto/ripemd160" //nolint:staticcheck // SA1019: package golang.org/x/crypto/ripemd160 is deprecated
 )
 
 // Hashable represents an object which can be hashed. Usually these objects

From 3fdba9265fa8517538de77600bf7628255158788 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 22:53:28 +0300
Subject: [PATCH 31/34] add golangci-lint configuration

It's mostly based on neofs-http-gate configuration, but has exhaustive
disabled and some golint-specific warnings enabled (some of which are
important for us).
---
 .golangci.yml | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 .golangci.yml

diff --git a/.golangci.yml b/.golangci.yml
new file mode 100644
index 000000000..f4faf7672
--- /dev/null
+++ b/.golangci.yml
@@ -0,0 +1,58 @@
+# This file contains all available configuration options
+# with their default values.
+
+# options for analysis running
+run:
+  # timeout for analysis, e.g. 30s, 5m, default is 1m
+  timeout: 5m
+
+  # include test files or not, default is true
+  tests: true
+
+# output configuration options
+output:
+  # colored-line-number|line-number|json|tab|checkstyle|code-climate, default is "colored-line-number"
+  format: tab
+
+# all available settings of specific linters
+linters-settings:
+  exhaustive:
+    # indicates that switch statements are to be considered exhaustive if a
+    # 'default' case is present, even if all enum members aren't listed in the
+    # switch
+    default-signifies-exhaustive: true
+  govet:
+    # report about shadowed variables
+    check-shadowing: false
+
+linters:
+  enable:
+    # mandatory linters
+    - govet
+    - golint
+
+    # some default golangci-lint linters
+    - deadcode
+    - errcheck
+    - gosimple
+    - ineffassign
+    - staticcheck
+    - structcheck
+    - typecheck
+    - unused
+    - varcheck
+
+    # extra linters
+    # - exhaustive
+    - gofmt
+    - whitespace
+    - goimports
+  disable-all: true
+  fast: false
+
+issues:
+  include:
+    - EXC0002 # should have a comment
+    - EXC0003 # test/Test ... consider calling this
+    - EXC0004 # govet
+    - EXC0005 # C-style breaks

From 9d2712573fa7573e9c54141d5a255e6bcd82348b Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 23:17:03 +0300
Subject: [PATCH 32/34] *: enable godot linter and fix all its warnings

It's important for NeoGo to have clean documentation. No functional changes.
---
 .golangci.yml                             |  1 +
 cli/flags/address.go                      |  8 ++++----
 cli/input/input.go                        |  2 +-
 cli/nep11_test.go                         |  2 +-
 cli/paramcontext/context.go               |  2 +-
 cli/smartcontract/smart_contract.go       |  2 +-
 pkg/compiler/codegen.go                   |  4 ++--
 pkg/compiler/debug.go                     |  4 ++--
 pkg/compiler/inline.go                    | 10 +++++-----
 pkg/consensus/commit.go                   |  2 +-
 pkg/consensus/payload.go                  |  2 +-
 pkg/core/block/block.go                   |  2 +-
 pkg/core/block/header.go                  |  4 ++--
 pkg/core/dao/dao.go                       |  2 +-
 pkg/core/fee/calculate.go                 |  2 +-
 pkg/core/helper_test.go                   |  2 +-
 pkg/core/mempool/mem_pool.go              |  6 +++---
 pkg/core/mpt/batch_test.go                |  2 +-
 pkg/core/native/ledger.go                 |  4 ++--
 pkg/core/native/name_service_test.go      |  2 +-
 pkg/core/native/oracle.go                 |  4 ++--
 pkg/core/native/policy.go                 |  2 +-
 pkg/core/state/contract.go                |  2 +-
 pkg/core/state/notification_event.go      |  2 +-
 pkg/core/storage/badgerdb_store.go        |  6 +++---
 pkg/core/storage/store.go                 |  4 ++--
 pkg/core/transaction/attrtype.go          |  4 ++--
 pkg/core/transaction/helper_test.go       |  2 +-
 pkg/core/transaction/signer.go            |  2 +-
 pkg/core/transaction/transaction.go       |  8 ++++----
 pkg/crypto/keys/publickey.go              |  2 +-
 pkg/encoding/bigint/bigint.go             |  2 +-
 pkg/encoding/bigint/bigint_test.go        |  2 +-
 pkg/encoding/fixedn/fixed8.go             |  2 +-
 pkg/interop/native/std/std.go             | 10 +++++-----
 pkg/interop/types.go                      |  2 +-
 pkg/io/binaryReader.go                    |  2 +-
 pkg/network/capability/capability.go      | 12 ++++++------
 pkg/network/capability/type.go            |  8 ++++----
 pkg/network/discovery.go                  |  4 ++--
 pkg/network/message.go                    | 16 ++++++++--------
 pkg/network/payload/getblockbyindex.go    |  4 ++--
 pkg/network/payload/getblocks.go          |  4 ++--
 pkg/rpc/client/client.go                  |  6 +++---
 pkg/rpc/client/rpc.go                     |  2 +-
 pkg/rpc/request/types.go                  |  2 +-
 pkg/rpc/response/errors.go                | 18 +++++++++---------
 pkg/rpc/response/result/unclaimed_gas.go  |  4 ++--
 pkg/rpc/rpc_config.go                     |  2 +-
 pkg/rpc/server/server.go                  |  2 +-
 pkg/smartcontract/convertor.go            |  2 +-
 pkg/smartcontract/param_type.go           |  2 +-
 pkg/smartcontract/trigger/trigger_type.go |  2 +-
 pkg/util/uint256.go                       |  2 +-
 pkg/vm/opcode/opcode.go                   | 20 ++++++++++----------
 pkg/vm/stackitem/item.go                  |  4 ++--
 pkg/vm/vm.go                              |  8 ++++----
 pkg/vm/vm_test.go                         |  2 +-
 pkg/wallet/token.go                       |  2 +-
 pkg/wallet/wallet.go                      |  2 +-
 60 files changed, 127 insertions(+), 126 deletions(-)

diff --git a/.golangci.yml b/.golangci.yml
index f4faf7672..39a4d8e51 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -35,6 +35,7 @@ linters:
     - deadcode
     - errcheck
     - gosimple
+    - godot
     - ineffassign
     - staticcheck
     - structcheck
diff --git a/cli/flags/address.go b/cli/flags/address.go
index ce2276e63..56ccf851e 100644
--- a/cli/flags/address.go
+++ b/cli/flags/address.go
@@ -16,7 +16,7 @@ type Address struct {
 	Value util.Uint160
 }
 
-// AddressFlag is a flag with type string
+// AddressFlag is a flag with type string.
 type AddressFlag struct {
 	Name  string
 	Usage string
@@ -60,7 +60,7 @@ func (f AddressFlag) IsSet() bool {
 }
 
 // String returns a readable representation of this value
-// (for usage defaults)
+// (for usage defaults).
 func (f AddressFlag) String() string {
 	var names []string
 	eachName(f.Name, func(name string) {
@@ -77,13 +77,13 @@ func getNameHelp(name string) string {
 	return fmt.Sprintf("--%s value", name)
 }
 
-// GetName returns the name of the flag
+// GetName returns the name of the flag.
 func (f AddressFlag) GetName() string {
 	return f.Name
 }
 
 // Apply populates the flag given the flag set and environment
-// Ignores errors
+// Ignores errors.
 func (f AddressFlag) Apply(set *flag.FlagSet) {
 	eachName(f.Name, func(name string) {
 		set.Var(&f.Value, name, f.Usage)
diff --git a/cli/input/input.go b/cli/input/input.go
index ee62a531a..22eb4a6c8 100644
--- a/cli/input/input.go
+++ b/cli/input/input.go
@@ -17,7 +17,7 @@ type ReadWriter struct {
 	io.Writer
 }
 
-// ReadLine reads line from the input without trailing '\n'
+// ReadLine reads line from the input without trailing '\n'.
 func ReadLine(prompt string) (string, error) {
 	trm := Terminal
 	if trm == nil {
diff --git a/cli/nep11_test.go b/cli/nep11_test.go
index 3565b14b7..99fbeabbe 100644
--- a/cli/nep11_test.go
+++ b/cli/nep11_test.go
@@ -21,7 +21,7 @@ import (
 )
 
 const (
-	// nftOwnerAddr is the owner of NFT-ND HASHY token (../examples/nft-nd/nft.go)
+	// nftOwnerAddr is the owner of NFT-ND HASHY token (../examples/nft-nd/nft.go).
 	nftOwnerAddr   = "NbrUYaZgyhSkNoRo9ugRyEMdUZxrhkNaWB"
 	nftOwnerWallet = "../examples/my_wallet.json"
 	nftOwnerPass   = "qwerty"
diff --git a/cli/paramcontext/context.go b/cli/paramcontext/context.go
index 9df147fd0..c991e2e85 100644
--- a/cli/paramcontext/context.go
+++ b/cli/paramcontext/context.go
@@ -12,7 +12,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/wallet"
 )
 
-// validUntilBlockIncrement is the number of extra blocks to add to an exported transaction
+// validUntilBlockIncrement is the number of extra blocks to add to an exported transaction.
 const validUntilBlockIncrement = 50
 
 // InitAndSave creates incompletely signed transaction which can used
diff --git a/cli/smartcontract/smart_contract.go b/cli/smartcontract/smart_contract.go
index c3662696d..070a9ef7c 100644
--- a/cli/smartcontract/smart_contract.go
+++ b/cli/smartcontract/smart_contract.go
@@ -68,7 +68,7 @@ var (
 
 const (
 	// smartContractTmpl is written to a file when used with `init` command.
-	// %s is parsed to be the smartContractName
+	// %s is parsed to be the smartContractName.
 	smartContractTmpl = `package %s
 
 import "github.com/nspcc-dev/neo-go/pkg/interop/runtime"
diff --git a/pkg/compiler/codegen.go b/pkg/compiler/codegen.go
index 14a456165..2723f861b 100644
--- a/pkg/compiler/codegen.go
+++ b/pkg/compiler/codegen.go
@@ -126,7 +126,7 @@ const (
 	varArgument
 )
 
-// newLabel creates a new label to jump to
+// newLabel creates a new label to jump to.
 func (c *codegen) newLabel() (l uint16) {
 	li := len(c.l)
 	if li > math.MaxUint16 {
@@ -1498,7 +1498,7 @@ func (c *codegen) getLabelOffset(typ labelOffsetType, name string) uint16 {
 }
 
 // For `&&` and `||` it return an opcode which jumps only if result is known:
-// false && .. == false, true || .. = true
+// false && .. == false, true || .. = true.
 func getJumpForToken(tok token.Token, typ types.Type) (opcode.Opcode, bool) {
 	switch tok {
 	case token.GTR:
diff --git a/pkg/compiler/debug.go b/pkg/compiler/debug.go
index 042d47fd5..9ec74af29 100644
--- a/pkg/compiler/debug.go
+++ b/pkg/compiler/debug.go
@@ -340,7 +340,7 @@ func (d *DebugParam) UnmarshalJSON(data []byte) error {
 	return nil
 }
 
-// ToManifestParameter converts DebugParam to manifest.Parameter
+// ToManifestParameter converts DebugParam to manifest.Parameter.
 func (d *DebugParam) ToManifestParameter() manifest.Parameter {
 	return manifest.Parameter{
 		Name: d.Name,
@@ -348,7 +348,7 @@ func (d *DebugParam) ToManifestParameter() manifest.Parameter {
 	}
 }
 
-// ToManifestMethod converts MethodDebugInfo to manifest.Method
+// ToManifestMethod converts MethodDebugInfo to manifest.Method.
 func (m *MethodDebugInfo) ToManifestMethod() manifest.Method {
 	var (
 		result manifest.Method
diff --git a/pkg/compiler/inline.go b/pkg/compiler/inline.go
index 4da30043d..f3471863b 100644
--- a/pkg/compiler/inline.go
+++ b/pkg/compiler/inline.go
@@ -10,11 +10,11 @@ import (
 
 // inlineCall inlines call of n for function represented by f.
 // Call `f(a,b)` for definition `func f(x,y int)` is translated to block:
-// {
-//    x := a
-//    y := b
-//    <inline body of f directly>
-// }
+//   {
+//      x := a
+//      y := b
+//      <inline body of f directly>
+//   }
 func (c *codegen) inlineCall(f *funcScope, n *ast.CallExpr) {
 	labelSz := len(c.labelList)
 	offSz := len(c.inlineLabelOffsets)
diff --git a/pkg/consensus/commit.go b/pkg/consensus/commit.go
index 492a1a156..920d67745 100644
--- a/pkg/consensus/commit.go
+++ b/pkg/consensus/commit.go
@@ -11,7 +11,7 @@ type commit struct {
 }
 
 // signatureSize is an rfc6989 signature size in bytes
-// without leading byte (0x04, uncompressed)
+// without leading byte (0x04, uncompressed).
 const signatureSize = 64
 
 var _ payload.Commit = (*commit)(nil)
diff --git a/pkg/consensus/payload.go b/pkg/consensus/payload.go
index 2d17938ea..e4ae53066 100644
--- a/pkg/consensus/payload.go
+++ b/pkg/consensus/payload.go
@@ -233,7 +233,7 @@ func (p *Payload) encodeData() {
 	}
 }
 
-// decode data of payload into it's message
+// decode data of payload into its message.
 func (p *Payload) decodeData() error {
 	br := io.NewBinReaderFromBuf(p.Extensible.Data)
 	p.message.DecodeBinary(br)
diff --git a/pkg/core/block/block.go b/pkg/core/block/block.go
index 8feff8942..37d705ef5 100644
--- a/pkg/core/block/block.go
+++ b/pkg/core/block/block.go
@@ -215,7 +215,7 @@ func (b *Block) UnmarshalJSON(data []byte) error {
 	return nil
 }
 
-// GetExpectedBlockSize returns expected block size which should be equal to io.GetVarSize(b)
+// GetExpectedBlockSize returns expected block size which should be equal to io.GetVarSize(b).
 func (b *Block) GetExpectedBlockSize() int {
 	var transactionsSize int
 	for _, tx := range b.Transactions {
diff --git a/pkg/core/block/header.go b/pkg/core/block/header.go
index e7515dcab..c4025428d 100644
--- a/pkg/core/block/header.go
+++ b/pkg/core/block/header.go
@@ -11,7 +11,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/util"
 )
 
-// Header holds the base info of a block
+// Header holds the base info of a block.
 type Header struct {
 	// Version of the block.
 	Version uint32
@@ -84,7 +84,7 @@ func (b *Header) DecodeBinary(br *io.BinReader) {
 	b.Script.DecodeBinary(br)
 }
 
-// EncodeBinary implements Serializable interface
+// EncodeBinary implements Serializable interface.
 func (b *Header) EncodeBinary(bw *io.BinWriter) {
 	b.encodeHashableFields(bw)
 	bw.WriteVarUint(1)
diff --git a/pkg/core/dao/dao.go b/pkg/core/dao/dao.go
index 9e1f371f7..12e4ecfe7 100644
--- a/pkg/core/dao/dao.go
+++ b/pkg/core/dao/dao.go
@@ -17,7 +17,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/util"
 )
 
-// HasTransaction errors
+// HasTransaction errors.
 var (
 	// ErrAlreadyExists is returned when transaction exists in dao.
 	ErrAlreadyExists = errors.New("transaction already exists")
diff --git a/pkg/core/fee/calculate.go b/pkg/core/fee/calculate.go
index c15874932..4942f3f89 100644
--- a/pkg/core/fee/calculate.go
+++ b/pkg/core/fee/calculate.go
@@ -10,7 +10,7 @@ import (
 // ECDSAVerifyPrice is a gas price of a single verification.
 const ECDSAVerifyPrice = 1 << 15
 
-// Calculate returns network fee for transaction
+// Calculate returns network fee for transaction.
 func Calculate(base int64, script []byte) (int64, int) {
 	var (
 		netFee int64
diff --git a/pkg/core/helper_test.go b/pkg/core/helper_test.go
index 32a470175..24c8cafd1 100644
--- a/pkg/core/helper_test.go
+++ b/pkg/core/helper_test.go
@@ -44,7 +44,7 @@ import (
 	"go.uber.org/zap/zaptest"
 )
 
-// multisig address which possess all NEO
+// multisig address which possess all NEO.
 var neoOwner = testchain.MultisigScriptHash()
 
 // newTestChain should be called before newBlock invocation to properly setup
diff --git a/pkg/core/mempool/mem_pool.go b/pkg/core/mempool/mem_pool.go
index 1215b9f52..53b6f60bb 100644
--- a/pkg/core/mempool/mem_pool.go
+++ b/pkg/core/mempool/mem_pool.go
@@ -47,7 +47,7 @@ type item struct {
 type items []item
 
 // utilityBalanceAndFees stores sender's balance and overall fees of
-// sender's transactions which are currently in mempool
+// sender's transactions which are currently in mempool.
 type utilityBalanceAndFees struct {
 	balance *big.Int
 	feeSum  *big.Int
@@ -158,7 +158,7 @@ func (mp *Pool) HasConflicts(t *transaction.Transaction, fee Feer) bool {
 }
 
 // tryAddSendersFee tries to add system fee and network fee to the total sender`s fee in mempool
-// and returns false if both balance check is required and sender has not enough GAS to pay
+// and returns false if both balance check is required and sender has not enough GAS to pay.
 func (mp *Pool) tryAddSendersFee(tx *transaction.Transaction, feer Feer, needCheck bool) bool {
 	payer := tx.Signers[mp.payerIndex].Account
 	senderFee, ok := mp.fees[payer]
@@ -304,7 +304,7 @@ func (mp *Pool) Remove(hash util.Uint256, feer Feer) {
 	mp.lock.Unlock()
 }
 
-// removeInternal is an internal unlocked representation of Remove
+// removeInternal is an internal unlocked representation of Remove.
 func (mp *Pool) removeInternal(hash util.Uint256, feer Feer) {
 	if tx, ok := mp.verifiedMap[hash]; ok {
 		var num int
diff --git a/pkg/core/mpt/batch_test.go b/pkg/core/mpt/batch_test.go
index dffb4b9ae..9438b8e2b 100644
--- a/pkg/core/mpt/batch_test.go
+++ b/pkg/core/mpt/batch_test.go
@@ -281,7 +281,7 @@ var _ = printNode
 
 // This function is unused, but is helpful for debugging
 // as it provides more readable Trie representation compared to
-// `spew.Dump()`
+// `spew.Dump()`.
 func printNode(prefix string, n Node) {
 	switch tn := n.(type) {
 	case *HashNode:
diff --git a/pkg/core/native/ledger.go b/pkg/core/native/ledger.go
index 4dfd6b313..ad9b68185 100644
--- a/pkg/core/native/ledger.go
+++ b/pkg/core/native/ledger.go
@@ -192,7 +192,7 @@ func getTransactionAndHeight(cd *dao.Cached, item stackitem.Item) (*transaction.
 	return cd.GetTransaction(hash)
 }
 
-// BlockToStackItem converts block.Block to stackitem.Item
+// BlockToStackItem converts block.Block to stackitem.Item.
 func BlockToStackItem(b *block.Block) stackitem.Item {
 	return stackitem.NewArray([]stackitem.Item{
 		stackitem.NewByteArray(b.Hash().BytesBE()),
@@ -206,7 +206,7 @@ func BlockToStackItem(b *block.Block) stackitem.Item {
 	})
 }
 
-// TransactionToStackItem converts transaction.Transaction to stackitem.Item
+// TransactionToStackItem converts transaction.Transaction to stackitem.Item.
 func TransactionToStackItem(t *transaction.Transaction) stackitem.Item {
 	return stackitem.NewArray([]stackitem.Item{
 		stackitem.NewByteArray(t.Hash().BytesBE()),
diff --git a/pkg/core/native/name_service_test.go b/pkg/core/native/name_service_test.go
index bc741051f..325ffd831 100644
--- a/pkg/core/native/name_service_test.go
+++ b/pkg/core/native/name_service_test.go
@@ -10,7 +10,7 @@ import (
 )
 
 // The specification is following C# code:
-// string domain = string.Join('.', name.Split('.')[^2..]);
+//   string domain = string.Join('.', name.Split('.')[^2..]);
 func TestParseDomain(t *testing.T) {
 	testCases := []struct {
 		name   string
diff --git a/pkg/core/native/oracle.go b/pkg/core/native/oracle.go
index abd99fbf5..b6deb469c 100644
--- a/pkg/core/native/oracle.go
+++ b/pkg/core/native/oracle.go
@@ -56,7 +56,7 @@ const (
 	maxFilterLength   = 128
 	maxCallbackLength = 32
 	maxUserDataLength = 512
-	// maxRequestsCount is the maximum number of requests per URL
+	// maxRequestsCount is the maximum number of requests per URL.
 	maxRequestsCount = 256
 
 	// DefaultOracleRequestPrice is default amount GAS needed for oracle request.
@@ -520,7 +520,7 @@ func (o *Oracle) getSerializableFromDAO(d dao.DAO, key []byte, item io.Serializa
 	return getSerializableFromDAO(o.ID, d, key, item)
 }
 
-// updateCache updates cached Oracle values if they've been changed
+// updateCache updates cached Oracle values if they've been changed.
 func (o *Oracle) updateCache(d dao.DAO) error {
 	orc, _ := o.Module.Load().(services.Oracle)
 	if orc == nil {
diff --git a/pkg/core/native/policy.go b/pkg/core/native/policy.go
index 8c063bca7..78f346605 100644
--- a/pkg/core/native/policy.go
+++ b/pkg/core/native/policy.go
@@ -243,7 +243,7 @@ func (p *Policy) isBlocked(ic *interop.Context, args []stackitem.Item) stackitem
 	return stackitem.NewBool(p.IsBlockedInternal(ic.DAO, hash))
 }
 
-// IsBlockedInternal checks whether provided account is blocked
+// IsBlockedInternal checks whether provided account is blocked.
 func (p *Policy) IsBlockedInternal(dao dao.DAO, hash util.Uint160) bool {
 	p.lock.RLock()
 	defer p.lock.RUnlock()
diff --git a/pkg/core/state/contract.go b/pkg/core/state/contract.go
index 6c2fd0310..3c6da196b 100644
--- a/pkg/core/state/contract.go
+++ b/pkg/core/state/contract.go
@@ -54,7 +54,7 @@ func (c *Contract) EncodeBinary(w *io.BinWriter) {
 	stackitem.EncodeBinaryStackItem(si, w)
 }
 
-// ToStackItem converts state.Contract to stackitem.Item
+// ToStackItem converts state.Contract to stackitem.Item.
 func (c *Contract) ToStackItem() (stackitem.Item, error) {
 	rawNef, err := c.NEF.Bytes()
 	if err != nil {
diff --git a/pkg/core/state/notification_event.go b/pkg/core/state/notification_event.go
index d7b2706e8..a7c032b76 100644
--- a/pkg/core/state/notification_event.go
+++ b/pkg/core/state/notification_event.go
@@ -129,7 +129,7 @@ func (ne *NotificationEvent) UnmarshalJSON(data []byte) error {
 	return nil
 }
 
-// appExecResultAux is an auxiliary struct for JSON marshalling
+// appExecResultAux is an auxiliary struct for JSON marshalling.
 type appExecResultAux struct {
 	Container util.Uint256 `json:"container"`
 }
diff --git a/pkg/core/storage/badgerdb_store.go b/pkg/core/storage/badgerdb_store.go
index 277487058..619ca592a 100644
--- a/pkg/core/storage/badgerdb_store.go
+++ b/pkg/core/storage/badgerdb_store.go
@@ -17,12 +17,12 @@ type BadgerDBStore struct {
 	db *badger.DB
 }
 
-// BadgerDBBatch is a wrapper around badger.WriteBatch, compatible with Batch interface
+// BadgerDBBatch is a wrapper around badger.WriteBatch, compatible with Batch interface.
 type BadgerDBBatch struct {
 	batch *badger.WriteBatch
 }
 
-// Delete implements the Batch interface
+// Delete implements the Batch interface.
 func (b *BadgerDBBatch) Delete(key []byte) {
 	err := b.batch.Delete(key)
 	if err != nil {
@@ -30,7 +30,7 @@ func (b *BadgerDBBatch) Delete(key []byte) {
 	}
 }
 
-// Put implements the Batch interface
+// Put implements the Batch interface.
 func (b *BadgerDBBatch) Put(key, value []byte) {
 	keycopy := make([]byte, len(key))
 	copy(keycopy, key)
diff --git a/pkg/core/storage/store.go b/pkg/core/storage/store.go
index 14bd13888..fe2d15703 100644
--- a/pkg/core/storage/store.go
+++ b/pkg/core/storage/store.go
@@ -69,7 +69,7 @@ func (k KeyPrefix) Bytes() []byte {
 }
 
 // AppendPrefix appends byteslice b to the given KeyPrefix.
-// AppendKeyPrefix(SYSVersion, []byte{0x00, 0x01})
+// AppendKeyPrefix(SYSVersion, []byte{0x00, 0x01}).
 func AppendPrefix(k KeyPrefix, b []byte) []byte {
 	dest := make([]byte, len(b)+1)
 	dest[0] = byte(k)
@@ -78,7 +78,7 @@ func AppendPrefix(k KeyPrefix, b []byte) []byte {
 }
 
 // AppendPrefixInt append int n to the given KeyPrefix.
-//AppendPrefixInt(SYSCurrentHeader, 10001)
+//   AppendPrefixInt(SYSCurrentHeader, 10001)
 func AppendPrefixInt(k KeyPrefix, n int) []byte {
 	b := make([]byte, 4)
 	binary.LittleEndian.PutUint32(b, uint32(n))
diff --git a/pkg/core/transaction/attrtype.go b/pkg/core/transaction/attrtype.go
index c6879fefa..7f339245f 100644
--- a/pkg/core/transaction/attrtype.go
+++ b/pkg/core/transaction/attrtype.go
@@ -6,9 +6,9 @@ package transaction
 type AttrType uint8
 
 const (
-	// ReservedLowerBound is the lower bound of reserved attribute types
+	// ReservedLowerBound is the lower bound of reserved attribute types.
 	ReservedLowerBound = 0xe0
-	// ReservedUpperBound is the upper bound of reserved attribute types
+	// ReservedUpperBound is the upper bound of reserved attribute types.
 	ReservedUpperBound = 0xff
 )
 
diff --git a/pkg/core/transaction/helper_test.go b/pkg/core/transaction/helper_test.go
index 13987a18c..53f53e079 100644
--- a/pkg/core/transaction/helper_test.go
+++ b/pkg/core/transaction/helper_test.go
@@ -8,7 +8,7 @@ import (
 )
 
 var (
-	// tx from C# privnet 0x25426643feed564cd3e57f346d6c68692f5622b3063da11c5572d99ee1a5b49a
+	// tx from C# privnet 0x25426643feed564cd3e57f346d6c68692f5622b3063da11c5572d99ee1a5b49a.
 	rawInvocationTX = "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"
 )
 
diff --git a/pkg/core/transaction/signer.go b/pkg/core/transaction/signer.go
index 7cb93940e..ef409e25b 100644
--- a/pkg/core/transaction/signer.go
+++ b/pkg/core/transaction/signer.go
@@ -8,7 +8,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/util"
 )
 
-// The maximum number of AllowedContracts or AllowedGroups
+// The maximum number of AllowedContracts or AllowedGroups.
 const maxSubitems = 16
 
 // Signer implements a Transaction signer.
diff --git a/pkg/core/transaction/transaction.go b/pkg/core/transaction/transaction.go
index d49b8061d..893c72024 100644
--- a/pkg/core/transaction/transaction.go
+++ b/pkg/core/transaction/transaction.go
@@ -230,7 +230,7 @@ func (t *Transaction) DecodeHashableFields(buf []byte) error {
 	return nil
 }
 
-// Bytes converts the transaction to []byte
+// Bytes converts the transaction to []byte.
 func (t *Transaction) Bytes() []byte {
 	buf := io.NewBufBinWriter()
 	t.EncodeBinary(buf.BinWriter)
@@ -240,7 +240,7 @@ func (t *Transaction) Bytes() []byte {
 	return buf.Bytes()
 }
 
-// NewTransactionFromBytes decodes byte array into *Transaction
+// NewTransactionFromBytes decodes byte array into *Transaction.
 func NewTransactionFromBytes(b []byte) (*Transaction, error) {
 	tx := &Transaction{}
 	r := io.NewBinReaderFromBuf(b)
@@ -257,7 +257,7 @@ func NewTransactionFromBytes(b []byte) (*Transaction, error) {
 }
 
 // FeePerByte returns NetworkFee of the transaction divided by
-// its size
+// its size.
 func (t *Transaction) FeePerByte() int64 {
 	return t.NetworkFee / int64(t.Size())
 }
@@ -280,7 +280,7 @@ func (t *Transaction) Sender() util.Uint160 {
 }
 
 // transactionJSON is a wrapper for Transaction and
-// used for correct marhalling of transaction.Data
+// used for correct marhalling of transaction.Data.
 type transactionJSON struct {
 	TxID            util.Uint256 `json:"hash"`
 	Size            int          `json:"size"`
diff --git a/pkg/crypto/keys/publickey.go b/pkg/crypto/keys/publickey.go
index a3660d616..b7954bdd1 100644
--- a/pkg/crypto/keys/publickey.go
+++ b/pkg/crypto/keys/publickey.go
@@ -203,7 +203,7 @@ func NewPublicKeyFromASN1(data []byte) (*PublicKey, error) {
 // 1. Secp256k1 (Koblitz curve): y² = x³ + b,
 // 2. Secp256r1 (Random curve): y² = x³ - 3x + b.
 // To decode compressed curve point we perform the following operation: y = sqrt(x³ + ax + b mod p)
-// where `p` denotes the order of the underlying curve field
+// where `p` denotes the order of the underlying curve field.
 func decodeCompressedY(x *big.Int, ylsb uint, curve elliptic.Curve) (*big.Int, error) {
 	var a *big.Int
 	switch curve.(type) {
diff --git a/pkg/encoding/bigint/bigint.go b/pkg/encoding/bigint/bigint.go
index ed562821d..15d6df77b 100644
--- a/pkg/encoding/bigint/bigint.go
+++ b/pkg/encoding/bigint/bigint.go
@@ -9,7 +9,7 @@ import (
 const (
 	// MaxBytesLen is the maximum length of serialized integer suitable for Neo VM.
 	MaxBytesLen = 33 // 32 bytes for 256-bit integer plus 1 if padding needed
-	// wordSizeBytes is a size of a big.Word (uint) in bytes.`
+	// wordSizeBytes is a size of a big.Word (uint) in bytes.
 	wordSizeBytes = bits.UintSize / 8
 )
 
diff --git a/pkg/encoding/bigint/bigint_test.go b/pkg/encoding/bigint/bigint_test.go
index 7b0455c34..bb8c2207c 100644
--- a/pkg/encoding/bigint/bigint_test.go
+++ b/pkg/encoding/bigint/bigint_test.go
@@ -149,7 +149,7 @@ var stringCases = []struct {
 
 // this cases are from stdlib
 // https://github.com/dotnet/runtime/blob/master/src/libraries/System.Runtime.Numerics/tests/BigInteger/ToByteArray.cs#L96
-// note that they are in big-endian
+// note that they are in big-endian.
 var stdlibCases = []struct {
 	numStr string
 	buf    []byte
diff --git a/pkg/encoding/fixedn/fixed8.go b/pkg/encoding/fixedn/fixed8.go
index 01abc8720..af3b82f9c 100644
--- a/pkg/encoding/fixedn/fixed8.go
+++ b/pkg/encoding/fixedn/fixed8.go
@@ -65,7 +65,7 @@ func Fixed8FromFloat(val float64) Fixed8 {
 }
 
 // Fixed8FromString parses s which must be a fixed point number
-// with precision up to 10^-8
+// with precision up to 10^-8.
 func Fixed8FromString(s string) (Fixed8, error) {
 	num, err := FromString(s, precision)
 	if err != nil {
diff --git a/pkg/interop/native/std/std.go b/pkg/interop/native/std/std.go
index af263c8ba..135de27eb 100644
--- a/pkg/interop/native/std/std.go
+++ b/pkg/interop/native/std/std.go
@@ -46,11 +46,11 @@ func JSONSerialize(item interface{}) []byte {
 // JSONDeserialize deserializes value from json. It uses `jsonDeserialize` method of StdLib
 // native contract.
 // It performs deserialization as follows:
-// strings -> []byte (string) from base64
-// integers -> (u)int* types
-// null -> interface{}(nil)
-// arrays -> []interface{}
-// maps -> map[string]interface{}
+//   strings -> []byte (string) from base64
+//   integers -> (u)int* types
+//   null -> interface{}(nil)
+//   arrays -> []interface{}
+//   maps -> map[string]interface{}
 func JSONDeserialize(data []byte) interface{} {
 	return contract.Call(interop.Hash160(Hash), "jsonDeserialize", contract.NoneFlag,
 		data)
diff --git a/pkg/interop/types.go b/pkg/interop/types.go
index f6ae0b11e..5ed473ccc 100644
--- a/pkg/interop/types.go
+++ b/pkg/interop/types.go
@@ -13,5 +13,5 @@ type Hash256 []byte
 type PublicKey []byte
 
 // Interface represents interop interface type which is needed for
-// transparent handling of VM-internal types (e.g. storage.Context)
+// transparent handling of VM-internal types (e.g. storage.Context).
 type Interface interface{}
diff --git a/pkg/io/binaryReader.go b/pkg/io/binaryReader.go
index 6915f5109..fdcb08249 100644
--- a/pkg/io/binaryReader.go
+++ b/pkg/io/binaryReader.go
@@ -167,7 +167,7 @@ func (r *BinReader) ReadVarUint() uint64 {
 }
 
 // ReadVarBytes reads the next set of bytes from the underlying reader.
-// ReadVarUInt() is used to determine how large that slice is
+// ReadVarUInt() is used to determine how large that slice is.
 func (r *BinReader) ReadVarBytes(maxSize ...int) []byte {
 	n := r.ReadVarUint()
 	ms := MaxArraySize
diff --git a/pkg/network/capability/capability.go b/pkg/network/capability/capability.go
index 7b489ef3a..32073129f 100644
--- a/pkg/network/capability/capability.go
+++ b/pkg/network/capability/capability.go
@@ -6,10 +6,10 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/io"
 )
 
-// MaxCapabilities is the maximum number of capabilities per payload
+// MaxCapabilities is the maximum number of capabilities per payload.
 const MaxCapabilities = 32
 
-// Capabilities is a list of Capability
+// Capabilities is a list of Capability.
 type Capabilities []Capability
 
 // DecodeBinary implements Serializable interface.
@@ -49,7 +49,7 @@ func (cs Capabilities) checkUniqueCapabilities() error {
 	return nil
 }
 
-// Capability describes network service available for node
+// Capability describes network service available for node.
 type Capability struct {
 	Type Type
 	Data io.Serializable
@@ -80,7 +80,7 @@ func (c *Capability) EncodeBinary(bw *io.BinWriter) {
 	c.Data.EncodeBinary(bw)
 }
 
-// Node represents full node capability with start height
+// Node represents full node capability with start height.
 type Node struct {
 	StartHeight uint32
 }
@@ -95,9 +95,9 @@ func (n *Node) EncodeBinary(bw *io.BinWriter) {
 	bw.WriteU32LE(n.StartHeight)
 }
 
-// Server represents TCP or WS server capability with port
+// Server represents TCP or WS server capability with port.
 type Server struct {
-	// Port is the port this server is listening on
+	// Port is the port this server is listening on.
 	Port uint16
 }
 
diff --git a/pkg/network/capability/type.go b/pkg/network/capability/type.go
index b25b15397..0955c1b38 100644
--- a/pkg/network/capability/type.go
+++ b/pkg/network/capability/type.go
@@ -1,13 +1,13 @@
 package capability
 
-// Type represents node capability type
+// Type represents node capability type.
 type Type byte
 
 const (
-	// TCPServer represents TCP node capability type
+	// TCPServer represents TCP node capability type.
 	TCPServer Type = 0x01
-	// WSServer represents WebSocket node capability type
+	// WSServer represents WebSocket node capability type.
 	WSServer Type = 0x02
-	// FullNode represents full node capability type
+	// FullNode represents full node capability type.
 	FullNode Type = 0x10
 )
diff --git a/pkg/network/discovery.go b/pkg/network/discovery.go
index 25da5a5ba..1a56b703f 100644
--- a/pkg/network/discovery.go
+++ b/pkg/network/discovery.go
@@ -28,7 +28,7 @@ type Discoverer interface {
 	GoodPeers() []AddressWithCapabilities
 }
 
-// AddressWithCapabilities represents node address with its capabilities
+// AddressWithCapabilities represents node address with its capabilities.
 type AddressWithCapabilities struct {
 	Address      string
 	Capabilities capability.Capabilities
@@ -94,7 +94,7 @@ func (d *DefaultDiscovery) PoolCount() int {
 }
 
 // pushToPoolOrDrop tries to push address given into the pool, but if the pool
-// is already full, it just drops it
+// is already full, it just drops it.
 func (d *DefaultDiscovery) pushToPoolOrDrop(addr string) {
 	select {
 	case d.pool <- addr:
diff --git a/pkg/network/message.go b/pkg/network/message.go
index 1a8025cb0..f2892aae9 100644
--- a/pkg/network/message.go
+++ b/pkg/network/message.go
@@ -34,10 +34,10 @@ type Message struct {
 	StateRootInHeader bool
 }
 
-// MessageFlag represents compression level of message payload
+// MessageFlag represents compression level of message payload.
 type MessageFlag byte
 
-// Possible message flags
+// Possible message flags.
 const (
 	Compressed MessageFlag = 1 << iota
 	None       MessageFlag = 0
@@ -48,17 +48,17 @@ type CommandType byte
 
 // Valid protocol commands used to send between nodes.
 const (
-	// handshaking
+	// Handshaking.
 	CMDVersion CommandType = 0x00
 	CMDVerack  CommandType = 0x01
 
-	// connectivity
+	// Connectivity.
 	CMDGetAddr CommandType = 0x10
 	CMDAddr    CommandType = 0x11
 	CMDPing    CommandType = 0x18
 	CMDPong    CommandType = 0x19
 
-	// synchronization
+	// Synchronization.
 	CMDGetHeaders       CommandType = 0x20
 	CMDHeaders          CommandType = 0x21
 	CMDGetBlocks        CommandType = 0x24
@@ -73,13 +73,13 @@ const (
 	CMDP2PNotaryRequest             = CommandType(payload.P2PNotaryRequestType)
 	CMDReject           CommandType = 0x2f
 
-	// SPV protocol
+	// SPV protocol.
 	CMDFilterLoad  CommandType = 0x30
 	CMDFilterAdd   CommandType = 0x31
 	CMDFilterClear CommandType = 0x32
 	CMDMerkleBlock CommandType = 0x38
 
-	// others
+	// Others.
 	CMDAlert CommandType = 0x40
 )
 
@@ -197,7 +197,7 @@ func (m *Message) Bytes() ([]byte, error) {
 }
 
 // tryCompressPayload sets message's compressed payload to serialized
-// payload and compresses it in case if its size exceeds CompressionMinSize
+// payload and compresses it in case if its size exceeds CompressionMinSize.
 func (m *Message) tryCompressPayload() error {
 	if m.Payload == nil {
 		return nil
diff --git a/pkg/network/payload/getblockbyindex.go b/pkg/network/payload/getblockbyindex.go
index a4e59db1d..372af4d08 100644
--- a/pkg/network/payload/getblockbyindex.go
+++ b/pkg/network/payload/getblockbyindex.go
@@ -6,13 +6,13 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/io"
 )
 
-// GetBlockByIndex payload
+// GetBlockByIndex payload.
 type GetBlockByIndex struct {
 	IndexStart uint32
 	Count      int16
 }
 
-// NewGetBlockByIndex returns GetBlockByIndex payload with specified start index and count
+// NewGetBlockByIndex returns GetBlockByIndex payload with specified start index and count.
 func NewGetBlockByIndex(indexStart uint32, count int16) *GetBlockByIndex {
 	return &GetBlockByIndex{
 		IndexStart: indexStart,
diff --git a/pkg/network/payload/getblocks.go b/pkg/network/payload/getblocks.go
index e3434ebce..b881559a3 100644
--- a/pkg/network/payload/getblocks.go
+++ b/pkg/network/payload/getblocks.go
@@ -12,9 +12,9 @@ const (
 	MaxHashesCount = 500
 )
 
-// GetBlocks contains fields and methods to be shared with the
+// GetBlocks contains getblocks message payload fields.
 type GetBlocks struct {
-	// hash of latest block that node requests
+	// Hash of the latest block that node requests.
 	HashStart util.Uint256
 	Count     int16
 }
diff --git a/pkg/rpc/client/client.go b/pkg/rpc/client/client.go
index 4623a9070..9011e680c 100644
--- a/pkg/rpc/client/client.go
+++ b/pkg/rpc/client/client.go
@@ -21,7 +21,7 @@ import (
 const (
 	defaultDialTimeout    = 4 * time.Second
 	defaultRequestTimeout = 4 * time.Second
-	// number of blocks after which cache is expired
+	// Number of blocks after which cache is expired.
 	cacheTimeout = 100
 )
 
@@ -52,14 +52,14 @@ type Options struct {
 	RequestTimeout time.Duration
 }
 
-// cache stores cache values for the RPC client methods
+// cache stores cache values for the RPC client methods.
 type cache struct {
 	calculateValidUntilBlock calculateValidUntilBlockCache
 	nativeHashes             map[string]util.Uint160
 }
 
 // calculateValidUntilBlockCache stores cached number of validators and
-// cache expiration value in blocks
+// cache expiration value in blocks.
 type calculateValidUntilBlockCache struct {
 	validatorsCount uint32
 	expiresAt       uint32
diff --git a/pkg/rpc/client/rpc.go b/pkg/rpc/client/rpc.go
index db88ff0df..e51078fbf 100644
--- a/pkg/rpc/client/rpc.go
+++ b/pkg/rpc/client/rpc.go
@@ -463,7 +463,7 @@ func (c *Client) InvokeContractVerify(contract util.Uint160, params []smartcontr
 	return c.invokeSomething("invokecontractverify", p, signers, witnesses...)
 }
 
-// invokeSomething is an inner wrapper for Invoke* functions
+// invokeSomething is an inner wrapper for Invoke* functions.
 func (c *Client) invokeSomething(method string, p request.RawParams, signers []transaction.Signer, witnesses ...transaction.Witness) (*result.Invoke, error) {
 	var resp = new(result.Invoke)
 	if signers != nil {
diff --git a/pkg/rpc/request/types.go b/pkg/rpc/request/types.go
index 8da4f31b5..450815489 100644
--- a/pkg/rpc/request/types.go
+++ b/pkg/rpc/request/types.go
@@ -61,7 +61,7 @@ type In struct {
 // batch: https://www.jsonrpc.org/specification#batch.
 type Batch []In
 
-// MarshalJSON implements json.Marshaler interface
+// MarshalJSON implements json.Marshaler interface.
 func (r Request) MarshalJSON() ([]byte, error) {
 	if r.In != nil {
 		return json.Marshal(r.In)
diff --git a/pkg/rpc/response/errors.go b/pkg/rpc/response/errors.go
index 70201403b..e19df1166 100644
--- a/pkg/rpc/response/errors.go
+++ b/pkg/rpc/response/errors.go
@@ -20,17 +20,17 @@ type (
 var (
 	// ErrInvalidParams represents a generic 'invalid parameters' error.
 	ErrInvalidParams = NewInvalidParamsError("", nil)
-	// ErrAlreadyExists represents SubmitError with code -501
+	// ErrAlreadyExists represents SubmitError with code -501.
 	ErrAlreadyExists = NewSubmitError(-501, "Block or transaction already exists and cannot be sent repeatedly.")
-	// ErrOutOfMemory represents SubmitError with code -502
+	// ErrOutOfMemory represents SubmitError with code -502.
 	ErrOutOfMemory = NewSubmitError(-502, "The memory pool is full and no more transactions can be sent.")
-	// ErrUnableToVerify represents SubmitError with code -503
+	// ErrUnableToVerify represents SubmitError with code -503.
 	ErrUnableToVerify = NewSubmitError(-503, "The block cannot be validated.")
-	// ErrValidationFailed represents SubmitError with code -504
+	// ErrValidationFailed represents SubmitError with code -504.
 	ErrValidationFailed = NewSubmitError(-504, "Block or transaction validation failed.")
-	// ErrPolicyFail represents SubmitError with code -505
+	// ErrPolicyFail represents SubmitError with code -505.
 	ErrPolicyFail = NewSubmitError(-505, "One of the Policy filters failed.")
-	// ErrUnknown represents SubmitError with code -500
+	// ErrUnknown represents SubmitError with code -500.
 	ErrUnknown = NewSubmitError(-500, "Unknown error.")
 )
 
@@ -47,7 +47,7 @@ func NewError(code int64, httpCode int, message string, data string, cause error
 }
 
 // NewParseError creates a new error with code
-// -32700.:%s
+// -32700.
 func NewParseError(data string, cause error) *Error {
 	return NewError(-32700, http.StatusBadRequest, "Parse Error", data, cause)
 }
@@ -77,13 +77,13 @@ func NewInternalServerError(data string, cause error) *Error {
 }
 
 // NewRPCError creates a new error with
-// code -100
+// code -100.
 func NewRPCError(message string, data string, cause error) *Error {
 	return NewError(-100, http.StatusUnprocessableEntity, message, data, cause)
 }
 
 // NewSubmitError creates a new error with
-// specified error code and error message
+// specified error code and error message.
 func NewSubmitError(code int64, message string) *Error {
 	return NewError(code, http.StatusUnprocessableEntity, message, "", nil)
 }
diff --git a/pkg/rpc/response/result/unclaimed_gas.go b/pkg/rpc/response/result/unclaimed_gas.go
index af051acdd..ae62b4124 100644
--- a/pkg/rpc/response/result/unclaimed_gas.go
+++ b/pkg/rpc/response/result/unclaimed_gas.go
@@ -9,13 +9,13 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/util"
 )
 
-// UnclaimedGas response wrapper
+// UnclaimedGas response wrapper.
 type UnclaimedGas struct {
 	Address   util.Uint160
 	Unclaimed big.Int
 }
 
-// unclaimedGas is an auxiliary struct for JSON marhsalling
+// unclaimedGas is an auxiliary struct for JSON marhsalling.
 type unclaimedGas struct {
 	Address   string `json:"address"`
 	Unclaimed string `json:"unclaimed"`
diff --git a/pkg/rpc/rpc_config.go b/pkg/rpc/rpc_config.go
index 27bd8bb4b..17aedec0c 100644
--- a/pkg/rpc/rpc_config.go
+++ b/pkg/rpc/rpc_config.go
@@ -5,7 +5,7 @@ import (
 )
 
 type (
-	// Config is an RPC service configuration information
+	// Config is an RPC service configuration information.
 	Config struct {
 		Address              string `yaml:"Address"`
 		Enabled              bool   `yaml:"Enabled"`
diff --git a/pkg/rpc/server/server.go b/pkg/rpc/server/server.go
index 5c06eb6b3..3a62b3e6d 100644
--- a/pkg/rpc/server/server.go
+++ b/pkg/rpc/server/server.go
@@ -1179,7 +1179,7 @@ func (s *Server) getNextBlockValidators(_ request.Params) (interface{}, *respons
 	return res, nil
 }
 
-// getCommittee returns the current list of NEO committee members
+// getCommittee returns the current list of NEO committee members.
 func (s *Server) getCommittee(_ request.Params) (interface{}, *response.Error) {
 	keys, err := s.chain.GetCommittee()
 	if err != nil {
diff --git a/pkg/smartcontract/convertor.go b/pkg/smartcontract/convertor.go
index 680238f29..c592807b8 100644
--- a/pkg/smartcontract/convertor.go
+++ b/pkg/smartcontract/convertor.go
@@ -7,7 +7,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
 )
 
-// ParameterFromStackItem converts stackitem.Item to Parameter
+// ParameterFromStackItem converts stackitem.Item to Parameter.
 func ParameterFromStackItem(i stackitem.Item, seen map[stackitem.Item]bool) Parameter {
 	switch t := i.(type) {
 	case stackitem.Null, *stackitem.Pointer:
diff --git a/pkg/smartcontract/param_type.go b/pkg/smartcontract/param_type.go
index 2875e60bd..2ea611a95 100644
--- a/pkg/smartcontract/param_type.go
+++ b/pkg/smartcontract/param_type.go
@@ -38,7 +38,7 @@ const (
 // fileBytesParamType is a string representation of `filebytes` parameter type used in cli.
 const fileBytesParamType string = "filebytes"
 
-// validParamTypes contains a map of known ParamTypes
+// validParamTypes contains a map of known ParamTypes.
 var validParamTypes = map[ParamType]bool{
 	UnknownType:          true,
 	AnyType:              true,
diff --git a/pkg/smartcontract/trigger/trigger_type.go b/pkg/smartcontract/trigger/trigger_type.go
index 60f3c1b08..86a00ff39 100644
--- a/pkg/smartcontract/trigger/trigger_type.go
+++ b/pkg/smartcontract/trigger/trigger_type.go
@@ -40,7 +40,7 @@ const (
 	All Type = OnPersist | PostPersist | Verification | Application
 )
 
-// FromString converts string to trigger Type
+// FromString converts string to trigger Type.
 func FromString(str string) (Type, error) {
 	triggers := []Type{OnPersist, PostPersist, Verification, Application, All}
 	str = strings.ToLower(str)
diff --git a/pkg/util/uint256.go b/pkg/util/uint256.go
index 9e3c0df2f..ff764d4da 100644
--- a/pkg/util/uint256.go
+++ b/pkg/util/uint256.go
@@ -63,7 +63,7 @@ func (u Uint256) BytesBE() []byte {
 	return u[:]
 }
 
-// Reverse reverses the Uint256 object
+// Reverse reverses the Uint256 object.
 func (u Uint256) Reverse() Uint256 {
 	res, _ := Uint256DecodeBytesLE(u.BytesBE())
 	return res
diff --git a/pkg/vm/opcode/opcode.go b/pkg/vm/opcode/opcode.go
index e1fd89a56..3d24b7ea7 100644
--- a/pkg/vm/opcode/opcode.go
+++ b/pkg/vm/opcode/opcode.go
@@ -7,7 +7,7 @@ type Opcode byte
 
 // Viable list of supported instruction constants.
 const (
-	// Constants
+	// Constants.
 	PUSHINT8   Opcode = 0x00
 	PUSHINT16  Opcode = 0x01
 	PUSHINT32  Opcode = 0x02
@@ -43,7 +43,7 @@ const (
 	PUSH15 Opcode = 0x1F
 	PUSH16 Opcode = 0x20
 
-	// Flow control
+	// Flow control.
 	NOP       Opcode = 0x21
 	JMP       Opcode = 0x22
 	JMPL      Opcode = 0x23 // JMP_L
@@ -68,7 +68,7 @@ const (
 	CALLA     Opcode = 0x36
 	CALLT     Opcode = 0x37
 
-	// Exceptions
+	// Exceptions.
 	ABORT      Opcode = 0x38
 	ASSERT     Opcode = 0x39
 	THROW      Opcode = 0x3A
@@ -81,7 +81,7 @@ const (
 	RET     Opcode = 0x40
 	SYSCALL Opcode = 0x41
 
-	// Stack
+	// Stack.
 	DEPTH    Opcode = 0x43
 	DROP     Opcode = 0x45
 	NIP      Opcode = 0x46
@@ -98,7 +98,7 @@ const (
 	REVERSE4 Opcode = 0x54
 	REVERSEN Opcode = 0x55
 
-	// Slots
+	// Slots.
 	INITSSLOT Opcode = 0x56
 	INITSLOT  Opcode = 0x57
 	LDSFLD0   Opcode = 0x58
@@ -150,7 +150,7 @@ const (
 	STARG6    Opcode = 0x86
 	STARG     Opcode = 0x87
 
-	// Splice
+	// Splice.
 	NEWBUFFER Opcode = 0x88
 	MEMCPY    Opcode = 0x89
 	CAT       Opcode = 0x8B
@@ -158,7 +158,7 @@ const (
 	LEFT      Opcode = 0x8D
 	RIGHT     Opcode = 0x8E
 
-	// Bitwise logic
+	// Bitwise logic.
 	INVERT   Opcode = 0x90
 	AND      Opcode = 0x91
 	OR       Opcode = 0x92
@@ -166,7 +166,7 @@ const (
 	EQUAL    Opcode = 0x97
 	NOTEQUAL Opcode = 0x98
 
-	// Arithmetic
+	// Arithmetic.
 	SIGN        Opcode = 0x99
 	ABS         Opcode = 0x9A
 	NEGATE      Opcode = 0x9B
@@ -195,7 +195,7 @@ const (
 	MAX         Opcode = 0xBA
 	WITHIN      Opcode = 0xBB
 
-	// Advanced data structures (arrays, structures, maps)
+	// Advanced data structures (arrays, structures, maps).
 	PACK         Opcode = 0xC0
 	UNPACK       Opcode = 0xC1
 	NEWARRAY0    Opcode = 0xC2
@@ -216,7 +216,7 @@ const (
 	CLEARITEMS   Opcode = 0xD3
 	POPITEM      Opcode = 0xD4
 
-	// Types
+	// Types.
 	ISNULL  Opcode = 0xD8
 	ISTYPE  Opcode = 0xD9
 	CONVERT Opcode = 0xDB
diff --git a/pkg/vm/stackitem/item.go b/pkg/vm/stackitem/item.go
index a0f8ba061..a8af99573 100644
--- a/pkg/vm/stackitem/item.go
+++ b/pkg/vm/stackitem/item.go
@@ -980,12 +980,12 @@ func (p *Pointer) Convert(typ Type) (Item, error) {
 	}
 }
 
-// ScriptHash returns pointer item hash
+// ScriptHash returns pointer item hash.
 func (p *Pointer) ScriptHash() util.Uint160 {
 	return p.hash
 }
 
-// Position returns pointer item position
+// Position returns pointer item position.
 func (p *Pointer) Position() int {
 	return p.pos
 }
diff --git a/pkg/vm/vm.go b/pkg/vm/vm.go
index 46f106482..f284d8c04 100644
--- a/pkg/vm/vm.go
+++ b/pkg/vm/vm.go
@@ -1487,7 +1487,7 @@ func getTryParams(op opcode.Opcode, p []byte) ([]byte, []byte) {
 	return p[:i], p[i:]
 }
 
-// getJumpCondition performs opcode specific comparison of a and b
+// getJumpCondition performs opcode specific comparison of a and b.
 func getJumpCondition(op opcode.Opcode, a, b *big.Int) bool {
 	cmp := a.Cmp(b)
 	switch op {
@@ -1790,17 +1790,17 @@ func bytesToPublicKey(b []byte, curve elliptic.Curve) *keys.PublicKey {
 	return pkey
 }
 
-// GetCallingScriptHash implements ScriptHashGetter interface
+// GetCallingScriptHash implements ScriptHashGetter interface.
 func (v *VM) GetCallingScriptHash() util.Uint160 {
 	return v.Context().callingScriptHash
 }
 
-// GetEntryScriptHash implements ScriptHashGetter interface
+// GetEntryScriptHash implements ScriptHashGetter interface.
 func (v *VM) GetEntryScriptHash() util.Uint160 {
 	return v.getContextScriptHash(v.Istack().Len() - 1)
 }
 
-// GetCurrentScriptHash implements ScriptHashGetter interface
+// GetCurrentScriptHash implements ScriptHashGetter interface.
 func (v *VM) GetCurrentScriptHash() util.Uint160 {
 	return v.getContextScriptHash(0)
 }
diff --git a/pkg/vm/vm_test.go b/pkg/vm/vm_test.go
index 2b3e97477..c70f9a282 100644
--- a/pkg/vm/vm_test.go
+++ b/pkg/vm/vm_test.go
@@ -641,7 +641,7 @@ func TestNOT(t *testing.T) {
 	t.Run("Buffer1", getTestFuncForVM(prog, false, stackitem.NewBuffer([]byte{1})))
 }
 
-// getBigInt returns 2^a+b
+// getBigInt returns 2^a+b.
 func getBigInt(a, b int64) *big.Int {
 	p := new(big.Int).Exp(big.NewInt(2), big.NewInt(a), nil)
 	p.Add(p, big.NewInt(b))
diff --git a/pkg/wallet/token.go b/pkg/wallet/token.go
index 0c1e90e9f..ecea33f93 100644
--- a/pkg/wallet/token.go
+++ b/pkg/wallet/token.go
@@ -25,7 +25,7 @@ func NewToken(tokenHash util.Uint160, name, symbol string, decimals int64, stand
 	}
 }
 
-// Address returns token address from hash
+// Address returns token address from hash.
 func (t *Token) Address() string {
 	return address.Uint160ToString(t.Hash)
 }
diff --git a/pkg/wallet/wallet.go b/pkg/wallet/wallet.go
index 4b8bf364e..e365849fb 100644
--- a/pkg/wallet/wallet.go
+++ b/pkg/wallet/wallet.go
@@ -54,7 +54,7 @@ func NewWallet(location string) (*Wallet, error) {
 	return newWallet(file), nil
 }
 
-// NewWalletFromFile creates a Wallet from the given wallet file path
+// NewWalletFromFile creates a Wallet from the given wallet file path.
 func NewWalletFromFile(path string) (*Wallet, error) {
 	file, err := os.OpenFile(path, os.O_RDWR, os.ModeAppend)
 	if err != nil {

From c76f8b8fbe254160b3c2793d19aeb2bff60d753c Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 12 May 2021 23:25:06 +0300
Subject: [PATCH 33/34] Makefile: use golangci-lint instead of golint

It includes golint and also has a lot of other useful linters.
---
 .circleci/config.yml            |  4 ++--
 .github/workflows/run_tests.yml | 25 +++++--------------------
 Makefile                        |  2 +-
 3 files changed, 8 insertions(+), 23 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 7b528d9eb..17e8ac260 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -41,8 +41,8 @@ jobs:
       - run:
           name: go-lint
           command: |
-            go get -u -v golang.org/x/lint/golint
-            golint -set_exit_status ./...
+            curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.40.0
+            make lint
 
   vet:
     working_directory: /go/src/github.com/nspcc-dev/neo-go
diff --git a/.github/workflows/run_tests.yml b/.github/workflows/run_tests.yml
index 190770028..8fecf7582 100644
--- a/.github/workflows/run_tests.yml
+++ b/.github/workflows/run_tests.yml
@@ -16,29 +16,14 @@ env:
 jobs:
   lint:
     name: Lint
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
 
     steps:
       - uses: actions/checkout@v2
-
-      - name: Set up Go
-        uses: actions/setup-go@v2
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v2
         with:
-          go-version: 1.16
-
-      - name: Restore Go modules from cache
-        uses: actions/cache@v2
-        with:
-          path: /home/runner/go/pkg/mod
-          key: deps-${{ hashFiles('go.sum') }}
-
-      - name: Update Go modules
-        run: go mod download -json
-
-      - name: Run linter
-        run: |
-          go get -u -v golang.org/x/lint/golint
-          make lint
+          version: latest
 
   vet:
     name: Vet
@@ -189,4 +174,4 @@ jobs:
         run: go mod download -json
 
       - name: Build Docker image
-        run: make image
\ No newline at end of file
+        run: make image
diff --git a/Makefile b/Makefile
index 06261b346..4ea0dc735 100644
--- a/Makefile
+++ b/Makefile
@@ -84,7 +84,7 @@ vet:
 	@go vet ./...
 
 lint:
-	@go list ./... | xargs -L1 golint -set_exit_status
+	@golangci-lint run
 
 fmt:
 	@gofmt -l -w -s $$(find . -type f -name '*.go'| grep -v "/vendor/")

From 50cb0450f25d61d3a4bd5577de480a5a5348b212 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Thu, 13 May 2021 00:06:08 +0300
Subject: [PATCH 34/34] circleci/workflows: drop vet run

golangci-lint already includes govet, so having it in a separate task doesn't
add any value (only increases CI running time).
---
 .circleci/config.yml            | 14 --------------
 .github/workflows/run_tests.yml | 24 ------------------------
 docs/release-instruction.md     |  1 -
 3 files changed, 39 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 17e8ac260..b2353748f 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -44,16 +44,6 @@ jobs:
             curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.40.0
             make lint
 
-  vet:
-    working_directory: /go/src/github.com/nspcc-dev/neo-go
-    executor: go1_16
-    steps:
-      - checkout
-      - gomod
-      - run:
-          name: go-vet
-          command: go vet ./...
-
   test_1_14:
     working_directory: /go/src/github.com/nspcc-dev/neo-go
     executor: go1_14
@@ -123,10 +113,6 @@ workflows:
   version: 2
   workflow:
     jobs:
-      - vet:
-          filters:
-            tags:
-              only: v/[0-9]+\.[0-9]+\.[0-9]+/
       - lint:
           filters:
             tags:
diff --git a/.github/workflows/run_tests.yml b/.github/workflows/run_tests.yml
index 8fecf7582..43d4587e3 100644
--- a/.github/workflows/run_tests.yml
+++ b/.github/workflows/run_tests.yml
@@ -25,30 +25,6 @@ jobs:
         with:
           version: latest
 
-  vet:
-    name: Vet
-    runs-on: ubuntu-18.04
-
-    steps:
-      - uses: actions/checkout@v2
-
-      - name: Set up Go
-        uses: actions/setup-go@v2
-        with:
-          go-version: 1.16
-
-      - name: Restore Go modules from cache
-        uses: actions/cache@v2
-        with:
-          path: /home/runner/go/pkg/mod
-          key: deps-${{ hashFiles('go.sum') }}
-
-      - name: Update Go modules
-        run: go mod download -json
-
-      - name: Run vet
-        run: go vet ./...
-
   test_cover:
     name: Coverage
     runs-on: ubuntu-18.04
diff --git a/docs/release-instruction.md b/docs/release-instruction.md
index bd02b1fc1..6310de5b9 100644
--- a/docs/release-instruction.md
+++ b/docs/release-instruction.md
@@ -8,7 +8,6 @@ list for a new release.
 These should run successfuly:
  * build
  * unit-tests
- * vet
  * lint
  * privnet with consensus nodes