*: remove io/ioutil uses

Close #1764.

cli/contract_test.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"encoding/hex"
 	"encoding/json"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -35,12 +34,12 @@ func TestCalcHash(t *testing.T) {
 	e := newExecutor(t, false)
 
 	nefPath := "./testdata/verify.nef"
-	src, err := ioutil.ReadFile(nefPath)
+	src, err := os.ReadFile(nefPath)
 	require.NoError(t, err)
 	nefF, err := nef.FileFromBytes(src)
 	require.NoError(t, err)
 	manifestPath := "./testdata/verify.manifest.json"
-	manifestBytes, err := ioutil.ReadFile(manifestPath)
+	manifestBytes, err := os.ReadFile(manifestPath)
 	require.NoError(t, err)
 	manif := &manifest.Manifest{}
 	err = json.Unmarshal(manifestBytes, manif)
@@ -67,12 +66,12 @@ func TestCalcHash(t *testing.T) {
 	})
 	t.Run("invalid nef file", func(t *testing.T) {
 		p := filepath.Join(tmpDir, "neogo.calchash.verify.nef")
-		require.NoError(t, ioutil.WriteFile(p, src[:4], os.ModePerm))
+		require.NoError(t, os.WriteFile(p, src[:4], os.ModePerm))
 		e.RunWithError(t, append(cmd, "--sender", sender.StringLE(), "--in", p, "--manifest", manifestPath)...)
 	})
 	t.Run("invalid manifest file", func(t *testing.T) {
 		p := filepath.Join(tmpDir, "neogo.calchash.verify.manifest.json")
-		require.NoError(t, ioutil.WriteFile(p, manifestBytes[:4], os.ModePerm))
+		require.NoError(t, os.WriteFile(p, manifestBytes[:4], os.ModePerm))
 		e.RunWithError(t, append(cmd, "--sender", sender.StringLE(), "--in", nefPath, "--manifest", p)...)
 	})
 
@@ -106,7 +105,7 @@ func TestContractBindings(t *testing.T) {
 	e.Run(t, "neo-go", "contract", "init", "--name", ctrPath)
 
 	srcPath := filepath.Join(ctrPath, "main.go")
-	require.NoError(t, ioutil.WriteFile(srcPath, []byte(`package testcontract
+	require.NoError(t, os.WriteFile(srcPath, []byte(`package testcontract
 import(
 	alias "github.com/nspcc-dev/neo-go/pkg/interop/native/ledger"
 )
@@ -140,7 +139,7 @@ func Blocks() []*alias.Block {
 
 	// Replace `pkg/interop` in go.mod to avoid getting an actual module version.
 	goMod := filepath.Join(ctrPath, "go.mod")
-	data, err := ioutil.ReadFile(goMod)
+	data, err := os.ReadFile(goMod)
 	require.NoError(t, err)
 
 	i := bytes.IndexByte(data, '\n')
@@ -150,7 +149,7 @@ func Blocks() []*alias.Block {
 	require.NoError(t, err)
 	data = append(data, "\nreplace github.com/nspcc-dev/neo-go/pkg/interop => "...)
 	data = append(data, filepath.Join(wd, "../pkg/interop")...)
-	require.NoError(t, ioutil.WriteFile(goMod, data, os.ModePerm))
+	require.NoError(t, os.WriteFile(goMod, data, os.ModePerm))
 
 	cmd = append(cmd, "--config", cfgPath,
 		"--out", filepath.Join(tmpDir, "out.nef"),
@@ -165,7 +164,7 @@ func Blocks() []*alias.Block {
 		"--config", bindingsPath, "--manifest", manifestPath,
 		"--out", outPath, "--hash", "0x0123456789987654321001234567899876543210")
 
-	bs, err := ioutil.ReadFile(outPath)
+	bs, err := os.ReadFile(outPath)
 	require.NoError(t, err)
 	require.Equal(t, `// Package testcontract contains wrappers for testcontract contract.
 package testcontract
@@ -244,23 +243,23 @@ func TestContractInitAndCompile(t *testing.T) {
 		e.RunWithError(t, append(cmd, "--config", cfgName)...)
 	})
 	t.Run("provided corrupted config", func(t *testing.T) {
-		data, err := ioutil.ReadFile(cfgPath)
+		data, err := os.ReadFile(cfgPath)
 		require.NoError(t, err)
 		badCfg := filepath.Join(tmpDir, "bad.yml")
-		require.NoError(t, ioutil.WriteFile(badCfg, data[:len(data)-5], os.ModePerm))
+		require.NoError(t, os.WriteFile(badCfg, data[:len(data)-5], os.ModePerm))
 		e.RunWithError(t, append(cmd, "--config", badCfg)...)
 	})
 
 	// Replace `pkg/interop` in go.mod to avoid getting an actual module version.
 	goMod := filepath.Join(ctrPath, "go.mod")
-	data, err := ioutil.ReadFile(goMod)
+	data, err := os.ReadFile(goMod)
 	require.NoError(t, err)
 
 	wd, err := os.Getwd()
 	require.NoError(t, err)
 	data = append(data, "\nreplace github.com/nspcc-dev/neo-go/pkg/interop => "...)
 	data = append(data, filepath.Join(wd, "../pkg/interop")...)
-	require.NoError(t, ioutil.WriteFile(goMod, data, os.ModePerm))
+	require.NoError(t, os.WriteFile(goMod, data, os.ModePerm))
 
 	cmd = append(cmd, "--config", cfgPath)
 	e.Run(t, cmd...)
@@ -481,7 +480,7 @@ func TestContractManifestGroups(t *testing.T) {
 	})
 	t.Run("corrupted NEF file", func(t *testing.T) {
 		f := filepath.Join(tmpDir, "invalid.nef")
-		require.NoError(t, ioutil.WriteFile(f, []byte{1, 2, 3}, os.ModePerm))
+		require.NoError(t, os.WriteFile(f, []byte{1, 2, 3}, os.ModePerm))
 		e.RunWithError(t, "neo-go", "contract", "manifest", "add-group",
 			"--wallet", testWalletPath, "--account", testWalletAccount,
 			"--sender", testWalletAccount, "--nef", f)
@@ -494,7 +493,7 @@ func TestContractManifestGroups(t *testing.T) {
 	})
 	t.Run("corrupted manifest file", func(t *testing.T) {
 		f := filepath.Join(tmpDir, "invalid.manifest.json")
-		require.NoError(t, ioutil.WriteFile(f, []byte{1, 2, 3}, os.ModePerm))
+		require.NoError(t, os.WriteFile(f, []byte{1, 2, 3}, os.ModePerm))
 		e.RunWithError(t, "neo-go", "contract", "manifest", "add-group",
 			"--wallet", testWalletPath, "--account", testWalletAccount,
 			"--sender", testWalletAccount, "--nef", nefName,
@@ -573,7 +572,7 @@ func TestContract_TestInvokeScript(t *testing.T) {
 			"--in", badNef)
 	})
 	t.Run("invalid nef", func(t *testing.T) {
-		require.NoError(t, ioutil.WriteFile(badNef, []byte("qwer"), os.ModePerm))
+		require.NoError(t, os.WriteFile(badNef, []byte("qwer"), os.ModePerm))
 		e.RunWithError(t, "neo-go", "contract", "testinvokescript",
 			"--rpc-endpoint", "http://"+e.RPC.Addr,
 			"--in", badNef)
@@ -689,10 +688,9 @@ func TestComlileAndInvokeFunction(t *testing.T) {
 			e.RunWithError(t, cmd...)
 		})
 		t.Run("corrupted wallet", func(t *testing.T) {
-			tmp, err := ioutil.TempDir("", "tmp")
+			tmp := t.TempDir()
-			require.NoError(t, err)
 			tmpPath := filepath.Join(tmp, "wallet.json")
-			require.NoError(t, ioutil.WriteFile(tmpPath, []byte("{"), os.ModePerm))
+			require.NoError(t, os.WriteFile(tmpPath, []byte("{"), os.ModePerm))
 
 			cmd := append(cmd, "--wallet", tmpPath,
 				h.StringLE(), "getValue")
@@ -854,9 +852,9 @@ func TestComlileAndInvokeFunction(t *testing.T) {
 			os.Remove(manifestName)
 		})
 
-		rawNef, err := ioutil.ReadFile(nefName)
+		rawNef, err := os.ReadFile(nefName)
 		require.NoError(t, err)
-		rawManifest, err := ioutil.ReadFile(manifestName)
+		rawManifest, err := os.ReadFile(manifestName)
 		require.NoError(t, err)
 
 		e.In.WriteString("one\r")
@@ -918,7 +916,7 @@ func TestContractInspect(t *testing.T) {
 func TestCompileExamples(t *testing.T) {
 	tmpDir := t.TempDir()
 	const examplePath = "../examples"
-	infos, err := ioutil.ReadDir(examplePath)
+	infos, err := os.ReadDir(examplePath)
 	require.NoError(t, err)
 
 	// For proper nef generation.
@@ -933,7 +931,7 @@ func TestCompileExamples(t *testing.T) {
 			continue
 		}
 		t.Run(info.Name(), func(t *testing.T) {
-			infos, err := ioutil.ReadDir(filepath.Join(examplePath, info.Name()))
+			infos, err := os.ReadDir(filepath.Join(examplePath, info.Name()))
 			require.NoError(t, err)
 			require.False(t, len(infos) == 0, "detected smart contract folder with no contract in it")
 
@@ -951,7 +949,7 @@ func TestCompileExamples(t *testing.T) {
 			e.Run(t, opts...)
 
 			if info.Name() == "storage" {
-				rawM, err := ioutil.ReadFile(manifestF)
+				rawM, err := os.ReadFile(manifestF)
 				require.NoError(t, err)
 
 				m := new(manifest.Manifest)
@@ -983,7 +981,7 @@ func TestCompileExamples(t *testing.T) {
 	})
 }
 
-func filterFilename(infos []os.FileInfo, ext string) string {
+func filterFilename(infos []os.DirEntry, ext string) string {
 	for _, info := range infos {
 		if !info.IsDir() {
 			name := info.Name()

cli/dump_test.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -29,7 +28,7 @@ func TestDBRestoreDump(t *testing.T) {
 	require.NoError(t, err)
 
 	cfgPath := filepath.Join(tmpDir, "protocol.unit_testnet.yml")
-	require.NoError(t, ioutil.WriteFile(cfgPath, out, os.ModePerm))
+	require.NoError(t, os.WriteFile(cfgPath, out, os.ModePerm))
 
 	// generated via `go run ./scripts/gendump/main.go --out ./cli/testdata/chain50x2.acc --blocks 50 --txs 2`
 	const inDump = "./testdata/chain50x2.acc"
@@ -61,14 +60,14 @@ func TestDBRestoreDump(t *testing.T) {
 	t.Run("bad logger config", func(t *testing.T) {
 		badConfigDir := t.TempDir()
 		logfile := filepath.Join(badConfigDir, "logdir")
-		require.NoError(t, ioutil.WriteFile(logfile, []byte{1, 2, 3}, os.ModePerm))
+		require.NoError(t, os.WriteFile(logfile, []byte{1, 2, 3}, os.ModePerm))
 		cfg = loadConfig(t)
 		cfg.ApplicationConfiguration.LogPath = filepath.Join(logfile, "file.log")
 		out, err = yaml.Marshal(cfg)
 		require.NoError(t, err)
 
 		cfgPath = filepath.Join(badConfigDir, "protocol.unit_testnet.yml")
-		require.NoError(t, ioutil.WriteFile(cfgPath, out, os.ModePerm))
+		require.NoError(t, os.WriteFile(cfgPath, out, os.ModePerm))
 
 		e.RunWithError(t, "neo-go", "db", "dump", "--unittest",
 			"--config-path", badConfigDir, "--out", dumpPath)
@@ -76,14 +75,14 @@ func TestDBRestoreDump(t *testing.T) {
 	t.Run("bad storage config", func(t *testing.T) {
 		badConfigDir := t.TempDir()
 		logfile := filepath.Join(badConfigDir, "logdir")
-		require.NoError(t, ioutil.WriteFile(logfile, []byte{1, 2, 3}, os.ModePerm))
+		require.NoError(t, os.WriteFile(logfile, []byte{1, 2, 3}, os.ModePerm))
 		cfg = loadConfig(t)
 		cfg.ApplicationConfiguration.DBConfiguration.Type = ""
 		out, err = yaml.Marshal(cfg)
 		require.NoError(t, err)
 
 		cfgPath = filepath.Join(badConfigDir, "protocol.unit_testnet.yml")
-		require.NoError(t, ioutil.WriteFile(cfgPath, out, os.ModePerm))
+		require.NoError(t, os.WriteFile(cfgPath, out, os.ModePerm))
 
 		e.RunWithError(t, "neo-go", "db", "dump", "--unittest",
 			"--config-path", badConfigDir, "--out", dumpPath)
@@ -98,9 +97,9 @@ func TestDBRestoreDump(t *testing.T) {
 
 	e.Run(t, baseCmd...)
 
-	d1, err := ioutil.ReadFile(inDump)
+	d1, err := os.ReadFile(inDump)
 	require.NoError(t, err)
-	d2, err := ioutil.ReadFile(dumpPath)
+	d2, err := os.ReadFile(dumpPath)
 	require.NoError(t, err)
 	require.Equal(t, d1, d2, "dumps differ")
 }

cli/executor_test.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"errors"
 	"io"
-	"io/ioutil"
 	"math"
 	"strings"
 	"sync"
@@ -269,7 +268,7 @@ func (e *executor) run(args ...string) error {
 	e.Err.Reset()
 	input.Terminal = term.NewTerminal(input.ReadWriter{
 		Reader: e.In,
-		Writer: ioutil.Discard,
+		Writer: io.Discard,
 	}, "")
 	err := e.CLI.Run(args)
 	input.Terminal = nil

cli/flags/address_test.go

@@ -2,7 +2,7 @@ package flags
 
 import (
 	"flag"
-	"io/ioutil"
+	"io"
 	"testing"
 
 	"github.com/nspcc-dev/neo-go/internal/random"
@@ -119,7 +119,7 @@ func TestAddressFlag_GetName(t *testing.T) {
 
 func TestAddress(t *testing.T) {
 	f := flag.NewFlagSet("", flag.ContinueOnError)
-	f.SetOutput(ioutil.Discard) // don't pollute test output
+	f.SetOutput(io.Discard) // don't pollute test output
 	addr := AddressFlag{Name: "addr, a"}
 	addr.Apply(f)
 	require.NoError(t, f.Parse([]string{"--addr", "NRHkiY2hLy5ypD32CKZtL6pNwhbFMqDEhR"}))

cli/flags/fixed8_test.go

@@ -2,7 +2,7 @@ package flags
 
 import (
 	"flag"
-	"io/ioutil"
+	"io"
 	"testing"
 
 	"github.com/nspcc-dev/neo-go/pkg/encoding/fixedn"
@@ -55,7 +55,7 @@ func TestFixed8Flag_GetName(t *testing.T) {
 
 func TestFixed8(t *testing.T) {
 	f := flag.NewFlagSet("", flag.ContinueOnError)
-	f.SetOutput(ioutil.Discard) // don't pollute test output
+	f.SetOutput(io.Discard) // don't pollute test output
 	gas := Fixed8Flag{Name: "gas, g"}
 	gas.Apply(f)
 	require.NoError(t, f.Parse([]string{"--gas", "0.123"}))

cli/nep11_test.go

@@ -7,8 +7,8 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"math/big"
+	"os"
 	"path/filepath"
 	"strconv"
 	"testing"
@@ -104,10 +104,10 @@ func TestNEP11_ND_OwnerOf_BalanceOf_Transfer(t *testing.T) {
 	tmpDir := t.TempDir()
 
 	// copy wallet to temp dir in order not to overwrite the original file
-	bytesRead, err := ioutil.ReadFile(nftOwnerWallet)
+	bytesRead, err := os.ReadFile(nftOwnerWallet)
 	require.NoError(t, err)
 	wall := filepath.Join(tmpDir, "my_wallet.json")
-	err = ioutil.WriteFile(wall, bytesRead, 0755)
+	err = os.WriteFile(wall, bytesRead, 0755)
 	require.NoError(t, err)
 
 	// transfer funds to contract owner
@@ -336,10 +336,10 @@ func TestNEP11_D_OwnerOf_BalanceOf_Transfer(t *testing.T) {
 	tmpDir := t.TempDir()
 
 	// copy wallet to temp dir in order not to overwrite the original file
-	bytesRead, err := ioutil.ReadFile(validatorWallet)
+	bytesRead, err := os.ReadFile(validatorWallet)
 	require.NoError(t, err)
 	wall := filepath.Join(tmpDir, "my_wallet.json")
-	err = ioutil.WriteFile(wall, bytesRead, 0755)
+	err = os.WriteFile(wall, bytesRead, 0755)
 	require.NoError(t, err)
 
 	// deploy NeoFS Object contract

cli/paramcontext/context.go

@@ -3,7 +3,7 @@ package paramcontext
 import (
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"os"
 
 	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
@@ -36,7 +36,7 @@ func InitAndSave(net netmode.Magic, tx *transaction.Transaction, acc *wallet.Acc
 
 // Read reads parameter context from file.
 func Read(filename string) (*context.ParameterContext, error) {
-	data, err := ioutil.ReadFile(filename)
+	data, err := os.ReadFile(filename)
 	if err != nil {
 		return nil, fmt.Errorf("can't read input file: %w", err)
 	}
@@ -52,7 +52,7 @@ func Read(filename string) (*context.ParameterContext, error) {
 func Save(c *context.ParameterContext, filename string) error {
 	if data, err := json.Marshal(c); err != nil {
 		return fmt.Errorf("can't marshal transaction: %w", err)
-	} else if err := ioutil.WriteFile(filename, data, 0644); err != nil {
+	} else if err := os.WriteFile(filename, data, 0644); err != nil {
 		return fmt.Errorf("can't write transaction to file: %w", err)
 	}
 	return nil

cli/server/dump.go

@@ -3,7 +3,6 @@ package server
 import (
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 
@@ -63,7 +62,7 @@ func (d *dump) tryPersist(prefix string, index uint32) error {
 }
 
 func readFile(path string) (*dump, error) {
-	data, err := ioutil.ReadFile(path)
+	data, err := os.ReadFile(path)
 	if err != nil {
 		return nil, err
 	}

cli/server/server_test.go

@@ -3,7 +3,6 @@ package server
 import (
 	"encoding/binary"
 	"flag"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -46,7 +45,7 @@ func TestHandleLoggingParams(t *testing.T) {
 
 	t.Run("logdir is a file", func(t *testing.T) {
 		logfile := filepath.Join(d, "logdir")
-		require.NoError(t, ioutil.WriteFile(logfile, []byte{1, 2, 3}, os.ModePerm))
+		require.NoError(t, os.WriteFile(logfile, []byte{1, 2, 3}, os.ModePerm))
 		set := flag.NewFlagSet("flagSet", flag.ExitOnError)
 		ctx := cli.NewContext(cli.NewApp(), set, nil)
 		cfg := config.ApplicationConfiguration{
@@ -196,7 +195,7 @@ func TestRestoreDB(t *testing.T) {
 	t.Run("invalid logger path", func(t *testing.T) {
 		badCfgDir := t.TempDir()
 		logfile := filepath.Join(badCfgDir, "logdir")
-		require.NoError(t, ioutil.WriteFile(logfile, []byte{1, 2, 3}, os.ModePerm))
+		require.NoError(t, os.WriteFile(logfile, []byte{1, 2, 3}, os.ModePerm))
 		cfg, err := config.LoadFile(filepath.Join(goodCfg, "protocol.privnet.yml"))
 		require.NoError(t, err, "could not load config")
 		cfg.ApplicationConfiguration.LogPath = filepath.Join(logfile, "file.log")
@@ -204,7 +203,7 @@ func TestRestoreDB(t *testing.T) {
 		require.NoError(t, err)
 
 		badCfgPath := filepath.Join(badCfgDir, "protocol.privnet.yml")
-		require.NoError(t, ioutil.WriteFile(badCfgPath, out, os.ModePerm))
+		require.NoError(t, os.WriteFile(badCfgPath, out, os.ModePerm))
 
 		*cfgPath = badCfgDir
 		require.Error(t, restoreDB(ctx))
@@ -220,7 +219,7 @@ func TestRestoreDB(t *testing.T) {
 		require.NoError(t, err)
 
 		badCfgPath := filepath.Join(badCfgDir, "protocol.privnet.yml")
-		require.NoError(t, ioutil.WriteFile(badCfgPath, out, os.ModePerm))
+		require.NoError(t, os.WriteFile(badCfgPath, out, os.ModePerm))
 
 		*cfgPath = badCfgDir
 		require.Error(t, restoreDB(ctx))
@@ -238,7 +237,7 @@ func TestRestoreDB(t *testing.T) {
 	})
 	t.Run("corrupted in: invalid block count", func(t *testing.T) {
 		inPath := filepath.Join(t.TempDir(), "file3.acc")
-		require.NoError(t, ioutil.WriteFile(inPath, []byte{1, 2, 3}, // file is expected to start from uint32
+		require.NoError(t, os.WriteFile(inPath, []byte{1, 2, 3}, // file is expected to start from uint32
 			os.ModePerm))
 		*in = inPath
 		require.Error(t, restoreDB(ctx))
@@ -247,10 +246,10 @@ func TestRestoreDB(t *testing.T) {
 	})
 	t.Run("corrupted in: corrupted block", func(t *testing.T) {
 		inPath := filepath.Join(t.TempDir(), "file3.acc")
-		b, err := ioutil.ReadFile(testDump)
+		b, err := os.ReadFile(testDump)
 		require.NoError(t, err)
 		b[5] = 0xff // file is expected to start from uint32 (4 bytes) followed by the first block, so corrupt the first block bytes
-		require.NoError(t, ioutil.WriteFile(inPath, b, os.ModePerm))
+		require.NoError(t, os.WriteFile(inPath, b, os.ModePerm))
 		*in = inPath
 		require.Error(t, restoreDB(ctx))
 
@@ -258,12 +257,12 @@ func TestRestoreDB(t *testing.T) {
 	})
 	t.Run("incremental dump", func(t *testing.T) {
 		inPath := filepath.Join(t.TempDir(), "file1_incremental.acc")
-		b, err := ioutil.ReadFile(testDump)
+		b, err := os.ReadFile(testDump)
 		require.NoError(t, err)
 		start := make([]byte, 4)
 		t.Run("good", func(t *testing.T) {
 			binary.LittleEndian.PutUint32(start, 1) // start from the first block
-			require.NoError(t, ioutil.WriteFile(inPath, append(start, b...),
+			require.NoError(t, os.WriteFile(inPath, append(start, b...),
 				os.ModePerm))
 			*in = inPath
 			*incremental = true
@@ -272,7 +271,7 @@ func TestRestoreDB(t *testing.T) {
 		})
 		t.Run("dump is too high", func(t *testing.T) {
 			binary.LittleEndian.PutUint32(start, 2) // start from the second block
-			require.NoError(t, ioutil.WriteFile(inPath, append(start, b...),
+			require.NoError(t, os.WriteFile(inPath, append(start, b...),
 				os.ModePerm))
 			*in = inPath
 			*incremental = true

cli/server_test.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -31,7 +30,7 @@ func TestServerStart(t *testing.T) {
 		require.NoError(t, err)
 
 		cfgPath := filepath.Join(tmpDir, "protocol.unit_testnet.yml")
-		require.NoError(t, ioutil.WriteFile(cfgPath, out, os.ModePerm))
+		require.NoError(t, os.WriteFile(cfgPath, out, os.ModePerm))
 		t.Cleanup(func() {
 			require.NoError(t, os.Remove(cfgPath))
 		})
@@ -47,7 +46,7 @@ func TestServerStart(t *testing.T) {
 	t.Run("bad logger config", func(t *testing.T) {
 		badConfigDir := t.TempDir()
 		logfile := filepath.Join(badConfigDir, "logdir")
-		require.NoError(t, ioutil.WriteFile(logfile, []byte{1, 2, 3}, os.ModePerm))
+		require.NoError(t, os.WriteFile(logfile, []byte{1, 2, 3}, os.ModePerm))
 		saveCfg(t, func(cfg *config.Config) {
 			cfg.ApplicationConfiguration.LogPath = filepath.Join(logfile, "file.log")
 		})

cli/smartcontract/generate.go

@@ -2,7 +2,6 @@ package smartcontract
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"strings"
 
@@ -47,7 +46,7 @@ func contractGenerateWrapper(ctx *cli.Context) error {
 
 	cfg := binding.NewConfig()
 	if cfgPath := ctx.String("config"); cfgPath != "" {
-		bs, err := ioutil.ReadFile(cfgPath)
+		bs, err := os.ReadFile(cfgPath)
 		if err != nil {
 			return cli.NewExitError(fmt.Errorf("can't read config file: %w", err), 1)
 		}

cli/smartcontract/generate_test.go

@@ -2,7 +2,6 @@ package smartcontract
 
 import (
 	"encoding/json"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -115,7 +114,7 @@ func TestGenerate(t *testing.T) {
 
 	rawManifest, err := json.Marshal(m)
 	require.NoError(t, err)
-	require.NoError(t, ioutil.WriteFile(manifestFile, rawManifest, os.ModePerm))
+	require.NoError(t, os.WriteFile(manifestFile, rawManifest, os.ModePerm))
 
 	h := util.Uint160{
 		0x04, 0x08, 0x15, 0x16, 0x23, 0x42, 0x43, 0x44, 0x00, 0x01,
@@ -139,7 +138,7 @@ callflags:
     doSomething: ReadStates
 `
 	cfgPath := filepath.Join(t.TempDir(), "binding.yml")
-	require.NoError(t, ioutil.WriteFile(cfgPath, []byte(rawCfg), os.ModePerm))
+	require.NoError(t, os.WriteFile(cfgPath, []byte(rawCfg), os.ModePerm))
 
 	require.NoError(t, app.Run([]string{"", "generate-wrapper",
 		"--manifest", manifestFile,
@@ -225,7 +224,7 @@ func MyFunc(in map[int]mycontract.Input) []mycontract.Output {
 }
 `
 
-	data, err := ioutil.ReadFile(outFile)
+	data, err := os.ReadFile(outFile)
 	require.NoError(t, err)
 	require.Equal(t, expected, string(data))
 }
@@ -245,7 +244,7 @@ func TestGenerateValidPackageName(t *testing.T) {
 
 	rawManifest, err := json.Marshal(m)
 	require.NoError(t, err)
-	require.NoError(t, ioutil.WriteFile(manifestFile, rawManifest, os.ModePerm))
+	require.NoError(t, os.WriteFile(manifestFile, rawManifest, os.ModePerm))
 
 	h := util.Uint160{
 		0x04, 0x08, 0x15, 0x16, 0x23, 0x42, 0x43, 0x44, 0x00, 0x01,
@@ -259,7 +258,7 @@ func TestGenerateValidPackageName(t *testing.T) {
 		"--hash", "0x" + h.StringLE(),
 	}))
 
-	data, err := ioutil.ReadFile(outFile)
+	data, err := os.ReadFile(outFile)
 	require.NoError(t, err)
 	require.Equal(t, `// Package myspacecontract contains wrappers for My space	contract contract.
 package myspacecontract
@@ -297,7 +296,7 @@ func TestGenerate_Errors(t *testing.T) {
 	})
 	t.Run("invalid manifest", func(t *testing.T) {
 		manifestFile := filepath.Join(t.TempDir(), "invalid.json")
-		require.NoError(t, ioutil.WriteFile(manifestFile, []byte("[]"), os.ModePerm))
+		require.NoError(t, os.WriteFile(manifestFile, []byte("[]"), os.ModePerm))
 		checkError(t, "", "--manifest", manifestFile)
 	})
 
@@ -305,7 +304,7 @@ func TestGenerate_Errors(t *testing.T) {
 	m := manifest.NewManifest("MyContract")
 	rawManifest, err := json.Marshal(m)
 	require.NoError(t, err)
-	require.NoError(t, ioutil.WriteFile(manifestFile, rawManifest, os.ModePerm))
+	require.NoError(t, os.WriteFile(manifestFile, rawManifest, os.ModePerm))
 
 	t.Run("invalid hash", func(t *testing.T) {
 		checkError(t, "invalid contract hash", "--manifest", manifestFile, "--hash", "xxx")
@@ -321,7 +320,7 @@ callflags:
     someFunc: ReadSometimes 
 `
 		cfgPath := filepath.Join(t.TempDir(), "binding.yml")
-		require.NoError(t, ioutil.WriteFile(cfgPath, []byte(rawCfg), os.ModePerm))
+		require.NoError(t, os.WriteFile(cfgPath, []byte(rawCfg), os.ModePerm))
 
 		checkError(t, "can't parse config file",
 			"--manifest", manifestFile, "--hash", util.Uint160{}.StringLE(),

cli/smartcontract/manifest.go

@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 
 	"github.com/nspcc-dev/neo-go/cli/flags"
@@ -78,7 +77,7 @@ func manifestAddGroup(ctx *cli.Context) error {
 		return cli.NewExitError(fmt.Errorf("can't marshal manifest: %w", err), 1)
 	}
 
-	err = ioutil.WriteFile(mPath, rawM, os.ModePerm)
+	err = os.WriteFile(mPath, rawM, os.ModePerm)
 	if err != nil {
 		return cli.NewExitError(fmt.Errorf("can't write manifest file: %w", err), 1)
 	}
@@ -90,7 +89,7 @@ func readNEFFile(filename string) (*nef.File, []byte, error) {
 		return nil, nil, errors.New("no nef file was provided")
 	}
 
-	f, err := ioutil.ReadFile(filename)
+	f, err := os.ReadFile(filename)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -108,7 +107,7 @@ func readManifest(filename string) (*manifest.Manifest, []byte, error) {
 		return nil, nil, errNoManifestFile
 	}
 
-	manifestBytes, err := ioutil.ReadFile(filename)
+	manifestBytes, err := os.ReadFile(filename)
 	if err != nil {
 		return nil, nil, err
 	}

cli/smartcontract/smart_contract.go

@@ -5,7 +5,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -455,7 +454,7 @@ func initSmartContract(ctx *cli.Context) error {
 	if err != nil {
 		return cli.NewExitError(err, 1)
 	}
-	if err := ioutil.WriteFile(filepath.Join(basePath, "neo-go.yml"), b, 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(basePath, "neo-go.yml"), b, 0644); err != nil {
 		return cli.NewExitError(err, 1)
 	}
 
@@ -468,12 +467,12 @@ func initSmartContract(ctx *cli.Context) error {
 require (
 	github.com/nspcc-dev/neo-go/pkg/interop ` + ver + `
 )`)
-	if err := ioutil.WriteFile(filepath.Join(basePath, "go.mod"), gm, 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(basePath, "go.mod"), gm, 0644); err != nil {
 		return cli.NewExitError(err, 1)
 	}
 
 	data := []byte(fmt.Sprintf(smartContractTmpl, contractName))
-	if err := ioutil.WriteFile(filepath.Join(basePath, fileName), data, 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(basePath, fileName), data, 0644); err != nil {
 		return cli.NewExitError(err, 1)
 	}
 
@@ -548,7 +547,7 @@ func calcHash(ctx *cli.Context) error {
 	if mpath == "" {
 		return cli.NewExitError(errors.New("no manifest file provided"), 1)
 	}
-	f, err := ioutil.ReadFile(p)
+	f, err := os.ReadFile(p)
 	if err != nil {
 		return cli.NewExitError(fmt.Errorf("can't read .nef file: %w", err), 1)
 	}
@@ -556,7 +555,7 @@ func calcHash(ctx *cli.Context) error {
 	if err != nil {
 		return cli.NewExitError(fmt.Errorf("can't unmarshal .nef file: %w", err), 1)
 	}
-	manifestBytes, err := ioutil.ReadFile(mpath)
+	manifestBytes, err := os.ReadFile(mpath)
 	if err != nil {
 		return cli.NewExitError(fmt.Errorf("failed to read manifest file: %w", err), 1)
 	}
@@ -734,7 +733,7 @@ func testInvokeScript(ctx *cli.Context) error {
 		return cli.NewExitError(errNoInput, 1)
 	}
 
-	b, err := ioutil.ReadFile(src)
+	b, err := os.ReadFile(src)
 	if err != nil {
 		return cli.NewExitError(err, 1)
 	}
@@ -798,7 +797,7 @@ func inspect(ctx *cli.Context) error {
 			return cli.NewExitError(fmt.Errorf("failed to compile: %w", err), 1)
 		}
 	} else {
-		f, err := ioutil.ReadFile(in)
+		f, err := os.ReadFile(in)
 		if err != nil {
 			return cli.NewExitError(fmt.Errorf("failed to read .nef file: %w", err), 1)
 		}
@@ -935,7 +934,7 @@ func contractDeploy(ctx *cli.Context) error {
 // ParseContractConfig reads contract configuration file (.yaml) and returns unmarshalled ProjectConfig.
 func ParseContractConfig(confFile string) (ProjectConfig, error) {
 	conf := ProjectConfig{}
-	confBytes, err := ioutil.ReadFile(confFile)
+	confBytes, err := os.ReadFile(confFile)
 	if err != nil {
 		return conf, cli.NewExitError(err, 1)
 	}

cli/smartcontract/smart_contract_test.go

@@ -3,7 +3,6 @@ package smartcontract
 import (
 	"encoding/hex"
 	"flag"
-	"io/ioutil"
 	"os"
 	"testing"
 
@@ -31,13 +30,13 @@ func TestInitSmartContract(t *testing.T) {
 	dirInfo, err := os.Stat(contractName)
 	require.NoError(t, err)
 	require.True(t, dirInfo.IsDir())
-	files, err := ioutil.ReadDir(contractName)
+	files, err := os.ReadDir(contractName)
 	require.NoError(t, err)
 	require.Equal(t, 3, len(files))
 	require.Equal(t, "go.mod", files[0].Name())
 	require.Equal(t, "main.go", files[1].Name())
 	require.Equal(t, "neo-go.yml", files[2].Name())
-	main, err := ioutil.ReadFile(contractName + "/" + files[1].Name())
+	main, err := os.ReadFile(contractName + "/" + files[1].Name())
 	require.NoError(t, err)
 	require.Equal(t,
 		`package `+contractName+`
@@ -56,7 +55,7 @@ func RuntimeNotify(args []interface{}) {
     runtime.Notify(notificationName, args)
 }`, string(main))
 
-	manifest, err := ioutil.ReadFile(contractName + "/" + files[2].Name())
+	manifest, err := os.ReadFile(contractName + "/" + files[2].Name())
 	require.NoError(t, err)
 	require.Equal(t,
 		`name: testContract

pkg/compiler/compiler.go

@@ -9,7 +9,6 @@ import (
 	"go/token"
 	"go/types"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -156,7 +155,7 @@ func getBuildInfo(name string, src interface{}) (*buildInfo, error) {
 		case string:
 			buf = []byte(s)
 		case io.Reader:
-			buf, err = ioutil.ReadAll(s)
+			buf, err = io.ReadAll(s)
 			if err != nil {
 				return nil, err
 			}
@@ -164,10 +163,7 @@ func getBuildInfo(name string, src interface{}) (*buildInfo, error) {
 			panic(fmt.Sprintf("unsupported src type: %T", s))
 		}
 		if strings.HasPrefix(runtime.Version(), "go1.15") {
-			dir, err = ioutil.TempDir("", "*")
+			dir = os.TempDir()
-			if err != nil {
-				return nil, err
-			}
 			name = filepath.Join(dir, filepath.Base(name))
 			absName = name
 			names = append(names, "file="+name)
@@ -259,7 +255,7 @@ func CompileAndSave(src string, o *Options) ([]byte, error) {
 		return nil, fmt.Errorf("error while serializing .nef file: %w", err)
 	}
 	out := fmt.Sprintf("%s.%s", o.Outfile, o.Ext)
-	err = ioutil.WriteFile(out, bytes, os.ModePerm)
+	err = os.WriteFile(out, bytes, os.ModePerm)
 	if err != nil {
 		return f.Script, err
 	}
@@ -289,7 +285,7 @@ func CompileAndSave(src string, o *Options) ([]byte, error) {
 		if err != nil {
 			return f.Script, err
 		}
-		if err := ioutil.WriteFile(o.DebugInfo, data, os.ModePerm); err != nil {
+		if err := os.WriteFile(o.DebugInfo, data, os.ModePerm); err != nil {
 			return f.Script, err
 		}
 	}
@@ -311,7 +307,7 @@ func CompileAndSave(src string, o *Options) ([]byte, error) {
 		if err != nil {
 			return nil, fmt.Errorf("can't marshal bindings configuration: %w", err)
 		}
-		err = ioutil.WriteFile(o.BindingsFile, data, os.ModePerm)
+		err = os.WriteFile(o.BindingsFile, data, os.ModePerm)
 		if err != nil {
 			return nil, fmt.Errorf("can't write bindings configuration: %w", err)
 		}
@@ -326,7 +322,7 @@ func CompileAndSave(src string, o *Options) ([]byte, error) {
 		if err != nil {
 			return f.Script, fmt.Errorf("failed to marshal manifest to JSON: %w", err)
 		}
-		return f.Script, ioutil.WriteFile(o.ManifestFile, mData, os.ModePerm)
+		return f.Script, os.WriteFile(o.ManifestFile, mData, os.ModePerm)
 	}
 
 	return f.Script, nil

pkg/compiler/compiler_test.go

@@ -2,7 +2,6 @@ package compiler_test
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -49,7 +48,7 @@ func TestCompiler(t *testing.T) {
 		{
 			name: "TestCompile",
 			function: func(t *testing.T) {
-				infos, err := ioutil.ReadDir(examplePath)
+				infos, err := os.ReadDir(examplePath)
 				require.NoError(t, err)
 				for _, info := range infos {
 					if !info.IsDir() {
@@ -66,7 +65,7 @@ func TestCompiler(t *testing.T) {
 		{
 			name: "TestCompileAndSave",
 			function: func(t *testing.T) {
-				infos, err := ioutil.ReadDir(exampleCompilePath)
+				infos, err := os.ReadDir(exampleCompilePath)
 				require.NoError(t, err)
 				err = os.MkdirAll(exampleSavePath, os.ModePerm)
 				require.NoError(t, err)

pkg/config/config.go

@@ -2,7 +2,6 @@ package config
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 
 	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
@@ -40,7 +39,7 @@ func LoadFile(configPath string) (Config, error) {
 		return Config{}, fmt.Errorf("config '%s' doesn't exist", configPath)
 	}
 
-	configData, err := ioutil.ReadFile(configPath)
+	configData, err := os.ReadFile(configPath)
 	if err != nil {
 		return Config{}, fmt.Errorf("unable to read config: %w", err)
 	}

pkg/core/block/helper_test.go

@@ -4,7 +4,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"os"
 	"testing"
 
 	"github.com/nspcc-dev/neo-go/internal/testserdes"
@@ -25,7 +25,7 @@ func getDecodedBlock(t *testing.T, i int) *Block {
 }
 
 func getBlockData(i int) (map[string]interface{}, error) {
-	b, err := ioutil.ReadFile(fmt.Sprintf("../test_data/block_%d.json", i))
+	b, err := os.ReadFile(fmt.Sprintf("../test_data/block_%d.json", i))
 	if err != nil {
 		return nil, err
 	}

pkg/core/interop_system_test.go

@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"math"
 	"math/big"
 	"os"
@@ -988,7 +987,7 @@ func TestGenerateManagementHelperContracts(t *testing.T) {
 	bytes, err := ne.Bytes()
 	require.NoError(t, err)
 	if saveState {
-		err = ioutil.WriteFile(helper1ContractNEFPath, bytes, os.ModePerm)
+		err = os.WriteFile(helper1ContractNEFPath, bytes, os.ModePerm)
 		require.NoError(t, err)
 	}
 
@@ -996,7 +995,7 @@ func TestGenerateManagementHelperContracts(t *testing.T) {
 	mData, err := json.Marshal(m)
 	require.NoError(t, err)
 	if saveState {
-		err = ioutil.WriteFile(helper1ContractManifestPath, mData, os.ModePerm)
+		err = os.WriteFile(helper1ContractManifestPath, mData, os.ModePerm)
 		require.NoError(t, err)
 	}
 
@@ -1022,7 +1021,7 @@ func TestGenerateManagementHelperContracts(t *testing.T) {
 	bytes, err = ne.Bytes()
 	require.NoError(t, err)
 	if saveState {
-		err = ioutil.WriteFile(helper2ContractNEFPath, bytes, os.ModePerm)
+		err = os.WriteFile(helper2ContractNEFPath, bytes, os.ModePerm)
 		require.NoError(t, err)
 	}
 
@@ -1030,7 +1029,7 @@ func TestGenerateManagementHelperContracts(t *testing.T) {
 	mData, err = json.Marshal(m)
 	require.NoError(t, err)
 	if saveState {
-		err = ioutil.WriteFile(helper2ContractManifestPath, mData, os.ModePerm)
+		err = os.WriteFile(helper2ContractManifestPath, mData, os.ModePerm)
 		require.NoError(t, err)
 	}
 
@@ -1041,12 +1040,12 @@ func TestGenerateManagementHelperContracts(t *testing.T) {
 func getTestContractState(t *testing.T, id1, id2 int32, sender2 util.Uint160) (*state.Contract, *state.Contract) {
 	errNotFound := errors.New("auto-generated oracle contract is not found, use TestGenerateOracleContract to regenerate")
 
-	neBytes, err := ioutil.ReadFile(helper1ContractNEFPath)
+	neBytes, err := os.ReadFile(helper1ContractNEFPath)
 	require.NoError(t, err, fmt.Errorf("nef1: %w", errNotFound))
 	ne, err := nef.FileFromBytes(neBytes)
 	require.NoError(t, err)
 
-	mBytes, err := ioutil.ReadFile(helper1ContractManifestPath)
+	mBytes, err := os.ReadFile(helper1ContractManifestPath)
 	require.NoError(t, err, fmt.Errorf("manifest1: %w", errNotFound))
 	m := &manifest.Manifest{}
 	err = json.Unmarshal(mBytes, m)
@@ -1060,12 +1059,12 @@ func getTestContractState(t *testing.T, id1, id2 int32, sender2 util.Uint160) (*
 		},
 	}
 
-	neBytes, err = ioutil.ReadFile(helper2ContractNEFPath)
+	neBytes, err = os.ReadFile(helper2ContractNEFPath)
 	require.NoError(t, err, fmt.Errorf("nef2: %w", errNotFound))
 	ne, err = nef.FileFromBytes(neBytes)
 	require.NoError(t, err)
 
-	mBytes, err = ioutil.ReadFile(helper2ContractManifestPath)
+	mBytes, err = os.ReadFile(helper2ContractManifestPath)
 	require.NoError(t, err, fmt.Errorf("manifest2: %w", errNotFound))
 	m = &manifest.Manifest{}
 	err = json.Unmarshal(mBytes, m)

pkg/core/native/native_test/management_test.go

@@ -5,7 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"testing"
 
@@ -49,12 +49,12 @@ func TestManagement_MinimumDeploymentFee(t *testing.T) {
 func getTestContractState(t *testing.T, id1, id2 int32, sender2 util.Uint160) (*state.Contract, *state.Contract) {
 	errNotFound := errors.New("auto-generated oracle contract is not found, use TestGenerateOracleContract to regenerate")
 
-	neBytes, err := ioutil.ReadFile(helper1ContractNEFPath)
+	neBytes, err := os.ReadFile(helper1ContractNEFPath)
 	require.NoError(t, err, fmt.Errorf("nef1: %w", errNotFound))
 	ne, err := nef.FileFromBytes(neBytes)
 	require.NoError(t, err)
 
-	mBytes, err := ioutil.ReadFile(helper1ContractManifestPath)
+	mBytes, err := os.ReadFile(helper1ContractManifestPath)
 	require.NoError(t, err, fmt.Errorf("manifest1: %w", errNotFound))
 	m := &manifest.Manifest{}
 	err = json.Unmarshal(mBytes, m)
@@ -68,12 +68,12 @@ func getTestContractState(t *testing.T, id1, id2 int32, sender2 util.Uint160) (*
 		},
 	}
 
-	neBytes, err = ioutil.ReadFile(helper2ContractNEFPath)
+	neBytes, err = os.ReadFile(helper2ContractNEFPath)
 	require.NoError(t, err, fmt.Errorf("nef2: %w", errNotFound))
 	ne, err = nef.FileFromBytes(neBytes)
 	require.NoError(t, err)
 
-	mBytes, err = ioutil.ReadFile(helper2ContractManifestPath)
+	mBytes, err = os.ReadFile(helper2ContractManifestPath)
 	require.NoError(t, err, fmt.Errorf("manifest2: %w", errNotFound))
 	m = &manifest.Manifest{}
 	err = json.Unmarshal(mBytes, m)

pkg/core/native/native_test/oracle_test.go

@@ -4,9 +4,9 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"math"
 	"math/big"
+	"os"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -45,12 +45,12 @@ func getOracleContractState(t *testing.T, sender util.Uint160, id int32) *state.
 	)
 	errNotFound := errors.New("auto-generated oracle contract is not found, use TestGenerateOracleContract to regenerate")
 
-	neBytes, err := ioutil.ReadFile(oracleContractNEFPath)
+	neBytes, err := os.ReadFile(oracleContractNEFPath)
 	require.NoError(t, err, fmt.Errorf("nef: %w", errNotFound))
 	ne, err := nef.FileFromBytes(neBytes)
 	require.NoError(t, err)
 
-	mBytes, err := ioutil.ReadFile(oracleContractManifestPath)
+	mBytes, err := os.ReadFile(oracleContractManifestPath)
 	require.NoError(t, err, fmt.Errorf("manifest: %w", errNotFound))
 	m := &manifest.Manifest{}
 	err = json.Unmarshal(mBytes, m)

pkg/core/oracle_test.go

@@ -6,7 +6,6 @@ import (
 	"errors"
 	"fmt"
 	gio "io"
-	"io/ioutil"
 	"net/http"
 	"os"
 	"path"
@@ -124,7 +123,7 @@ func TestGenerateOracleContract(t *testing.T) {
 	bytes, err := ne.Bytes()
 	require.NoError(t, err)
 	if saveState {
-		err = ioutil.WriteFile(oracleContractNEFPath, bytes, os.ModePerm)
+		err = os.WriteFile(oracleContractNEFPath, bytes, os.ModePerm)
 		require.NoError(t, err)
 	}
 
@@ -132,7 +131,7 @@ func TestGenerateOracleContract(t *testing.T) {
 	mData, err := json.Marshal(m)
 	require.NoError(t, err)
 	if saveState {
-		err = ioutil.WriteFile(oracleContractManifestPath, mData, os.ModePerm)
+		err = os.WriteFile(oracleContractManifestPath, mData, os.ModePerm)
 		require.NoError(t, err)
 	}
 
@@ -144,12 +143,12 @@ func TestGenerateOracleContract(t *testing.T) {
 func getOracleContractState(t *testing.T, sender util.Uint160, id int32) *state.Contract {
 	errNotFound := errors.New("auto-generated oracle contract is not found, use TestGenerateOracleContract to regenerate")
 
-	neBytes, err := ioutil.ReadFile(oracleContractNEFPath)
+	neBytes, err := os.ReadFile(oracleContractNEFPath)
 	require.NoError(t, err, fmt.Errorf("nef: %w", errNotFound))
 	ne, err := nef.FileFromBytes(neBytes)
 	require.NoError(t, err)
 
-	mBytes, err := ioutil.ReadFile(oracleContractManifestPath)
+	mBytes, err := os.ReadFile(oracleContractManifestPath)
 	require.NoError(t, err, fmt.Errorf("manifest: %w", errNotFound))
 	m := &manifest.Manifest{}
 	err = json.Unmarshal(mBytes, m)
@@ -639,5 +638,5 @@ func newDefaultHTTPClient(returnOracleRedirectionErrOn func(address string) bool
 }
 
 func newResponseBody(resp []byte) gio.ReadCloser {
-	return ioutil.NopCloser(bytes.NewReader(resp))
+	return gio.NopCloser(bytes.NewReader(resp))
 }

pkg/rpc/server/server_test.go

@@ -5,7 +5,7 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	gio "io"
 	"math/big"
 	"net/http"
 	"net/http/httptest"
@@ -2029,7 +2029,7 @@ func doRPCCallOverHTTP(rpcCall string, url string, t *testing.T) []byte {
 	cl := http.Client{Timeout: time.Second}
 	resp, err := cl.Post(url, "application/json", strings.NewReader(rpcCall))
 	require.NoErrorf(t, err, "could not make a POST request")
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := gio.ReadAll(resp.Body)
 	assert.NoErrorf(t, err, "could not read response from the request: %s", rpcCall)
 	return bytes.TrimSpace(body)
 }

pkg/smartcontract/parameter.go

@@ -8,9 +8,9 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"math"
 	"math/bits"
+	"os"
 	"strconv"
 	"strings"
 	"unicode/utf8"
@@ -436,7 +436,7 @@ func NewParameterFromString(in string) (*Parameter, error) {
 		res.Type = inferParamType(val)
 	}
 	if res.Type == ByteArrayType && typStr == fileBytesParamType {
-		res.Value, err = ioutil.ReadFile(val)
+		res.Value, err = os.ReadFile(val)
 		if err != nil {
 			return nil, fmt.Errorf("failed to read '%s' parameter from file '%s': %w", fileBytesParamType, val, err)
 		}

pkg/vm/cli/cli.go

@@ -9,7 +9,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"math/big"
 	"os"
 	"strconv"
@@ -503,7 +502,7 @@ func handleReset(c *cli.Context) error {
 }
 
 func getManifestFromFile(name string) (*manifest.Manifest, error) {
-	bs, err := ioutil.ReadFile(name)
+	bs, err := os.ReadFile(name)
 	if err != nil {
 		return nil, fmt.Errorf("%w: can't read manifest", ErrInvalidParameter)
 	}

pkg/vm/cli/cli_test.go

@@ -7,7 +7,6 @@ import (
 	"encoding/json"
 	"fmt"
 	gio "io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -209,14 +208,14 @@ func TestLoad(t *testing.T) {
 	checkLoadgo := func(t *testing.T, tName, cName, cErrName string) {
 		t.Run("loadgo "+tName, func(t *testing.T) {
 			filename := filepath.Join(tmpDir, cName)
-			require.NoError(t, ioutil.WriteFile(filename, []byte(src), os.ModePerm))
+			require.NoError(t, os.WriteFile(filename, []byte(src), os.ModePerm))
 			filename = "'" + filename + "'"
 			filenameErr := filepath.Join(tmpDir, cErrName)
-			require.NoError(t, ioutil.WriteFile(filenameErr, []byte(src+"invalid_token"), os.ModePerm))
+			require.NoError(t, os.WriteFile(filenameErr, []byte(src+"invalid_token"), os.ModePerm))
 			filenameErr = "'" + filenameErr + "'"
 			goMod := []byte(`module test.example/vmcli
 go 1.16`)
-			require.NoError(t, ioutil.WriteFile(filepath.Join(tmpDir, "go.mod"), goMod, os.ModePerm))
+			require.NoError(t, os.WriteFile(filepath.Join(tmpDir, "go.mod"), goMod, os.ModePerm))
 
 			e := newTestVMCLI(t)
 			e.runProgWithTimeout(t, 10*time.Second,
@@ -244,7 +243,7 @@ go 1.16`)
 		}
 `
 		filename := filepath.Join(tmpDir, "vmtestcontract.go")
-		require.NoError(t, ioutil.WriteFile(filename, []byte(srcAllowNotify), os.ModePerm))
+		require.NoError(t, os.WriteFile(filename, []byte(srcAllowNotify), os.ModePerm))
 		filename = "'" + filename + "'"
 		wd, err := os.Getwd()
 		require.NoError(t, err)
@@ -254,7 +253,7 @@ require (
 )
 replace github.com/nspcc-dev/neo-go/pkg/interop => ` + filepath.Join(wd, "../../interop") + `
 go 1.16`)
-		require.NoError(t, ioutil.WriteFile(filepath.Join(tmpDir, "go.mod"), goMod, os.ModePerm))
+		require.NoError(t, os.WriteFile(filepath.Join(tmpDir, "go.mod"), goMod, os.ModePerm))
 
 		e := newTestVMCLI(t)
 		e.runProg(t,
@@ -271,15 +270,15 @@ go 1.16`)
 		filename := filepath.Join(tmpDir, "vmtestcontract.nef")
 		rawNef, err := nefFile.Bytes()
 		require.NoError(t, err)
-		require.NoError(t, ioutil.WriteFile(filename, rawNef, os.ModePerm))
+		require.NoError(t, os.WriteFile(filename, rawNef, os.ModePerm))
 		m, err := di.ConvertToManifest(&compiler.Options{})
 		require.NoError(t, err)
 		manifestFile := filepath.Join(tmpDir, "vmtestcontract.manifest.json")
 		rawManifest, err := json.Marshal(m)
 		require.NoError(t, err)
-		require.NoError(t, ioutil.WriteFile(manifestFile, rawManifest, os.ModePerm))
+		require.NoError(t, os.WriteFile(manifestFile, rawManifest, os.ModePerm))
 		filenameErr := filepath.Join(tmpDir, "vmtestcontract_err.nef")
-		require.NoError(t, ioutil.WriteFile(filenameErr, append([]byte{1, 2, 3, 4}, rawNef...), os.ModePerm))
+		require.NoError(t, os.WriteFile(filenameErr, append([]byte{1, 2, 3, 4}, rawNef...), os.ModePerm))
 		notExists := filepath.Join(tmpDir, "notexists.json")
 
 		manifestFile = "'" + manifestFile + "'"
@@ -325,7 +324,7 @@ func TestRunWithDifferentArguments(t *testing.T) {
 
 	tmpDir := t.TempDir()
 	filename := filepath.Join(tmpDir, "run_vmtestcontract.go")
-	require.NoError(t, ioutil.WriteFile(filename, []byte(src), os.ModePerm))
+	require.NoError(t, os.WriteFile(filename, []byte(src), os.ModePerm))
 
 	filename = "'" + filename + "'"
 	e := newTestVMCLI(t)

pkg/vm/json_test.go

@@ -7,7 +7,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"math/big"
 	"os"
 	"path/filepath"
@@ -129,7 +129,7 @@ func testSyscallHandler(v *VM, id uint32) error {
 }
 
 func testFile(t *testing.T, filename string) {
-	data, err := ioutil.ReadFile(filename)
+	data, err := os.ReadFile(filename)
 	require.NoError(t, err)
 
 	// get rid of possible BOM
@@ -472,7 +472,7 @@ func decodeBytes(data []byte) ([]byte, error) {
 	}
 
 	r := base64.NewDecoder(base64.StdEncoding, bytes.NewReader(data))
-	return ioutil.ReadAll(r)
+	return io.ReadAll(r)
 }
 
 func decodeHex(s string) ([]byte, error) {

pkg/vm/vm.go

@@ -7,7 +7,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"math"
 	"math/big"
 	"os"
@@ -234,7 +233,7 @@ func (v *VM) AddBreakPointRel(n int) {
 
 // LoadFileWithFlags loads a program in NEF format from the given path, ready to execute it.
 func (v *VM) LoadFileWithFlags(path string, f callflag.CallFlag) error {
-	b, err := ioutil.ReadFile(path)
+	b, err := os.ReadFile(path)
 	if err != nil {
 		return err
 	}

pkg/wallet/regenerate_test.go

@@ -3,7 +3,7 @@ package wallet
 import (
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"testing"
 
@@ -227,11 +227,11 @@ func TestRegenerateCLIWallet1_solo(t *testing.T) {
 	require.NoError(t, acc3.ConvertMultisig(1, keys.PublicKeys{getKeys(t)[0]}))
 
 	acc4 := getAccountWithScrypt(t, verifyWIF, "pass", scrypt) // deployed verify.go contract
-	f, err := ioutil.ReadFile(verifyNEFPath)
+	f, err := os.ReadFile(verifyNEFPath)
 	require.NoError(t, err)
 	nefFile, err := nef.FileFromBytes(f)
 	require.NoError(t, err)
-	manifestBytes, err := ioutil.ReadFile(verifyManifestPath)
+	manifestBytes, err := os.ReadFile(verifyManifestPath)
 	require.NoError(t, err)
 	m := &manifest.Manifest{}
 	require.NoError(t, json.Unmarshal(manifestBytes, m))

pkg/wallet/wallet.go

@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"errors"
 	"io"
-	"io/ioutil"
 	"os"
 
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
@@ -161,7 +160,7 @@ func (w *Wallet) savePretty() error {
 }
 
 func (w *Wallet) writeRaw(data []byte) error {
-	return ioutil.WriteFile(w.path, data, 0644)
+	return os.WriteFile(w.path, data, 0644)
 }
 
 // JSON outputs a pretty JSON representation of the wallet.

scripts/compare-dumps/compare-dumps.go

@@ -7,7 +7,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sort"
@@ -32,7 +31,7 @@ type storageOp struct {
 }
 
 func readFile(path string) (dump, error) {
-	data, err := ioutil.ReadFile(path)
+	data, err := os.ReadFile(path)
 	if err != nil {
 		return nil, err
 	}