remove deprecated "ioutil" and fix notes

app/update.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"os/signal"
 	"syscall"
@@ -22,9 +21,9 @@ import (
 )
 
 // checkUpdate checks whether an update exists. Update checking is instructed by following steps:
-//   1. If install means is known, use it as an update means.
-//      If install means is unknown, checkUpdate selects an available means from candidates.
-//   2. Check whether update exists. It it is found, cache the latest version.
+//  1. If install means is known, use it as an update means.
+//     If install means is unknown, checkUpdate selects an available means from candidates.
+//  2. Check whether update exists. If it is found, cache the latest version.
 func checkUpdate(ctx context.Context, cfg *config.Config, c *cache.Cache) error {
 	var (
 		m   updater.Means
@@ -109,7 +108,7 @@ func processUpdate(ctx context.Context, cfg *config.Config, w io.Writer, c *cach
 	// If auto update is enabled, do process update without user's confirmation.
 	if cfg.Meta.AutoUpdate {
 		// If canceled, ignore and return
-		err := update(ctx, ioutil.Discard, newUpdater(cfg, meta.Version, m), c)
+		err := update(ctx, io.Discard, newUpdater(cfg, meta.Version, m), c)
 		if errors.Is(err, context.Canceled) {
 			return nil
 		}

app/update_test.go

@@ -4,7 +4,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"testing"
 	"time"
 
@@ -324,7 +324,7 @@ func Test_processUpdate(t *testing.T) {
 
 func Test_update(t *testing.T) {
 	updater := updater.New(meta.Version, &dummyMeans{dummyMeansBuilderOption: dummyMeansBuilderOption{version: "v1.0.0"}})
-	err := update(context.Background(), ioutil.Discard, updater, &cache.Cache{SaveFunc: func() error { return nil }})
+	err := update(context.Background(), io.Discard, updater, &cache.Cache{SaveFunc: func() error { return nil }})
 	if err != nil {
 		t.Errorf("update must not return an error, but got '%s'", err)
 	}

config/config_test.go

@@ -4,7 +4,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -42,14 +41,13 @@ func init() {
 //
 // The directory structure is as follows:
 //
-//   - (temp dir): dir
-//     - config: $XDG_CONFIG_HOME
-//       - evans: evansCfgDir
-//
+//	─ (temp dir): dir
+//	   ─ config: $XDG_CONFIG_HOME
+//	      ─ evans: evansCfgDir
 func setupEnv(t *testing.T) (string, string, func()) {
 	cwd := getWorkDir(t)
 
-	dir, err := ioutil.TempDir("", "")
+	dir, err := os.MkdirTemp("", "")
 	if err != nil {
 		t.Fatalf("failed to create a temp dir to setup testing environment: %s", err)
 	}

config/migrate_test.go

@@ -1,7 +1,7 @@
 package config
 
 import (
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -21,12 +21,12 @@ func Test_migration(t *testing.T) {
 			_, cfgDir, cleanup := setupEnv(t)
 			defer cleanup()
 
-			b, err := ioutil.ReadFile(filepath.Join(oldCWD, "testdata", toFileName(oldVer)))
+			b, err := os.ReadFile(filepath.Join(oldCWD, "testdata", toFileName(oldVer)))
 			if err != nil {
 				t.Fatalf("failed to read a config file, but got '%s'", err)
 			}
 
-			err = ioutil.WriteFile(filepath.Join(cfgDir, "config.toml"), b, 0600)
+			err = os.WriteFile(filepath.Join(cfgDir, "config.toml"), b, 0600)
 			if err != nil {
 				t.Fatalf("failed to copy a config file to a temp config dir, but got '%s'", err)
 			}

e2e/e2e_test.go

@@ -2,7 +2,7 @@ package e2e_test
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -22,13 +22,12 @@ import (
 
 // TestMain prepares the test environment for E2E testing. TestMain do following things for clean up the environment.
 //
-//   - Set log output to ioutil.Discard.
+//   - Set log output to io.Discard.
 //   - Remove .evans.toml in this project root.
 //   - Change $XDG_CONFIG_HOME and $XDG_CACHE_HOME to ignore the root config and cache data.
 //     These envvars are reset at the end of E2E testing.
-//
 func TestMain(m *testing.M) {
-	logger.SetOutput(ioutil.Discard)
+	logger.SetOutput(io.Discard)
 
 	b, err := exec.Command("git", "rev-parse", "--show-cdup").Output()
 	if err != nil {
@@ -108,14 +107,14 @@ func compareWithGolden(t *testing.T, actual string) {
 	fname := normalizeFilename(name)
 
 	if *update {
-		if err := ioutil.WriteFile(fname, []byte(actual), 0600); err != nil {
+		if err := os.WriteFile(fname, []byte(actual), 0600); err != nil {
 			t.Fatalf("failed to update the golden file: %s", err)
 		}
 		return
 	}
 
 	// Load the golden file.
-	b, err := ioutil.ReadFile(fname)
+	b, err := os.ReadFile(fname)
 	if err != nil {
 		t.Fatalf("failed to load a golden file: %s", err)
 	}

e2e/e2egen/e2egen.go

@@ -2,7 +2,7 @@
 //
 // e2egen generates a new testcase stub from execution result. e2egen accepts following args.
 //
-//   e2egen <file> <Evans flags>
+//	e2egen <file> <Evans flags>
 //
 // file is the source code of REPL E2E test. Updated code is written to it. Evans flags are options of Evans.
 //
@@ -20,7 +20,6 @@ import (
 	"go/printer"
 	"go/token"
 	"io"
-	"io/ioutil"
 	"os"
 	"strconv"
 	"strings"
@@ -45,7 +44,7 @@ func realMain() int {
 
 	fileName, args := os.Args[1], os.Args[2:]
 
-	src, err := ioutil.ReadFile(fileName)
+	src, err := os.ReadFile(fileName)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "failed to read the file: %s", err)
 		return 1

fill/proto/interactive_filler.go

@@ -4,7 +4,7 @@ import (
 	"encoding/base64"
 	"fmt"
 	"io"
-	"io/ioutil"
+	"os"
 	"strconv"
 	"strings"
 
@@ -208,7 +208,7 @@ func (r *resolver) resolveField(f *desc.FieldDescriptor) error {
 						return b, nil
 					}
 				} else if r.opts.BytesFromFile {
-					b, err := ioutil.ReadFile(v)
+					b, err := os.ReadFile(v)
 					if err == nil {
 						return b, nil
 					}

grpc/grpc.go

@@ -5,12 +5,12 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"os"
 	"strings"
 	"time"
 
 	"crypto/tls"
 	"crypto/x509"
-	"io/ioutil"
 
 	"github.com/hashicorp/go-multierror"
 	"github.com/ktr0731/evans/grpc/grpcreflection"
@@ -121,7 +121,7 @@ func NewClient(addr, serverName string, useReflection, useTLS bool, cacert, cert
 	} else { // Enable TLS authentication
 		var tlsCfg tls.Config
 		if cacert != "" {
-			b, err := ioutil.ReadFile(cacert)
+			b, err := os.ReadFile(cacert)
 			if err != nil {
 				return nil, errors.Wrap(err, "failed to read the CA certificate")
 			}
@@ -308,6 +308,7 @@ func (c *client) NewBidiStream(ctx context.Context, streamDesc *grpc.StreamDesc,
 // fqrnToEndpoint converts FullQualifiedRPCName to endpoint
 //
 // e.g.
+//
 //	pkg_name.svc_name.rpc_name -> /pkg_name.svc_name/rpc_name
 func fqrnToEndpoint(fqrn string) (string, error) {
 	sp := strings.Split(fqrn, ".")

logger/logger.go

@@ -4,7 +4,6 @@ package logger
 
 import (
 	"io"
-	"io/ioutil"
 	"log"
 )
 
@@ -60,5 +59,5 @@ func Scriptf(format string, f func() []interface{}) {
 }
 
 func newDefaultLogger() *log.Logger {
-	return log.New(ioutil.Discard, "evans: ", 0)
+	return log.New(io.Discard, "evans: ", 0)
 }

repl/repl.go

@@ -5,7 +5,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sort"
@@ -181,7 +180,7 @@ func (r *REPL) printSplash(p string) {
 
 	_, err := os.Stat(abs)
 	if !os.IsNotExist(err) {
-		b, err := ioutil.ReadFile(abs)
+		b, err := os.ReadFile(abs)
 		if err == nil {
 			r.ui.Output(string(b))
 		}

repl/repl_test.go

@@ -3,7 +3,6 @@ package repl
 import (
 	"bytes"
 	"io"
-	"io/ioutil"
 	"os"
 	"runtime"
 	"strings"
@@ -56,7 +55,7 @@ func TestREPL_printSplash(t *testing.T) {
 		t.Fatalf("failed to get user home dir: %s", err)
 	}
 
-	f, err := ioutil.TempFile(home, "")
+	f, err := os.CreateTemp(home, "")
 	if err != nil {
 		t.Fatalf("failed to create a temp file: %s", err)
 	}