do not use ioutil (#9206)

test/fuzz/mempool/v0/fuzz_test.go

@@ -1,7 +1,7 @@
 package v0_test
 
 import (
-	"io/ioutil"
+	"io"
 	"os"
 	"path/filepath"
 	"testing"
@@ -25,7 +25,7 @@ func TestMempoolTestdataCases(t *testing.T) {
 			}()
 			f, err := os.Open(filepath.Join(testdataCasesDir, entry.Name()))
 			require.NoError(t, err)
-			input, err := ioutil.ReadAll(f)
+			input, err := io.ReadAll(f)
 			require.NoError(t, err)
 			mempoolv0.Fuzz(input)
 		})

test/fuzz/mempool/v1/fuzz_test.go

@@ -1,7 +1,7 @@
 package v1_test
 
 import (
-	"io/ioutil"
+	"io"
 	"os"
 	"path/filepath"
 	"testing"
@@ -25,7 +25,7 @@ func TestMempoolTestdataCases(t *testing.T) {
 			}()
 			f, err := os.Open(filepath.Join(testdataCasesDir, entry.Name()))
 			require.NoError(t, err)
-			input, err := ioutil.ReadAll(f)
+			input, err := io.ReadAll(f)
 			require.NoError(t, err)
 			mempoolv1.Fuzz(input)
 		})

test/fuzz/p2p/addrbook/init-corpus/main.go

@@ -5,7 +5,6 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"net"
 	"os"
@@ -49,7 +48,7 @@ func initCorpus(baseDir string) {
 			log.Fatalf("can't marshal %v: %v", addr, err)
 		}
 
-		if err := ioutil.WriteFile(filename, bz, 0644); err != nil {
+		if err := os.WriteFile(filename, bz, 0644); err != nil {
 			log.Fatalf("can't write %v to %q: %v", addr, filename, err)
 		}
 

test/fuzz/p2p/pex/init-corpus/main.go

@@ -4,7 +4,6 @@ package main
 import (
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"math/rand"
 	"os"
@@ -73,7 +72,7 @@ func initCorpus(rootDir string) {
 
 		filename := filepath.Join(rootDir, "corpus", fmt.Sprintf("%d", n))
 
-		if err := ioutil.WriteFile(filename, bz, 0644); err != nil {
+		if err := os.WriteFile(filename, bz, 0644); err != nil {
 			log.Fatalf("can't write %X to %q: %v", bz, filename, err)
 		}
 

test/fuzz/p2p/secret_connection/init-corpus/main.go

@@ -4,7 +4,6 @@ package main
 import (
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"path/filepath"
@@ -39,7 +38,7 @@ func initCorpus(baseDir string) {
 	for i, datum := range data {
 		filename := filepath.Join(corpusDir, fmt.Sprintf("%d", i))
 
-		if err := ioutil.WriteFile(filename, []byte(datum), 0644); err != nil {
+		if err := os.WriteFile(filename, []byte(datum), 0644); err != nil {
 			log.Fatalf("can't write %v to %q: %v", datum, filename, err)
 		}
 

test/fuzz/rpc/jsonrpc/server/handler.go

@@ -3,7 +3,7 @@ package handler
 import (
 	"bytes"
 	"encoding/json"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 
@@ -29,7 +29,7 @@ func Fuzz(data []byte) int {
 	rec := httptest.NewRecorder()
 	mux.ServeHTTP(rec, req)
 	res := rec.Result()
-	blob, err := ioutil.ReadAll(res.Body)
+	blob, err := io.ReadAll(res.Body)
 	if err != nil {
 		panic(err)
 	}