chore: update deprecated and unused code in esutil

esutil/bulk_indexer.go

@@ -176,7 +176,7 @@ func (item *BulkIndexerItem) marshallMeta() {
 		}
 		item.meta.WriteString(`"require_alias":`)
 		item.meta.Write(strconv.AppendBool(aux, item.RequireAlias))
-		aux = aux[:0]
+		_ = aux[:0]
 	}
 
 	if item.DocumentID != "" && item.IfSeqNo != nil && item.IfPrimaryTerm != nil {

esutil/bulk_indexer_benchmark_test.go

@@ -23,7 +23,7 @@ package esutil_test
 import (
 	"bytes"
 	"context"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"strconv"
 	"strings"
@@ -55,7 +55,7 @@ var mockResponseBody = `{
 type mockTransp struct{}
 
 func (t *mockTransp) RoundTrip(req *http.Request) (*http.Response, error) {
-	return &http.Response{Body: ioutil.NopCloser(strings.NewReader(mockResponseBody))}, nil // 1x alloc
+	return &http.Response{Body: io.NopCloser(strings.NewReader(mockResponseBody))}, nil // 1x alloc
 }
 
 func BenchmarkBulkIndexer(b *testing.B) {

esutil/bulk_indexer_internal_test.go

@@ -283,17 +283,17 @@ func TestBulkIndexer(t *testing.T) {
 		successFunc := func(ctx context.Context, item BulkIndexerItem, res BulkIndexerResponseItem) {
 			atomic.AddUint64(&countSuccessful, 1)
 
-			buf, err := ioutil.ReadAll(item.Body)
+			buf, err := io.ReadAll(item.Body)
 			if err != nil {
 				t.Fatalf("Unexpected error: %s", err)
 			}
 			successfulItemBodies = append(successfulItemBodies, string(buf))
 		}
-		failureFunc := func(ctx context.Context, item BulkIndexerItem, res BulkIndexerResponseItem, err error) {
+		failureFunc := func(ctx context.Context, item BulkIndexerItem, res BulkIndexerResponseItem, _ error) {
 			atomic.AddUint64(&countFailed, 1)
 			failedIDs = append(failedIDs, item.DocumentID)
 
-			buf, err := ioutil.ReadAll(item.Body)
+			buf, err := io.ReadAll(item.Body)
 			if err != nil {
 				t.Fatalf("Unexpected error: %s", err)
 			}

esutil/json_reader_benchmark_test.go

@@ -25,7 +25,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"strings"
 	"testing"
 
@@ -71,7 +70,7 @@ func BenchmarkJSONReader(b *testing.B) {
 		b.ResetTimer()
 
 		for i := 0; i < b.N; i++ {
-			out, _ := ioutil.ReadAll(esutil.NewJSONReader(map[string]string{"foo": "bar"}))
+			out, _ := io.ReadAll(esutil.NewJSONReader(map[string]string{"foo": "bar"}))
 			if string(out) != `{"foo":"bar"}`+"\n" {
 				b.Fatalf("Unexpected output: %q", out)
 			}
@@ -95,7 +94,7 @@ func BenchmarkJSONReader(b *testing.B) {
 		b.ResetTimer()
 
 		for i := 0; i < b.N; i++ {
-			out, _ := ioutil.ReadAll(esutil.NewJSONReader(Foo{Bar: "baz"}))
+			out, _ := io.ReadAll(esutil.NewJSONReader(Foo{Bar: "baz"}))
 			if string(out) != `{"bar":"BAZ"}`+"\n" {
 				b.Fatalf("Unexpected output: %q", out)
 			}

esutil/json_reader_internal_test.go

@@ -24,7 +24,6 @@ import (
 	"bytes"
 	"errors"
 	"io"
-	"io/ioutil"
 	"strings"
 	"testing"
 )
@@ -49,14 +48,14 @@ func (f Foo) EncodeJSON(w io.Writer) error {
 
 func TestJSONReader(t *testing.T) {
 	t.Run("Default", func(t *testing.T) {
-		out, _ := ioutil.ReadAll(NewJSONReader(map[string]string{"foo": "bar"}))
+		out, _ := io.ReadAll(NewJSONReader(map[string]string{"foo": "bar"}))
 		if string(out) != `{"foo":"bar"}`+"\n" {
 			t.Fatalf("Unexpected output: %s", out)
 		}
 	})
 
 	t.Run("Custom", func(t *testing.T) {
-		out, _ := ioutil.ReadAll(NewJSONReader(Foo{Bar: "baz"}))
+		out, _ := io.ReadAll(NewJSONReader(Foo{Bar: "baz"}))
 		if string(out) != `{"bar":"BAZ"}`+"\n" {
 			t.Fatalf("Unexpected output: %s", out)
 		}