all: Remove usage of deprecated io/ioutil (#7971)

As of Go 1.16 io/ioutil is deprecated. This replaces usage with the
corresponding functions in package os and package io.

lib/versioner/external_test.go

@@ -7,7 +7,6 @@
 package versioner
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -85,7 +84,7 @@ func prepForRemoval(t *testing.T, file string) {
 	if err := os.MkdirAll(filepath.Dir(file), 0755); err != nil {
 		t.Fatal(err)
 	}
-	if err := ioutil.WriteFile(file, []byte("hello\n"), 0644); err != nil {
+	if err := os.WriteFile(file, []byte("hello\n"), 0644); err != nil {
 		t.Fatal(err)
 	}
 }

lib/versioner/simple_test.go

@@ -7,8 +7,8 @@
 package versioner
 
 import (
-	"io/ioutil"
 	"math"
+	"os"
 	"path/filepath"
 	"testing"
 	"time"
@@ -55,7 +55,7 @@ func TestSimpleVersioningVersionCount(t *testing.T) {
 		t.Skip("Test takes some time, skipping.")
 	}
 
-	dir, err := ioutil.TempDir("", "")
+	dir, err := os.MkdirTemp("", "")
 	//defer os.RemoveAll(dir)
 	if err != nil {
 		t.Error(err)

lib/versioner/staggered_test.go

@@ -7,7 +7,7 @@
 package versioner
 
 import (
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"sort"
 	"strconv"
@@ -133,11 +133,11 @@ func TestCreateVersionPath(t *testing.T) {
 	)
 
 	// Create a test dir and file
-	tmpDir, err := ioutil.TempDir("", "")
+	tmpDir, err := os.MkdirTemp("", "")
 	if err != nil {
 		t.Fatal(err)
 	}
-	if err := ioutil.WriteFile(filepath.Join(tmpDir, archiveFile), []byte("sup"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpDir, archiveFile), []byte("sup"), 0644); err != nil {
 		t.Fatal(err)
 	}
 

lib/versioner/trashcan_test.go

@@ -7,7 +7,8 @@
 package versioner
 
 import (
-	"io/ioutil"
+	"io"
+	"os"
 	"testing"
 	"time"
 
@@ -19,12 +20,12 @@ func TestTrashcanArchiveRestoreSwitcharoo(t *testing.T) {
 	// This tests that trashcan versioner restoration correctly archives existing file, because trashcan versioner
 	// files are untagged, archiving existing file to replace with a restored version technically should collide in
 	// in names.
-	tmpDir1, err := ioutil.TempDir("", "")
+	tmpDir1, err := os.MkdirTemp("", "")
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	tmpDir2, err := ioutil.TempDir("", "")
+	tmpDir2, err := os.MkdirTemp("", "")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -105,7 +106,7 @@ func readFile(t *testing.T, filesystem fs.Filesystem, name string) string {
 		t.Fatal(err)
 	}
 	defer fd.Close()
-	buf, err := ioutil.ReadAll(fd)
+	buf, err := io.ReadAll(fd)
 	if err != nil {
 		t.Fatal(err)
 	}

lib/versioner/versioner_test.go

@@ -9,7 +9,6 @@ package versioner
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -56,7 +55,7 @@ func TestVersionerCleanOut(t *testing.T) {
 			oldTime := time.Now().Add(-8 * 24 * time.Hour)
 			for file, shouldRemove := range testcases {
 				os.MkdirAll(filepath.Dir(file), 0777)
-				if err := ioutil.WriteFile(file, []byte("data"), 0644); err != nil {
+				if err := os.WriteFile(file, []byte("data"), 0644); err != nil {
 					t.Fatal(err)
 				}
 				if shouldRemove {