Replace deprecated ioutil with io and os (#20776)

* Replace ioutil with io and os

* Replace ioutil in utils/file.go

* Minor fix to tests and excluded files

Co-authored-by: Tim Scheuermann <tim.scheuermann@mattermost.com>
Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

services/docextractor/archive.go

@@ -7,7 +7,6 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -25,7 +24,7 @@ func (ae *archiveExtractor) Match(filename string) bool {
 }
 
 func (ae *archiveExtractor) Extract(name string, r io.ReadSeeker) (string, error) {
-	dir, err := ioutil.TempDir(os.TempDir(), "archiver")
+	dir, err := os.MkdirTemp(os.TempDir(), "archiver")
 	if err != nil {
 		return "", fmt.Errorf("error creating temporary file: %v", err)
 	}
@@ -49,7 +48,7 @@ func (ae *archiveExtractor) Extract(name string, r io.ReadSeeker) (string, error
 			filename = strings.ReplaceAll(filename, "-", " ")
 			filename = strings.ReplaceAll(filename, ".", " ")
 			filename = strings.ReplaceAll(filename, ",", " ")
-			data, err2 := ioutil.ReadAll(file)
+			data, err2 := io.ReadAll(file)
 			if err2 != nil {
 				return err2
 			}

services/docextractor/mmpreview.go

@@ -10,7 +10,6 @@ package docextractor
 import (
 	"bytes"
 	"io"
-	"io/ioutil"
 	"mime/multipart"
 	"net/http"
 	"path"
@@ -63,7 +62,7 @@ func (mpe *mmPreviewExtractor) Extract(filename string, file io.ReadSeeker) (str
 	if resp.StatusCode != 200 {
 		return "", errors.New("Unable to generate file preview using mmpreview (The server has replied with an error)")
 	}
-	data, err := ioutil.ReadAll(resp.Body)
+	data, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return "", errors.Wrap(err, "unable to read the response from mmpreview")
 	}

services/docextractor/pdf.go

@@ -8,7 +8,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"path"
 	"strings"
@@ -33,7 +32,7 @@ func (pe *pdfExtractor) Extract(filename string, r io.ReadSeeker) (out string, o
 			outErr = errors.New("error extracting pdf text")
 		}
 	}()
-	f, err := ioutil.TempFile(os.TempDir(), "pdflib")
+	f, err := os.CreateTemp(os.TempDir(), "pdflib")
 	if err != nil {
 		return "", fmt.Errorf("error creating temporary file: %v", err)
 	}

services/docextractor/plain.go

@@ -5,7 +5,6 @@ package docextractor
 
 import (
 	"io"
-	"io/ioutil"
 	"unicode"
 	"unicode/utf8"
 )
@@ -47,6 +46,6 @@ func (pe *plainExtractor) Extract(filename string, r io.ReadSeeker) (string, err
 		}
 	}
 
-	text, _ := ioutil.ReadAll(r)
+	text, _ := io.ReadAll(r)
 	return string(runes[0:total]) + string(text), nil
 }