refactor: move from io/ioutil to io and os packages (#1546)

The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

core/data/data_test.go

@@ -2,13 +2,12 @@ package data
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"testing"
 )
 
 func TestMain(m *testing.M) {
-	dbFile, err := ioutil.TempFile(os.TempDir(), "owncast-test-db.db")
+	dbFile, err := os.CreateTemp(os.TempDir(), "owncast-test-db.db")
 	if err != nil {
 		panic(err)
 	}

core/streamState.go

@@ -4,7 +4,6 @@ import (
 	"bufio"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"time"
@@ -88,7 +87,7 @@ func SetStreamAsDisconnected() {
 
 	offlineFileData := static.GetOfflineSegment()
 	offlineFilename := "offline.ts"
-	offlineTmpFile, err := ioutil.TempFile(os.TempDir(), offlineFilename)
+	offlineTmpFile, err := os.CreateTemp(os.TempDir(), offlineFilename)
 	if err != nil {
 		log.Errorln("unable to create temp file for offline video segment")
 	}

core/transcoder/thumbnailGenerator.go

@@ -1,7 +1,6 @@
 package transcoder
 
 import (
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path"
@@ -54,15 +53,20 @@ func fireThumbnailGenerator(segmentPath string, variantIndex int) error {
 	previewGifFile := path.Join(config.WebRoot, "preview.gif")
 
 	framePath := path.Join(segmentPath, strconv.Itoa(variantIndex))
-	files, err := ioutil.ReadDir(framePath)
+	files, err := os.ReadDir(framePath)
 	if err != nil {
 		return err
 	}
 
 	var modTime time.Time
 	var names []string
-	for _, fi := range files {
-		if path.Ext(fi.Name()) != ".ts" {
+	for _, f := range files {
+		if path.Ext(f.Name()) != ".ts" {
+			continue
+		}
+
+		fi, err := f.Info()
+		if err != nil {
 			continue
 		}