Pull request: home: rm unnecessary func

Merge in DNS/adguard-home from imp-test to master

Squashed commit of the following:

commit 0ef7812e32b74647b43bb1d69b569e9b102e92b3
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Apr 22 14:12:00 2021 +0300

    home: rm unnecessary func

internal/home/auth_test.go

@@ -8,7 +8,6 @@ import (
 	"net/http"
 	"net/textproto"
 	"net/url"
-	"os"
 	"path/filepath"
 	"testing"
 	"time"
@@ -22,21 +21,6 @@ func TestMain(m *testing.M) {
 	aghtest.DiscardLogOutput(m)
 }
 
-func prepareTestDir(t *testing.T) string {
-	t.Helper()
-
-	const dir = "./agh-test"
-
-	require.Nil(t, os.RemoveAll(dir))
-	// TODO(e.burkov): Replace with testing.TempDir after updating Go
-	// version to 1.16.
-	require.Nil(t, os.MkdirAll(dir, 0o755))
-
-	t.Cleanup(func() { require.Nil(t, os.RemoveAll(dir)) })
-
-	return dir
-}
-
 func TestNewSessionToken(t *testing.T) {
 	// Successful case.
 	token, err := newSessionToken()
@@ -57,7 +41,7 @@ func TestNewSessionToken(t *testing.T) {
 }
 
 func TestAuth(t *testing.T) {
-	dir := prepareTestDir(t)
+	dir := t.TempDir()
 	fn := filepath.Join(dir, "sessions.db")
 
 	users := []User{{
@@ -132,7 +116,7 @@ func (w *testResponseWriter) WriteHeader(statusCode int) {
 }
 
 func TestAuthHTTP(t *testing.T) {
-	dir := prepareTestDir(t)
+	dir := t.TempDir()
 	fn := filepath.Join(dir, "sessions.db")
 
 	users := []User{

internal/home/authglinet_test.go

@@ -12,7 +12,7 @@ import (
 )
 
 func TestAuthGL(t *testing.T) {
-	dir := prepareTestDir(t)
+	dir := t.TempDir()
 
 	GLMode = true
 	t.Cleanup(func() {

internal/home/filter_test.go

@@ -43,7 +43,7 @@ func testStartFilterListener(t *testing.T) net.Listener {
 
 func TestFilters(t *testing.T) {
 	l := testStartFilterListener(t)
-	dir := prepareTestDir(t)
+	dir := t.TempDir()
 
 	Context = homeContext{
 		workDir: dir,

internal/home/home_test.go

@@ -114,7 +114,7 @@ func TestHome(t *testing.T) {
 	// Init new context
 	Context = homeContext{}
 
-	dir := prepareTestDir(t)
+	dir := t.TempDir()
 	fn := filepath.Join(dir, "AdGuardHome.yaml")
 
 	// Prepare the test config