Pull request: all: fix windows tempdir

Merge in DNS/adguard-home from try-fixing-windows-tests to master

Squashed commit of the following:

commit 25a43db5d53f24b98921efa21d8d2f231992e761
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Fri Mar 26 21:19:00 2021 +0300

    all: fix windows tempdir

internal/aghtest/os.go

@@ -1,13 +0,0 @@
-package aghtest
-
-import (
-	"testing"
-)
-
-// PrepareTestDir returns the full path to temporary created directory and
-// registers the appropriate cleanup for *t.
-func PrepareTestDir(t *testing.T) (dir string) {
-	t.Helper()
-
-	return prepareTestDir(t)
-}

internal/aghtest/os_others.go

@@ -1,13 +0,0 @@
-// +build !windows
-
-package aghtest
-
-import (
-	"testing"
-)
-
-func prepareTestDir(t *testing.T) (dir string) {
-	t.Helper()
-
-	return t.TempDir()
-}

internal/aghtest/os_windows.go

@@ -1,63 +0,0 @@
-// +build windows
-
-package aghtest
-
-import (
-	"io/ioutil"
-	"os"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-const (
-	maxRetryDur = 1000 * time.Millisecond
-	retryDur    = 5 * time.Millisecond
-)
-
-func prepareTestDir(t *testing.T) (dir string) {
-	// Windows, including the version of Windows Server that Github Actions
-	// uses, apparently likes to overly eagerly inspect new directories with
-	// its Windows Defender.  Disabling it might require additional
-	// workarounds, and until we've figured it out, just retry the deletion
-	// until the error goes away.
-	//
-	// The code is largely inspired by the one that has been introduced into
-	// the go command itself.  We should probably make a proposal to use the
-	// same mechanism in t.TempDir.
-	//
-	// See https://go-review.googlesource.com/c/go/+/172337.
-	//
-	// See https://github.com/golang/go/issues/44919.
-
-	t.Helper()
-
-	wd, err := os.Getwd()
-	require.NoError(t, err)
-
-	dir, err = ioutil.TempDir(wd, "agh-test")
-	require.NoError(t, err)
-	require.NotEmpty(t, dir)
-
-	t.Cleanup(func() {
-		start := time.Now()
-		for {
-			err = os.RemoveAll(dir)
-			if err == nil {
-				break
-			}
-
-			if time.Since(start) >= maxRetryDur {
-				break
-			}
-
-			time.Sleep(retryDur)
-		}
-
-		assert.NoError(t, err, "after %s", time.Since(start))
-	})
-
-	return dir
-}