auditbeat: fix golangci lint errors

auditbeat/helper/hasher/hasher.go

@@ -199,7 +199,7 @@ func (hasher *FileHasher) HashFile(path string) (map[HashType]Digest, error) {
 		}
 	}
 
-	var hashes []hash.Hash
+	hashes := make([]hash.Hash, 0)
 	for _, hashType := range hasher.config.HashTypes {
 		h, valid := validHashes[hashType]
 		if !valid {

auditbeat/module/auditd/audit_linux_test.go

@@ -350,7 +350,7 @@ func TestBuildMetricbeatEvent(t *testing.T) {
 }
 
 func buildSampleEvent(t testing.TB, lines []string, filename string) {
-	var msgs []*auparse.AuditMessage
+	msgs := make([]*auparse.AuditMessage, 0)
 	for _, txt := range lines {
 		m, err := auparse.ParseLogLine(txt)
 		if err != nil {

auditbeat/module/auditd/config_test.go

@@ -28,13 +28,14 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	conf "github.com/elastic/elastic-agent-libs/config"
 	"github.com/elastic/elastic-agent-libs/logp"
 )
 
 func TestConfig(t *testing.T) {
-	logp.TestingSetup()
+	require.NoError(t, logp.TestingSetup())
 
 	t.Run("Validate", func(t *testing.T) {
 		data := `
@@ -271,7 +272,7 @@ func parseConfig(t testing.TB, yaml string) (Config, error) {
 }
 
 func commands(rules []auditRule) []string {
-	var cmds []string
+	cmds := make([]string, 0)
 	for _, r := range rules {
 		cmds = append(cmds, r.flags)
 	}

auditbeat/module/file_integrity/eventreader_test.go

@@ -18,6 +18,7 @@
 package file_integrity
 
 import (
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -30,6 +31,7 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func init() {
@@ -145,8 +147,9 @@ func TestEventReader(t *testing.T) {
 		if err != nil {
 			t.Fatal(err)
 		}
-		f.WriteString(" world!")
-		f.Sync()
+		_, err = f.WriteString(" world!")
+		require.NoError(t, err)
+		require.NoError(t, f.Sync())
 		f.Close()
 
 		event := readTimeout(t, events)
@@ -198,8 +201,9 @@ func TestEventReader(t *testing.T) {
 		if err != nil {
 			t.Fatal(err)
 		}
-		f.WriteString("move-in")
-		f.Sync()
+		_, err = f.WriteString("move-in")
+		require.NoError(t, err)
+		require.NoError(t, f.Sync())
 		f.Close()
 		moveInOrig = f.Name()
 
@@ -286,7 +290,7 @@ func TestRaces(t *testing.T) {
 		for i := 0; i < 10; i++ {
 			for _, dir := range dirs {
 				fname := filepath.Join(dir, fmt.Sprintf("%d.dat", i))
-				ioutil.WriteFile(fname, []byte("hello"), fileMode)
+				require.NoError(t, ioutil.WriteFile(fname, []byte("hello"), fileMode))
 			}
 		}
 	}()
@@ -298,7 +302,7 @@ func TestRaces(t *testing.T) {
 	const marker = "test_file"
 	for _, dir := range dirs {
 		fname := filepath.Join(dir, marker)
-		ioutil.WriteFile(fname, []byte("hello"), fileMode)
+		require.NoError(t, ioutil.WriteFile(fname, []byte("hello"), fileMode))
 	}
 
 	got := 0
@@ -431,7 +435,8 @@ func rename(t *testing.T, oldPath, newPath string) {
 			return
 		}
 
-		if linkErr, ok := err.(*os.LinkError); ok && linkErr.Err == ErrorSharingViolation {
+		var e *os.LinkError
+		if errors.As(err, &e) && errors.Is(e.Err, ErrorSharingViolation) {
 			time.Sleep(time.Millisecond)
 			continue
 		}

auditbeat/module/file_integrity/fileinfo_test.go

@@ -27,6 +27,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestNewMetadata(t *testing.T) {
@@ -40,7 +41,7 @@ func TestNewMetadata(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	f.Sync()
+	require.NoError(t, f.Sync())
 	f.Close()
 
 	info, err := os.Lstat(f.Name())
@@ -106,7 +107,7 @@ func TestSetUIDSetGIDBits(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	f.Sync()
+	require.NoError(t, f.Sync())
 	f.Close()
 
 	info, err := os.Lstat(f.Name())

auditbeat/module/file_integrity/metricset.go

@@ -41,7 +41,7 @@ const (
 	namespace = "."
 )
 
-var underTest = false
+var underTest = false //nolint:unused // Used in Darwin-only builds.
 
 func init() {
 	mb.Registry.MustAddMetricSet(moduleName, metricsetName, New,

auditbeat/module/file_integrity/metricset_test.go

@@ -29,6 +29,7 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	"github.com/elastic/beats/v7/auditbeat/core"
 	"github.com/elastic/beats/v7/auditbeat/datastore"
@@ -49,7 +50,7 @@ func TestData(t *testing.T) {
 	go func() {
 		time.Sleep(100 * time.Millisecond)
 		file := filepath.Join(dir, "file.data")
-		ioutil.WriteFile(file, []byte("hello world"), 0o600)
+		require.NoError(t, ioutil.WriteFile(file, []byte("hello world"), 0o600))
 	}()
 
 	ms := mbtest.NewPushMetricSetV2(t, getConfig(dir))
@@ -136,8 +137,8 @@ func TestActions(t *testing.T) {
 	}
 
 	// Create some files in first directory
-	ioutil.WriteFile(createdFilepath, []byte("hello world"), 0o600)
-	ioutil.WriteFile(updatedFilepath, []byte("hello world"), 0o600)
+	require.NoError(t, ioutil.WriteFile(createdFilepath, []byte("hello world"), 0o600))
+	require.NoError(t, ioutil.WriteFile(updatedFilepath, []byte("hello world"), 0o600))
 
 	ms := mbtest.NewPushMetricSetV2(t, getConfig(dir, newDir))
 	events := mbtest.RunPushMetricSetV2(10*time.Second, 5, ms)
@@ -201,7 +202,7 @@ func TestExcludedFiles(t *testing.T) {
 	go func() {
 		for _, f := range []string{"FILE.TXT", "FILE.TXT.SWP", "file.txt.swo", ".git/HEAD", ".gitignore"} {
 			file := filepath.Join(dir, f)
-			ioutil.WriteFile(file, []byte("hello world"), 0o600)
+			_ = ioutil.WriteFile(file, []byte("hello world"), 0o600)
 		}
 	}()
 
@@ -264,10 +265,7 @@ func TestIncludedExcludedFiles(t *testing.T) {
 
 	for _, f := range []string{"FILE.TXT", ".ssh/known_hosts", ".ssh/known_hosts.swp"} {
 		file := filepath.Join(dir, f)
-		err := ioutil.WriteFile(file, []byte("hello world"), 0o600)
-		if err != nil {
-			t.Fatal(err)
-		}
+		require.NoError(t, ioutil.WriteFile(file, []byte("hello world"), 0o600))
 	}
 
 	events := mbtest.RunPushMetricSetV2(10*time.Second, 3, ms)
@@ -339,8 +337,9 @@ func TestErrorReporting(t *testing.T) {
 	done := make(chan struct{}, 1)
 	go func() {
 		for {
-			f.WriteString("can't read this\n")
-			f.Sync()
+			_, err := f.WriteString("can't read this\n")
+			require.NoError(t, err)
+			require.NoError(t, f.Sync())
 			select {
 			case <-done:
 				return
@@ -366,6 +365,7 @@ func TestErrorReporting(t *testing.T) {
 
 	var event *mb.Event
 	for idx, ev := range events {
+		ev := ev
 		t.Log("event[", idx, "] = ", ev)
 		if match(&ev) {
 			event = &ev

auditbeat/module/file_integrity/monitor/monitor.go

@@ -45,7 +45,7 @@ func New(recursive bool, IsExcludedPath func(path string) bool) (Watcher, error)
 	// Use our simulated recursive watches unless the fsnotify implementation
 	// supports OS-provided recursive watches
 	if recursive && watcher.SetRecursive() != nil {
-		return newRecursiveWatcher(watcher, IsExcludedPath), nil
+		return newRecursiveWatcher(watcher, IsExcludedPath), nil //nolint:nilerr // Ignore SetRecursive() errors.
 	}
 	return (*nonRecursiveWatcher)(watcher), nil
 }

auditbeat/module/file_integrity/monitor/recursive.go

@@ -144,20 +144,19 @@ func (watcher *recursiveWatcher) deliver(ev fsnotify.Event) {
 	}
 }
 
-func (watcher *recursiveWatcher) forwardEvents() error {
+func (watcher *recursiveWatcher) forwardEvents() {
 	defer watcher.close()
 
 	for {
 		select {
 		case <-watcher.done:
-			return nil
-
+			return
 		case path := <-watcher.addC:
 			watcher.addErrC <- watcher.addRecursive(path)
 
 		case event, ok := <-watcher.inner.Events:
 			if !ok {
-				return nil
+				return
 			}
 			if event.Name == "" {
 				continue