Fix filecount for paths with trailing slash (influxdata#6332)

plugins/inputs/filecount/filecount.go

@@ -267,11 +267,11 @@ func (fc *FileCount) onlyDirectories(directories []string) []string {
 func (fc *FileCount) getDirs() []string {
 	dirs := make([]string, len(fc.Directories))
 	for i, dir := range fc.Directories {
-		dirs[i] = dir
+		dirs[i] = filepath.Clean(dir)
 	}
 
 	if fc.Directory != "" {
-		dirs = append(dirs, fc.Directory)
+		dirs = append(dirs, filepath.Clean(fc.Directory))
 	}
 
 	return dirs

plugins/inputs/filecount/filecount_test.go

@@ -2,11 +2,13 @@ package filecount
 
 import (
 	"os"
+	"path/filepath"
 	"runtime"
 	"strings"
 	"testing"
 	"time"
 
+	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/internal"
 	"github.com/influxdata/telegraf/testutil"
 	"github.com/stretchr/testify/require"
@@ -117,6 +119,37 @@ func TestMTimeFilter(t *testing.T) {
 	fileCountEquals(t, fc, len(matches), 0)
 }
 
+// Paths with a trailing slash will not exactly match paths produced during the
+// walk as these paths are cleaned before being returned from godirwalk. #6329
+func TestDirectoryWithTrailingSlash(t *testing.T) {
+	plugin := &FileCount{
+		Directories: []string{getTestdataDir() + string(filepath.Separator)},
+		Name:        "*",
+		Recursive:   true,
+		Fs:          getFakeFileSystem(getTestdataDir()),
+	}
+
+	var acc testutil.Accumulator
+	err := plugin.Gather(&acc)
+	require.NoError(t, err)
+
+	expected := []telegraf.Metric{
+		testutil.MustMetric(
+			"filecount",
+			map[string]string{
+				"directory": getTestdataDir(),
+			},
+			map[string]interface{}{
+				"count":      9,
+				"size_bytes": 5096,
+			},
+			time.Unix(0, 0),
+		),
+	}
+
+	testutil.RequireMetricsEqual(t, expected, acc.GetTelegrafMetrics(), testutil.IgnoreTime())
+}
+
 func getNoFilterFileCount() FileCount {
 	return FileCount{
 		Directories: []string{getTestdataDir()},