pkg/fileutil: add "ReadDirOption"

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>

pkg/fileutil/read_dir_test.go

@@ -0,0 +1,67 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fileutil
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"reflect"
+	"testing"
+)
+
+func TestReadDir(t *testing.T) {
+	tmpdir, err := ioutil.TempDir("", "")
+	defer os.RemoveAll(tmpdir)
+	if err != nil {
+		t.Fatalf("unexpected ioutil.TempDir error: %v", err)
+	}
+
+	files := []string{"def", "abc", "xyz", "ghi"}
+	for _, f := range files {
+		writeFunc(t, filepath.Join(tmpdir, f))
+	}
+	fs, err := ReadDir(tmpdir)
+	if err != nil {
+		t.Fatalf("error calling ReadDir: %v", err)
+	}
+	wfs := []string{"abc", "def", "ghi", "xyz"}
+	if !reflect.DeepEqual(fs, wfs) {
+		t.Fatalf("ReadDir: got %v, want %v", fs, wfs)
+	}
+
+	files = []string{"def.wal", "abc.wal", "xyz.wal", "ghi.wal"}
+	for _, f := range files {
+		writeFunc(t, filepath.Join(tmpdir, f))
+	}
+	fs, err = ReadDir(tmpdir, WithExt(".wal"))
+	if err != nil {
+		t.Fatalf("error calling ReadDir: %v", err)
+	}
+	wfs = []string{"abc.wal", "def.wal", "ghi.wal", "xyz.wal"}
+	if !reflect.DeepEqual(fs, wfs) {
+		t.Fatalf("ReadDir: got %v, want %v", fs, wfs)
+	}
+}
+
+func writeFunc(t *testing.T, path string) {
+	fh, err := os.Create(path)
+	if err != nil {
+		t.Fatalf("error creating file: %v", err)
+	}
+	if err = fh.Close(); err != nil {
+		t.Fatalf("error closing file: %v", err)
+	}
+}