pkg/stringutil: add tests

For later "runner" cleanup

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

pkg/stringutil/rand_test.go

@@ -0,0 +1,30 @@
+// 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 stringutil
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestUniqueStrings(t *testing.T) {
+	ss := UniqueStrings(10, 50)
+	for i := 1; i < len(ss); i++ {
+		if ss[i-1] == ss[i] {
+			t.Fatalf("ss[i-1] %q == ss[i] %q", ss[i-1], ss[i])
+		}
+	}
+	fmt.Println(ss)
+}