Rename 'tests/unit-tests' directory to 'tests/unit'

Change-Id: I78ea29938259fac288781bed12fb2399ac7eba26
diff --git a/tests/unit/security/v2/validation-error.t.cpp b/tests/unit/security/v2/validation-error.t.cpp
new file mode 100644
index 0000000..1db3aac
--- /dev/null
+++ b/tests/unit/security/v2/validation-error.t.cpp
@@ -0,0 +1,61 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2013-2018 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#include "security/v2/validation-error.hpp"
+
+#include "boost-test.hpp"
+#include <boost/lexical_cast.hpp>
+
+namespace ndn {
+namespace security {
+namespace v2 {
+namespace tests {
+
+BOOST_AUTO_TEST_SUITE(Security)
+BOOST_AUTO_TEST_SUITE(V2)
+BOOST_AUTO_TEST_SUITE(TestValidationError)
+
+BOOST_AUTO_TEST_CASE(Basic)
+{
+  ValidationError e1{ValidationError::Code::INVALID_SIGNATURE};
+  BOOST_CHECK_EQUAL(e1.getCode(), 1);
+  BOOST_CHECK_EQUAL(e1.getInfo(), "");
+  BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(e1), "Invalid signature");
+
+  ValidationError e2{ValidationError::Code::NO_SIGNATURE, "message"};
+  BOOST_CHECK_EQUAL(e2.getCode(), 2);
+  BOOST_CHECK_EQUAL(e2.getInfo(), "message");
+  BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(e2), "Missing signature (message)");
+
+  ValidationError e3{65535, "other message"};
+  BOOST_CHECK_EQUAL(e3.getCode(), 65535);
+  BOOST_CHECK_EQUAL(e3.getInfo(), "other message");
+  BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(e3), "Custom error code 65535 (other message)");
+}
+
+BOOST_AUTO_TEST_SUITE_END() // TestValidationError
+BOOST_AUTO_TEST_SUITE_END() // V2
+BOOST_AUTO_TEST_SUITE_END() // Security
+
+} // namespace tests
+} // namespace v2
+} // namespace security
+} // namespace ndn