diff --git a/tests/unit-tests/security/transform/digest-filter.t.cpp b/tests/unit-tests/security/transform/digest-filter.t.cpp
index c6e296f..a3f0314 100644
--- a/tests/unit-tests/security/transform/digest-filter.t.cpp
+++ b/tests/unit-tests/security/transform/digest-filter.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2013-2016 Regents of the University of California.
+/*
+ * Copyright (c) 2013-2017 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -19,11 +19,12 @@
  * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
  */
 
+#include "security/transform/digest-filter.hpp"
+
+#include "encoding/buffer-stream.hpp"
 #include "security/transform/buffer-source.hpp"
 #include "security/transform/step-source.hpp"
-#include "security/transform/digest-filter.hpp"
 #include "security/transform/stream-sink.hpp"
-#include "encoding/buffer-stream.hpp"
 
 #include "boost-test.hpp"
 
@@ -36,34 +37,33 @@
 BOOST_AUTO_TEST_SUITE(Transform)
 BOOST_AUTO_TEST_SUITE(TestDigestFilter)
 
+static const uint8_t in[] = {
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
+};
+static const uint8_t out[] = {
+  0x3e, 0x14, 0xfd, 0x66, 0x9a, 0x79, 0x80, 0x65,
+  0xc4, 0x0d, 0x61, 0xf8, 0x6a, 0xc7, 0x98, 0x29,
+  0xc0, 0x6b, 0x90, 0x8f, 0xbb, 0x19, 0xa0, 0x85,
+  0xf7, 0xfa, 0x7b, 0x2d, 0xd6, 0x8c, 0xd5, 0xa3
+};
+
 BOOST_AUTO_TEST_CASE(Basic)
 {
-  uint8_t in[128] = {
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
-  };
-
-  uint8_t out[] = {
-    0x3e, 0x14, 0xfd, 0x66, 0x9a, 0x79, 0x80, 0x65,
-    0xc4, 0x0d, 0x61, 0xf8, 0x6a, 0xc7, 0x98, 0x29,
-    0xc0, 0x6b, 0x90, 0x8f, 0xbb, 0x19, 0xa0, 0x85,
-    0xf7, 0xfa, 0x7b, 0x2d, 0xd6, 0x8c, 0xd5, 0xa3
-  };
-
   OBufferStream os;
   bufferSource(in, sizeof(in)) >> digestFilter(DigestAlgorithm::SHA256) >> streamSink(os);
 
@@ -73,32 +73,6 @@
 
 BOOST_AUTO_TEST_CASE(StepByStep)
 {
-  uint8_t in[128] = {
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
-  };
-
-  uint8_t out[] = {
-    0x3e, 0x14, 0xfd, 0x66, 0x9a, 0x79, 0x80, 0x65,
-    0xc4, 0x0d, 0x61, 0xf8, 0x6a, 0xc7, 0x98, 0x29,
-    0xc0, 0x6b, 0x90, 0x8f, 0xbb, 0x19, 0xa0, 0x85,
-    0xf7, 0xfa, 0x7b, 0x2d, 0xd6, 0x8c, 0xd5, 0xa3
-  };
-
   StepSource source;
   OBufferStream os;
   source >> digestFilter(DigestAlgorithm::SHA256) >> streamSink(os);
@@ -116,7 +90,7 @@
 
 BOOST_AUTO_TEST_CASE(EmptyInput)
 {
-  uint8_t out[] = {
+  const uint8_t out[] = {
     0xe3, 0xb0, 0xc4, 0x42, 0x98, 0xfc, 0x1c, 0x14,
     0x9a, 0xfb, 0xf4, 0xc8, 0x99, 0x6f, 0xb9, 0x24,
     0x27, 0xae, 0x41, 0xe4, 0x64, 0x9b, 0x93, 0x4c,
@@ -132,11 +106,9 @@
   BOOST_CHECK_EQUAL_COLLECTIONS(out, out + sizeof(out), buf->begin(), buf->end());
 }
 
-BOOST_AUTO_TEST_CASE(Error)
+BOOST_AUTO_TEST_CASE(InvalidAlgorithm)
 {
-  OBufferStream os;
-  BOOST_REQUIRE_THROW(stepSource() >> digestFilter(DigestAlgorithm::NONE) >> streamSink(os),
-                      transform::Error);
+  BOOST_CHECK_THROW(DigestFilter{DigestAlgorithm::NONE}, Error);
 }
 
 BOOST_AUTO_TEST_SUITE_END() // TestDigestFilter