tests: improve Block test suite

* Reorder test cases to follow function order in block.hpp.
* Move prependVarNumber and prependNonNegativeInteger tests
  to EncodingBuffer test suite.
* Add test for Block() default constructor.
* Add test for Block(uint32_t) constructor.
* Add test for Block::parse function.

refs #4171

Change-Id: Ia4eaf36f6ced9c2dabc7531ba541a5a2f92bae89
diff --git a/tests/unit-tests/encoding/encoding-buffer.t.cpp b/tests/unit-tests/encoding/encoding-buffer.t.cpp
new file mode 100644
index 0000000..00240b8
--- /dev/null
+++ b/tests/unit-tests/encoding/encoding-buffer.t.cpp
@@ -0,0 +1,204 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2013-2017 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 "encoding/encoding-buffer.hpp"
+#include "encoding/block.hpp"
+
+#include "boost-test.hpp"
+
+namespace ndn {
+namespace tests {
+
+class BufferEstimatorFixture
+{
+public:
+  EncodingBuffer buffer;
+  EncodingEstimator estimator;
+};
+
+BOOST_AUTO_TEST_SUITE(Encoding)
+BOOST_AUTO_TEST_SUITE(TestEncodingBuffer)
+
+BOOST_AUTO_TEST_CASE(ConstructFromBlock)
+{
+  auto buf = make_shared<Buffer>(10);
+  std::memset(buf->get(), 0, 10);
+
+  Block block(0xab, buf);
+  block.encode();
+
+  {
+    EncodingBuffer buffer(block);
+    BOOST_CHECK_EQUAL(buffer.size(), 12);
+    BOOST_CHECK_EQUAL(buffer.capacity(), 12);
+  }
+
+  (*buf)[1] = 0xe0;
+  (*buf)[2] = 2;
+  block = Block(buf, buf->begin() + 1, buf->begin() + 5);
+  BOOST_CHECK_EQUAL(block.type(), 0xe0);
+
+  {
+    EncodingBuffer buffer(block);
+    BOOST_CHECK_EQUAL(buffer.size(), 4);
+    BOOST_CHECK_EQUAL(buffer.capacity(), 10);
+  }
+}
+
+BOOST_FIXTURE_TEST_SUITE(PrependVarNumber, BufferEstimatorFixture)
+
+BOOST_AUTO_TEST_CASE(OneByte1)
+{
+  size_t s1 = buffer.prependVarNumber(252);
+  size_t s2 = estimator.prependVarNumber(252);
+  BOOST_CHECK_EQUAL(buffer.size(), 1);
+  BOOST_CHECK_EQUAL(s1, 1);
+  BOOST_CHECK_EQUAL(s2, 1);
+}
+
+BOOST_AUTO_TEST_CASE(ThreeBytes1)
+{
+  size_t s1 = buffer.prependVarNumber(253);
+  size_t s2 = estimator.prependVarNumber(253);
+  BOOST_CHECK_EQUAL(buffer.size(), 3);
+  BOOST_CHECK_EQUAL(s1, 3);
+  BOOST_CHECK_EQUAL(s2, 3);
+}
+
+BOOST_AUTO_TEST_CASE(ThreeBytes2)
+{
+  size_t s1 = buffer.prependVarNumber(255);
+  size_t s2 = estimator.prependVarNumber(255);
+  BOOST_CHECK_EQUAL(buffer.size(), 3);
+  BOOST_CHECK_EQUAL(s1, 3);
+  BOOST_CHECK_EQUAL(s2, 3);
+}
+
+BOOST_AUTO_TEST_CASE(ThreeBytes3)
+{
+  size_t s1 = buffer.prependVarNumber(65535);
+  size_t s2 = estimator.prependVarNumber(65535);
+  BOOST_CHECK_EQUAL(buffer.size(), 3);
+  BOOST_CHECK_EQUAL(s1, 3);
+  BOOST_CHECK_EQUAL(s2, 3);
+}
+
+BOOST_AUTO_TEST_CASE(FiveBytes1)
+{
+  size_t s1 = buffer.prependVarNumber(65536);
+  size_t s2 = estimator.prependVarNumber(65536);
+  BOOST_CHECK_EQUAL(buffer.size(), 5);
+  BOOST_CHECK_EQUAL(s1, 5);
+  BOOST_CHECK_EQUAL(s2, 5);
+}
+
+BOOST_AUTO_TEST_CASE(FiveBytes2)
+{
+  size_t s1 = buffer.prependVarNumber(4294967295LL);
+  size_t s2 = estimator.prependVarNumber(4294967295LL);
+  BOOST_CHECK_EQUAL(buffer.size(), 5);
+  BOOST_CHECK_EQUAL(s1, 5);
+  BOOST_CHECK_EQUAL(s2, 5);
+}
+
+BOOST_AUTO_TEST_CASE(NineBytes)
+{
+  size_t s1 = buffer.prependVarNumber(4294967296LL);
+  size_t s2 = estimator.prependVarNumber(4294967296LL);
+  BOOST_CHECK_EQUAL(buffer.size(), 9);
+  BOOST_CHECK_EQUAL(s1, 9);
+  BOOST_CHECK_EQUAL(s2, 9);
+}
+
+BOOST_AUTO_TEST_SUITE_END() // PrependVarNumber
+
+BOOST_FIXTURE_TEST_SUITE(PrependNonNegativeNumber, BufferEstimatorFixture)
+
+BOOST_AUTO_TEST_CASE(NonNegativeNumberOneByte1)
+{
+  size_t s1 = buffer.prependNonNegativeInteger(252);
+  size_t s2 = estimator.prependNonNegativeInteger(252);
+  BOOST_CHECK_EQUAL(buffer.size(), 1);
+  BOOST_CHECK_EQUAL(s1, 1);
+  BOOST_CHECK_EQUAL(s2, 1);
+}
+
+BOOST_AUTO_TEST_CASE(NonNegativeNumberOneByte2)
+{
+  size_t s1 = buffer.prependNonNegativeInteger(255);
+  size_t s2 = estimator.prependNonNegativeInteger(255);
+  BOOST_CHECK_EQUAL(buffer.size(), 1);
+  BOOST_CHECK_EQUAL(s1, 1);
+  BOOST_CHECK_EQUAL(s2, 1);
+}
+
+BOOST_AUTO_TEST_CASE(NonNegativeNumberTwoBytes1)
+{
+  size_t s1 = buffer.prependNonNegativeInteger(256);
+  size_t s2 = estimator.prependNonNegativeInteger(256);
+  BOOST_CHECK_EQUAL(buffer.size(), 2);
+  BOOST_CHECK_EQUAL(s1, 2);
+  BOOST_CHECK_EQUAL(s2, 2);
+}
+
+BOOST_AUTO_TEST_CASE(NonNegativeNumberTwoBytes2)
+{
+  size_t s1 = buffer.prependNonNegativeInteger(65535);
+  size_t s2 = estimator.prependNonNegativeInteger(65535);
+  BOOST_CHECK_EQUAL(buffer.size(), 2);
+  BOOST_CHECK_EQUAL(s1, 2);
+  BOOST_CHECK_EQUAL(s2, 2);
+}
+
+BOOST_AUTO_TEST_CASE(NonNegativeNumberFourBytes1)
+{
+  size_t s1 = buffer.prependNonNegativeInteger(65536);
+  size_t s2 = estimator.prependNonNegativeInteger(65536);
+  BOOST_CHECK_EQUAL(buffer.size(), 4);
+  BOOST_CHECK_EQUAL(s1, 4);
+  BOOST_CHECK_EQUAL(s2, 4);
+}
+
+BOOST_AUTO_TEST_CASE(NonNegativeNumberFourBytes2)
+{
+  size_t s1 = buffer.prependNonNegativeInteger(4294967295LL);
+  size_t s2 = estimator.prependNonNegativeInteger(4294967295LL);
+  BOOST_CHECK_EQUAL(buffer.size(), 4);
+  BOOST_CHECK_EQUAL(s1, 4);
+  BOOST_CHECK_EQUAL(s2, 4);
+}
+
+BOOST_AUTO_TEST_CASE(NonNegativeNumberEightBytes)
+{
+  size_t s1 = buffer.prependNonNegativeInteger(4294967296LL);
+  size_t s2 = estimator.prependNonNegativeInteger(4294967296LL);
+  BOOST_CHECK_EQUAL(buffer.size(), 8);
+  BOOST_CHECK_EQUAL(s1, 8);
+  BOOST_CHECK_EQUAL(s2, 8);
+}
+
+BOOST_AUTO_TEST_SUITE_END() // PrependNonNegativeNumber
+
+BOOST_AUTO_TEST_SUITE_END() // TestEncodingBuffer
+BOOST_AUTO_TEST_SUITE_END() // Encoding
+
+} // namespace tests
+} // namespace ndn