diff --git a/tests/unit/data.t.cpp b/tests/unit/data.t.cpp
index e6c7b4b..4bb0f64 100644
--- a/tests/unit/data.t.cpp
+++ b/tests/unit/data.t.cpp
@@ -89,7 +89,8 @@
   BOOST_CHECK_EQUAL(d.getContentType(), tlv::ContentType_Blob);
   BOOST_CHECK_EQUAL(d.getFreshnessPeriod(), DEFAULT_FRESHNESS_PERIOD);
   BOOST_CHECK(!d.getFinalBlock());
-  BOOST_CHECK_EQUAL(d.getContent().type(), tlv::Content);
+  BOOST_CHECK_EQUAL(d.hasContent(), false);
+  BOOST_CHECK_EQUAL(d.getContent().isValid(), false);
   BOOST_CHECK_EQUAL(d.getContent().value_size(), 0);
   BOOST_CHECK(!d.getSignatureInfo());
   BOOST_CHECK_EQUAL(d.getSignatureType(), -1);
@@ -173,7 +174,7 @@
   Data d;
   d.setSignatureInfo(SignatureInfo(tlv::DigestSha256));
   d.setSignatureValue(std::make_shared<Buffer>());
-  BOOST_CHECK_EQUAL(d.wireEncode(), "060D 0700 1400 1500 16031B0100 1700"_block);
+  BOOST_CHECK_EQUAL(d.wireEncode(), "060B 0700 1400 16031B0100 1700"_block);
 }
 
 BOOST_FIXTURE_TEST_CASE(Full, DataSigningKeyFixture)
@@ -249,6 +250,7 @@
   BOOST_CHECK_EQUAL(d.getContentType(), tlv::ContentType_Blob);
   BOOST_CHECK_EQUAL(d.getFreshnessPeriod(), 0_ms);
   BOOST_CHECK_EQUAL(d.getFinalBlock().has_value(), false);
+  BOOST_CHECK_EQUAL(d.hasContent(), false);
   BOOST_CHECK_EQUAL(d.getContent().value_size(), 0);
   BOOST_CHECK_EQUAL(d.getSignatureType(), tlv::DigestSha256);
   BOOST_CHECK_EQUAL(d.getKeyLocator().has_value(), false);
@@ -262,7 +264,7 @@
   d.setName("/E");
   BOOST_CHECK_EQUAL(d.hasWire(), false);
   BOOST_CHECK_EQUAL(d.wireEncode(),
-                    "0630 0703080145 1400 1500 16031B0100 "
+                    "062E 0703(080145) 1400 1603(1B0100) "
                     "1720612A79399E60304A9F701C1ECAC7956BF2F1B046E6C6F0D6C29B3FE3A29BAD76"_block);
 }
 
@@ -273,6 +275,7 @@
   BOOST_CHECK_EQUAL(d.getContentType(), tlv::ContentType_Blob);
   BOOST_CHECK_EQUAL(d.getFreshnessPeriod(), 0_ms);
   BOOST_CHECK_EQUAL(d.getFinalBlock().has_value(), false);
+  BOOST_CHECK_EQUAL(d.hasContent(), false);
   BOOST_CHECK_EQUAL(d.getContent().value_size(), 0);
   BOOST_CHECK_EQUAL(d.getSignatureType(), tlv::DigestSha256);
   BOOST_CHECK_EQUAL(d.getKeyLocator().has_value(), false);
@@ -286,6 +289,7 @@
   BOOST_CHECK_EQUAL(d.getContentType(), tlv::ContentType_Blob);
   BOOST_CHECK_EQUAL(d.getFreshnessPeriod(), 10_s);
   BOOST_CHECK_EQUAL(d.getFinalBlock().has_value(), false);
+  BOOST_CHECK_EQUAL(d.hasContent(), true);
   BOOST_CHECK_EQUAL(std::string(reinterpret_cast<const char*>(d.getContent().value()),
                                 d.getContent().value_size()), "SUCCESS!");
   BOOST_CHECK_EQUAL(d.getSignatureType(), tlv::SignatureSha256WithRsa);
@@ -302,6 +306,7 @@
   BOOST_CHECK_EQUAL(d.getContentType(), tlv::ContentType_Blob);
   BOOST_CHECK_EQUAL(d.getFreshnessPeriod(), 0_ms);
   BOOST_CHECK_EQUAL(d.getFinalBlock().has_value(), false);
+  BOOST_CHECK_EQUAL(d.hasContent(), true);
   BOOST_CHECK_EQUAL(d.getContent().value_size(), 0);
   BOOST_CHECK_EQUAL(d.getSignatureType(), tlv::DigestSha256);
   BOOST_CHECK_EQUAL(d.getKeyLocator().has_value(), false);
@@ -499,36 +504,58 @@
 BOOST_AUTO_TEST_CASE(SetContent)
 {
   Data d;
-  BOOST_CHECK_EQUAL(d.getContent().type(), tlv::Content);
+  BOOST_CHECK_EQUAL(d.hasContent(), false);
+  BOOST_CHECK_EQUAL(d.getContent().type(), tlv::Invalid);
   BOOST_CHECK_EQUAL(d.getContent().value_size(), 0);
 
+  // Block overload, used directly as Content
   const uint8_t direct[] = {0xca, 0xfe};
-  d.setContent("1502CAFE"_block); // Block overload, used directly as Content
+  d.setContent("1502CAFE"_block);
+  BOOST_CHECK_EQUAL(d.hasContent(), true);
   BOOST_CHECK_EQUAL(d.getContent().type(), tlv::Content);
   BOOST_CHECK_EQUAL_COLLECTIONS(d.getContent().value_begin(), d.getContent().value_end(),
                                 direct, direct + sizeof(direct));
 
+  // Block overload, nested inside Content element
   const uint8_t nested[] = {0x99, 0x02, 0xca, 0xfe};
-  d.setContent(Block(nested, sizeof(nested))); // Block overload, nested inside Content element
+  d.setContent(Block(nested, sizeof(nested)));
+  BOOST_CHECK_EQUAL(d.hasContent(), true);
   BOOST_CHECK_EQUAL(d.getContent().type(), tlv::Content);
   BOOST_CHECK_EQUAL_COLLECTIONS(d.getContent().value_begin(), d.getContent().value_end(),
                                 nested, nested + sizeof(nested));
 
-  d.setContent(nested, sizeof(nested)); // raw buffer overload
+  // Block overload, default constructed (invalid)
+  BOOST_CHECK_THROW(d.setContent(Block{}), std::invalid_argument);
+
+  // raw buffer overload
+  d.setContent(nested, sizeof(nested));
+  BOOST_CHECK_EQUAL(d.hasContent(), true);
   BOOST_CHECK_EQUAL(d.getContent().type(), tlv::Content);
   BOOST_CHECK_EQUAL_COLLECTIONS(d.getContent().value_begin(), d.getContent().value_end(),
                                 nested, nested + sizeof(nested));
-
-  d.setContent(std::make_shared<Buffer>(direct, sizeof(direct))); // ConstBufferPtr overload
-  BOOST_CHECK_EQUAL(d.getContent().type(), tlv::Content);
-  BOOST_CHECK_EQUAL_COLLECTIONS(d.getContent().value_begin(), d.getContent().value_end(),
-                                direct, direct + sizeof(direct));
-
-  d.setContent(std::make_shared<Buffer>()); // ConstBufferPtr overload, empty buffer
+  d.setContent(nullptr, 0);
+  BOOST_CHECK_EQUAL(d.hasContent(), true);
   BOOST_CHECK_EQUAL(d.getContent().type(), tlv::Content);
   BOOST_CHECK_EQUAL(d.getContent().value_size(), 0);
+  BOOST_CHECK_THROW(d.setContent(nullptr, 1), std::invalid_argument);
 
+  // ConstBufferPtr overload
+  d.setContent(std::make_shared<Buffer>(direct, sizeof(direct)));
+  BOOST_CHECK_EQUAL(d.hasContent(), true);
+  BOOST_CHECK_EQUAL(d.getContent().type(), tlv::Content);
+  BOOST_CHECK_EQUAL_COLLECTIONS(d.getContent().value_begin(), d.getContent().value_end(),
+                                direct, direct + sizeof(direct));
+  d.setContent(std::make_shared<Buffer>());
+  BOOST_CHECK_EQUAL(d.hasContent(), true);
+  BOOST_CHECK_EQUAL(d.getContent().type(), tlv::Content);
+  BOOST_CHECK_EQUAL(d.getContent().value_size(), 0);
   BOOST_CHECK_THROW(d.setContent(nullptr), std::invalid_argument);
+
+  // unset
+  d.unsetContent();
+  BOOST_CHECK_EQUAL(d.hasContent(), false);
+  BOOST_CHECK_EQUAL(d.getContent().type(), tlv::Invalid);
+  BOOST_CHECK_EQUAL(d.getContent().value_size(), 0);
 }
 
 BOOST_AUTO_TEST_CASE(SetSignatureValue)
@@ -594,12 +621,18 @@
 
 BOOST_AUTO_TEST_CASE(Print)
 {
-  Data d(Block(DATA1, sizeof(DATA1)));
-  BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(d),
+  Data d1(Block(DATA1, sizeof(DATA1)));
+  BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(d1),
                     "Name: /local/ndn/prefix\n"
-                    "MetaInfo: ContentType: 0, FreshnessPeriod: 10000 milliseconds\n"
-                    "Content: (size: 8)\n"
-                    "Signature: (type: SignatureSha256WithRsa, value_length: 128)\n");
+                    "MetaInfo: [ContentType: 0, FreshnessPeriod: 10000 milliseconds]\n"
+                    "Content: [8 bytes]\n"
+                    "Signature: [type: SignatureSha256WithRsa, length: 128]\n");
+
+  Data d2("/foo");
+  BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(d2),
+                    "Name: /foo\n"
+                    "MetaInfo: [ContentType: 0]\n"
+                    "Signature: [type: Unknown(65535), length: 0]\n");
 }
 
 BOOST_AUTO_TEST_SUITE_END() // TestData
diff --git a/tests/unit/interest.t.cpp b/tests/unit/interest.t.cpp
index b675503..2887c99 100644
--- a/tests/unit/interest.t.cpp
+++ b/tests/unit/interest.t.cpp
@@ -897,12 +897,11 @@
   BOOST_CHECK(!i.hasApplicationParameters());
 
   // Block overload
-  i.setApplicationParameters(Block{});
-  BOOST_CHECK_EQUAL(i.getApplicationParameters(), "2400"_block);
   i.setApplicationParameters("2401C0"_block);
   BOOST_CHECK_EQUAL(i.getApplicationParameters(), "2401C0"_block);
   i.setApplicationParameters("8001C1"_block);
   BOOST_CHECK_EQUAL(i.getApplicationParameters(), "24038001C1"_block);
+  BOOST_CHECK_THROW(i.setApplicationParameters(Block{}), std::invalid_argument);
 
   // raw buffer+size overload
   i.setApplicationParameters(PARAMETERS1, sizeof(PARAMETERS1));
@@ -1159,7 +1158,7 @@
   });
 
   // Test failure with missing InterestSignatureInfo
-  i3.setApplicationParameters(Block());
+  i3.setApplicationParameters(nullptr, 0);
   BOOST_CHECK_EXCEPTION(i3.extractSignedRanges(), tlv::Error, [] (const auto& e) {
     return e.what() == "Interest missing InterestSignatureInfo"s;
   });
diff --git a/tests/unit/metadata-object.t.cpp b/tests/unit/metadata-object.t.cpp
index 364600e..632e15f 100644
--- a/tests/unit/metadata-object.t.cpp
+++ b/tests/unit/metadata-object.t.cpp
@@ -85,23 +85,34 @@
 {
   Data data;
 
-  // invalid content type
-  data.setName(Name("/ndn/unit/test").append(metadataComponent));
-  data.setContentType(tlv::ContentType_Key);
-  BOOST_CHECK_THROW(MetadataObject metadata(data), tlv::Error);
-
   // invalid metadata name
   data.setName("/ndn/unit/test");
-  data.setContentType(tlv::ContentType_Blob);
-  BOOST_CHECK_THROW(MetadataObject metadata(data), tlv::Error);
+  BOOST_CHECK_EXCEPTION(MetadataObject{data}, tlv::Error, [] (const auto& e) {
+    return e.what() == "Name /ndn/unit/test is not a valid MetadataObject name"s;
+  });
+  data.setName(Name("/ndn/unit/test").append(metadataComponent));
+  BOOST_CHECK_EXCEPTION(MetadataObject{data}, tlv::Error, [] (const auto& e) {
+    return e.what() == "Name /ndn/unit/test/32=metadata is not a valid MetadataObject name"s;
+  });
+
+  // invalid content type
+  data.setName(Name("/ndn/unit/test").append(metadataComponent).appendVersion().appendSegment(0));
+  data.setContentType(tlv::ContentType_Key);
+  BOOST_CHECK_EXCEPTION(MetadataObject{data}, tlv::Error, [] (const auto& e) {
+    return e.what() == "MetadataObject has invalid ContentType 2"s;
+  });
 
   // empty content
-  data.setName(Name("ndn/unit/test").append(metadataComponent));
-  BOOST_CHECK_THROW(MetadataObject metadata(data), tlv::Error);
+  data.setContentType(tlv::ContentType_Blob);
+  BOOST_CHECK_EXCEPTION(MetadataObject{data}, tlv::Error, [] (const auto& e) {
+    return e.what() == "MetadataObject is empty"s;
+  });
 
   // non-empty content with no name element
   data.setContent("F000"_block);
-  BOOST_CHECK_THROW(MetadataObject metadata(data), tlv::Error);
+  BOOST_CHECK_EXCEPTION(MetadataObject{data}, tlv::Error, [] (const auto& e) {
+    return e.what() == "No sub-element of type 7 found in block of type 21"s;
+  });
 }
 
 BOOST_AUTO_TEST_CASE(IsValidName)
diff --git a/tests/unit/prefix-announcement.t.cpp b/tests/unit/prefix-announcement.t.cpp
index 31449e4..03fa7f9 100644
--- a/tests/unit/prefix-announcement.t.cpp
+++ b/tests/unit/prefix-announcement.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2018 Regents of the University of California.
+ * Copyright (c) 2013-2020 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -92,60 +92,75 @@
   // wrong ContentType
   Data data0 = makePrefixAnnData();
   data0.setContentType(tlv::ContentType_Blob);
-  BOOST_CHECK_THROW(PrefixAnnouncement pa0(data0), tlv::Error);
+  BOOST_CHECK_EXCEPTION(PrefixAnnouncement{data0}, tlv::Error, [] (const auto& e) {
+    return e.what() == "Data is not a prefix announcement: ContentType is 0"s;
+  });
 
   // Name has no "32=PA" keyword
   Data data1 = makePrefixAnnData();
   setNameComponent(data1, -3, name::Component::fromEscapedString("32=not-PA"));
-  BOOST_CHECK_THROW(PrefixAnnouncement pa1(data1), tlv::Error);
+  BOOST_CHECK_EXCEPTION(PrefixAnnouncement{data1}, tlv::Error, [] (const auto& e) {
+    return e.what() == "Data is not a prefix announcement: wrong name structure"s;
+  });
 
   // Name has no version component
   Data data2 = makePrefixAnnData();
   setNameComponent(data2, -2, "not-version");
-  BOOST_CHECK_THROW(PrefixAnnouncement pa2(data2), tlv::Error);
+  BOOST_CHECK_EXCEPTION(PrefixAnnouncement{data2}, tlv::Error, [] (const auto& e) {
+    return e.what() == "Data is not a prefix announcement: wrong name structure"s;
+  });
 
   // Name has no segment number component
   Data data3 = makePrefixAnnData();
   setNameComponent(data3, -2, "not-segment");
-  BOOST_CHECK_THROW(PrefixAnnouncement pa3(data3), tlv::Error);
+  BOOST_CHECK_EXCEPTION(PrefixAnnouncement{data3}, tlv::Error, [] (const auto& e) {
+    return e.what() == "Data is not a prefix announcement: wrong name structure"s;
+  });
+
+  // Data without Content
+  Data data4 = makePrefixAnnData();
+  data4.unsetContent();
+  BOOST_CHECK_EXCEPTION(PrefixAnnouncement{data4}, tlv::Error, [] (const auto& e) {
+    return e.what() == "Prefix announcement is empty"s;
+  });
 
   // Content has no ExpirationPeriod element
-  Data data4 = makePrefixAnnData();
-  Block payload4 = data4.getContent();
-  payload4.parse();
-  payload4.remove(tlv::nfd::ExpirationPeriod);
-  payload4.encode();
-  data4.setContent(payload4);
-  BOOST_CHECK_THROW(PrefixAnnouncement pa4(data4), tlv::Error);
-
-  // ExpirationPeriod is malformed
   Data data5 = makePrefixAnnData();
   Block payload5 = data5.getContent();
   payload5.parse();
   payload5.remove(tlv::nfd::ExpirationPeriod);
-  payload5.push_back("6D03010101"_block);
-  payload5.encode();
   data5.setContent(payload5);
-  BOOST_CHECK_THROW(PrefixAnnouncement pa5(data5), tlv::Error);
+  BOOST_CHECK_EXCEPTION(PrefixAnnouncement{data5}, tlv::Error, [] (const auto& e) {
+    return e.what() == "No sub-element of type 109 found in block of type 21"s;
+  });
 
-  // ValidityPeriod is malformed
+  // ExpirationPeriod is malformed
   Data data6 = makePrefixAnnData();
   Block payload6 = data6.getContent();
   payload6.parse();
-  payload6.remove(tlv::ValidityPeriod);
-  payload6.push_back("FD00FD00"_block);
-  payload6.encode();
+  payload6.remove(tlv::nfd::ExpirationPeriod);
+  payload6.push_back("6D03010101"_block);
   data6.setContent(payload6);
-  BOOST_CHECK_THROW(PrefixAnnouncement pa6(data6), tlv::Error);
+  BOOST_CHECK_THROW(PrefixAnnouncement{data6}, tlv::Error);
 
-  // Content has unrecognized critical element
+  // ValidityPeriod is malformed
   Data data7 = makePrefixAnnData();
   Block payload7 = data7.getContent();
   payload7.parse();
-  payload7.push_back("0200"_block);
-  payload7.encode();
+  payload7.remove(tlv::ValidityPeriod);
+  payload7.push_back("FD00FD00"_block);
   data7.setContent(payload7);
-  BOOST_CHECK_THROW(PrefixAnnouncement pa7(data7), tlv::Error);
+  BOOST_CHECK_THROW(PrefixAnnouncement{data7}, tlv::Error);
+
+  // Content has unrecognized critical element
+  Data data8 = makePrefixAnnData();
+  Block payload8 = data8.getContent();
+  payload8.parse();
+  payload8.push_back("0200"_block);
+  data8.setContent(payload8);
+  BOOST_CHECK_EXCEPTION(PrefixAnnouncement{data8}, tlv::Error, [] (const auto& e) {
+    return e.what() == "Unrecognized element of critical type 2"s;
+  });
 }
 
 BOOST_FIXTURE_TEST_CASE(EncodeEmpty, IdentityManagementFixture)
diff --git a/tests/unit/security/key-chain.t.cpp b/tests/unit/security/key-chain.t.cpp
index ba2bd7c..b6dd0c6 100644
--- a/tests/unit/security/key-chain.t.cpp
+++ b/tests/unit/security/key-chain.t.cpp
@@ -291,6 +291,10 @@
   key3Cert2.setName(key3Cert2Name);
   m_keyChain.addCertificate(key3, key3Cert2);
   BOOST_CHECK_EQUAL(key3.getCertificates().size(), 2);
+  // Add empty cert
+  Certificate key3Cert3 = key3Cert1;
+  key3Cert3.unsetContent();
+  BOOST_CHECK_THROW(m_keyChain.addCertificate(key3, key3Cert3), std::invalid_argument);
 
   // Default certificate setting
   BOOST_CHECK_EQUAL(key3.getDefaultCertificate().getName(), key3CertName);