Adding to_string method on keepalive (#3976)

* adding to_string method on keepalive

* Improve the test case

Co-authored-by: Dimitrios Siganos <dimitris@siganos.org>

nano/core_test/message.cpp

@@ -276,3 +276,31 @@ TEST (message, bulk_pull_serialization)
 	ASSERT_FALSE (error);
 	ASSERT_TRUE (header.bulk_pull_ascending ());
 }
+
+TEST (message, keepalive_to_string)
+{
+	nano::message_header hdr{ nano::dev::network_params.network, nano::message_type::keepalive };
+	std::string expected = hdr.to_string ();
+
+	nano::keepalive keepalive = nano::keepalive (nano::dev::network_params.network);
+	ASSERT_EQ (keepalive.to_string (), expected + "\n:::0\n:::0\n:::0\n:::0\n:::0\n:::0\n:::0\n:::0");
+
+	expected.append ("\n:::0");
+
+	keepalive.peers[1] = nano::endpoint{ boost::asio::ip::make_address_v6 ("::1"), 45 };
+	expected.append ("\n::1:45");
+
+	keepalive.peers[2] = nano::endpoint{ boost::asio::ip::make_address_v6 ("2001:db8:85a3:8d3:1319:8a2e:370:7348"), 0 };
+	expected.append ("\n2001:db8:85a3:8d3:1319:8a2e:370:7348:0");
+
+	keepalive.peers[3] = nano::endpoint{ boost::asio::ip::make_address_v6 ("::"), 65535 };
+	expected.append ("\n:::65535");
+
+	for (int i = 4; i < keepalive.peers.size (); i++)
+	{
+		keepalive.peers[i] = nano::endpoint{ boost::asio::ip::make_address_v6 ("::ffff:1.2.3.4"), 1234 };
+		expected.append ("\n::ffff:1.2.3.4:1234");
+	}
+
+	ASSERT_EQ (keepalive.to_string (), expected);
+}

nano/node/messages.cpp

@@ -144,7 +144,7 @@ nano::stat::detail nano::to_stat_detail (nano::message_type message_type)
 	return {};
 }
 
-std::string nano::message_header::to_string ()
+std::string nano::message_header::to_string () const
 {
 	// Cast to uint16_t to get integer value since uint8_t is treated as an unsigned char in string formatting.
 	uint16_t type_l = static_cast<uint16_t> (type);
@@ -712,6 +712,21 @@ bool nano::keepalive::operator== (nano::keepalive const & other_a) const
 	return peers == other_a.peers;
 }
 
+std::string nano::keepalive::to_string () const
+{
+	std::stringstream stream;
+
+	stream << header.to_string ();
+
+	for (auto peer = peers.begin (); peer != peers.end (); ++peer)
+	{
+		stream << "\n"
+			   << peer->address ().to_string () + ":" + std::to_string (peer->port ());
+	}
+
+	return stream.str ();
+}
+
 /*
  * publish
  */

nano/node/messages.hpp

@@ -64,7 +64,7 @@ public:
 	uint8_t version_max;
 	uint8_t version_using;
 	uint8_t version_min;
-	std::string to_string ();
+	std::string to_string () const;
 
 public:
 	nano::message_type type;
@@ -160,6 +160,7 @@ public:
 	bool operator== (nano::keepalive const &) const;
 	std::array<nano::endpoint, 8> peers;
 	static std::size_t constexpr size = 8 * (16 + 2);
+	std::string to_string () const;
 };
 
 class publish final : public message