Add unit tests for UDPServer

This PR aims to help "fix" #43440

tests/core/io/test_udp_server.h

@@ -0,0 +1,293 @@
+/**************************************************************************/
+/*  test_udp_server.h                                                     */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#ifndef TEST_UDP_SERVER_H
+#define TEST_UDP_SERVER_H
+
+#include "core/io/packet_peer_udp.h"
+#include "core/io/udp_server.h"
+#include "tests/test_macros.h"
+
+namespace TestUDPServer {
+
+const int PORT = 12345;
+const IPAddress LOCALHOST("127.0.0.1");
+const uint32_t SLEEP_DURATION = 1000;
+const uint64_t MAX_WAIT_USEC = 100000;
+
+Ref<UDPServer> create_server(const IPAddress &p_address, int p_port) {
+	Ref<UDPServer> server;
+	server.instantiate();
+
+	Error err = server->listen(PORT, LOCALHOST);
+	REQUIRE_EQ(Error::OK, err);
+	REQUIRE(server->is_listening());
+	CHECK_FALSE(server->is_connection_available());
+	CHECK_EQ(server->get_max_pending_connections(), 16);
+
+	return server;
+}
+
+Ref<PacketPeerUDP> create_client(const IPAddress &p_address, int p_port) {
+	Ref<PacketPeerUDP> client;
+	client.instantiate();
+
+	Error err = client->connect_to_host(LOCALHOST, PORT);
+	REQUIRE_EQ(Error::OK, err);
+	CHECK(client->is_bound());
+	CHECK(client->is_socket_connected());
+
+	return client;
+}
+
+Ref<PacketPeerUDP> accept_connection(Ref<UDPServer> &p_server) {
+	// Required to get the connection properly established.
+	const uint64_t time = OS::get_singleton()->get_ticks_usec();
+	while (!p_server->is_connection_available() && (OS::get_singleton()->get_ticks_usec() - time) < MAX_WAIT_USEC) {
+		p_server->poll();
+		OS::get_singleton()->delay_usec(SLEEP_DURATION);
+	}
+
+	CHECK_EQ(p_server->poll(), Error::OK);
+	REQUIRE(p_server->is_connection_available());
+	Ref<PacketPeerUDP> client_from_server = p_server->take_connection();
+	REQUIRE(client_from_server.is_valid());
+	CHECK(client_from_server->is_bound());
+	CHECK(client_from_server->is_socket_connected());
+
+	return client_from_server;
+}
+
+Error poll(Ref<UDPServer> p_server, Error p_err) {
+	const uint64_t time = OS::get_singleton()->get_ticks_usec();
+	Error err = p_server->poll();
+	while (err != p_err && (OS::get_singleton()->get_ticks_usec() - time) < MAX_WAIT_USEC) {
+		err = p_server->poll();
+		OS::get_singleton()->delay_usec(SLEEP_DURATION);
+	}
+	return err;
+}
+
+TEST_CASE("[UDPServer] Instantiation") {
+	Ref<UDPServer> server;
+	server.instantiate();
+
+	REQUIRE(server.is_valid());
+	CHECK_EQ(false, server->is_listening());
+}
+
+TEST_CASE("[UDPServer] Accept a connection and receive/send data") {
+	Ref<UDPServer> server = create_server(LOCALHOST, PORT);
+	Ref<PacketPeerUDP> client = create_client(LOCALHOST, PORT);
+
+	// Sending data from client to server.
+	const String hello_world = "Hello World!";
+	CHECK_EQ(client->put_var(hello_world), Error::OK);
+
+	Variant hello_world_received;
+	Ref<PacketPeerUDP> client_from_server = accept_connection(server);
+	CHECK_EQ(client_from_server->get_var(hello_world_received), Error::OK);
+	CHECK_EQ(String(hello_world_received), hello_world);
+
+	// Sending data from server to client.
+	const Variant pi = 3.1415;
+	CHECK_EQ(client_from_server->put_var(pi), Error::OK);
+
+	const uint64_t time = OS::get_singleton()->get_ticks_usec();
+	// get_available_packet_count() is the recommended way to call _poll(), because there is no public poll().
+	while (client->get_available_packet_count() == 0 && (OS::get_singleton()->get_ticks_usec() - time) < MAX_WAIT_USEC) {
+		server->poll();
+		OS::get_singleton()->delay_usec(SLEEP_DURATION);
+	}
+
+	CHECK_EQ(server->poll(), Error::OK);
+	CHECK_GT(client->get_available_packet_count(), 0);
+
+	Variant pi_received;
+	CHECK_EQ(client->get_var(pi_received), Error::OK);
+	CHECK_EQ(pi_received, pi);
+
+	client->close();
+	server->stop();
+	CHECK_FALSE(server->is_listening());
+}
+
+TEST_CASE("[UDPServer] Handle multiple clients at the same time") {
+	Ref<UDPServer> server = create_server(LOCALHOST, PORT);
+
+	Vector<Ref<PacketPeerUDP>> clients;
+	for (int i = 0; i < 5; i++) {
+		Ref<PacketPeerUDP> c = create_client(LOCALHOST, PORT);
+
+		// Sending data from client to server.
+		const String hello_client = "Hello " + itos(i);
+		CHECK_EQ(c->put_var(hello_client), Error::OK);
+
+		clients.push_back(c);
+	}
+
+	for (int i = 0; i < clients.size(); i++) {
+		Ref<PacketPeerUDP> cfs = accept_connection(server);
+
+		Variant hello_world_received;
+		CHECK_EQ(cfs->get_var(hello_world_received), Error::OK);
+		CHECK_EQ(String(hello_world_received), "Hello " + itos(i));
+
+		// Sending data from server to client.
+		const Variant pi = 3.1415 + i;
+		CHECK_EQ(cfs->put_var(pi), Error::OK);
+	}
+
+	const uint64_t time = OS::get_singleton()->get_ticks_usec();
+	for (int i = 0; i < clients.size(); i++) {
+		Ref<PacketPeerUDP> c = clients[i];
+		// get_available_packet_count() is the recommended way to call _poll(), because there is no public poll().
+		// Because `time` is defined outside the for, we will wait the max amount of time only for the first client.
+		while (c->get_available_packet_count() == 0 && (OS::get_singleton()->get_ticks_usec() - time) < MAX_WAIT_USEC) {
+			server->poll();
+			OS::get_singleton()->delay_usec(SLEEP_DURATION);
+		}
+
+		// The recommended way to call _poll(), because there is no public poll().
+		CHECK_GT(c->get_available_packet_count(), 0);
+
+		Variant pi_received;
+		const Variant pi = 3.1415 + i;
+		CHECK_EQ(c->get_var(pi_received), Error::OK);
+		CHECK_EQ(pi_received, pi);
+	}
+
+	for (Ref<PacketPeerUDP> &c : clients) {
+		c->close();
+	}
+	server->stop();
+}
+
+TEST_CASE("[UDPServer] When stopped shouldn't accept new connections") {
+	Ref<UDPServer> server = create_server(LOCALHOST, PORT);
+	Ref<PacketPeerUDP> client = create_client(LOCALHOST, PORT);
+
+	// Sending data from client to server.
+	const String hello_world = "Hello World!";
+	CHECK_EQ(client->put_var(hello_world), Error::OK);
+
+	Variant hello_world_received;
+	Ref<PacketPeerUDP> client_from_server = accept_connection(server);
+	CHECK_EQ(client_from_server->get_var(hello_world_received), Error::OK);
+	CHECK_EQ(String(hello_world_received), hello_world);
+
+	client->close();
+	server->stop();
+	CHECK_FALSE(server->is_listening());
+
+	Ref<PacketPeerUDP> new_client = create_client(LOCALHOST, PORT);
+	CHECK_EQ(new_client->put_var(hello_world), Error::OK);
+
+	REQUIRE_EQ(poll(server, Error::ERR_UNCONFIGURED), Error::ERR_UNCONFIGURED);
+	CHECK_FALSE(server->is_connection_available());
+
+	const uint64_t time = OS::get_singleton()->get_ticks_usec();
+	// get_available_packet_count() is the recommended way to call _poll(), because there is no public poll().
+	while (new_client->get_available_packet_count() == 0 && (OS::get_singleton()->get_ticks_usec() - time) < MAX_WAIT_USEC) {
+		OS::get_singleton()->delay_usec(SLEEP_DURATION);
+	}
+
+	const int packet_count = new_client->get_available_packet_count();
+	CHECK((packet_count == 0 || packet_count == -1));
+}
+
+TEST_CASE("[UDPServer] Should disconnect client") {
+	Ref<UDPServer> server = create_server(LOCALHOST, PORT);
+	Ref<PacketPeerUDP> client = create_client(LOCALHOST, PORT);
+
+	// Sending data from client to server.
+	const String hello_world = "Hello World!";
+	CHECK_EQ(client->put_var(hello_world), Error::OK);
+
+	Variant hello_world_received;
+	Ref<PacketPeerUDP> client_from_server = accept_connection(server);
+	CHECK_EQ(client_from_server->get_var(hello_world_received), Error::OK);
+	CHECK_EQ(String(hello_world_received), hello_world);
+
+	server->stop();
+	CHECK_FALSE(server->is_listening());
+	CHECK_FALSE(client_from_server->is_bound());
+	CHECK_FALSE(client_from_server->is_socket_connected());
+
+	// Sending data from client to server.
+	CHECK_EQ(client->put_var(hello_world), Error::OK);
+
+	const uint64_t time = OS::get_singleton()->get_ticks_usec();
+	// get_available_packet_count() is the recommended way to call _poll(), because there is no public poll().
+	while (client->get_available_packet_count() == 0 && (OS::get_singleton()->get_ticks_usec() - time) < MAX_WAIT_USEC) {
+		OS::get_singleton()->delay_usec(SLEEP_DURATION);
+	}
+
+	const int packet_count = client->get_available_packet_count();
+	CHECK((packet_count == 0 || packet_count == -1));
+
+	client->close();
+}
+
+TEST_CASE("[UDPServer] Should drop new connections when pending max connection is reached") {
+	Ref<UDPServer> server = create_server(LOCALHOST, PORT);
+	server->set_max_pending_connections(3);
+
+	Vector<Ref<PacketPeerUDP>> clients;
+	for (int i = 0; i < 5; i++) {
+		Ref<PacketPeerUDP> c = create_client(LOCALHOST, PORT);
+
+		// Sending data from client to server.
+		const String hello_client = "Hello " + itos(i);
+		CHECK_EQ(c->put_var(hello_client), Error::OK);
+
+		clients.push_back(c);
+	}
+
+	for (int i = 0; i < server->get_max_pending_connections(); i++) {
+		Ref<PacketPeerUDP> cfs = accept_connection(server);
+
+		Variant hello_world_received;
+		CHECK_EQ(cfs->get_var(hello_world_received), Error::OK);
+		CHECK_EQ(String(hello_world_received), "Hello " + itos(i));
+	}
+
+	CHECK_EQ(poll(server, Error::OK), Error::OK);
+
+	REQUIRE_FALSE(server->is_connection_available());
+	Ref<PacketPeerUDP> client_from_server = server->take_connection();
+	REQUIRE_FALSE_MESSAGE(client_from_server.is_valid(), "A Packet Peer UDP from the UDP Server should be a null pointer because the pending connection was dropped.");
+
+	server->stop();
+}
+
+} // namespace TestUDPServer
+
+#endif // TEST_UDP_SERVER_H

tests/test_main.cpp

@@ -55,6 +55,7 @@
 #include "tests/core/io/test_resource.h"
 #include "tests/core/io/test_stream_peer.h"
 #include "tests/core/io/test_stream_peer_buffer.h"
+#include "tests/core/io/test_udp_server.h"
 #include "tests/core/io/test_xml_parser.h"
 #include "tests/core/math/test_aabb.h"
 #include "tests/core/math/test_astar.h"