Set up basic deterministic lockstep

server/tests/WebsocketLockstepTests.cpp

@@ -0,0 +1,90 @@
+#include "game_server/InternalGameServer.h"
+#include "game_server/WebsocketGameClient.h"
+#include "game_server/WebsocketGameServer.h"
+#include <chrono>
+#include <cstdlib>
+#include <iostream>
+#include <memory>
+#include <thread>
+
+namespace {
+
+void require(bool condition, const char* message)
+{
+	if (condition) return;
+	std::cerr << "WebsocketLockstepTests: " << message << '\n';
+	std::exit(EXIT_FAILURE);
+}
+
+template <class Predicate>
+bool waitFor(Predicate predicate)
+{
+	const auto deadline =
+		std::chrono::steady_clock::now() + std::chrono::seconds(3);
+	while (std::chrono::steady_clock::now() < deadline) {
+		if (predicate()) return true;
+		std::this_thread::sleep_for(std::chrono::milliseconds(10));
+	}
+	return false;
+}
+
+} // namespace
+
+int main()
+{
+	FRG::CampaignConfig campaign;
+	campaign.id = "test_lockstep";
+
+	FRG::InternalGameServer authoritative;
+	authoritative.startCampaign(campaign, {}, true, false);
+	FRG::WebsocketGameServer server(
+		authoritative, {"player"}, "lockstep-v2:test_lockstep",
+		"127.0.0.1", 0);
+	auto client = std::make_unique<FRG::WebsocketGameClient>(
+		"127.0.0.1", std::to_string(server.port()), "/");
+
+	require(
+		waitFor([&]() { return client->connected(); }),
+		"client did not connect");
+	require(
+		waitFor([&]() {
+			client->update(0);
+			return client->initialized();
+		}),
+		"client did not receive initial state");
+	require(client->localPlayerId() == "player", "wrong player slot assigned");
+
+	FRG::WebsocketGameClient overflow(
+		"127.0.0.1", std::to_string(server.port()), "/");
+	require(
+		waitFor([&]() {
+			overflow.update(0);
+			return overflow.rejected();
+		}),
+		"connection beyond configured slots was not rejected");
+
+	client->submit(FRG::SetCharacterDestinationCommand{
+		{}, "spoofed", Eigen::Vector3f(1.234f, 0.f, 2.345f), "ignored"});
+	std::this_thread::sleep_for(std::chrono::milliseconds(20));
+	server.update();
+	server.update();
+	require(
+		waitFor([&]() {
+			client->update(0);
+			return client->snapshot()->revision > 1;
+		}),
+		"client did not consume finalized lockstep ticks");
+
+	client.reset();
+	std::this_thread::sleep_for(std::chrono::milliseconds(50));
+	FRG::WebsocketGameClient replacement(
+		"127.0.0.1", std::to_string(server.port()), "/");
+	require(
+		waitFor([&]() {
+			replacement.update(0);
+			return replacement.initialized();
+		}),
+		"disconnected player slot was not reusable");
+
+	return EXIT_SUCCESS;
+}