From 316a4432767efbea70c1409edf5f546e61077c54 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 3 Dec 2022 18:18:19 +0200
Subject: [PATCH] Add unit tests for the event bus

---
 source/game/eventsource.h |   2 +-
 tests/eventbus.cpp        | 100 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 101 insertions(+), 1 deletion(-)
 create mode 100644 tests/eventbus.cpp

diff --git a/source/game/eventsource.h b/source/game/eventsource.h
index ccb830f..1748f15 100644
--- a/source/game/eventsource.h
+++ b/source/game/eventsource.h
@@ -29,7 +29,7 @@ public:
 
 	template<typename T>
 	void add_observer(EventObserver &obs, std::function<void(const T &)> cb)
-	{ static_cast<EventDispatcher<T> &>(*this).add_observer(obs, std::move(cb)); }
+	{ static_cast<EventDispatcher<T> &>(*this).add_observer(&obs, std::move(cb)); }
 
 	void remove_observer(EventObserver &obs) override
 	{ (static_cast<EventDispatcher<E> &>(*this).remove_observer(&obs), ...); }
diff --git a/tests/eventbus.cpp b/tests/eventbus.cpp
new file mode 100644
index 0000000..6e4e0b5
--- /dev/null
+++ b/tests/eventbus.cpp
@@ -0,0 +1,100 @@
+#include <msp/game/eventbus.h>
+#include <msp/game/eventobserver.h>
+#include <msp/game/eventsource.h>
+#include <msp/test/test.h>
+
+using namespace std;
+using namespace Msp;
+
+class EventBusTests: public Test::RegisteredTest<EventBusTests>
+{
+public:
+	EventBusTests();
+
+	static const char *get_name() { return "Event bus"; }
+
+private:
+	void broadcast_events();
+	void targeted_events();
+	void observe_single();
+	void observer_lifetime();
+};
+
+struct E1 { int value; };
+struct E2 { int value; };
+
+EventBusTests::EventBusTests()
+{
+	add(&EventBusTests::broadcast_events, "Broadcast events");
+	add(&EventBusTests::targeted_events, "Targeted events");
+	add(&EventBusTests::observe_single, "Observe single source");
+	add(&EventBusTests::observer_lifetime, "Observer lifetime");
+}
+
+void EventBusTests::broadcast_events()
+{
+	Game::EventBus bus;
+	Game::EventSource<E1> src1(bus);
+	Game::EventSource<E2> src2(bus);
+	Game::EventObserver obs1(bus);
+	Game::EventObserver obs2(bus);
+	int value11 = 0;
+	int value12 = 0;
+	int value21 = 0;
+	int value22 = 0;
+	obs1.observe<E1>([&value11](const E1 &e){ value11 = e.value; });
+	obs1.observe<E2>([&value12](const E2 &e){ value12 = e.value; });
+	obs2.observe<E1>([&value21](const E1 &e){ value21 = e.value; });
+	obs2.observe<E2>([&value22](const E2 &e){ value22 = e.value; });
+	src1.emit<E1>(42);
+	src2.emit<E2>(7777);
+	EXPECT_EQUAL(value11, 42);
+	EXPECT_EQUAL(value21, 42);
+	EXPECT_EQUAL(value12, 7777);
+	EXPECT_EQUAL(value22, 7777);
+}
+
+void EventBusTests::targeted_events()
+{
+	Game::EventBus bus;
+	Game::EventSource<E1> src(bus);
+	Game::EventObserver obs1(bus);
+	Game::EventObserver obs2(bus);
+	int value1 = 0;
+	int value2 = 0;
+	obs1.observe<E1>([&value1](const E1 &e){ value1 = e.value; });
+	obs2.observe<E1>([&value2](const E1 &e){ value2 = e.value; });
+	src.emit_to<E1>(obs1, 42);
+	EXPECT_EQUAL(value1, 42);
+	EXPECT_EQUAL(value2, 0);
+}
+
+void EventBusTests::observe_single()
+{
+	Game::EventBus bus;
+	Game::EventSource<E1> src1(bus);
+	Game::EventSource<E1> src2(bus);
+	Game::EventObserver obs(bus);
+	int value1 = 0;
+	int value2 = 0;
+	obs.observe<E1>(src1, [&value1](const E1 &e){ value1 = e.value; });
+	src1.emit<E1>(42);
+	src2.emit<E1>(7777);
+	EXPECT_EQUAL(value1, 42);
+	EXPECT_EQUAL(value2, 0);
+}
+
+void EventBusTests::observer_lifetime()
+{
+	Game::EventBus bus;
+	Game::EventSource<E1> src(bus);
+	int value = 0;
+	{
+		Game::EventObserver obs(bus);
+		obs.observe<E1>([&value](const E1 &e){ value = e.value; });
+		src.emit<E1>(42);
+		EXPECT_EQUAL(value, 42);
+	}
+	src.emit<E1>(7777);
+	EXPECT_EQUAL(value, 42);
+}
-- 
2.45.2