1 files changed, 119 insertions, 0 deletions
diff --git a/test/test_observer_list.cc b/test/test_observer_list.cc
new file mode 100644
index 0000000..705f701
--- /dev/null
+++ b/test/test_observer_list.cc
@@ -0,0 +1,119 @@
+#include "common.hh"
+
+#include "observer_list.hh"
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+namespace {
+
+class Observer {
+public:
+  virtual ~Observer() = default;
+  virtual void foo() = 0;
+};
+
+class MockObserver : public Observer {
+public:
+  MOCK_METHOD(void, foo, (), (override));
+};
+
+}  // namespace
+
+TEST(observer_list, empty) {
+  ObserverList<Observer> observers;
+  EXPECT_TRUE(observers.empty());
+  auto it = observers.notify();
+  EXPECT_FALSE(it);
+  ++it;
+  EXPECT_FALSE(it);
+}
+
+TEST(observer_list, sanity) {
+  ObserverList<Observer> observers;
+  MockObserver observer;
+  observers.add(&observer);
+  EXPECT_CALL(observer, foo());
+  for (auto it = observers.notify(); it; ++it)
+    it->foo();
+}
+
+TEST(observer_list, observer_removing_next_observer) {
+  ObserverList<Observer> observers;
+  MockObserver observer1;
+  MockObserver observer2;
+  observers.add(&observer1);
+  observers.add(&observer2);
+  EXPECT_CALL(observer1, foo())
+    .WillOnce([&]() { observers.remove(&observer2); })
+    .WillOnce(testing::Return());
+  EXPECT_CALL(observer2, foo())
+    .Times(0);
+  for (auto it = observers.notify(); it; ++it)
+    it->foo();
+
+  for (auto it = observers.notify(); it; ++it)
+    it->foo();
+}
+
+TEST(observer_list, observer_removing_previous_observer) {
+  ObserverList<Observer> observers;
+  MockObserver observer1;
+  MockObserver observer2;
+  observers.add(&observer1);
+  observers.add(&observer2);
+  EXPECT_CALL(observer1, foo());
+  EXPECT_CALL(observer2, foo())
+    .WillOnce([&]() { observers.remove(&observer1); })
+    .WillOnce(testing::Return());
+  for (auto it = observers.notify(); it; ++it)
+    it->foo();
+
+  for (auto it = observers.notify(); it; ++it)
+    it->foo();
+}
+
+TEST(observer_list, observer_removing_itself) {
+  ObserverList<Observer> observers;
+  MockObserver observer;
+  observers.add(&observer);
+  EXPECT_CALL(observer, foo())
+    .WillOnce([&]() { observers.remove(&observer); });
+  for (auto it = observers.notify(); it; ++it)
+    it->foo();
+  EXPECT_TRUE(observers.empty());
+}
+
+TEST(observer_list, observer_adding_observer) {
+  ObserverList<Observer> observers;
+  MockObserver observer1;
+  MockObserver observer2;
+  observers.add(&observer1);
+  EXPECT_CALL(observer1, foo())
+    .WillOnce([&]() { observers.add(&observer2); })
+    .WillOnce(testing::Return());
+  EXPECT_CALL(observer2, foo());
+  for (auto it = observers.notify(); it; ++it)
+    it->foo();
+
+  for (auto it = observers.notify(); it; ++it)
+    it->foo();
+}
+
+TEST(observer_list, observer_start_new_notify) {
+  ObserverList<Observer> observers;
+  MockObserver observer1;
+  MockObserver observer2;
+  observers.add(&observer1);
+  observers.add(&observer2);
+  EXPECT_CALL(observer1, foo())
+    .WillOnce([&]() {
+      observers.remove(&observer1);
+      for (auto it = observers.notify(); it; ++it)
+        it->foo();
+    });
+  EXPECT_CALL(observer2, foo())
+    .Times(2);
+  for (auto it = observers.notify(); it; ++it)
+    it->foo();
+}