Zhur 8 timer

tdd_intro/homework/08_timer/test.cpp

@@ -22,3 +22,194 @@ Timer can be started again any time, no metter in what state it is
 */
 
 #include <gtest/gtest.h>
+#include <chrono>
+
+typedef std::chrono::high_resolution_clock Clock;
+typedef Clock::duration Duration;
+typedef std::chrono::time_point<Clock> TimePoint;
+
+class ITimer {
+public:
+  virtual ~ITimer() {}
+
+  virtual void Start(int64_t nanos) = 0;
+  virtual bool IsExpired() const = 0;
+  virtual Duration TimeLeft() const = 0;
+};
+
+class ICurrentTime {
+public:
+    virtual ~ICurrentTime() {}
+
+    virtual void Reset() = 0;
+    virtual void AddTime(int64_t nanos) = 0;
+    virtual TimePoint GetTime() const = 0;
+};
+
+class CurrentTime : public ICurrentTime {
+public:
+    void Reset() override;
+    void AddTime(int64_t nanos) override;
+    TimePoint GetTime() const override;
+private:
+    TimePoint m_time;
+};
+
+class Timer : public ITimer
+{
+public:
+    Timer(CurrentTime& currentTime)
+        : m_currentTime(currentTime)
+    {
+    }
+
+    void Start(int64_t nanos) override;
+    bool IsExpired() const override;
+    Duration TimeLeft() const override;
+private:
+    CurrentTime& m_currentTime;
+    TimePoint m_expirationTime;
+};
+
+void Timer::Start(int64_t nanos)
+{
+    m_currentTime.Reset();
+    m_expirationTime = m_currentTime.GetTime() + Duration(nanos);
+}
+
+bool Timer::IsExpired() const
+{
+    return m_currentTime.GetTime() > m_expirationTime;
+}
+
+Duration Timer::TimeLeft() const
+{
+    if (IsExpired())
+    {
+        return Duration(0);
+    }
+
+    return m_expirationTime - m_currentTime.GetTime();
+}
+
+void CurrentTime::Reset()
+{
+    m_time = Clock::now();
+}
+
+void CurrentTime::AddTime(int64_t nanos)
+{
+    m_time += Duration(nanos);
+}
+
+TimePoint CurrentTime::GetTime() const
+{
+    return m_time;
+}
+
+TEST(Timer, IsExpired_TimeNotChanged)
+{
+    CurrentTime currentTime;
+    Timer timer(currentTime);
+
+    const int64_t aLotOfTime = 5000;
+
+    timer.Start(aLotOfTime);
+    EXPECT_FALSE(timer.IsExpired());
+}
+
+TEST(Timer, IsExpired_Expired)
+{
+    CurrentTime currentTime;
+    Timer timer(currentTime);
+
+    const int64_t timeForTimer = 2000;
+    const int64_t timeToGo = 3000;
+
+    timer.Start(timeForTimer);
+    currentTime.AddTime(timeToGo);
+
+    EXPECT_TRUE(timer.IsExpired());
+}
+
+TEST(Timer, IsExpired_NotExpired)
+{
+    CurrentTime currentTime;
+    Timer timer(currentTime);
+
+    const int64_t timeForTimer = 2000;
+    const int64_t timeToGo = 1000;
+
+    timer.Start(timeForTimer);
+    currentTime.AddTime(timeToGo);
+
+    EXPECT_FALSE(timer.IsExpired());
+}
+
+TEST(Timer, AtLimit_NotExpired)
+{
+    CurrentTime currentTime;
+    Timer timer(currentTime);
+
+    const int64_t timeForTimer = 2000;
+    const int64_t timeToGo = 2000;
+
+    timer.Start(timeForTimer);
+    currentTime.AddTime(timeToGo);
+
+    EXPECT_FALSE(timer.IsExpired());
+}
+
+TEST(Timer, TimeLeft_WholeTimeLeft)
+{
+    CurrentTime currentTime;
+    Timer timer(currentTime);
+
+    const int64_t timeForTimer = 2000;
+
+    timer.Start(timeForTimer);
+
+    EXPECT_EQ(Duration(timeForTimer), timer.TimeLeft());
+}
+
+TEST(Timer, TimeLeft_SomeTimeLeft)
+{
+    CurrentTime currentTime;
+    Timer timer(currentTime);
+
+    const int64_t timeForTimer = 2000;
+    const int64_t timeToGo = 1000;
+
+    timer.Start(timeForTimer);
+    currentTime.AddTime(timeToGo);
+
+    EXPECT_EQ(Duration(timeForTimer - timeToGo), timer.TimeLeft());
+}
+
+TEST(Timer, TimeLeft_Expired)
+{
+    CurrentTime currentTime;
+    Timer timer(currentTime);
+
+    const int64_t timeForTimer = 1000;
+    const int64_t timeToGo = 2000;
+
+    timer.Start(timeForTimer);
+    currentTime.AddTime(timeToGo);
+
+    EXPECT_EQ(Duration(0), timer.TimeLeft());
+}
+
+TEST(Timer, TimeLeft_NoTimeLeft)
+{
+    CurrentTime currentTime;
+    Timer timer(currentTime);
+
+    const int64_t timeForTimer = 2000;
+    const int64_t timeToGo = 2000;
+
+    timer.Start(timeForTimer);
+    currentTime.AddTime(timeToGo);
+
+    EXPECT_EQ(Duration(0), timer.TimeLeft());
+}