source/time: Implement
diff --git a/test/source/time.cpp b/test/source/time.cpp
new file mode 100644
index 0000000..0ee612f
--- /dev/null
+++ b/test/source/time.cpp
@@ -0,0 +1,204 @@
+#include <cerrno>
+#include <chrono>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <memory>
+#include <sdeventplus/clock.hpp>
+#include <sdeventplus/exception.hpp>
+#include <sdeventplus/source/time.hpp>
+#include <sdeventplus/test/sdevent.hpp>
+#include <systemd/sd-event.h>
+#include <time.h>
+#include <utility>
+
+namespace sdeventplus
+{
+namespace source
+{
+namespace
+{
+
+using testing::DoAll;
+using testing::Return;
+using testing::SaveArg;
+using testing::SetArgPointee;
+
+using UniqueEvent = std::unique_ptr<Event, std::function<void(Event*)>>;
+
+class TimeTest : public testing::Test
+{
+  protected:
+    testing::StrictMock<test::SdEventMock> mock;
+    sd_event_source* const expected_source =
+        reinterpret_cast<sd_event_source*>(1234);
+    sd_event* const expected_event = reinterpret_cast<sd_event*>(2345);
+    UniqueEvent event = make_event(expected_event);
+
+    UniqueEvent make_event(sd_event* event)
+    {
+        auto deleter = [this, event](Event* e) {
+            EXPECT_CALL(this->mock, sd_event_unref(event))
+                .WillOnce(Return(nullptr));
+            delete e;
+        };
+        return UniqueEvent(new Event(event, std::false_type(), &mock), deleter);
+    }
+
+    void expect_time_destroy(sd_event* event, sd_event_source* source)
+    {
+        {
+            testing::InSequence sequence;
+            EXPECT_CALL(mock, sd_event_source_set_enabled(source, SD_EVENT_OFF))
+                .WillOnce(Return(0));
+            EXPECT_CALL(mock, sd_event_source_unref(source))
+                .WillOnce(Return(nullptr));
+        }
+        EXPECT_CALL(mock, sd_event_unref(event)).WillOnce(Return(nullptr));
+    }
+};
+
+TEST_F(TimeTest, ConstructSuccess)
+{
+    constexpr ClockId id = ClockId::RealTime;
+    const Time<id>::TimePoint expected_time(std::chrono::seconds{2});
+    const Time<id>::Accuracy expected_accuracy(std::chrono::milliseconds{50});
+    Time<id>::TimePoint saved_time;
+    Time<id>::Callback callback = [&saved_time](Time<id>&,
+                                                Time<id>::TimePoint time) {
+        saved_time = time;
+    };
+
+    EXPECT_CALL(mock, sd_event_ref(expected_event))
+        .WillOnce(Return(expected_event));
+    sd_event_time_handler_t handler;
+    EXPECT_CALL(mock,
+                sd_event_add_time(expected_event, testing::_, CLOCK_REALTIME,
+                                  2000000, 50000, testing::_, nullptr))
+        .WillOnce(DoAll(SetArgPointee<1>(expected_source), SaveArg<5>(&handler),
+                        Return(0)));
+    void* userdata;
+    EXPECT_CALL(mock, sd_event_source_set_userdata(expected_source, testing::_))
+        .WillOnce(DoAll(SaveArg<1>(&userdata), Return(nullptr)));
+    Time<id> time(*event, expected_time, expected_accuracy,
+                  std::move(callback));
+    EXPECT_EQ(expected_event, time.get_event().get());
+    EXPECT_EQ(expected_source, time.get());
+
+    EXPECT_EQ(0, handler(nullptr, 2000100, userdata));
+    EXPECT_EQ(Time<id>::TimePoint(std::chrono::microseconds(2000100)),
+              saved_time);
+
+    expect_time_destroy(expected_event, expected_source);
+}
+
+TEST_F(TimeTest, ConstructError)
+{
+    constexpr ClockId id = ClockId::Monotonic;
+    const Time<id>::TimePoint expected_time(std::chrono::seconds{2});
+    const Time<id>::Accuracy expected_accuracy(std::chrono::milliseconds{50});
+    Time<id>::Callback callback = [](Time<id>&, Time<id>::TimePoint) {};
+
+    EXPECT_CALL(mock,
+                sd_event_add_time(expected_event, testing::_, CLOCK_MONOTONIC,
+                                  2000000, 50000, testing::_, nullptr))
+        .WillOnce(Return(-ENOSYS));
+    EXPECT_THROW(
+        Time<id>(*event, expected_time, expected_accuracy, std::move(callback)),
+        SdEventError);
+}
+
+class TimeMethodTest : public TimeTest
+{
+  protected:
+    static constexpr ClockId id = ClockId::BootTime;
+    std::unique_ptr<Time<id>> time;
+
+    void SetUp()
+    {
+        EXPECT_CALL(mock, sd_event_ref(expected_event))
+            .WillOnce(Return(expected_event));
+        EXPECT_CALL(mock, sd_event_add_time(expected_event, testing::_,
+                                            CLOCK_BOOTTIME, 2000000, 50000,
+                                            testing::_, nullptr))
+            .WillOnce(DoAll(SetArgPointee<1>(expected_source), Return(0)));
+        EXPECT_CALL(mock,
+                    sd_event_source_set_userdata(expected_source, testing::_))
+            .WillOnce(Return(nullptr));
+        time = std::make_unique<Time<id>>(
+            *event, Time<id>::TimePoint(std::chrono::seconds{2}),
+            std::chrono::milliseconds{50},
+            [](Time<id>&, Time<id>::TimePoint) {});
+    }
+
+    void TearDown()
+    {
+        expect_time_destroy(expected_event, expected_source);
+        time.reset();
+    }
+};
+
+TEST_F(TimeMethodTest, SetTimeSuccess)
+{
+    EXPECT_CALL(mock, sd_event_source_set_time(expected_source, 1000000))
+        .WillOnce(Return(0));
+    time->set_time(Time<id>::TimePoint(std::chrono::seconds{1}));
+}
+
+TEST_F(TimeMethodTest, SetTimeError)
+{
+    EXPECT_CALL(mock, sd_event_source_set_time(expected_source, 1000000))
+        .WillOnce(Return(-EINVAL));
+    EXPECT_THROW(time->set_time(Time<id>::TimePoint(std::chrono::seconds{1})),
+                 SdEventError);
+}
+
+TEST_F(TimeMethodTest, GetTimeSuccess)
+{
+    EXPECT_CALL(mock, sd_event_source_get_time(expected_source, testing::_))
+        .WillOnce(DoAll(SetArgPointee<1>(10), Return(0)));
+    EXPECT_EQ(Time<id>::TimePoint(std::chrono::microseconds{10}),
+              time->get_time());
+}
+
+TEST_F(TimeMethodTest, GetTimeError)
+{
+    EXPECT_CALL(mock, sd_event_source_get_time(expected_source, testing::_))
+        .WillOnce(Return(-ENOSYS));
+    EXPECT_THROW(time->get_time(), SdEventError);
+}
+
+TEST_F(TimeMethodTest, SetAccuracySuccess)
+{
+    EXPECT_CALL(mock,
+                sd_event_source_set_time_accuracy(expected_source, 5000000))
+        .WillOnce(Return(0));
+    time->set_accuracy(std::chrono::seconds{5});
+}
+
+TEST_F(TimeMethodTest, SetAccuracyError)
+{
+    EXPECT_CALL(mock,
+                sd_event_source_set_time_accuracy(expected_source, 5000000))
+        .WillOnce(Return(-EINVAL));
+    EXPECT_THROW(time->set_accuracy(std::chrono::seconds{5}), SdEventError);
+}
+
+TEST_F(TimeMethodTest, GetAccuracySuccess)
+{
+    EXPECT_CALL(mock,
+                sd_event_source_get_time_accuracy(expected_source, testing::_))
+        .WillOnce(DoAll(SetArgPointee<1>(1000), Return(0)));
+    EXPECT_EQ(std::chrono::milliseconds{1}, time->get_accuracy());
+}
+
+TEST_F(TimeMethodTest, GetAccuracyError)
+{
+    EXPECT_CALL(mock,
+                sd_event_source_get_time_accuracy(expected_source, testing::_))
+        .WillOnce(Return(-ENOSYS));
+    EXPECT_THROW(time->get_accuracy(), SdEventError);
+}
+
+} // namespace
+} // namespace source
+} // namespace sdeventplus