sched-host-tran: handle with the scheduled time

Add the basic process to handle with the scheduled time

Tested:
1. Scheduled time is 0
  # busctl set-property xyz.openbmc_project.State.ScheduledHostTransition \
    /xyz/openbmc_project/state/host0 \
    xyz.openbmc_project.State.ScheduledHostTransition ScheduledTime t 1
    ------
    Feb 19 08:09:47 witherspoon phosphor-scheduled-host-transition[28263]: \
    The function Scheduled Host Transition is disabled.
2. Scheduled time is the past
 # busctl set-property xyz.openbmc_project.State.ScheduledHostTransition \
   /xyz/openbmc_project/state/host0 \
   xyz.openbmc_project.State.ScheduledHostTransition ScheduledTime t 1582100042
   ------
   Failed to set property ScheduledTime on interface xyz.openbmc_project.State.\
   ScheduledHostTransition: Scheduled time is in the past
   Feb 19 08:14:42 witherspoon phosphor-scheduled-host-transition[28263]: \
   Scheduled time is earlier than current time. Fail to do host transition.
   Feb 19 08:14:42 witherspoon phosphor-scheduled-host-transition[28263]: \
   Scheduled time is in the past

Change-Id: I0b6a98dcb6d0e70336bf42fc88a633abf3e64633
Signed-off-by: Carol Wang <wangkair@cn.ibm.com>
diff --git a/test/test_scheduled_host_transition.cpp b/test/test_scheduled_host_transition.cpp
new file mode 100644
index 0000000..f5ffa2c
--- /dev/null
+++ b/test/test_scheduled_host_transition.cpp
@@ -0,0 +1,54 @@
+#include "scheduled_host_transition.hpp"
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <sdbusplus/bus.hpp>
+#include <sdbusplus/test/sdbus_mock.hpp>
+#include <xyz/openbmc_project/ScheduledTime/error.hpp>
+
+namespace phosphor
+{
+namespace state
+{
+namespace manager
+{
+
+using namespace std::chrono;
+using InvalidTimeError =
+    sdbusplus::xyz::openbmc_project::ScheduledTime::Error::InvalidTime;
+
+class TestScheduledHostTransition : public testing::Test
+{
+  public:
+    sdbusplus::SdBusMock sdbusMock;
+    sdbusplus::bus::bus mockedBus = sdbusplus::get_mocked_new(&sdbusMock);
+    ScheduledHostTransition scheduledHostTransition;
+
+    TestScheduledHostTransition() : scheduledHostTransition(mockedBus, "")
+    {
+        // Empty
+    }
+
+    seconds getCurrentTime()
+    {
+        return scheduledHostTransition.getTime();
+    }
+};
+
+TEST_F(TestScheduledHostTransition, disableHostTransition)
+{
+    EXPECT_EQ(scheduledHostTransition.scheduledTime(0), 0);
+}
+
+TEST_F(TestScheduledHostTransition, invalidScheduledTime)
+{
+    // scheduled time is 1 min earlier than current time
+    uint64_t schTime =
+        static_cast<uint64_t>((getCurrentTime() - seconds(60)).count());
+    EXPECT_THROW(scheduledHostTransition.scheduledTime(schTime),
+                 InvalidTimeError);
+}
+
+} // namespace manager
+} // namespace state
+} // namespace phosphor