test: add test to force building of sdjournal mock

Add test to force building of sdjournal mock.  This
will ensure it won't break down chain users later.

Change-Id: Ida9745595af251df800ec8e98abaa39728c9ba86
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/test/sdtest.cpp b/test/sdtest.cpp
new file mode 100644
index 0000000..82cf511
--- /dev/null
+++ b/test/sdtest.cpp
@@ -0,0 +1,16 @@
+#include <phosphor-logging/test/sdjournal_mock.hpp>
+
+namespace phosphor
+{
+namespace logging
+{
+
+TEST(LoggingSwapTest, BasicTestToEnsureItCompiles)
+{
+    SdJournalMock mockInstance;
+    auto* old = SwapJouralHandler(&mockInstance);
+    SwapJouralHandler(old);
+}
+
+} // namespace logging
+} // namespace phosphor