Fix test: previous code was enforcing chip::optional behavior on in-place construction

Author: andreilitvin

src/app/tests/TestNullable.cpp

@@ -169,24 +169,26 @@ static void TestMove(nlTestSuite * inSuite, void * inContext)
     CtorDtorCounter::ResetCounter();
 
     {
-        auto testSrc = MakeNullable<MovableCtorDtorCounter>(400);
-        Nullable<MovableCtorDtorCounter> testDst(std::move(testSrc));
-        NL_TEST_ASSERT(inSuite, CtorDtorCounter::created == 2 && CtorDtorCounter::destroyed == 1);
+        auto testSrc = MakeNullable<MovableCtorDtorCounter>(400);     // contstruct
+        Nullable<MovableCtorDtorCounter> testDst(std::move(testSrc)); // move construct
+        NL_TEST_ASSERT(inSuite, CtorDtorCounter::created == 2 && CtorDtorCounter::destroyed == 0);
         NL_TEST_ASSERT(inSuite, !testDst.IsNull() && testDst.Value().m == 400);
+        // destroy both testsSrc and testDst
     }
     NL_TEST_ASSERT(inSuite, CtorDtorCounter::created == 2 && CtorDtorCounter::destroyed == 2);
 
+    CtorDtorCounter::ResetCounter();
     {
-        Nullable<MovableCtorDtorCounter> testDst;
-        NL_TEST_ASSERT(inSuite, CtorDtorCounter::created == 2 && CtorDtorCounter::destroyed == 2);
+        Nullable<MovableCtorDtorCounter> testDst;  // no object construction
+        NL_TEST_ASSERT(inSuite, CtorDtorCounter::created == 0 && CtorDtorCounter::destroyed == 0);
         NL_TEST_ASSERT(inSuite, !!testDst.IsNull());
 
-        auto testSrc = MakeNullable<MovableCtorDtorCounter>(401);
-        testDst      = std::move(testSrc);
-        NL_TEST_ASSERT(inSuite, CtorDtorCounter::created == 4 && CtorDtorCounter::destroyed == 3);
+        auto testSrc = MakeNullable<MovableCtorDtorCounter>(401); // construct object
+        testDst      = std::move(testSrc);  // construct a copy
+        NL_TEST_ASSERT(inSuite, CtorDtorCounter::created == 2 && CtorDtorCounter::destroyed == 0);
         NL_TEST_ASSERT(inSuite, !testDst.IsNull() && testDst.Value().m == 401);
     }
-    NL_TEST_ASSERT(inSuite, CtorDtorCounter::created == 4 && CtorDtorCounter::destroyed == 4);
+    NL_TEST_ASSERT(inSuite, CtorDtorCounter::created == 2 && CtorDtorCounter::destroyed == 2);
 }
 
 static void TestUpdate(nlTestSuite * inSuite, void * inContext)