Add test cases for String::toInt() and String::toDouble() with invalid buffer

Author: giulcioffi

test/src/String/test_toDouble.cpp

@@ -34,3 +34,10 @@ TEST_CASE ("Testing String::toDouble when string contains a number", "[String-to
   double const val = str.toDouble();
   REQUIRE(val == -1.2345);
 }
+
+TEST_CASE ("Testing String::toDouble when string does not have a buffer", "[String-toDouble-04]")
+{
+  char *buffer = NULL;
+  arduino::String str(buffer);
+  REQUIRE(str.toDouble() == 0);
+}

test/src/String/test_toInt.cpp

@@ -34,3 +34,10 @@ TEST_CASE ("Testing String::toInt when string contains a number", "[String-toInt
   int const val = str.toInt();
   REQUIRE(val == -1);
 }
+
+TEST_CASE ("Testing String::toInt when string does not have a buffer", "[String-toInt-04]")
+{
+  char *buffer = NULL;
+  arduino::String str(buffer);
+  REQUIRE(str.toInt() == 0);
+}