add missing lib

lib/ArduinoJson/test/DynamicJsonBuffer/size.cpp

@@ -0,0 +1,27 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+TEST_CASE("DynamicJsonBuffer::size()") {
+  DynamicJsonBuffer buffer;
+
+  SECTION("Initial size is 0") {
+    REQUIRE(0 == buffer.size());
+  }
+
+  SECTION("Increases after alloc()") {
+    buffer.alloc(1);
+    REQUIRE(1U <= buffer.size());
+    buffer.alloc(1);
+    REQUIRE(2U <= buffer.size());
+  }
+
+  SECTION("Goes back to 0 after clear()") {
+    buffer.alloc(1);
+    buffer.clear();
+    REQUIRE(0 == buffer.size());
+  }
+}