add arduino json lib

#182

lib/ArduinoJson/test/JsonObject/invalid.cpp

@@ -0,0 +1,35 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+using namespace Catch::Matchers;
+
+TEST_CASE("JsonObject::invalid()") {
+  JsonObject& obj = JsonObject::invalid();
+
+  SECTION("SubscriptFails") {
+    REQUIRE_FALSE(obj["key"].success());
+  }
+
+  SECTION("AddFails") {
+    obj.set("hello", "world");
+    REQUIRE(0 == obj.size());
+  }
+
+  SECTION("CreateNestedArrayFails") {
+    REQUIRE_FALSE(obj.createNestedArray("hello").success());
+  }
+
+  SECTION("CreateNestedObjectFails") {
+    REQUIRE_FALSE(obj.createNestedObject("world").success());
+  }
+
+  SECTION("PrintToWritesBraces") {
+    char buffer[32];
+    obj.printTo(buffer, sizeof(buffer));
+    REQUIRE_THAT(buffer, Equals("{}"));
+  }
+}