Rename tests/JsonObject/invalid.cpp to unbound.cpp

extras/tests/JsonObject/unbound.cpp

@@ -0,0 +1,27 @@
+// ArduinoJson - https://arduinojson.org
+// Copyright © 2014-2023, Benoit BLANCHON
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+using namespace Catch::Matchers;
+
+TEST_CASE("Unbound JsonObject") {
+  JsonObject obj;
+
+  SECTION("retrieve member") {
+    REQUIRE(obj["key"].isNull());
+  }
+
+  SECTION("add member") {
+    obj["hello"] = "world";
+    REQUIRE(0 == obj.size());
+  }
+
+  SECTION("serialize") {
+    char buffer[32];
+    serializeJson(obj, buffer, sizeof(buffer));
+    REQUIRE_THAT(buffer, Equals("null"));
+  }
+}