JsonVariant automatically promotes to JsonObject or JsonArray on write

test/MemberProxy/add.cpp

@@ -0,0 +1,25 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+using namespace ARDUINOJSON_NAMESPACE;
+
+TEST_CASE("MemberProxy::add()") {
+  DynamicJsonDocument doc(4096);
+  MemberProxy<JsonDocument&, const char*> mp = doc["hello"];
+
+  SECTION("add(int)") {
+    mp.add(42);
+
+    REQUIRE(doc.as<std::string>() == "{\"hello\":[42]}");
+  }
+
+  SECTION("add(const char*)") {
+    mp.add("world");
+
+    REQUIRE(doc.as<std::string>() == "{\"hello\":[\"world\"]}");
+  }
+}