Add more tests for JsonVariantConst

extras/tests/JsonVariantConst/size.cpp

@@ -0,0 +1,36 @@
+// ArduinoJson - https://arduinojson.org
+// Copyright © 2014-2024, Benoit BLANCHON
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+TEST_CASE("JsonVariantConst::size()") {
+  JsonDocument doc;
+  JsonVariantConst variant = doc.to<JsonVariant>();
+
+  SECTION("unbound reference") {
+    JsonVariantConst unbound;
+
+    CHECK(unbound.size() == 0);
+  }
+
+  SECTION("int") {
+    doc.set(42);
+
+    CHECK(variant.size() == 0);
+  }
+
+  SECTION("string") {
+    doc.set("hello");
+
+    CHECK(variant.size() == 0);
+  }
+
+  SECTION("object") {
+    doc["a"] = 1;
+    doc["b"] = 2;
+
+    CHECK(variant.size() == 2);
+  }
+}