Add more tests for JsonVariantConst

extras/tests/JsonVariantConst/subscript.cpp

@@ -0,0 +1,68 @@
+// ArduinoJson - https://arduinojson.org
+// Copyright © 2014-2024, Benoit BLANCHON
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+TEST_CASE("JsonVariantConst::operator[]") {
+  JsonDocument doc;
+  JsonVariantConst var = doc.to<JsonVariant>();
+
+  SECTION("null") {
+    REQUIRE(0 == var.size());
+    REQUIRE(var["0"].isNull());
+    REQUIRE(var[0].isNull());
+  }
+
+  SECTION("string") {
+    doc.set("hello world");
+    REQUIRE(0 == var.size());
+    REQUIRE(var["0"].isNull());
+    REQUIRE(var[0].isNull());
+  }
+
+  SECTION("array") {
+    JsonArray array = doc.to<JsonArray>();
+    array.add("A");
+    array.add("B");
+
+    REQUIRE(std::string("A") == var[0]);
+    REQUIRE(std::string("B") == var[1]);
+    REQUIRE(std::string("A") ==
+            var[static_cast<unsigned char>(0)]);  // issue #381
+    REQUIRE(var[666].isNull());
+    REQUIRE(var[3].isNull());
+    REQUIRE(var["0"].isNull());
+  }
+
+  SECTION("object") {
+    JsonObject object = doc.to<JsonObject>();
+    object["a"] = "A";
+    object["b"] = "B";
+
+    SECTION("supports const char*") {
+      REQUIRE(std::string("A") == var["a"]);
+      REQUIRE(std::string("B") == var["b"]);
+      REQUIRE(var["c"].isNull());
+      REQUIRE(var[0].isNull());
+    }
+
+    SECTION("supports std::string") {
+      REQUIRE(std::string("A") == var[std::string("a")]);
+      REQUIRE(std::string("B") == var[std::string("b")]);
+      REQUIRE(var[std::string("c")].isNull());
+    }
+
+#if defined(HAS_VARIABLE_LENGTH_ARRAY) && \
+    !defined(SUBSCRIPT_CONFLICTS_WITH_BUILTIN_OPERATOR)
+    SECTION("supports VLA") {
+      size_t i = 16;
+      char vla[i];
+      strcpy(vla, "a");
+
+      REQUIRE(std::string("A") == var[vla]);
+    }
+#endif
+  }
+}