Added nesting() to JsonArray, JsonDocument, JsonObject, and JsonVariant

test/JsonVariant/CMakeLists.txt

@@ -10,6 +10,7 @@ add_executable(JsonVariantTests
 	is.cpp
 	isnull.cpp
 	memoryUsage.cpp
+	nesting.cpp
 	misc.cpp
 	or.cpp
 	set.cpp

test/JsonVariant/nesting.cpp

@@ -0,0 +1,31 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+TEST_CASE("JsonVariant::nesting()") {
+  DynamicJsonDocument doc(4096);
+  JsonVariant var = doc.to<JsonVariant>();
+
+  SECTION("return 0 if uninitialized") {
+    JsonVariant unitialized;
+    REQUIRE(unitialized.nesting() == 0);
+  }
+
+  SECTION("returns 0 for string") {
+    var.set("hello");
+    REQUIRE(var.nesting() == 0);
+  }
+
+  SECTION("returns 1 for empty object") {
+    var.to<JsonObject>();
+    REQUIRE(var.nesting() == 1);
+  }
+
+  SECTION("returns 1 for empty array") {
+    var.to<JsonArray>();
+    REQUIRE(var.nesting() == 1);
+  }
+}