Added memoryUsage() to JsonArray, JsonObject, and JsonVariant

test/JsonArray/CMakeLists.txt

@@ -11,6 +11,7 @@ add_executable(JsonArrayTests
 	get.cpp
 	isNull.cpp
 	iterator.cpp
+	memoryUsage.cpp
 	remove.cpp
 	size.cpp
 	std_string.cpp

test/JsonArray/memoryUsage.cpp

@@ -0,0 +1,42 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+TEST_CASE("JsonArray::memoryUsage()") {
+  DynamicJsonDocument doc(4096);
+  JsonArray arr = doc.to<JsonArray>();
+
+  SECTION("return 0 if uninitialized") {
+    JsonArray unitialized;
+    REQUIRE(unitialized.memoryUsage() == 0);
+  }
+
+  SECTION("JSON_ARRAY_SIZE(0) if empty") {
+    REQUIRE(arr.memoryUsage() == JSON_ARRAY_SIZE(0));
+  }
+
+  SECTION("JSON_ARRAY_SIZE(1) after add") {
+    arr.add("hello");
+    REQUIRE(arr.memoryUsage() == JSON_ARRAY_SIZE(1));
+  }
+
+  SECTION("includes the size of the string") {
+    arr.add(std::string("hello"));
+    REQUIRE(arr.memoryUsage() == JSON_ARRAY_SIZE(1) + 6);
+  }
+
+  SECTION("includes the size of the nested array") {
+    JsonArray nested = arr.createNestedArray();
+    nested.add(42);
+    REQUIRE(arr.memoryUsage() == 2 * JSON_ARRAY_SIZE(1));
+  }
+
+  SECTION("includes the size of the nested arrect") {
+    JsonObject nested = arr.createNestedObject();
+    nested["hello"] = "world";
+    REQUIRE(arr.memoryUsage() == JSON_OBJECT_SIZE(1) + JSON_ARRAY_SIZE(1));
+  }
+}

test/JsonArray/size.cpp

@@ -9,7 +9,7 @@ TEST_CASE("JsonArray::size()") {
   DynamicJsonDocument doc(4096);
   JsonArray array = doc.to<JsonArray>();
 
-  SECTION("InitialSizeIsZero") {
+  SECTION("returns 0 is empty") {
     REQUIRE(0U == array.size());
   }
 

test/JsonObject/CMakeLists.txt

@@ -11,6 +11,7 @@ add_executable(JsonObjectTests
 	invalid.cpp
 	isNull.cpp
 	iterator.cpp
+	memoryUsage.cpp
 	remove.cpp
 	size.cpp
 	std_string.cpp

test/JsonObject/memoryUsage.cpp

@@ -0,0 +1,43 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+#include <string>
+
+TEST_CASE("JsonObject::memoryUsage()") {
+  DynamicJsonDocument doc(4096);
+  JsonObject obj = doc.to<JsonObject>();
+
+  SECTION("return 0 if uninitialized") {
+    JsonObject unitialized;
+    REQUIRE(unitialized.memoryUsage() == 0);
+  }
+
+  SECTION("JSON_OBJECT_SIZE(0) for empty object") {
+    REQUIRE(obj.memoryUsage() == JSON_OBJECT_SIZE(0));
+  }
+
+  SECTION("JSON_OBJECT_SIZE(1) after add") {
+    obj["hello"] = 42;
+    REQUIRE(obj.memoryUsage() == JSON_OBJECT_SIZE(1));
+  }
+
+  SECTION("includes the size of the key") {
+    obj[std::string("hello")] = 42;
+    REQUIRE(obj.memoryUsage() == JSON_OBJECT_SIZE(1) + 6);
+  }
+
+  SECTION("includes the size of the nested array") {
+    JsonArray nested = obj.createNestedArray("nested");
+    nested.add(42);
+    REQUIRE(obj.memoryUsage() == JSON_OBJECT_SIZE(1) + JSON_ARRAY_SIZE(1));
+  }
+
+  SECTION("includes the size of the nested object") {
+    JsonObject nested = obj.createNestedObject("nested");
+    nested["hello"] = "world";
+    REQUIRE(obj.memoryUsage() == 2 * JSON_OBJECT_SIZE(1));
+  }
+}

test/JsonVariant/CMakeLists.txt

@@ -9,6 +9,7 @@ add_executable(JsonVariantTests
 	get.cpp
 	is.cpp
 	isnull.cpp
+	memoryUsage.cpp
 	misc.cpp
 	or.cpp
 	set.cpp

test/JsonVariant/memoryUsage.cpp

@@ -0,0 +1,39 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+#include <string>
+
+TEST_CASE("JsonVariant::memoryUsage()") {
+  DynamicJsonDocument doc(4096);
+  JsonVariant var = doc.to<JsonVariant>();
+
+  SECTION("returns 0 if uninitialized") {
+    JsonVariant unitialized;
+    REQUIRE(unitialized.memoryUsage() == 0);
+  }
+
+  SECTION("returns size of object") {
+    JsonObject obj = var.to<JsonObject>();
+    obj["hello"] = 42;
+    REQUIRE(var.memoryUsage() == JSON_OBJECT_SIZE(1));
+  }
+
+  SECTION("returns size of array") {
+    JsonArray arr = var.to<JsonArray>();
+    arr.add(42);
+    REQUIRE(var.memoryUsage() == JSON_ARRAY_SIZE(1));
+  }
+
+  SECTION("returns size of owned string") {
+    var.set(std::string("hello"));
+    REQUIRE(var.memoryUsage() == 6);
+  }
+
+  SECTION("returns size of owned raw") {
+    var.set(serialized(std::string("hello")));
+    REQUIRE(var.memoryUsage() == 5);
+  }
+}