Removed default capacity of `DynamicJsonDocument`

CHANGELOG.md

@@ -6,6 +6,23 @@ HEAD
 
 * Import functions in the ArduinoJson namespace to get clearer errors
 * Improved syntax highlighting in Arduino IDE
+* Removed default capacity of `DynamicJsonDocument`
+
+> ### BREAKING CHANGES
+> 
+> The parameter to the constructor of `DynamicJsonDocument` is now mandatory
+>
+> Old code:
+>
+> ```c++
+> DynamicJsonDocument doc;
+> ```
+>
+> New code:
+>
+> ```c++
+> DynamicJsonDocument doc(1024);
+> ```
 
 v6.7.0-beta (2018-12-07)
 -----------

README.md

@@ -60,7 +60,7 @@ Here is a program that parses a JSON document with ArduinoJson.
 ```c++
 char json[] = "{\"sensor\":\"gps\",\"time\":1351824120,\"data\":[48.756080,2.302038]}";
 
-DynamicJsonDocument doc;
+DynamicJsonDocument doc(1024);
 deserializeJson(doc, json);
 
 JsonObjectRef root = doc.as<JsonObject>();
@@ -77,7 +77,7 @@ See the [tutorial on arduinojson.org](https://arduinojson.org/doc/decoding/?utm_
 Here is a program that generates a JSON document with ArduinoJson:
 
 ```c++
-DynamicJsonDocument doc;
+DynamicJsonDocument doc(1024);
 
 JsonObject root = doc.to<JsonObject>();
 root["sensor"] = "gps";

examples/ProgmemExample/ProgmemExample.ino

@@ -14,7 +14,7 @@
 void setup() {
 #ifdef PROGMEM  // <- check that Flash strings are supported
 
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(1024);
 
   // You can use a Flash String as your JSON input.
   // WARNING: the content of the Flash String will be duplicated in the

examples/StringExample/StringExample.ino

@@ -11,7 +11,7 @@
 #include <ArduinoJson.h>
 
 void setup() {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(1024);
 
   // You can use a String as your JSON input.
   // WARNING: the content of the String will be duplicated in the JsonBuffer.

fuzzing/json_fuzzer.cpp

@@ -1,7 +1,7 @@
 #include <ArduinoJson.h>
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   DeserializationError error = deserializeJson(doc, data, size);
   if (!error) {
     std::string json;

fuzzing/msgpack_fuzzer.cpp

@@ -1,7 +1,7 @@
 #include <ArduinoJson.h>
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   DeserializationError error = deserializeMsgPack(doc, data, size);
   if (!error) {
     std::string json;

src/ArduinoJson/Configuration.hpp

@@ -53,11 +53,6 @@
 #define ARDUINOJSON_DEFAULT_NESTING_LIMIT 10
 #endif
 
-// Default capacity for DynamicJsonDocument
-#ifndef ARDUINOJSON_DEFAULT_POOL_SIZE
-#define ARDUINOJSON_DEFAULT_POOL_SIZE 1024
-#endif
-
 #else  // ARDUINOJSON_EMBEDDED_MODE
 
 // On a computer we have plenty of memory so we can use doubles
@@ -89,11 +84,6 @@
 #define ARDUINOJSON_DEFAULT_NESTING_LIMIT 50
 #endif
 
-// Default capacity for DynamicJsonDocument
-#ifndef ARDUINOJSON_DEFAULT_POOL_SIZE
-#define ARDUINOJSON_DEFAULT_POOL_SIZE 16384
-#endif
-
 #endif  // ARDUINOJSON_EMBEDDED_MODE
 
 #ifdef ARDUINO

src/ArduinoJson/Document/DynamicJsonDocument.hpp

@@ -12,7 +12,7 @@ namespace ARDUINOJSON_NAMESPACE {
 
 class DynamicJsonDocument : public JsonDocument {
  public:
-  DynamicJsonDocument(size_t capa = ARDUINOJSON_DEFAULT_POOL_SIZE)
+  explicit DynamicJsonDocument(size_t capa)
       : JsonDocument(allocPool(addPadding(capa))) {}
 
   DynamicJsonDocument(const DynamicJsonDocument& src)

test/IntegrationTests/gbathree.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("Gbathree") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   DeserializationError error = deserializeJson(
       doc,

test/IntegrationTests/issue772.cpp

@@ -8,7 +8,8 @@
 // https://github.com/bblanchon/ArduinoJson/issues/772
 
 TEST_CASE("Issue772") {
-  DynamicJsonDocument doc1, doc2;
+  DynamicJsonDocument doc1(4096);
+  DynamicJsonDocument doc2(4096);
   DeserializationError err;
   std::string data =
       "{\"state\":{\"reported\":{\"timestamp\":\"2018-07-02T09:40:12Z\","

test/IntegrationTests/round_trip.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 void check(std::string originalJson) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(16384);
 
   std::string prettyJson;
   deserializeJson(doc, originalJson);

test/JsonArray/add.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonArray::add()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonArray array = doc.to<JsonArray>();
 
   SECTION("int") {
@@ -51,7 +51,7 @@ TEST_CASE("JsonArray::add()") {
 #endif
 
   SECTION("nested array") {
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     JsonArray arr = doc2.to<JsonArray>();
 
     array.add(arr);
@@ -62,7 +62,7 @@ TEST_CASE("JsonArray::add()") {
   }
 
   SECTION("nested object") {
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     JsonObject obj = doc2.to<JsonObject>();
 
     array.add(obj);
@@ -74,7 +74,7 @@ TEST_CASE("JsonArray::add()") {
 
   SECTION("array subscript") {
     const char* str = "hello";
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     JsonArray arr = doc2.to<JsonArray>();
     arr.add(str);
 
@@ -85,7 +85,7 @@ TEST_CASE("JsonArray::add()") {
 
   SECTION("object subscript") {
     const char* str = "hello";
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     JsonObject obj = doc2.to<JsonObject>();
     obj["x"] = str;
 

test/JsonArray/copyFrom.cpp

@@ -7,7 +7,7 @@
 
 TEST_CASE("JsonArray::copyFrom()") {
   SECTION("OneDimension") {
-    DynamicJsonDocument doc;
+    DynamicJsonDocument doc(4096);
     JsonArray array = doc.to<JsonArray>();
     char json[32];
     int source[] = {1, 2, 3};
@@ -34,7 +34,7 @@ TEST_CASE("JsonArray::copyFrom()") {
   }
 
   SECTION("TwoDimensions") {
-    DynamicJsonDocument doc;
+    DynamicJsonDocument doc(4096);
     JsonArray array = doc.to<JsonArray>();
     char json[32];
     int source[][3] = {{1, 2, 3}, {4, 5, 6}};

test/JsonArray/copyTo.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonArray::copyTo()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("BiggerOneDimensionIntegerArray") {
     char json[] = "[1,2,3]";

test/JsonArray/createNested.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonArray basics") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonArray array = doc.to<JsonArray>();
 
   SECTION("CreateNestedArray") {

test/JsonArray/equals.cpp

@@ -6,11 +6,11 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonArray::operator==()") {
-  DynamicJsonDocument doc1;
+  DynamicJsonDocument doc1(4096);
   JsonArray array1 = doc1.to<JsonArray>();
   JsonArrayConst array1c = array1;
 
-  DynamicJsonDocument doc2;
+  DynamicJsonDocument doc2(4096);
   JsonArray array2 = doc2.to<JsonArray>();
   JsonArrayConst array2c = array2;
 

test/JsonArray/get.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonArray::get()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   deserializeJson(doc, "[1,2,3]");
   JsonArray array = doc.as<JsonArray>();
 

test/JsonArray/isNull.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonArray::isNull()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("returns true") {
     JsonArray arr;
@@ -20,7 +20,7 @@ TEST_CASE("JsonArray::isNull()") {
 }
 
 TEST_CASE("JsonArrayConst::isNull()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("returns true") {
     JsonArrayConst arr;

test/JsonArray/remove.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonArray::remove()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonArray _array = doc.to<JsonArray>();
   _array.add(1);
   _array.add(2);

test/JsonArray/size.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonArray::size()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonArray array = doc.to<JsonArray>();
 
   SECTION("InitialSizeIsZero") {

test/JsonArray/std_string.cpp

@@ -11,7 +11,7 @@ static void eraseString(std::string &str) {
 }
 
 TEST_CASE("std::string") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonArray array = doc.to<JsonArray>();
 
   SECTION("add()") {

test/JsonArray/subscript.cpp

@@ -7,7 +7,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonArray::operator[]") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonArray array = doc.to<JsonArray>();
   array.add(0);
 
@@ -52,7 +52,7 @@ TEST_CASE("JsonArray::operator[]") {
   }
 
   SECTION("nested array") {
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     JsonArray arr2 = doc2.to<JsonArray>();
 
     array[0] = arr2;
@@ -63,7 +63,7 @@ TEST_CASE("JsonArray::operator[]") {
   }
 
   SECTION("nested object") {
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     JsonObject obj = doc2.to<JsonObject>();
 
     array[0] = obj;
@@ -74,7 +74,7 @@ TEST_CASE("JsonArray::operator[]") {
   }
 
   SECTION("array subscript") {
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     JsonArray arr2 = doc2.to<JsonArray>();
     const char* str = "hello";
 
@@ -87,7 +87,7 @@ TEST_CASE("JsonArray::operator[]") {
 
   SECTION("object subscript") {
     const char* str = "hello";
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     JsonObject obj = doc2.to<JsonObject>();
 
     obj["x"] = str;
@@ -146,7 +146,7 @@ TEST_CASE("JsonArray::operator[]") {
 }
 
 TEST_CASE("JsonArrayConst::operator[]") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonArray array = doc.to<JsonArray>();
   array.add(0);
 

test/JsonDeserializer/deserializeJsonArray.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("deserialize JSON array") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("An empty array") {
     DeserializationError err = deserializeJson(doc, "[]");

test/JsonDeserializer/deserializeJsonObject.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("deserialize JSON object") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("An empty object") {
     DeserializationError err = deserializeJson(doc, "{}");

test/JsonDeserializer/deserializeJsonValue.cpp

@@ -13,7 +13,7 @@ using ARDUINOJSON_NAMESPACE::isnan;
 }  // namespace my
 
 TEST_CASE("deserializeJson(DynamicJsonDocument&)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("null char*") {
     DeserializationError err = deserializeJson(doc, static_cast<char*>(0));

test/JsonDeserializer/input_types.cpp

@@ -7,7 +7,7 @@
 #include <sstream>
 
 TEST_CASE("deserializeJson(const std::string&)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("should accept const string") {
     const std::string input("[42]");
@@ -36,7 +36,7 @@ TEST_CASE("deserializeJson(const std::string&)") {
 }
 
 TEST_CASE("deserializeJson(std::istream&)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("array") {
     std::istringstream json(" [ 42 /* comment */ ] ");

test/JsonDeserializer/nestingLimit.cpp

@@ -10,7 +10,7 @@
   REQUIRE(DeserializationError::TooDeep == expression);
 
 TEST_CASE("JsonDeserializer nestingLimit") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("limit = 0") {
     doc.nestingLimit = 0;

test/JsonDocument/DynamicJsonDocument.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("DynamicJsonDocument") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("serializeJson()") {
     JsonObject obj = doc.to<JsonObject>();
@@ -136,7 +136,7 @@ TEST_CASE("DynamicJsonDocument copies") {
   }
 
   SECTION("Assign from StaticJsonDocument") {
-    DynamicJsonDocument ddoc;
+    DynamicJsonDocument ddoc(4096);
     ddoc.to<JsonVariant>().set(666);
 
     StaticJsonDocument<200> sdoc;

test/JsonDocument/StaticJsonDocument.cpp

@@ -73,7 +73,7 @@ TEST_CASE("StaticJsonDocument") {
 
   SECTION("Assign from DynamicJsonDocument") {
     StaticJsonDocument<200> doc1;
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     doc1.to<JsonVariant>().set(666);
     deserializeJson(doc2, "{\"hello\":\"world\"}");
     doc2.nestingLimit = 42;
@@ -100,7 +100,7 @@ TEST_CASE("StaticJsonDocument") {
   }
 
   SECTION("Construct from DynamicJsonDocument") {
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     deserializeJson(doc2, "{\"hello\":\"world\"}");
     doc2.nestingLimit = 42;
 

test/JsonObject/containsKey.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonObject::containsKey()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject obj = doc.to<JsonObject>();
   obj["hello"] = 42;
 

test/JsonObject/copy.cpp

@@ -6,8 +6,8 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonObject::copyFrom()") {
-  DynamicJsonDocument doc1;
-  DynamicJsonDocument doc2;
+  DynamicJsonDocument doc1(4096);
+  DynamicJsonDocument doc2(4096);
 
   JsonObject obj1 = doc1.to<JsonObject>();
   JsonObject obj2 = doc2.to<JsonObject>();

test/JsonObject/createNestedArray.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonObject::createNestedArray()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject obj = doc.to<JsonObject>();
 
   SECTION("key is a const char*") {

test/JsonObject/createNestedObject.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonObject::createNestedObject()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject obj = doc.to<JsonObject>();
 
   SECTION("key is a const char*") {

test/JsonObject/equals.cpp

@@ -6,11 +6,11 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonObject::operator==()") {
-  DynamicJsonDocument doc1;
+  DynamicJsonDocument doc1(4096);
   JsonObject obj1 = doc1.to<JsonObject>();
   JsonObjectConst obj1c = obj1;
 
-  DynamicJsonDocument doc2;
+  DynamicJsonDocument doc2(4096);
   JsonObject obj2 = doc2.to<JsonObject>();
   JsonObjectConst obj2c = obj2;
 

test/JsonObject/isNull.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonObject::isNull()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("returns true") {
     JsonObject obj;
@@ -20,7 +20,7 @@ TEST_CASE("JsonObject::isNull()") {
 }
 
 TEST_CASE("JsonObjectConst::isNull()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("returns true") {
     JsonObjectConst obj;

test/JsonObject/remove.cpp

@@ -7,7 +7,7 @@
 #include <string>
 
 TEST_CASE("JsonObject::remove()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject obj = doc.to<JsonObject>();
   obj["a"] = 0;
   obj["b"] = 1;

test/JsonObject/size.cpp

@@ -7,7 +7,7 @@
 #include <string>
 
 TEST_CASE("JsonObject::size()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject obj = doc.to<JsonObject>();
 
   SECTION("initial size is zero") {

test/JsonObject/std_string.cpp

@@ -11,7 +11,7 @@ static void eraseString(std::string &str) {
 }
 
 TEST_CASE("std::string") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("operator[]") {
     char json[] = "{\"key\":\"value\"}";

test/JsonObject/subscript.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonObject::operator[]") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject obj = doc.to<JsonObject>();
 
   SECTION("int") {
@@ -52,7 +52,7 @@ TEST_CASE("JsonObject::operator[]") {
   }
 
   SECTION("array") {
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     JsonArray arr = doc2.to<JsonArray>();
 
     obj["hello"] = arr;
@@ -63,7 +63,7 @@ TEST_CASE("JsonObject::operator[]") {
   }
 
   SECTION("object") {
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     JsonObject obj2 = doc2.to<JsonObject>();
 
     obj["hello"] = obj2;
@@ -74,7 +74,7 @@ TEST_CASE("JsonObject::operator[]") {
   }
 
   SECTION("array subscript") {
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     JsonArray arr = doc2.to<JsonArray>();
     arr.add(42);
 
@@ -84,7 +84,7 @@ TEST_CASE("JsonObject::operator[]") {
   }
 
   SECTION("object subscript") {
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     JsonObject obj2 = doc2.to<JsonObject>();
     obj2["x"] = 42;
 

test/JsonSerializer/JsonArrayPretty.cpp

@@ -15,7 +15,7 @@ static void check(JsonArray array, std::string expected) {
 }
 
 TEST_CASE("serializeJsonPretty(JsonArray)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonArray array = doc.to<JsonArray>();
 
   SECTION("Empty") {

test/JsonSerializer/JsonObject.cpp

@@ -17,7 +17,7 @@ void check(const JsonObject obj, const std::string &expected) {
 }
 
 TEST_CASE("serializeJson(JsonObject)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject obj = doc.to<JsonObject>();
 
   SECTION("EmptyObject") {
@@ -93,8 +93,8 @@ TEST_CASE("serializeJson(JsonObject)") {
   }
 
   SECTION("ThreeNestedArrays") {
-    DynamicJsonDocument b;
-    DynamicJsonDocument c;
+    DynamicJsonDocument b(4096);
+    DynamicJsonDocument c(4096);
 
     obj.createNestedArray("a");
     obj["b"] = b.to<JsonArray>();
@@ -104,8 +104,8 @@ TEST_CASE("serializeJson(JsonObject)") {
   }
 
   SECTION("ThreeNestedObjects") {
-    DynamicJsonDocument b;
-    DynamicJsonDocument c;
+    DynamicJsonDocument b(4096);
+    DynamicJsonDocument c(4096);
 
     obj.createNestedObject("a");
     obj["b"] = b.to<JsonObject>();

test/JsonSerializer/JsonObjectPretty.cpp

@@ -18,7 +18,7 @@ void check(const JsonObject obj, const std::string expected) {
 }
 
 TEST_CASE("serializeJsonPretty(JsonObject)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject obj = doc.to<JsonObject>();
 
   SECTION("EmptyObject") {

test/JsonSerializer/JsonVariant.cpp

@@ -8,7 +8,7 @@
 
 template <typename T>
 void check(T value, const std::string &expected) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   doc.to<JsonVariant>().set(value);
   char buffer[256] = "";
   size_t returnValue = serializeJson(doc, buffer, sizeof(buffer));

test/JsonSerializer/misc.cpp

@@ -4,7 +4,7 @@
 
 template <typename T>
 void check(T value, const std::string &expected) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   doc.to<JsonVariant>().set(value);
   char buffer[256] = "";
   size_t returnValue = serializeJson(doc, buffer, sizeof(buffer));
@@ -13,7 +13,7 @@ void check(T value, const std::string &expected) {
 }
 
 TEST_CASE("serializeJson(JsonObjectSubscript)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   deserializeJson(doc, "{\"hello\":42}");
   JsonObject obj = doc.as<JsonObject>();
   std::string result;
@@ -24,7 +24,7 @@ TEST_CASE("serializeJson(JsonObjectSubscript)") {
 }
 
 TEST_CASE("serializeJson(JsonArraySubscript)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   deserializeJson(doc, "[42]");
   JsonArray arr = doc.as<JsonArray>();
   std::string result;
@@ -35,7 +35,7 @@ TEST_CASE("serializeJson(JsonArraySubscript)") {
 }
 
 TEST_CASE("serializeJson(JsonVariantSubscript)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   deserializeJson(doc, "[42]");
   JsonVariant var = doc.as<JsonVariant>();
   std::string result;

test/JsonSerializer/std_stream.cpp

@@ -7,7 +7,7 @@
 #include <sstream>
 
 TEST_CASE("operator<<(std::ostream)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   std::ostringstream os;
 
   SECTION("JsonVariant containing false") {

test/JsonSerializer/std_string.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("serialize JsonArray to std::string") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonArray array = doc.to<JsonArray>();
   array.add(4);
   array.add(2);
@@ -27,7 +27,7 @@ TEST_CASE("serialize JsonArray to std::string") {
 }
 
 TEST_CASE("serialize JsonObject to std::string") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject obj = doc.to<JsonObject>();
   obj["key"] = "value";
 

test/JsonVariant/as.cpp

@@ -9,7 +9,7 @@
 static const char* null = 0;
 
 TEST_CASE("JsonVariant::as()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant variant = doc.to<JsonVariant>();
 
   SECTION("not set") {

test/JsonVariant/compare.cpp

@@ -9,7 +9,7 @@ static const char* null = 0;
 
 template <typename T>
 void checkEquals(T a, T b) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant variant = doc.to<JsonVariant>();
   variant.set(a);
 
@@ -30,7 +30,7 @@ void checkEquals(T a, T b) {
 
 template <typename T>
 void checkGreater(T a, T b) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant variant = doc.to<JsonVariant>();
   variant.set(a);
 
@@ -47,7 +47,7 @@ void checkGreater(T a, T b) {
 
 template <typename T>
 void checkLower(T a, T b) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant variant = doc.to<JsonVariant>();
   variant.set(a);
 
@@ -111,7 +111,7 @@ TEST_CASE("JsonVariant comparisons") {
   }
 
   SECTION("null") {
-    DynamicJsonDocument doc;
+    DynamicJsonDocument doc(4096);
     JsonVariant variant = doc.to<JsonVariant>();
     variant.set(null);
 
@@ -126,7 +126,7 @@ TEST_CASE("JsonVariant comparisons") {
   }
 
   SECTION("StringLiteral") {
-    DynamicJsonDocument doc;
+    DynamicJsonDocument doc(4096);
     deserializeJson(doc, "\"hello\"");
     JsonVariant variant = doc.as<JsonVariant>();
 
@@ -153,7 +153,7 @@ TEST_CASE("JsonVariant comparisons") {
   }
 
   SECTION("String") {
-    DynamicJsonDocument doc;
+    DynamicJsonDocument doc(4096);
     JsonVariant variant = doc.to<JsonVariant>();
     variant.set("hello");
 
@@ -185,7 +185,7 @@ TEST_CASE("JsonVariant comparisons") {
     char vla[i];
     strcpy(vla, "hello");
 
-    DynamicJsonDocument doc;
+    DynamicJsonDocument doc(4096);
     JsonVariant variant = doc.to<JsonVariant>();
     variant.set("hello");
 
@@ -200,7 +200,7 @@ TEST_CASE("JsonVariant comparisons") {
     char vla[i];
     strcpy(vla, "hello");
 
-    DynamicJsonDocument doc;
+    DynamicJsonDocument doc(4096);
     JsonVariant variant = doc.to<JsonVariant>();
     variant.set("world");
 
@@ -211,7 +211,7 @@ TEST_CASE("JsonVariant comparisons") {
   }
 #endif
 
-  DynamicJsonDocument doc1, doc2, doc3;
+  DynamicJsonDocument doc1(4096), doc2(4096), doc3(4096);
   JsonVariant variant1 = doc1.to<JsonVariant>();
   JsonVariant variant2 = doc2.to<JsonVariant>();
   JsonVariant variant3 = doc3.to<JsonVariant>();
@@ -329,10 +329,10 @@ TEST_CASE("JsonVariant comparisons") {
   }
 
   // SECTION("VariantsOfDifferentTypes") {
-  //   DynamicJsonDocument doc1;
+  //   DynamicJsonDocument doc1(4096);
   //   JsonObject obj = doc1.to<JsonObject>();
 
-  //   DynamicJsonDocument doc2;
+  //   DynamicJsonDocument doc2(4096);
   //   JsonArray arr = doc2.to<JsonArray>();
   //   JsonVariant variants[] = {
   //       true, 42, 666.667, "hello", arr, obj,

test/JsonVariant/copy.cpp

@@ -6,8 +6,8 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonVariant::set(JsonVariant)") {
-  DynamicJsonDocument doc1;
-  DynamicJsonDocument doc2;
+  DynamicJsonDocument doc1(4096);
+  DynamicJsonDocument doc2(4096);
   JsonVariant var1 = doc1.to<JsonVariant>();
   JsonVariant var2 = doc2.to<JsonVariant>();
 

test/JsonVariant/get.cpp

@@ -9,7 +9,7 @@
 
 template <typename T>
 void checkValue(T expected) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant variant = doc.to<JsonVariant>();
 
   variant.set(expected);
@@ -24,7 +24,7 @@ void checkReference(T &expected) {
 
 template <typename T>
 void checkNumericType() {
-  DynamicJsonDocument docMin, docMax;
+  DynamicJsonDocument docMin(4096), docMax(4096);
   JsonVariant variantMin = docMin.to<JsonVariant>();
   JsonVariant variantMax = docMax.to<JsonVariant>();
 
@@ -132,7 +132,7 @@ TEST_CASE("JsonVariant set()/get()") {
 #endif
 
   SECTION("CanStoreObject") {
-    DynamicJsonDocument doc;
+    DynamicJsonDocument doc(4096);
     JsonObject object = doc.to<JsonObject>();
 
     checkValue<JsonObject>(object);

test/JsonVariant/is.cpp

@@ -19,7 +19,7 @@ void checkIsArray(TVariant var) {
 }
 
 void testArray(JsonArray value) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   JsonVariant var = doc.to<JsonVariant>();
   var.set(value);
@@ -44,7 +44,7 @@ void checkIsBool(TVariant var) {
 }
 
 void testBool(bool value) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant var = doc.to<JsonVariant>();
   var.set(value);
 
@@ -66,7 +66,7 @@ void checkIsFloat(TVariant var) {
 }
 
 void testFloat(double value) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant var = doc.to<JsonVariant>();
   var.set(value);
 
@@ -89,7 +89,7 @@ void checkIsInteger(TVariant var) {
 
 template <typename T>
 void testInteger(T value) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant var = doc.to<JsonVariant>();
   var.set(value);
 
@@ -112,7 +112,7 @@ void checkIsString(TVariant var) {
 }
 
 void testString(const char *value) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant var = doc.to<JsonVariant>();
   var.set(value);
 
@@ -122,7 +122,7 @@ void testString(const char *value) {
 
 TEST_CASE("JsonVariant::is()") {
   SECTION("JsonArray") {
-    DynamicJsonDocument doc;
+    DynamicJsonDocument doc(4096);
     JsonArray array = doc.to<JsonArray>();
     testArray(array);
   }

test/JsonVariant/isnull.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonVariant::isNull()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant variant = doc.to<JsonVariant>();
 
   SECTION("return true when Undefined") {
@@ -20,7 +20,7 @@ TEST_CASE("JsonVariant::isNull()") {
   }
 
   SECTION("return false when EmptyArray") {
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     JsonArray array = doc2.to<JsonArray>();
 
     variant.set(array);
@@ -28,7 +28,7 @@ TEST_CASE("JsonVariant::isNull()") {
   }
 
   SECTION("return false when EmptyObject") {
-    DynamicJsonDocument doc2;
+    DynamicJsonDocument doc2(4096);
     JsonObject obj = doc2.to<JsonObject>();
 
     variant.set(obj);

test/JsonVariant/misc.cpp

@@ -13,7 +13,7 @@ TEST_CASE("JsonVariant from JsonArray") {
   }
 
   SECTION("JsonArray is not null") {
-    DynamicJsonDocument doc;
+    DynamicJsonDocument doc(4096);
     JsonArray arr = doc.to<JsonArray>();
     arr.add(12);
     arr.add(34);
@@ -35,7 +35,7 @@ TEST_CASE("JsonVariant from JsonObject") {
   }
 
   SECTION("JsonObject is not null") {
-    DynamicJsonDocument doc;
+    DynamicJsonDocument doc(4096);
     JsonObject obj = doc.to<JsonObject>();
     obj["a"] = 12;
     obj["b"] = 34;

test/JsonVariant/or.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonVariant::operator|()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant variant = doc.to<JsonVariant>();
 
   SECTION("undefined") {

test/JsonVariant/set.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonVariant and strings") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant variant = doc.to<JsonVariant>();
 
   SECTION("stores const char* by reference") {

test/JsonVariant/subscript.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("JsonVariant::operator[]") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant var = doc.to<JsonVariant>();
 
   SECTION("The JsonVariant is undefined") {
@@ -122,7 +122,7 @@ TEST_CASE("JsonVariant::operator[]") {
 }
 
 TEST_CASE("JsonVariantConst::operator[]") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant var = doc.to<JsonVariant>();
   JsonVariantConst cvar = var;
 

test/Misc/unsigned_char.cpp

@@ -29,7 +29,7 @@ TEST_CASE("unsigned char[]") {
   }
 
   SECTION("JsonVariant") {
-    DynamicJsonDocument doc;
+    DynamicJsonDocument doc(4096);
 
     SECTION("set") {
       unsigned char value[] = "42";
@@ -92,7 +92,7 @@ TEST_CASE("unsigned char[]") {
     SECTION("operator[]") {
       unsigned char key[] = "hello";
 
-      DynamicJsonDocument doc;
+      DynamicJsonDocument doc(4096);
       JsonObject obj = doc.to<JsonObject>();
       obj[key] = "world";
 
@@ -102,7 +102,7 @@ TEST_CASE("unsigned char[]") {
     SECTION("JsonObject::operator[] const") {
       unsigned char key[] = "hello";
 
-      DynamicJsonDocument doc;
+      DynamicJsonDocument doc(4096);
       deserializeJson(doc, "{\"hello\":\"world\"}");
 
       JsonObject obj = doc.as<JsonObject>();
@@ -113,7 +113,7 @@ TEST_CASE("unsigned char[]") {
     SECTION("containsKey()") {
       unsigned char key[] = "hello";
 
-      DynamicJsonDocument doc;
+      DynamicJsonDocument doc(4096);
       deserializeJson(doc, "{\"hello\":\"world\"}");
       JsonObject obj = doc.as<JsonObject>();
       REQUIRE(true == obj.containsKey(key));
@@ -122,7 +122,7 @@ TEST_CASE("unsigned char[]") {
     SECTION("remove()") {
       unsigned char key[] = "hello";
 
-      DynamicJsonDocument doc;
+      DynamicJsonDocument doc(4096);
       deserializeJson(doc, "{\"hello\":\"world\"}");
       JsonObject obj = doc.as<JsonObject>();
       obj.remove(key);
@@ -133,7 +133,7 @@ TEST_CASE("unsigned char[]") {
     SECTION("createNestedArray()") {
       unsigned char key[] = "hello";
 
-      DynamicJsonDocument doc;
+      DynamicJsonDocument doc(4096);
       JsonObject obj = doc.to<JsonObject>();
       obj.createNestedArray(key);
     }
@@ -141,7 +141,7 @@ TEST_CASE("unsigned char[]") {
     SECTION("createNestedObject()") {
       unsigned char key[] = "hello";
 
-      DynamicJsonDocument doc;
+      DynamicJsonDocument doc(4096);
       JsonObject obj = doc.to<JsonObject>();
       obj.createNestedObject(key);
     }
@@ -151,7 +151,7 @@ TEST_CASE("unsigned char[]") {
     SECTION("operator=") {  // issue #416
       unsigned char value[] = "world";
 
-      DynamicJsonDocument doc;
+      DynamicJsonDocument doc(4096);
       JsonObject obj = doc.to<JsonObject>();
       obj["hello"] = value;
 
@@ -161,7 +161,7 @@ TEST_CASE("unsigned char[]") {
     SECTION("set()") {
       unsigned char value[] = "world";
 
-      DynamicJsonDocument doc;
+      DynamicJsonDocument doc(4096);
       JsonObject obj = doc.to<JsonObject>();
       obj["hello"].set(value);
 
@@ -173,7 +173,7 @@ TEST_CASE("unsigned char[]") {
     SECTION("add()") {
       unsigned char value[] = "world";
 
-      DynamicJsonDocument doc;
+      DynamicJsonDocument doc(4096);
       JsonArray arr = doc.to<JsonArray>();
       arr.add(value);
 
@@ -185,7 +185,7 @@ TEST_CASE("unsigned char[]") {
     SECTION("set()") {
       unsigned char value[] = "world";
 
-      DynamicJsonDocument doc;
+      DynamicJsonDocument doc(4096);
       JsonArray arr = doc.to<JsonArray>();
       arr.add("hello");
       arr[0].set(value);
@@ -196,7 +196,7 @@ TEST_CASE("unsigned char[]") {
     SECTION("operator=") {
       unsigned char value[] = "world";
 
-      DynamicJsonDocument doc;
+      DynamicJsonDocument doc(4096);
       JsonArray arr = doc.to<JsonArray>();
       arr.add("hello");
       arr[0] = value;

test/MixedConfiguration/use_double_0.cpp

@@ -4,7 +4,7 @@
 #include <catch.hpp>
 
 TEST_CASE("ARDUINOJSON_USE_DOUBLE == 0") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject root = doc.to<JsonObject>();
 
   root["pi"] = 3.14;

test/MixedConfiguration/use_double_1.cpp

@@ -4,7 +4,7 @@
 #include <catch.hpp>
 
 TEST_CASE("ARDUINOJSON_USE_DOUBLE == 1") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject root = doc.to<JsonObject>();
 
   root["pi"] = 3.14;

test/MixedConfiguration/use_long_long_0.cpp

@@ -17,7 +17,7 @@ std::string get_expected_json<8>() {
 }
 
 TEST_CASE("ARDUINOJSON_USE_LONG_LONG == 0") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject root = doc.to<JsonObject>();
 
   root["A"] = 123456789123456789;

test/MixedConfiguration/use_long_long_1.cpp

@@ -4,7 +4,7 @@
 #include <catch.hpp>
 
 TEST_CASE("ARDUINOJSON_USE_LONG_LONG == 1") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject root = doc.to<JsonObject>();
 
   root["A"] = 123456789123456789;

test/MsgPackDeserializer/deserializeArray.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("deserialize MsgPack array") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("fixarray") {
     SECTION("empty") {

test/MsgPackDeserializer/deserializeObject.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("deserialize MsgPack object") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("fixmap") {
     SECTION("empty") {

test/MsgPackDeserializer/deserializeVariant.cpp

@@ -7,22 +7,22 @@
 
 template <typename T, typename U>
 static void check(const char* input, U expected) {
-  DynamicJsonDocument variant;
+  DynamicJsonDocument doc(4096);
 
-  DeserializationError error = deserializeMsgPack(variant, input);
+  DeserializationError error = deserializeMsgPack(doc, input);
 
   REQUIRE(error == DeserializationError::Ok);
-  REQUIRE(variant.is<T>());
-  REQUIRE(variant.as<T>() == expected);
+  REQUIRE(doc.is<T>());
+  REQUIRE(doc.as<T>() == expected);
 }
 
 static void checkIsNull(const char* input) {
-  DynamicJsonDocument variant;
+  DynamicJsonDocument doc(4096);
 
-  DeserializationError error = deserializeMsgPack(variant, input);
+  DeserializationError error = deserializeMsgPack(doc, input);
 
   REQUIRE(error == DeserializationError::Ok);
-  REQUIRE(variant.as<JsonVariant>().isNull());
+  REQUIRE(doc.as<JsonVariant>().isNull());
 }
 
 TEST_CASE("deserialize MsgPack value") {

test/MsgPackDeserializer/incompleteInput.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 DeserializationError deserialize(const char* input, size_t len) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   return deserializeMsgPack(doc, input, len);
 }

test/MsgPackDeserializer/input_types.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("deserializeMsgPack(const std::string&)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("should accept const string") {
     const std::string input("\x92\x01\x02");
@@ -46,7 +46,7 @@ TEST_CASE("deserializeMsgPack(const std::string&)") {
 }
 
 TEST_CASE("deserializeMsgPack(std::istream&)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   SECTION("should accept a zero in input") {
     std::istringstream input(std::string("\x92\x00\x02", 3));

test/MsgPackDeserializer/nestingLimit.cpp

@@ -7,7 +7,7 @@
 
 static void check(const char* input, DeserializationError expected,
                   uint8_t limit) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   doc.nestingLimit = limit;
 
   DeserializationError error = deserializeMsgPack(doc, input);

test/MsgPackDeserializer/notSupported.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 static void checkNotSupported(const char* input) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
 
   DeserializationError error = deserializeMsgPack(doc, input);
 

test/MsgPackSerializer/destination_types.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("serialize MsgPack to various destination types") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject object = doc.to<JsonObject>();
   object["hello"] = "world";
   const char *expected_result = "\x81\xA5hello\xA5world";

test/MsgPackSerializer/measure.cpp

@@ -6,7 +6,7 @@
 #include <catch.hpp>
 
 TEST_CASE("measureMsgPack()") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject object = doc.to<JsonObject>();
   object["hello"] = "world";
 

test/MsgPackSerializer/misc.cpp

@@ -4,7 +4,7 @@
 
 template <typename T>
 void check(T value, const std::string &expected) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   doc.to<JsonVariant>().set(value);
   char buffer[256] = "";
   size_t returnValue = serializeMsgPack(doc, buffer, sizeof(buffer));
@@ -13,7 +13,7 @@ void check(T value, const std::string &expected) {
 }
 
 TEST_CASE("serializeMsgPack(JsonObjectSubscript)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   deserializeJson(doc, "{\"hello\":42}");
   JsonObject obj = doc.as<JsonObject>();
   std::string result;
@@ -24,7 +24,7 @@ TEST_CASE("serializeMsgPack(JsonObjectSubscript)") {
 }
 
 TEST_CASE("serializeMsgPack(JsonArraySubscript)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   deserializeJson(doc, "[42]");
   JsonArray arr = doc.as<JsonArray>();
   std::string result;
@@ -35,7 +35,7 @@ TEST_CASE("serializeMsgPack(JsonArraySubscript)") {
 }
 
 TEST_CASE("serializeMsgPack(JsonVariantSubscript)") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   deserializeJson(doc, "[42]");
   JsonVariant var = doc.as<JsonVariant>();
   std::string result;

test/MsgPackSerializer/serializeObject.cpp

@@ -28,7 +28,7 @@ static void check(const JsonObject object, const char (&expected_data)[N]) {
 //}
 
 TEST_CASE("serialize MsgPack object") {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonObject object = doc.to<JsonObject>();
 
   SECTION("empty") {

test/MsgPackSerializer/serializeVariant.cpp

@@ -7,7 +7,7 @@
 
 template <typename T>
 void check(T value, const char* expected_data, size_t expected_len) {
-  DynamicJsonDocument doc;
+  DynamicJsonDocument doc(4096);
   JsonVariant variant = doc.to<JsonVariant>();
   variant.set(value);
   std::string expected(expected_data, expected_data + expected_len);