diff --git a/CHANGELOG.md b/CHANGELOG.md
index 20aaa183..9434822d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -33,8 +33,8 @@ HEAD
 > 
 > ```c++
 > DynamicJsonObject obj;
-> bool success = deserializeJson(obj, json);
-> if (success) {
+> JsonError error = deserializeJson(obj, json);
+> if (error) {
 > 
 > }
 > ```
diff --git a/examples/JsonConfigFile/JsonConfigFile.ino b/examples/JsonConfigFile/JsonConfigFile.ino
index 442a8651..ebf03738 100644
--- a/examples/JsonConfigFile/JsonConfigFile.ino
+++ b/examples/JsonConfigFile/JsonConfigFile.ino
@@ -35,9 +35,9 @@ void loadConfiguration(const char *filename, Config &config) {
   StaticJsonObject<512> root;
 
   // Parse the root object
-  bool success = deserializeJson(root, file);
+  JsonError error = deserializeJson(root, file);
 
-  if (!success)
+  if (error)
     Serial.println(F("Failed to read file, using default configuration"));
 
   // Copy values from the JsonObject to the Config
diff --git a/examples/JsonHttpClient/JsonHttpClient.ino b/examples/JsonHttpClient/JsonHttpClient.ino
index 8ce57a7f..aeae598a 100644
--- a/examples/JsonHttpClient/JsonHttpClient.ino
+++ b/examples/JsonHttpClient/JsonHttpClient.ino
@@ -76,8 +76,8 @@ void setup() {
   DynamicJsonObject root(capacity);
 
   // Parse JSON object
-  bool success = deserializeJson(root, client);
-  if (!root.success()) {
+  JsonError error = deserializeJson(root, client);
+  if (error) {
     Serial.println(F("Parsing failed!"));
     return;
   }
diff --git a/examples/JsonParserExample/JsonParserExample.ino b/examples/JsonParserExample/JsonParserExample.ino
index 6c8063a5..1f9cb306 100644
--- a/examples/JsonParserExample/JsonParserExample.ino
+++ b/examples/JsonParserExample/JsonParserExample.ino
@@ -36,10 +36,10 @@ void setup() {
   // It's a reference to the JsonObject, the actual bytes are inside the
   // JsonBuffer with all the other nodes of the object tree.
   // Memory is freed when jsonBuffer goes out of scope.
-  bool success = deserializeJson(root, json);
+  JsonError error = deserializeJson(root, json);
 
   // Test if parsing succeeds.
-  if (!success) {
+  if (error) {
     Serial.println("parseObject() failed");
     return;
   }
diff --git a/fuzzing/fuzzer.cpp b/fuzzing/fuzzer.cpp
index 24b2f191..358273c3 100644
--- a/fuzzing/fuzzer.cpp
+++ b/fuzzing/fuzzer.cpp
@@ -16,10 +16,11 @@ class memstream : public std::istream {
 };
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
-  DynamicJsonBuffer jsonBuffer;
+  DynamicJsonVariant variant;
   memstream json(data, size);
+  JsonError error = deserializeJson(variant, json);
   JsonVariant variant = jsonBuffer.parse(json);
-  if (variant.success()) {
+  if (!error) {
     variant.as<std::string>();  // <- serialize to JSON
   }
   return 0;
diff --git a/src/ArduinoJson/Deserialization/JsonParser.hpp b/src/ArduinoJson/Deserialization/JsonParser.hpp
index b30abddc..3c132448 100644
--- a/src/ArduinoJson/Deserialization/JsonParser.hpp
+++ b/src/ArduinoJson/Deserialization/JsonParser.hpp
@@ -5,6 +5,7 @@
 #pragma once
 
 #include "../JsonBuffer.hpp"
+#include "../JsonError.hpp"
 #include "../JsonVariant.hpp"
 #include "../TypeTraits/IsConst.hpp"
 #include "StringWriter.hpp"
@@ -24,9 +25,9 @@ class JsonParser {
         _reader(reader),
         _writer(writer),
         _nestingLimit(nestingLimit) {}
-  bool parse(JsonArray &destination);
-  bool parse(JsonObject &destination);
-  bool parse(JsonVariant &destination);
+  JsonError parse(JsonArray &destination);
+  JsonError parse(JsonObject &destination);
+  JsonError parse(JsonVariant &destination);
 
  private:
   JsonParser &operator=(const JsonParser &);  // non-copiable
@@ -37,12 +38,12 @@ class JsonParser {
   }
 
   const char *parseString();
-  bool parseAnythingTo(JsonVariant *destination);
-  FORCE_INLINE bool parseAnythingToUnsafe(JsonVariant *destination);
+  JsonError parseAnythingTo(JsonVariant *destination);
+  FORCE_INLINE JsonError parseAnythingToUnsafe(JsonVariant *destination);
 
-  inline bool parseArrayTo(JsonVariant *destination);
-  inline bool parseObjectTo(JsonVariant *destination);
-  inline bool parseStringTo(JsonVariant *destination);
+  inline JsonError parseArrayTo(JsonVariant *destination);
+  inline JsonError parseObjectTo(JsonVariant *destination);
+  inline JsonError parseStringTo(JsonVariant *destination);
 
   static inline bool isBetween(char c, char min, char max) {
     return min <= c && c <= max;
diff --git a/src/ArduinoJson/Deserialization/JsonParserImpl.hpp b/src/ArduinoJson/Deserialization/JsonParserImpl.hpp
index 3543d870..3e767a2a 100644
--- a/src/ArduinoJson/Deserialization/JsonParserImpl.hpp
+++ b/src/ArduinoJson/Deserialization/JsonParserImpl.hpp
@@ -18,18 +18,18 @@ inline bool ArduinoJson::Internals::JsonParser<TReader, TWriter>::eat(
 }
 
 template <typename TReader, typename TWriter>
-inline bool
+inline ArduinoJson::JsonError
 ArduinoJson::Internals::JsonParser<TReader, TWriter>::parseAnythingTo(
     JsonVariant *destination) {
-  if (_nestingLimit == 0) return false;
+  if (_nestingLimit == 0) return JsonError::TooDeep;
   _nestingLimit--;
-  bool success = parseAnythingToUnsafe(destination);
+  JsonError error = parseAnythingToUnsafe(destination);
   _nestingLimit++;
-  return success;
+  return error;
 }
 
 template <typename TReader, typename TWriter>
-inline bool
+inline ArduinoJson::JsonError
 ArduinoJson::Internals::JsonParser<TReader, TWriter>::parseAnythingToUnsafe(
     JsonVariant *destination) {
   skipSpacesAndComments(_reader);
@@ -47,92 +47,76 @@ ArduinoJson::Internals::JsonParser<TReader, TWriter>::parseAnythingToUnsafe(
 }
 
 template <typename TReader, typename TWriter>
-inline bool ArduinoJson::Internals::JsonParser<TReader, TWriter>::parse(
-    JsonArray &array) {
+inline ArduinoJson::JsonError
+ArduinoJson::Internals::JsonParser<TReader, TWriter>::parse(JsonArray &array) {
   // Check opening braket
-  if (!eat('[')) goto ERROR_MISSING_BRACKET;
-  if (eat(']')) goto SUCCESS_EMPTY_ARRAY;
+  if (!eat('[')) return JsonError::OpeningBracketExpected;
+  if (eat(']')) return JsonError::Ok;
 
   // Read each value
   for (;;) {
     // 1 - Parse value
     JsonVariant value;
-    if (!parseAnythingTo(&value)) goto ERROR_INVALID_VALUE;
-    if (!array.add(value)) goto ERROR_NO_MEMORY;
+    JsonError error = parseAnythingTo(&value);
+    if (error != JsonError::Ok) return error;
+    if (!array.add(value)) return JsonError::NoMemory;
 
     // 2 - More values?
-    if (eat(']')) goto SUCCES_NON_EMPTY_ARRAY;
-    if (!eat(',')) goto ERROR_MISSING_COMMA;
+    if (eat(']')) return JsonError::Ok;
+    if (!eat(',')) return JsonError::ClosingBracketExpected;
   }
-
-SUCCESS_EMPTY_ARRAY:
-SUCCES_NON_EMPTY_ARRAY:
-  return true;
-
-ERROR_INVALID_VALUE:
-ERROR_MISSING_BRACKET:
-ERROR_MISSING_COMMA:
-ERROR_NO_MEMORY:
-  return false;
 }
 
 template <typename TReader, typename TWriter>
-inline bool ArduinoJson::Internals::JsonParser<TReader, TWriter>::parse(
+inline ArduinoJson::JsonError
+ArduinoJson::Internals::JsonParser<TReader, TWriter>::parse(
     JsonObject &object) {
   // Check opening brace
-  if (!eat('{')) goto ERROR_MISSING_BRACE;
-  if (eat('}')) goto SUCCESS_EMPTY_OBJECT;
+  if (!eat('{')) return JsonError::OpeningBraceExpected;
+  if (eat('}')) return JsonError::Ok;
 
   // Read each key value pair
   for (;;) {
     // 1 - Parse key
     const char *key = parseString();
-    if (!key) goto ERROR_INVALID_KEY;
-    if (!eat(':')) goto ERROR_MISSING_COLON;
+    if (!key) return JsonError::NoMemory;
+    if (!eat(':')) return JsonError::ColonExpected;
 
     // 2 - Parse value
     JsonVariant value;
-    if (!parseAnythingTo(&value)) goto ERROR_INVALID_VALUE;
-    if (!object.set(key, value)) goto ERROR_NO_MEMORY;
+    JsonError error = parseAnythingTo(&value);
+    if (error != JsonError::Ok) return error;
+    if (!object.set(key, value)) return JsonError::NoMemory;
 
     // 3 - More keys/values?
-    if (eat('}')) goto SUCCESS_NON_EMPTY_OBJECT;
-    if (!eat(',')) goto ERROR_MISSING_COMMA;
+    if (eat('}')) return JsonError::Ok;
+    if (!eat(',')) return JsonError::ClosingBraceExpected;
   }
-
-SUCCESS_EMPTY_OBJECT:
-SUCCESS_NON_EMPTY_OBJECT:
-  return true;
-
-ERROR_INVALID_KEY:
-ERROR_INVALID_VALUE:
-ERROR_MISSING_BRACE:
-ERROR_MISSING_COLON:
-ERROR_MISSING_COMMA:
-ERROR_NO_MEMORY:
-  return false;
 }
 
 template <typename TReader, typename TWriter>
-inline bool ArduinoJson::Internals::JsonParser<TReader, TWriter>::parse(
+inline ArduinoJson::JsonError
+ArduinoJson::Internals::JsonParser<TReader, TWriter>::parse(
     JsonVariant &variant) {
   return parseAnythingTo(&variant);
 }
 
 template <typename TReader, typename TWriter>
-inline bool ArduinoJson::Internals::JsonParser<TReader, TWriter>::parseArrayTo(
+inline ArduinoJson::JsonError
+ArduinoJson::Internals::JsonParser<TReader, TWriter>::parseArrayTo(
     JsonVariant *destination) {
   JsonArray *array = new (_buffer) JsonArray(_buffer);
-  if (!array) return false;
+  if (!array) return JsonError::NoMemory;
   *destination = array;
   return parse(*array);
 }
 
 template <typename TReader, typename TWriter>
-inline bool ArduinoJson::Internals::JsonParser<TReader, TWriter>::parseObjectTo(
+inline ArduinoJson::JsonError
+ArduinoJson::Internals::JsonParser<TReader, TWriter>::parseObjectTo(
     JsonVariant *destination) {
   JsonObject *object = new (_buffer) JsonObject(_buffer);
-  if (!object) return false;
+  if (!object) return JsonError::NoMemory;
   *destination = object;
   return parse(*object);
 }
@@ -177,15 +161,16 @@ ArduinoJson::Internals::JsonParser<TReader, TWriter>::parseString() {
 }
 
 template <typename TReader, typename TWriter>
-inline bool ArduinoJson::Internals::JsonParser<TReader, TWriter>::parseStringTo(
+inline ArduinoJson::JsonError
+ArduinoJson::Internals::JsonParser<TReader, TWriter>::parseStringTo(
     JsonVariant *destination) {
   bool hasQuotes = isQuote(_reader.current());
   const char *value = parseString();
-  if (value == NULL) return false;
+  if (value == NULL) return JsonError::NoMemory;
   if (hasQuotes) {
     *destination = value;
   } else {
     *destination = RawJson(value);
   }
-  return true;
+  return JsonError::Ok;
 }
diff --git a/src/ArduinoJson/JsonError.hpp b/src/ArduinoJson/JsonError.hpp
new file mode 100644
index 00000000..e62dae6f
--- /dev/null
+++ b/src/ArduinoJson/JsonError.hpp
@@ -0,0 +1,83 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#pragma once
+
+namespace ArduinoJson {
+
+class JsonError {
+ public:
+  enum Code {
+    Ok,
+    OpeningBraceExpected,
+    ClosingBraceExpected,
+    OpeningBracketExpected,
+    ClosingBracketExpected,
+    ColonExpected,
+    TooDeep,
+    NoMemory
+  };
+
+  JsonError(Code code) : _code(code) {}
+
+  bool operator==(Code code) const {
+    return _code == code;
+  }
+
+  bool operator!=(Code code) const {
+    return _code != code;
+  }
+
+  operator bool() const {
+    return _code != Ok;
+  }
+
+  const char* c_str() const {
+    return to_string(_code);
+  }
+
+  friend const char* to_string(const JsonError err) {
+    return to_string(err._code);
+  }
+
+  friend const char* to_string(JsonError::Code code) {
+    switch (code) {
+      case Ok:
+        return "Ok";
+      case OpeningBraceExpected:
+        return "OpeningBraceExpected";
+      case ClosingBraceExpected:
+        return "ClosingBraceExpected";
+      case OpeningBracketExpected:
+        return "OpeningBracketExpected";
+      case ClosingBracketExpected:
+        return "ClosingBracketExpected";
+      case ColonExpected:
+        return "ColonExpected";
+      case TooDeep:
+        return "TooDeep";
+      case NoMemory:
+        return "NoMemory";
+      default:
+        return "???";
+    }
+  }
+
+ private:
+  Code _code;
+};
+
+#if ARDUINOJSON_ENABLE_STD_STREAM
+inline std::ostream& operator<<(std::ostream& s, const JsonError& e) {
+  s << to_string(e);
+  return s;
+}
+
+inline std::ostream& operator<<(std::ostream& s, JsonError::Code e) {
+  s << to_string(e);
+  return s;
+}
+#endif
+
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/deserializeJson.hpp b/src/ArduinoJson/deserializeJson.hpp
index c192c32b..4593529f 100644
--- a/src/ArduinoJson/deserializeJson.hpp
+++ b/src/ArduinoJson/deserializeJson.hpp
@@ -7,33 +7,36 @@
 #include "Deserialization/JsonParser.hpp"
 
 namespace ArduinoJson {
-// bool deserializeJson(TDestination& destination, TString json);
+// JsonError deserializeJson(TDestination& destination, TString json);
 // TDestination = JsonArray, JsonObject, JsonVariant
 // TString = const std::string&, const String&
 template <typename TDestination, typename TString>
-typename Internals::EnableIf<!Internals::IsArray<TString>::value, bool>::type
+typename Internals::EnableIf<!Internals::IsArray<TString>::value,
+                             JsonError>::type
 deserializeJson(TDestination &destination, const TString &json,
                 uint8_t nestingLimit = ARDUINOJSON_DEFAULT_NESTING_LIMIT) {
   return Internals::makeParser(&destination.buffer(), json, nestingLimit)
       .parse(destination);
 }
 //
-// bool deserializeJson(TDestination& destination, TString json);
+// JsonError deserializeJson(TDestination& destination, TString json);
 // TDestination = JsonArray, JsonObject, JsonVariant
 // TString = const char*, const char[N], const FlashStringHelper*
 template <typename TDestination, typename TString>
-bool deserializeJson(TDestination &destination, TString *json,
-                     uint8_t nestingLimit = ARDUINOJSON_DEFAULT_NESTING_LIMIT) {
+JsonError deserializeJson(
+    TDestination &destination, TString *json,
+    uint8_t nestingLimit = ARDUINOJSON_DEFAULT_NESTING_LIMIT) {
   return Internals::makeParser(&destination.buffer(), json, nestingLimit)
       .parse(destination);
 }
 //
-// bool deserializeJson(TDestination& destination, TString json);
+// JsonError deserializeJson(TDestination& destination, TString json);
 // TDestination = JsonArray, JsonObject, JsonVariant
 // TString = std::istream&, Stream&
 template <typename TDestination, typename TString>
-bool deserializeJson(TDestination &destination, TString &json,
-                     uint8_t nestingLimit = ARDUINOJSON_DEFAULT_NESTING_LIMIT) {
+JsonError deserializeJson(
+    TDestination &destination, TString &json,
+    uint8_t nestingLimit = ARDUINOJSON_DEFAULT_NESTING_LIMIT) {
   return Internals::makeParser(&destination.buffer(), json, nestingLimit)
       .parse(destination);
 }
diff --git a/test/DynamicJsonBuffer/no_memory.cpp b/test/DynamicJsonBuffer/no_memory.cpp
index be39c04d..5587a1ce 100644
--- a/test/DynamicJsonBuffer/no_memory.cpp
+++ b/test/DynamicJsonBuffer/no_memory.cpp
@@ -27,9 +27,9 @@ TEST_CASE("DynamicJsonBuffer no memory") {
   //   char json[] = "[{}]";
   //   DynamicJsonArray arr;
 
-  //   bool success = deserializeJson(arr, json);
+  //   JsonError err = deserializeJson(arr, json);
 
-  //   REQUIRE(success == false);
+  //   REQUIRE(err != JsonError::Ok);
   // }
 
   // TODO: uncomment
@@ -37,9 +37,9 @@ TEST_CASE("DynamicJsonBuffer no memory") {
   //   char json[] = "{[]}";
   //   DynamicJsonObject obj;
 
-  //   bool success = deserializeJson(obj, json);
+  //   JsonError err = deserializeJson(obj, json);
 
-  //   REQUIRE(success == false);
+  //   REQUIRE(err != JsonError::Ok);
   // }
 
   SECTION("startString()") {
diff --git a/test/IntegrationTests/gbathree.cpp b/test/IntegrationTests/gbathree.cpp
index 0f12dbf2..dd6b293f 100644
--- a/test/IntegrationTests/gbathree.cpp
+++ b/test/IntegrationTests/gbathree.cpp
@@ -8,7 +8,7 @@
 TEST_CASE("Gbathree") {
   DynamicJsonObject _object;
 
-  bool success = deserializeJson(
+  JsonError error = deserializeJson(
       _object,
       "{\"protocol_name\":\"fluorescence\",\"repeats\":1,\"wait\":0,"
       "\"averages\":1,\"measurements\":3,\"meas2_light\":15,\"meas1_"
@@ -22,7 +22,7 @@ TEST_CASE("Gbathree") {
       "[15,15,15,15]],\"altc\":[2,2,2,2],\"altd\":[2,2,2,2]}");
 
   SECTION("Success") {
-    REQUIRE(success == true);
+    REQUIRE(error == JsonError::Ok);
   }
 
   SECTION("ProtocolName") {
diff --git a/test/JsonArray/copyTo.cpp b/test/JsonArray/copyTo.cpp
index 3a83a461..9c31e880 100644
--- a/test/JsonArray/copyTo.cpp
+++ b/test/JsonArray/copyTo.cpp
@@ -10,8 +10,8 @@ TEST_CASE("JsonArray::copyTo()") {
 
   SECTION("BiggerOneDimensionIntegerArray") {
     char json[] = "[1,2,3]";
-    bool success = deserializeJson(array, json);
-    REQUIRE(success == true);
+    JsonError err = deserializeJson(array, json);
+    REQUIRE(err == JsonError::Ok);
 
     int destination[4] = {0};
     size_t result = array.copyTo(destination);
@@ -25,8 +25,8 @@ TEST_CASE("JsonArray::copyTo()") {
 
   SECTION("SmallerOneDimensionIntegerArray") {
     char json[] = "[1,2,3]";
-    bool success = deserializeJson(array, json);
-    REQUIRE(success == true);
+    JsonError err = deserializeJson(array, json);
+    REQUIRE(err == JsonError::Ok);
 
     int destination[2] = {0};
     size_t result = array.copyTo(destination);
@@ -39,8 +39,8 @@ TEST_CASE("JsonArray::copyTo()") {
   SECTION("TwoOneDimensionIntegerArray") {
     char json[] = "[[1,2],[3],[4]]";
 
-    bool success = deserializeJson(array, json);
-    REQUIRE(success == true);
+    JsonError err = deserializeJson(array, json);
+    REQUIRE(err == JsonError::Ok);
 
     int destination[3][2] = {{0}};
     array.copyTo(destination);
diff --git a/test/JsonParser/CMakeLists.txt b/test/JsonParser/CMakeLists.txt
index fa5ec203..19381c40 100644
--- a/test/JsonParser/CMakeLists.txt
+++ b/test/JsonParser/CMakeLists.txt
@@ -4,6 +4,7 @@
 
 add_executable(JsonParserTests
 	JsonArray.cpp
+	JsonError.cpp
 	JsonObject.cpp
 	JsonVariant.cpp
 	nestingLimit.cpp
diff --git a/test/JsonParser/JsonArray.cpp b/test/JsonParser/JsonArray.cpp
index af12c548..5a9a6b14 100644
--- a/test/JsonParser/JsonArray.cpp
+++ b/test/JsonParser/JsonArray.cpp
@@ -8,339 +8,346 @@
 TEST_CASE("deserializeJson(JsonArray&)") {
   DynamicJsonArray arr;
 
-  SECTION("EmptyArray") {
-    bool success = deserializeJson(arr, "[]");
+  SECTION("An empty array") {
+    JsonError err = deserializeJson(arr, "[]");
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
     REQUIRE(0 == arr.size());
   }
 
-  SECTION("MissingOpeningBracket") {
-    bool success = deserializeJson(arr, "]");
-    REQUIRE_FALSE(success == true);
+  SECTION("Spaces") {
+    SECTION("Before the opening bracket") {
+      JsonError err = deserializeJson(arr, "  []");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(0 == arr.size());
+    }
+
+    SECTION("Before first value") {
+      JsonError err = deserializeJson(arr, "[ \t\r\n42]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(1 == arr.size());
+      REQUIRE(arr[0] == 42);
+    }
+
+    SECTION("After first value") {
+      JsonError err = deserializeJson(arr, "[42 \t\r\n]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(1 == arr.size());
+      REQUIRE(arr[0] == 42);
+    }
   }
 
-  SECTION("ArrayWithNoEnd") {
-    bool success = deserializeJson(arr, "[");
-    REQUIRE_FALSE(success == true);
+  SECTION("Values types") {
+    SECTION("On integer") {
+      JsonError err = deserializeJson(arr, "[42]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(1 == arr.size());
+      REQUIRE(arr[0] == 42);
+    }
+
+    SECTION("Two integers") {
+      JsonError err = deserializeJson(arr, "[42,84]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(2 == arr.size());
+      REQUIRE(arr[0] == 42);
+      REQUIRE(arr[1] == 84);
+    }
+
+    SECTION("Double") {
+      JsonError err = deserializeJson(arr, "[4.2,1e2]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(2 == arr.size());
+      REQUIRE(arr[0] == 4.2);
+      REQUIRE(arr[1] == 1e2);
+    }
+
+    SECTION("Unsigned long") {
+      JsonError err = deserializeJson(arr, "[4294967295]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(1 == arr.size());
+      REQUIRE(arr[0] == 4294967295UL);
+    }
+
+    SECTION("Boolean") {
+      JsonError err = deserializeJson(arr, "[true,false]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(2 == arr.size());
+      REQUIRE(arr[0] == true);
+      REQUIRE(arr[1] == false);
+    }
+
+    SECTION("Null") {
+      JsonError err = deserializeJson(arr, "[null,null]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(2 == arr.size());
+      REQUIRE(arr[0].as<char *>() == 0);
+      REQUIRE(arr[1].as<char *>() == 0);
+    }
   }
 
-  SECTION("EmptyArrayWithLeadingSpaces") {
-    bool success = deserializeJson(arr, "  []");
+  SECTION("Quotes") {
+    SECTION("Double quotes") {
+      JsonError err = deserializeJson(arr, "[ \"hello\" , \"world\" ]");
 
-    REQUIRE(success == true);
-    REQUIRE(0 == arr.size());
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(2 == arr.size());
+      REQUIRE(arr[0] == "hello");
+      REQUIRE(arr[1] == "world");
+    }
+
+    SECTION("Single quotes") {
+      JsonError err = deserializeJson(arr, "[ 'hello' , 'world' ]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(2 == arr.size());
+      REQUIRE(arr[0] == "hello");
+      REQUIRE(arr[1] == "world");
+    }
+
+    SECTION("No quotes") {
+      JsonError err = deserializeJson(arr, "[ hello , world ]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(2 == arr.size());
+      REQUIRE(arr[0] == "hello");
+      REQUIRE(arr[1] == "world");
+    }
+
+    SECTION("Double quotes (empty strings)") {
+      JsonError err = deserializeJson(arr, "[\"\",\"\"]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(2 == arr.size());
+      REQUIRE(arr[0] == "");
+      REQUIRE(arr[1] == "");
+    }
+
+    SECTION("Single quotes (empty strings)") {
+      JsonError err = deserializeJson(arr, "[\'\',\'\']");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(2 == arr.size());
+      REQUIRE(arr[0] == "");
+      REQUIRE(arr[1] == "");
+    }
+
+    SECTION("No quotes (empty strings)") {
+      JsonError err = deserializeJson(arr, "[,]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(2 == arr.size());
+      REQUIRE(arr[0] == "");
+      REQUIRE(arr[1] == "");
+    }
+
+    SECTION("Closing single quotes missing") {
+      JsonError err = deserializeJson(arr, "[\"]");
+
+      REQUIRE(err != JsonError::Ok);
+    }
+
+    SECTION("Closing double quotes missing") {
+      JsonError err = deserializeJson(arr, "[\']");
+
+      REQUIRE(err != JsonError::Ok);
+    }
   }
 
-  SECTION("Garbage") {
-    bool success = deserializeJson(arr, "%*$£¤");
+  SECTION("Block comments") {
+    SECTION("Before opening bracket") {
+      JsonError err = deserializeJson(arr, "/*COMMENT*/  [\"hello\"]");
 
-    REQUIRE_FALSE(success == true);
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(1 == arr.size());
+      REQUIRE(arr[0] == "hello");
+    }
+
+    SECTION("After opening bracket") {
+      JsonError err = deserializeJson(arr, "[/*COMMENT*/ \"hello\"]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(1 == arr.size());
+      REQUIRE(arr[0] == "hello");
+    }
+
+    SECTION("Before closing bracket") {
+      JsonError err = deserializeJson(arr, "[\"hello\"/*COMMENT*/]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(1 == arr.size());
+      REQUIRE(arr[0] == "hello");
+    }
+
+    SECTION("After closing bracket") {
+      JsonError err = deserializeJson(arr, "[\"hello\"]/*COMMENT*/");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(1 == arr.size());
+      REQUIRE(arr[0] == "hello");
+    }
+
+    SECTION("Before comma") {
+      JsonError err = deserializeJson(arr, "[\"hello\"/*COMMENT*/,\"world\"]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(2 == arr.size());
+      REQUIRE(arr[0] == "hello");
+      REQUIRE(arr[1] == "world");
+    }
+
+    SECTION("After comma") {
+      JsonError err = deserializeJson(arr, "[\"hello\",/*COMMENT*/ \"world\"]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(2 == arr.size());
+      REQUIRE(arr[0] == "hello");
+      REQUIRE(arr[1] == "world");
+    }
+
+    SECTION("/*/") {
+      JsonError err = deserializeJson(arr, "[/*/\n]");
+      REQUIRE(err != JsonError::Ok);
+    }
+
+    SECTION("Unfinished comment") {
+      JsonError err = deserializeJson(arr, "[/*COMMENT]");
+      REQUIRE(err != JsonError::Ok);
+    }
+
+    SECTION("Final slash missing") {
+      JsonError err = deserializeJson(arr, "[/*COMMENT*]");
+      REQUIRE(err != JsonError::Ok);
+    }
   }
 
-  SECTION("OneInteger") {
-    bool success = deserializeJson(arr, "[42]");
+  SECTION("Line comments") {
+    SECTION("Before opening bracket") {
+      JsonError err = deserializeJson(arr, "//COMMENT\n\t[\"hello\"]");
 
-    REQUIRE(success == true);
-    REQUIRE(1 == arr.size());
-    REQUIRE(arr[0] == 42);
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(1 == arr.size());
+      REQUIRE(arr[0] == "hello");
+    }
+
+    SECTION("After opening bracket") {
+      JsonError err = deserializeJson(arr, "[//COMMENT\n\"hello\"]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(1 == arr.size());
+      REQUIRE(arr[0] == "hello");
+    }
+
+    SECTION("Before closing bracket") {
+      JsonError err = deserializeJson(arr, "[\"hello\"//COMMENT\r\n]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(1 == arr.size());
+      REQUIRE(arr[0] == "hello");
+    }
+
+    SECTION("After closing bracket") {
+      JsonError err = deserializeJson(arr, "[\"hello\"]//COMMENT\n");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(1 == arr.size());
+      REQUIRE(arr[0] == "hello");
+    }
+
+    SECTION("Before comma") {
+      JsonError err = deserializeJson(arr, "[\"hello\"//COMMENT\n,\"world\"]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(2 == arr.size());
+      REQUIRE(arr[0] == "hello");
+      REQUIRE(arr[1] == "world");
+    }
+
+    SECTION("After comma") {
+      JsonError err = deserializeJson(arr, "[\"hello\",//COMMENT\n\"world\"]");
+
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(2 == arr.size());
+      REQUIRE(arr[0] == "hello");
+      REQUIRE(arr[1] == "world");
+    }
+
+    SECTION("Invalid comment") {
+      JsonError err = deserializeJson(arr, "[/COMMENT\n]");
+      REQUIRE(err != JsonError::Ok);
+    }
+
+    SECTION("End document with comment") {
+      JsonError err = deserializeJson(arr, "[//COMMENT");
+      REQUIRE(err != JsonError::Ok);
+    }
   }
 
-  SECTION("OneIntegerWithSpacesBefore") {
-    bool success = deserializeJson(arr, "[ \t\r\n42]");
+  SECTION("Misc") {
+    SECTION("Garbage") {
+      JsonError err = deserializeJson(arr, "%*$£¤");
 
-    REQUIRE(success == true);
-    REQUIRE(1 == arr.size());
-    REQUIRE(arr[0] == 42);
-  }
+      REQUIRE(err != JsonError::Ok);
+    }
 
-  SECTION("OneIntegerWithSpaceAfter") {
-    bool success = deserializeJson(arr, "[42 \t\r\n]");
+    SECTION("The opening bracket is missing") {
+      JsonError err = deserializeJson(arr, "]");
 
-    REQUIRE(success == true);
-    REQUIRE(1 == arr.size());
-    REQUIRE(arr[0] == 42);
-  }
+      REQUIRE(err != JsonError::Ok);  // TODO
+    }
 
-  SECTION("TwoIntegers") {
-    bool success = deserializeJson(arr, "[42,84]");
+    SECTION("The closing bracket is missing") {
+      JsonError err = deserializeJson(arr, "[");
+      REQUIRE(err != JsonError::Ok);  // TODO
+    }
 
-    REQUIRE(success == true);
-    REQUIRE(2 == arr.size());
-    REQUIRE(arr[0] == 42);
-    REQUIRE(arr[1] == 84);
-  }
+    SECTION("Escape sequences") {
+      JsonError err =
+          deserializeJson(arr, "[\"1\\\"2\\\\3\\/4\\b5\\f6\\n7\\r8\\t9\"]");
 
-  SECTION("TwoDoubles") {
-    bool success = deserializeJson(arr, "[4.2,1e2]");
+      REQUIRE(err == JsonError::Ok);
+      REQUIRE(1 == arr.size());
+      REQUIRE(arr[0] == "1\"2\\3/4\b5\f6\n7\r8\t9");
+    }
 
-    REQUIRE(success == true);
-    REQUIRE(2 == arr.size());
-    REQUIRE(arr[0] == 4.2);
-    REQUIRE(arr[1] == 1e2);
-  }
+    SECTION("Unterminated escape sequence") {
+      JsonError err = deserializeJson(arr, "\"\\\0\"", 4);
+      REQUIRE(err != JsonError::Ok);
+    }
 
-  SECTION("UnsignedLong") {
-    bool success = deserializeJson(arr, "[4294967295]");
+    SECTION("Nested objects") {
+      char jsonString[] =
+          " [ { \"a\" : 1 , \"b\" : 2 } , { \"c\" : 3 , \"d\" : 4 } ] ";
 
-    REQUIRE(success == true);
-    REQUIRE(1 == arr.size());
-    REQUIRE(arr[0] == 4294967295UL);
-  }
+      JsonError err = deserializeJson(arr, jsonString);
 
-  SECTION("TwoBooleans") {
-    bool success = deserializeJson(arr, "[true,false]");
+      JsonObject &object1 = arr[0];
+      const JsonObject &object2 = arr[1];
+      JsonObject &object3 = arr[2];
 
-    REQUIRE(success == true);
-    REQUIRE(2 == arr.size());
-    REQUIRE(arr[0] == true);
-    REQUIRE(arr[1] == false);
-  }
+      REQUIRE(err == JsonError::Ok);
 
-  SECTION("TwoNulls") {
-    bool success = deserializeJson(arr, "[null,null]");
+      REQUIRE(true == object1.success());
+      REQUIRE(true == object2.success());
+      REQUIRE(false == object3.success());
 
-    REQUIRE(success == true);
-    REQUIRE(2 == arr.size());
-    REQUIRE(arr[0].as<char *>() == 0);
-    REQUIRE(arr[1].as<char *>() == 0);
-  }
+      REQUIRE(2 == object1.size());
+      REQUIRE(2 == object2.size());
+      REQUIRE(0 == object3.size());
 
-  SECTION("TwoStringsDoubleQuotes") {
-    bool success = deserializeJson(arr, "[ \"hello\" , \"world\" ]");
-
-    REQUIRE(success == true);
-    REQUIRE(2 == arr.size());
-    REQUIRE(arr[0] == "hello");
-    REQUIRE(arr[1] == "world");
-  }
-
-  SECTION("TwoStringsSingleQuotes") {
-    bool success = deserializeJson(arr, "[ 'hello' , 'world' ]");
-
-    REQUIRE(success == true);
-    REQUIRE(2 == arr.size());
-    REQUIRE(arr[0] == "hello");
-    REQUIRE(arr[1] == "world");
-  }
-
-  SECTION("TwoStringsNoQuotes") {
-    bool success = deserializeJson(arr, "[ hello , world ]");
-
-    REQUIRE(success == true);
-    REQUIRE(2 == arr.size());
-    REQUIRE(arr[0] == "hello");
-    REQUIRE(arr[1] == "world");
-  }
-
-  SECTION("EmptyStringsDoubleQuotes") {
-    bool success = deserializeJson(arr, "[\"\",\"\"]");
-
-    REQUIRE(success == true);
-    REQUIRE(2 == arr.size());
-    REQUIRE(arr[0] == "");
-    REQUIRE(arr[1] == "");
-  }
-
-  SECTION("EmptyStringSingleQuotes") {
-    bool success = deserializeJson(arr, "[\'\',\'\']");
-
-    REQUIRE(success == true);
-    REQUIRE(2 == arr.size());
-    REQUIRE(arr[0] == "");
-    REQUIRE(arr[1] == "");
-  }
-
-  SECTION("EmptyStringNoQuotes") {
-    bool success = deserializeJson(arr, "[,]");
-
-    REQUIRE(success == true);
-    REQUIRE(2 == arr.size());
-    REQUIRE(arr[0] == "");
-    REQUIRE(arr[1] == "");
-  }
-
-  SECTION("ClosingDoubleQuoteMissing") {
-    bool success = deserializeJson(arr, "[\"]");
-
-    REQUIRE_FALSE(success == true);
-  }
-
-  SECTION("ClosingSignleQuoteMissing") {
-    bool success = deserializeJson(arr, "[\']");
-
-    REQUIRE_FALSE(success == true);
-  }
-
-  SECTION("StringWithEscapedChars") {
-    bool success =
-        deserializeJson(arr, "[\"1\\\"2\\\\3\\/4\\b5\\f6\\n7\\r8\\t9\"]");
-
-    REQUIRE(success == true);
-    REQUIRE(1 == arr.size());
-    REQUIRE(arr[0] == "1\"2\\3/4\b5\f6\n7\r8\t9");
-  }
-
-  SECTION("StringWithUnterminatedEscapeSequence") {
-    bool success = deserializeJson(arr, "\"\\\0\"", 4);
-    REQUIRE_FALSE(success == true);
-  }
-
-  SECTION("CCommentBeforeOpeningBracket") {
-    bool success = deserializeJson(arr, "/*COMMENT*/  [\"hello\"]");
-
-    REQUIRE(success == true);
-    REQUIRE(1 == arr.size());
-    REQUIRE(arr[0] == "hello");
-  }
-
-  SECTION("CCommentAfterOpeningBracket") {
-    bool success = deserializeJson(arr, "[/*COMMENT*/ \"hello\"]");
-
-    REQUIRE(success == true);
-    REQUIRE(1 == arr.size());
-    REQUIRE(arr[0] == "hello");
-  }
-
-  SECTION("CCommentBeforeClosingBracket") {
-    bool success = deserializeJson(arr, "[\"hello\"/*COMMENT*/]");
-
-    REQUIRE(success == true);
-    REQUIRE(1 == arr.size());
-    REQUIRE(arr[0] == "hello");
-  }
-
-  SECTION("CCommentAfterClosingBracket") {
-    bool success = deserializeJson(arr, "[\"hello\"]/*COMMENT*/");
-
-    REQUIRE(success == true);
-    REQUIRE(1 == arr.size());
-    REQUIRE(arr[0] == "hello");
-  }
-
-  SECTION("CCommentBeforeComma") {
-    bool success = deserializeJson(arr, "[\"hello\"/*COMMENT*/,\"world\"]");
-
-    REQUIRE(success == true);
-    REQUIRE(2 == arr.size());
-    REQUIRE(arr[0] == "hello");
-    REQUIRE(arr[1] == "world");
-  }
-
-  SECTION("CCommentAfterComma") {
-    bool success = deserializeJson(arr, "[\"hello\",/*COMMENT*/ \"world\"]");
-
-    REQUIRE(success == true);
-    REQUIRE(2 == arr.size());
-    REQUIRE(arr[0] == "hello");
-    REQUIRE(arr[1] == "world");
-  }
-
-  SECTION("CppCommentBeforeOpeningBracket") {
-    bool success = deserializeJson(arr, "//COMMENT\n\t[\"hello\"]");
-
-    REQUIRE(success == true);
-    REQUIRE(1 == arr.size());
-    REQUIRE(arr[0] == "hello");
-  }
-
-  SECTION("CppCommentAfterOpeningBracket") {
-    bool success = deserializeJson(arr, "[//COMMENT\n\"hello\"]");
-
-    REQUIRE(success == true);
-    REQUIRE(1 == arr.size());
-    REQUIRE(arr[0] == "hello");
-  }
-
-  SECTION("CppCommentBeforeClosingBracket") {
-    bool success = deserializeJson(arr, "[\"hello\"//COMMENT\r\n]");
-
-    REQUIRE(success == true);
-    REQUIRE(1 == arr.size());
-    REQUIRE(arr[0] == "hello");
-  }
-
-  SECTION("CppCommentAfterClosingBracket") {
-    bool success = deserializeJson(arr, "[\"hello\"]//COMMENT\n");
-
-    REQUIRE(success == true);
-    REQUIRE(1 == arr.size());
-    REQUIRE(arr[0] == "hello");
-  }
-
-  SECTION("CppCommentBeforeComma") {
-    bool success = deserializeJson(arr, "[\"hello\"//COMMENT\n,\"world\"]");
-
-    REQUIRE(success == true);
-    REQUIRE(2 == arr.size());
-    REQUIRE(arr[0] == "hello");
-    REQUIRE(arr[1] == "world");
-  }
-
-  SECTION("CppCommentAfterComma") {
-    bool success = deserializeJson(arr, "[\"hello\",//COMMENT\n\"world\"]");
-
-    REQUIRE(success == true);
-    REQUIRE(2 == arr.size());
-    REQUIRE(arr[0] == "hello");
-    REQUIRE(arr[1] == "world");
-  }
-
-  SECTION("InvalidCppComment") {
-    bool success = deserializeJson(arr, "[/COMMENT\n]");
-    REQUIRE_FALSE(success == true);
-  }
-
-  SECTION("InvalidComment") {
-    bool success = deserializeJson(arr, "[/*/\n]");
-    REQUIRE_FALSE(success == true);
-  }
-
-  SECTION("UnfinishedCComment") {
-    bool success = deserializeJson(arr, "[/*COMMENT]");
-    REQUIRE_FALSE(success == true);
-  }
-
-  SECTION("EndsInCppComment") {
-    bool success = deserializeJson(arr, "[//COMMENT");
-    REQUIRE_FALSE(success == true);
-  }
-
-  SECTION("AfterClosingStar") {
-    bool success = deserializeJson(arr, "[/*COMMENT*");
-    REQUIRE_FALSE(success == true);
-  }
-
-  SECTION("DeeplyNested") {
-    bool success = deserializeJson(
-        arr, "[[[[[[[[[[[[[[[[[[[\"Not too deep\"]]]]]]]]]]]]]]]]]]]");
-    REQUIRE(success == true);
-  }
-
-  SECTION("ObjectNestedInArray") {
-    char jsonString[] =
-        " [ { \"a\" : 1 , \"b\" : 2 } , { \"c\" : 3 , \"d\" : 4 } ] ";
-
-    bool success = deserializeJson(arr, jsonString);
-
-    JsonObject &object1 = arr[0];
-    const JsonObject &object2 = arr[1];
-    JsonObject &object3 = arr[2];
-
-    REQUIRE(true == success);
-
-    REQUIRE(true == object1.success());
-    REQUIRE(true == object2.success());
-    REQUIRE(false == object3.success());
-
-    REQUIRE(2 == object1.size());
-    REQUIRE(2 == object2.size());
-    REQUIRE(0 == object3.size());
-
-    REQUIRE(1 == object1["a"].as<int>());
-    REQUIRE(2 == object1["b"].as<int>());
-    REQUIRE(3 == object2["c"].as<int>());
-    REQUIRE(4 == object2["d"].as<int>());
-    REQUIRE(0 == object3["e"].as<int>());
+      REQUIRE(1 == object1["a"].as<int>());
+      REQUIRE(2 == object1["b"].as<int>());
+      REQUIRE(3 == object2["c"].as<int>());
+      REQUIRE(4 == object2["d"].as<int>());
+      REQUIRE(0 == object3["e"].as<int>());
+    }
   }
 }
diff --git a/test/JsonParser/JsonError.cpp b/test/JsonParser/JsonError.cpp
new file mode 100644
index 00000000..21714ba0
--- /dev/null
+++ b/test/JsonParser/JsonError.cpp
@@ -0,0 +1,44 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+void testStringification(JsonError error, std::string expected) {
+  REQUIRE(error.c_str() == expected);
+}
+
+void testBoolification(JsonError error, bool expected) {
+  CHECK(error == expected);
+}
+
+#define TEST_STRINGIFICATION(symbol) \
+  testStringification(JsonError::symbol, #symbol)
+
+#define TEST_BOOLIFICATION(symbol, expected) \
+  testBoolification(JsonError::symbol, expected)
+
+TEST_CASE("JsonError") {
+  SECTION("c_str()") {
+    TEST_STRINGIFICATION(Ok);
+    TEST_STRINGIFICATION(OpeningBraceExpected);
+    TEST_STRINGIFICATION(ClosingBraceExpected);
+    TEST_STRINGIFICATION(OpeningBracketExpected);
+    TEST_STRINGIFICATION(ClosingBracketExpected);
+    TEST_STRINGIFICATION(ColonExpected);
+    TEST_STRINGIFICATION(TooDeep);
+    TEST_STRINGIFICATION(NoMemory);
+  }
+
+  SECTION("as boolean") {
+    TEST_BOOLIFICATION(Ok, false);
+    TEST_BOOLIFICATION(OpeningBraceExpected, true);
+    TEST_BOOLIFICATION(ClosingBraceExpected, true);
+    TEST_BOOLIFICATION(OpeningBracketExpected, true);
+    TEST_BOOLIFICATION(ClosingBracketExpected, true);
+    TEST_BOOLIFICATION(ColonExpected, true);
+    TEST_BOOLIFICATION(TooDeep, true);
+    TEST_BOOLIFICATION(NoMemory, true);
+  }
+}
diff --git a/test/JsonParser/JsonObject.cpp b/test/JsonParser/JsonObject.cpp
index 41bc3e5f..87200bf7 100644
--- a/test/JsonParser/JsonObject.cpp
+++ b/test/JsonParser/JsonObject.cpp
@@ -9,36 +9,36 @@ TEST_CASE("deserializeJson(JsonObject&)") {
   DynamicJsonObject obj;
 
   SECTION("An empty object") {
-    bool success = deserializeJson(obj, "{}");
-    REQUIRE(success == true);
+    JsonError err = deserializeJson(obj, "{}");
+    REQUIRE(err == JsonError::Ok);
     REQUIRE(obj.size() == 0);
   }
 
   SECTION("Quotes") {
     SECTION("Double quotes") {
-      bool success = deserializeJson(obj, "{\"key\":\"value\"}");
-      REQUIRE(success == true);
+      JsonError err = deserializeJson(obj, "{\"key\":\"value\"}");
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 1);
       REQUIRE(obj["key"] == "value");
     }
 
     SECTION("Single quotes") {
-      bool success = deserializeJson(obj, "{'key':'value'}");
-      REQUIRE(success == true);
+      JsonError err = deserializeJson(obj, "{'key':'value'}");
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 1);
       REQUIRE(obj["key"] == "value");
     }
 
     SECTION("No quotes") {
-      bool success = deserializeJson(obj, "{key:value}");
-      REQUIRE(success == true);
+      JsonError err = deserializeJson(obj, "{key:value}");
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 1);
       REQUIRE(obj["key"] == "value");
     }
 
     SECTION("No quotes, allow underscore in key") {
-      bool success = deserializeJson(obj, "{_k_e_y_:42}");
-      REQUIRE(success == true);
+      JsonError err = deserializeJson(obj, "{_k_e_y_:42}");
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 1);
       REQUIRE(obj["_k_e_y_"] == 42);
     }
@@ -46,46 +46,46 @@ TEST_CASE("deserializeJson(JsonObject&)") {
 
   SECTION("Spaces") {
     SECTION("Before the key") {
-      bool success = deserializeJson(obj, "{ \"key\":\"value\"}");
-      REQUIRE(success == true);
+      JsonError err = deserializeJson(obj, "{ \"key\":\"value\"}");
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 1);
       REQUIRE(obj["key"] == "value");
     }
 
     SECTION("After the key") {
-      bool success = deserializeJson(obj, "{\"key\" :\"value\"}");
-      REQUIRE(success == true);
+      JsonError err = deserializeJson(obj, "{\"key\" :\"value\"}");
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 1);
       REQUIRE(obj["key"] == "value");
     }
 
     SECTION("Before the value") {
-      bool success = deserializeJson(obj, "{\"key\": \"value\"}");
-      REQUIRE(success == true);
+      JsonError err = deserializeJson(obj, "{\"key\": \"value\"}");
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 1);
       REQUIRE(obj["key"] == "value");
     }
 
     SECTION("After the value") {
-      bool success = deserializeJson(obj, "{\"key\":\"value\" }");
-      REQUIRE(success == true);
+      JsonError err = deserializeJson(obj, "{\"key\":\"value\" }");
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 1);
       REQUIRE(obj["key"] == "value");
     }
 
     SECTION("Before the colon") {
-      bool success =
+      JsonError err =
           deserializeJson(obj, "{\"key1\":\"value1\" ,\"key2\":\"value2\"}");
-      REQUIRE(success == true);
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 2);
       REQUIRE(obj["key1"] == "value1");
       REQUIRE(obj["key2"] == "value2");
     }
 
     SECTION("After the colon") {
-      bool success =
+      JsonError err =
           deserializeJson(obj, "{\"key1\":\"value1\" ,\"key2\":\"value2\"}");
-      REQUIRE(success == true);
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 2);
       REQUIRE(obj["key1"] == "value1");
       REQUIRE(obj["key2"] == "value2");
@@ -94,41 +94,41 @@ TEST_CASE("deserializeJson(JsonObject&)") {
 
   SECTION("Values types") {
     SECTION("String") {
-      bool success =
+      JsonError err =
           deserializeJson(obj, "{\"key1\":\"value1\",\"key2\":\"value2\"}");
-      REQUIRE(success == true);
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 2);
       REQUIRE(obj["key1"] == "value1");
       REQUIRE(obj["key2"] == "value2");
     }
 
     SECTION("Integer") {
-      bool success = deserializeJson(obj, "{\"key1\":42,\"key2\":-42}");
-      REQUIRE(success == true);
+      JsonError err = deserializeJson(obj, "{\"key1\":42,\"key2\":-42}");
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 2);
       REQUIRE(obj["key1"] == 42);
       REQUIRE(obj["key2"] == -42);
     }
 
     SECTION("Double") {
-      bool success = deserializeJson(obj, "{\"key1\":12.345,\"key2\":-7E89}");
-      REQUIRE(success == true);
+      JsonError err = deserializeJson(obj, "{\"key1\":12.345,\"key2\":-7E89}");
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 2);
       REQUIRE(obj["key1"] == 12.345);
       REQUIRE(obj["key2"] == -7E89);
     }
 
     SECTION("Booleans") {
-      bool success = deserializeJson(obj, "{\"key1\":true,\"key2\":false}");
-      REQUIRE(success == true);
+      JsonError err = deserializeJson(obj, "{\"key1\":true,\"key2\":false}");
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 2);
       REQUIRE(obj["key1"] == true);
       REQUIRE(obj["key2"] == false);
     }
 
     SECTION("Null") {
-      bool success = deserializeJson(obj, "{\"key1\":null,\"key2\":null}");
-      REQUIRE(success == true);
+      JsonError err = deserializeJson(obj, "{\"key1\":null,\"key2\":null}");
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(obj.size() == 2);
       REQUIRE(obj["key1"].as<char *>() == 0);
       REQUIRE(obj["key2"].as<char *>() == 0);
@@ -137,13 +137,13 @@ TEST_CASE("deserializeJson(JsonObject&)") {
     SECTION("Array") {
       char jsonString[] = " { \"ab\" : [ 1 , 2 ] , \"cd\" : [ 3 , 4 ] } ";
 
-      bool success = deserializeJson(obj, jsonString);
+      JsonError err = deserializeJson(obj, jsonString);
 
       JsonArray &array1 = obj["ab"];
       const JsonArray &array2 = obj["cd"];
       JsonArray &array3 = obj["ef"];
 
-      REQUIRE(true == success);
+      REQUIRE(err == JsonError::Ok);
 
       REQUIRE(true == array1.success());
       REQUIRE(true == array2.success());
@@ -165,33 +165,33 @@ TEST_CASE("deserializeJson(JsonObject&)") {
 
   SECTION("Misc") {
     SECTION("The opening brace is missing") {
-      bool success = deserializeJson(obj, "}");
-      REQUIRE(success == false);
+      JsonError err = deserializeJson(obj, "}");
+      REQUIRE(err == JsonError::OpeningBraceExpected);
     }
 
     SECTION("The closing brace is missing") {
-      bool success = deserializeJson(obj, "{");
-      REQUIRE(success == false);
+      JsonError err = deserializeJson(obj, "{\"hello\":\"world\"");
+      REQUIRE(err == JsonError::ClosingBraceExpected);
     }
 
     SECTION("A quoted key without value") {
-      bool success = deserializeJson(obj, "{\"key\"}");
-      REQUIRE(success == false);
+      JsonError err = deserializeJson(obj, "{\"key\"}");
+      REQUIRE(err == JsonError::ColonExpected);
     }
 
     SECTION("A non-quoted key without value") {
-      bool success = deserializeJson(obj, "{key}");
-      REQUIRE(success == false);
+      JsonError err = deserializeJson(obj, "{key}");
+      REQUIRE(err == JsonError::ColonExpected);
     }
 
     SECTION("A dangling comma") {
-      bool success = deserializeJson(obj, "{\"key1\":\"value1\",}");
-      REQUIRE(success == false);
+      JsonError err = deserializeJson(obj, "{\"key1\":\"value1\",}");
+      REQUIRE(err == JsonError::ColonExpected);
     }
 
     SECTION("null as a key") {
-      bool success = deserializeJson(obj, "null:\"value\"}");
-      REQUIRE(success == false);
+      JsonError err = deserializeJson(obj, "{null:\"value\"}");
+      REQUIRE(err == JsonError::Ok);
     }
   }
 }
diff --git a/test/JsonParser/JsonVariant.cpp b/test/JsonParser/JsonVariant.cpp
index 9141c2d4..f1b5c38a 100644
--- a/test/JsonParser/JsonVariant.cpp
+++ b/test/JsonParser/JsonVariant.cpp
@@ -11,79 +11,79 @@ TEST_CASE("deserializeJson(JsonVariant&)") {
   DynamicJsonVariant variant;
 
   SECTION("EmptyObject") {
-    bool success = deserializeJson(variant, "{}");
+    JsonError err = deserializeJson(variant, "{}");
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
     REQUIRE(variant.is<JsonObject>());
   }
 
   SECTION("EmptyArray") {
-    bool success = deserializeJson(variant, "[]");
+    JsonError err = deserializeJson(variant, "[]");
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
     REQUIRE(variant.is<JsonArray>());
   }
 
   SECTION("Integer") {
-    bool success = deserializeJson(variant, "-42");
+    JsonError err = deserializeJson(variant, "-42");
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
     REQUIRE(variant.is<int>());
     REQUIRE_FALSE(variant.is<bool>());
     REQUIRE(variant == -42);
   }
 
   SECTION("Double") {
-    bool success = deserializeJson(variant, "-1.23e+4");
+    JsonError err = deserializeJson(variant, "-1.23e+4");
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
     REQUIRE_FALSE(variant.is<int>());
     REQUIRE(variant.is<double>());
     REQUIRE(variant.as<double>() == Approx(-1.23e+4));
   }
 
   SECTION("Double quoted string") {
-    bool success = deserializeJson(variant, "\"hello world\"");
+    JsonError err = deserializeJson(variant, "\"hello world\"");
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
     REQUIRE(variant.is<char*>());
     REQUIRE_THAT(variant.as<char*>(), Equals("hello world"));
   }
 
   SECTION("Single quoted string") {
-    bool success = deserializeJson(variant, "\'hello world\'");
+    JsonError err = deserializeJson(variant, "\'hello world\'");
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
     REQUIRE(variant.is<char*>());
     REQUIRE_THAT(variant.as<char*>(), Equals("hello world"));
   }
 
   SECTION("True") {
-    bool success = deserializeJson(variant, "true");
+    JsonError err = deserializeJson(variant, "true");
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
     REQUIRE(variant.is<bool>());
     REQUIRE(variant == true);
   }
 
   SECTION("False") {
-    bool success = deserializeJson(variant, "false");
+    JsonError err = deserializeJson(variant, "false");
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
     REQUIRE(variant.is<bool>());
     REQUIRE(variant == false);
   }
 
   SECTION("OpenBrace") {
-    bool success = deserializeJson(variant, "{");
+    JsonError err = deserializeJson(variant, "{");
 
-    REQUIRE(success == false);
+    REQUIRE(err != JsonError::Ok);
   }
 
   SECTION("Incomplete string") {
-    bool success = deserializeJson(variant, "\"hello");
+    JsonError err = deserializeJson(variant, "\"hello");
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
     REQUIRE(variant.is<char*>());
     REQUIRE_THAT(variant.as<char*>(), Equals("hello"));
   }
diff --git a/test/JsonParser/StaticJsonArray.cpp b/test/JsonParser/StaticJsonArray.cpp
index 0775fc02..6cc5208d 100644
--- a/test/JsonParser/StaticJsonArray.cpp
+++ b/test/JsonParser/StaticJsonArray.cpp
@@ -10,61 +10,61 @@ TEST_CASE("deserializeJson(StaticJsonArray&)") {
     StaticJsonArray<JSON_ARRAY_SIZE(0)> arr;
     char input[] = "[]";
 
-    bool success = deserializeJson(arr, input);
+    JsonError err = deserializeJson(arr, input);
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
   }
 
   SECTION("TooSmallBufferForArrayWithOneValue") {
     StaticJsonArray<JSON_ARRAY_SIZE(1) - 1> arr;
     char input[] = "[1]";
 
-    bool success = deserializeJson(arr, input);
+    JsonError err = deserializeJson(arr, input);
 
-    REQUIRE(success == false);
+    REQUIRE(err != JsonError::Ok);
   }
 
   SECTION("BufferOfTheRightSizeForArrayWithOneValue") {
     StaticJsonArray<JSON_ARRAY_SIZE(1)> arr;
     char input[] = "[1]";
 
-    bool success = deserializeJson(arr, input);
+    JsonError err = deserializeJson(arr, input);
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
   }
 
   SECTION("TooSmallBufferForArrayWithNestedObject") {
     StaticJsonArray<JSON_ARRAY_SIZE(1) + JSON_OBJECT_SIZE(0) - 1> arr;
     char input[] = "[{}]";
 
-    bool success = deserializeJson(arr, input);
+    JsonError err = deserializeJson(arr, input);
 
-    REQUIRE(success == false);
+    REQUIRE(err != JsonError::Ok);
   }
 
   SECTION("BufferOfTheRightSizeForArrayWithNestedObject") {
     StaticJsonArray<JSON_ARRAY_SIZE(1) + JSON_OBJECT_SIZE(0)> arr;
     char input[] = "[{}]";
 
-    bool success = deserializeJson(arr, input);
+    JsonError err = deserializeJson(arr, input);
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
   }
 
   SECTION("CharPtrNull") {
     StaticJsonArray<100> arr;
 
-    bool success = deserializeJson(arr, static_cast<char*>(0));
+    JsonError err = deserializeJson(arr, static_cast<char*>(0));
 
-    REQUIRE(success == false);
+    REQUIRE(err != JsonError::Ok);
   }
 
   SECTION("ConstCharPtrNull") {
     StaticJsonArray<100> arr;
 
-    bool success = deserializeJson(arr, static_cast<const char*>(0));
+    JsonError err = deserializeJson(arr, static_cast<const char*>(0));
 
-    REQUIRE(success == false);
+    REQUIRE(err != JsonError::Ok);
   }
 
   SECTION("CopyStringNotSpaces") {
diff --git a/test/JsonParser/StaticJsonObject.cpp b/test/JsonParser/StaticJsonObject.cpp
index a738e49e..ffed607f 100644
--- a/test/JsonParser/StaticJsonObject.cpp
+++ b/test/JsonParser/StaticJsonObject.cpp
@@ -10,60 +10,60 @@ TEST_CASE("deserializeJson(StaticJsonObject&)") {
     StaticJsonObject<JSON_OBJECT_SIZE(0)> obj;
     char input[] = "{}";
 
-    bool success = deserializeJson(obj, input);
+    JsonError err = deserializeJson(obj, input);
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
   }
 
   SECTION("TooSmallBufferForObjectWithOneValue") {
     StaticJsonObject<JSON_OBJECT_SIZE(1) - 1> obj;
     char input[] = "{\"a\":1}";
 
-    bool success = deserializeJson(obj, input);
+    JsonError err = deserializeJson(obj, input);
 
-    REQUIRE(success == false);
+    REQUIRE(err != JsonError::Ok);
   }
 
   SECTION("BufferOfTheRightSizeForObjectWithOneValue") {
     StaticJsonObject<JSON_OBJECT_SIZE(1)> obj;
     char input[] = "{\"a\":1}";
 
-    bool success = deserializeJson(obj, input);
+    JsonError err = deserializeJson(obj, input);
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
   }
 
   SECTION("TooSmallBufferForObjectWithNestedObject") {
     StaticJsonObject<JSON_OBJECT_SIZE(1) + JSON_ARRAY_SIZE(0) - 1> obj;
     char input[] = "{\"a\":[]}";
 
-    bool success = deserializeJson(obj, input);
+    JsonError err = deserializeJson(obj, input);
 
-    REQUIRE(success == false);
+    REQUIRE(err != JsonError::Ok);
   }
 
   SECTION("BufferOfTheRightSizeForObjectWithNestedObject") {
     StaticJsonObject<JSON_OBJECT_SIZE(1) + JSON_ARRAY_SIZE(0)> obj;
     char input[] = "{\"a\":[]}";
 
-    bool success = deserializeJson(obj, input);
+    JsonError err = deserializeJson(obj, input);
 
-    REQUIRE(success == true);
+    REQUIRE(err == JsonError::Ok);
   }
 
   SECTION("CharPtrNull") {
     StaticJsonObject<100> obj;
 
-    bool success = deserializeJson(obj, static_cast<char*>(0));
+    JsonError err = deserializeJson(obj, static_cast<char*>(0));
 
-    REQUIRE(success == false);
+    REQUIRE(err != JsonError::Ok);
   }
 
   SECTION("ConstCharPtrNull") {
     StaticJsonObject<100> obj;
 
-    bool success = deserializeJson(obj, static_cast<const char*>(0));
+    JsonError err = deserializeJson(obj, static_cast<const char*>(0));
 
-    REQUIRE(success == false);
+    REQUIRE(err != JsonError::Ok);
   }
 }
diff --git a/test/JsonParser/nestingLimit.cpp b/test/JsonParser/nestingLimit.cpp
index 290dae67..710a9fb5 100644
--- a/test/JsonParser/nestingLimit.cpp
+++ b/test/JsonParser/nestingLimit.cpp
@@ -5,44 +5,45 @@
 #include <ArduinoJson.h>
 #include <catch.hpp>
 
-bool tryParseArray(const char *json, uint8_t nestingLimit) {
+JsonError tryParseArray(const char *json, uint8_t nestingLimit) {
   DynamicJsonArray array;
   return deserializeJson(array, json, nestingLimit);
 }
 
-bool tryParseObject(const char *json, uint8_t nestingLimit) {
+JsonError tryParseObject(const char *json, uint8_t nestingLimit) {
   DynamicJsonObject obj;
   return deserializeJson(obj, json, nestingLimit);
 }
 
 TEST_CASE("JsonParser nestingLimit") {
   SECTION("ParseArrayWithNestingLimit0") {
-    REQUIRE(true == tryParseArray("[]", 0));
-    REQUIRE(false == tryParseArray("[[]]", 0));
+    REQUIRE(tryParseArray("[]", 0) == JsonError::Ok);
+    REQUIRE(tryParseArray("[[]]", 0) == JsonError::TooDeep);
   }
 
   SECTION("ParseArrayWithNestingLimit1") {
-    REQUIRE(true == tryParseArray("[[]]", 1));
-    REQUIRE(false == tryParseArray("[[[]]]", 1));
+    REQUIRE(tryParseArray("[[]]", 1) == JsonError::Ok);
+    REQUIRE(tryParseArray("[[[]]]", 1) == JsonError::TooDeep);
   }
 
   SECTION("ParseArrayWithNestingLimit2") {
-    REQUIRE(true == tryParseArray("[[[]]]", 2));
-    REQUIRE(false == tryParseArray("[[[[]]]]", 2));
+    REQUIRE(tryParseArray("[[[]]]", 2) == JsonError::Ok);
+    REQUIRE(tryParseArray("[[[[]]]]", 2) == JsonError::TooDeep);
   }
 
   SECTION("ParseObjectWithNestingLimit0") {
-    REQUIRE(true == tryParseObject("{}", 0));
-    REQUIRE(false == tryParseObject("{\"key\":{}}", 0));
+    REQUIRE(tryParseObject("{}", 0) == JsonError::Ok);
+    REQUIRE(tryParseObject("{\"key\":{}}", 0) == JsonError::TooDeep);
   }
 
   SECTION("ParseObjectWithNestingLimit1") {
-    REQUIRE(true == tryParseObject("{\"key\":{}}", 1));
-    REQUIRE(false == tryParseObject("{\"key\":{\"key\":{}}}", 1));
+    REQUIRE(tryParseObject("{\"key\":{}}", 1) == JsonError::Ok);
+    REQUIRE(tryParseObject("{\"key\":{\"key\":{}}}", 1) == JsonError::TooDeep);
   }
 
   SECTION("ParseObjectWithNestingLimit2") {
-    REQUIRE(true == tryParseObject("{\"key\":{\"key\":{}}}", 2));
-    REQUIRE(false == tryParseObject("{\"key\":{\"key\":{\"key\":{}}}}", 2));
+    REQUIRE(tryParseObject("{\"key\":{\"key\":{}}}", 2) == JsonError::Ok);
+    REQUIRE(tryParseObject("{\"key\":{\"key\":{\"key\":{}}}}", 2) ==
+            JsonError::TooDeep);
   }
 }
diff --git a/test/Misc/std_stream.cpp b/test/Misc/std_stream.cpp
index 9af55894..b2b171a3 100644
--- a/test/Misc/std_stream.cpp
+++ b/test/Misc/std_stream.cpp
@@ -56,9 +56,9 @@ TEST_CASE("std::stream") {
   SECTION("ParseArray") {
     std::istringstream json(" [ 42 /* comment */ ] ");
     DynamicJsonArray arr;
-    bool success = deserializeJson(arr, json);
+    JsonError err = deserializeJson(arr, json);
 
-    REQUIRE(true == success);
+    REQUIRE(err == JsonError::Ok);
     REQUIRE(1 == arr.size());
     REQUIRE(42 == arr[0]);
   }
@@ -66,9 +66,9 @@ TEST_CASE("std::stream") {
   SECTION("ParseObject") {
     std::istringstream json(" { hello : world // comment\n }");
     DynamicJsonObject obj;
-    bool success = deserializeJson(obj, json);
+    JsonError err = deserializeJson(obj, json);
 
-    REQUIRE(true == success);
+    REQUIRE(err == JsonError::Ok);
     REQUIRE(1 == obj.size());
     REQUIRE(std::string("world") == obj["hello"]);
   }
diff --git a/test/Misc/std_string.cpp b/test/Misc/std_string.cpp
index ea11cb35..9e58e0f1 100644
--- a/test/Misc/std_string.cpp
+++ b/test/Misc/std_string.cpp
@@ -19,10 +19,10 @@ TEST_CASE("std::string") {
     SECTION("deserializeJson") {
       std::string json("[\"hello\"]");
 
-      bool success = deserializeJson(array, json);
+      JsonError err = deserializeJson(array, json);
       eraseString(json);
 
-      REQUIRE(true == success);
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(std::string("hello") == array[0]);
     }
 
@@ -72,10 +72,10 @@ TEST_CASE("std::string") {
     SECTION("deserializeJson()") {
       std::string json("{\"hello\":\"world\"}");
 
-      bool success = deserializeJson(object, json);
+      JsonError err = deserializeJson(object, json);
       eraseString(json);
 
-      REQUIRE(true == success);
+      REQUIRE(err == JsonError::Ok);
       REQUIRE(std::string("world") == object["hello"]);
     }
 
diff --git a/test/Misc/unsigned_char.cpp b/test/Misc/unsigned_char.cpp
index 146a936c..23752b9e 100644
--- a/test/Misc/unsigned_char.cpp
+++ b/test/Misc/unsigned_char.cpp
@@ -14,18 +14,18 @@ TEST_CASE("unsigned char string") {
     unsigned char json[] = "[42]";
 
     StaticJsonArray<JSON_ARRAY_SIZE(1)> arr;
-    bool success = deserializeJson(arr, json);
+    JsonError err = deserializeJson(arr, json);
 
-    REQUIRE(true == success);
+    REQUIRE(err == JsonError::Ok);
   }
 
   SECTION("JsonBuffer::parseObject") {
     unsigned char json[] = "{\"a\":42}";
 
     StaticJsonObject<JSON_OBJECT_SIZE(1)> obj;
-    bool success = deserializeJson(obj, json);
+    JsonError err = deserializeJson(obj, json);
 
-    REQUIRE(true == success);
+    REQUIRE(err == JsonError::Ok);
   }
 
   SECTION("JsonVariant constructor") {
diff --git a/test/Misc/vla.cpp b/test/Misc/vla.cpp
index 9c16f510..98a110d3 100644
--- a/test/Misc/vla.cpp
+++ b/test/Misc/vla.cpp
@@ -23,9 +23,9 @@ TEST_CASE("Variable Length Array") {
     strcpy(vla, "[42]");
 
     StaticJsonArray<JSON_ARRAY_SIZE(1)> arr;
-    bool success = deserializeJson(arr, vla);
+    JsonError err = deserializeJson(arr, vla);
 
-    REQUIRE(true == success);
+    REQUIRE(err == JsonError::Ok);
   }
 
   SECTION("ParseObject") {