Added DeserializationError::EmptyInput

src/ArduinoJson/Deserialization/DeserializationError.hpp

@@ -20,6 +20,7 @@ class DeserializationError {
  public:
   enum Code {
     Ok,
+    EmptyInput,
     IncompleteInput,
     InvalidInput,
     NoMemory,
@@ -77,22 +78,12 @@ class DeserializationError {
   }
 
   const char* c_str() const {
-    switch (_code) {
-      case Ok:
-        return "Ok";
-      case TooDeep:
-        return "TooDeep";
-      case NoMemory:
-        return "NoMemory";
-      case InvalidInput:
-        return "InvalidInput";
-      case IncompleteInput:
-        return "IncompleteInput";
-      case NotSupported:
-        return "NotSupported";
-      default:
-        return "???";
-    }
+    static const char* messages[] = {
+        "Ok",       "EmptyInput",   "IncompleteInput", "InvalidInput",
+        "NoMemory", "NotSupported", "TooDeep"};
+    ARDUINOJSON_ASSERT(static_cast<size_t>(_code) <
+                       sizeof(messages) / sizeof(messages[0]));
+    return messages[_code];
   }
 
  private:

src/ArduinoJson/Json/JsonDeserializer.hpp

@@ -23,6 +23,7 @@ class JsonDeserializer {
   JsonDeserializer(MemoryPool &pool, TReader reader,
                    TStringStorage stringStorage)
       : _stringStorage(stringStorage),
+        _foundSomething(false),
         _latch(reader),
         _pool(&pool),
         _error(DeserializationError::Ok) {}
@@ -34,7 +35,7 @@ class JsonDeserializer {
 
     if (!_error && _latch.last() != 0 && !variant.isEnclosed()) {
       // We don't detect trailing characters earlier, so we need to check now
-      _error = DeserializationError::InvalidInput;
+      return DeserializationError::InvalidInput;
     }
 
     return _error;
@@ -559,7 +560,8 @@ class JsonDeserializer {
       switch (current()) {
         // end of string
         case '\0':
-          _error = DeserializationError::IncompleteInput;
+          _error = _foundSomething ? DeserializationError::IncompleteInput
+                                   : DeserializationError::EmptyInput;
           return false;
 
         // spaces
@@ -619,12 +621,14 @@ class JsonDeserializer {
 #endif
 
         default:
+          _foundSomething = true;
           return true;
       }
     }
   }
 
   TStringStorage _stringStorage;
+  bool _foundSomething;
   Latch<TReader> _latch;
   MemoryPool *_pool;
   char _buffer[64];  // using a member instead of a local variable because it

src/ArduinoJson/MsgPack/MsgPackDeserializer.hpp

@@ -21,22 +21,23 @@ class MsgPackDeserializer {
       : _pool(&pool),
         _reader(reader),
         _stringStorage(stringStorage),
-        _error(DeserializationError::Ok) {}
+        _error(DeserializationError::Ok),
+        _foundSomething(false) {}
 
   // TODO: add support for filter
   DeserializationError parse(VariantData &variant, AllowAllFilter,
                              NestingLimit nestingLimit) {
     parseVariant(variant, nestingLimit);
-    return _error;
+    return _foundSomething ? _error : DeserializationError::EmptyInput;
   }
 
  private:
   bool parseVariant(VariantData &variant, NestingLimit nestingLimit) {
     uint8_t code;
-    if (!readByte(code)) {
-      _error = DeserializationError::IncompleteInput;
+    if (!readByte(code))
       return false;
-    }
+
+    _foundSomething = true;
 
     if ((code & 0x80) == 0) {
       variant.setUnsignedInteger(code);
@@ -345,6 +346,7 @@ class MsgPackDeserializer {
   TReader _reader;
   TStringStorage _stringStorage;
   DeserializationError _error;
+  bool _foundSomething;
 };
 
 template <typename TInput>