Types-JSON

Src/Data/Myc.Data.Types.JSON.pas

@@ -0,0 +1,258 @@
+unit Myc.Data.Types.JSON;
+
+interface
+
+uses
+    System.SysUtils,
+    System.JSON,
+    Myc.Data.Types;
+
+type
+    // Provides methods for serializing and deserializing data values to/from JSON using the TDataType helpers.
+    TDataJsonConverter = class
+    public
+        // Serializes a data value to a TJSONValue.
+        class function ValueToJson(const Value: TDataType.TValue): TJSONValue;
+
+        // Deserializes a TJSONValue to a data value based on the provided data type.
+        class function JsonToValue(const Json: TJSONValue; const DataType: TDataType): TDataType.TValue;
+    end;
+
+implementation
+
+uses
+    System.Rtti,
+    System.TypInfo,
+    System.DateUtils,
+    System.Math;
+
+{ TDataJsonConverter }
+
+class function TDataJsonConverter.ValueToJson(const Value: TDataType.TValue): TJSONValue;
+var
+    jsonObject: TJSONObject;
+    jsonArray: TJSONArray;
+    i: Integer;
+begin
+    if not Assigned(Value.DataValue) then
+    begin
+        Result := TJSONNull.Create;
+        Exit;
+    end;
+
+    case Value.DataType.Kind of
+        dkVoid: Result := TJSONNull.Create;
+        dkOrdinal: Result := TJSONNumber.Create(Value.AsOrdinal.Value);
+        dkFloat: Result := TJSONNumber.Create(Value.AsFloat.Value);
+        dkText: Result := TJSONString.Create(Value.AsText.Value);
+        dkTimestamp: Result := TJSONString.Create(DateToISO8601(Value.AsTimestamp.Value, true));
+        dkDecimal:
+        begin
+            // Serialize as string to preserve precision.
+            var decValue := Value.AsDecimal;
+            var val := decValue.Value;
+            var scale := decValue.DataType.Scale;
+            var s: string;
+
+            if (scale = 0) then
+                s := IntToStr(val)
+            else
+            begin
+                s := IntToStr(Abs(val));
+                if (Length(s) <= scale) then
+                    s := StringOfChar('0', scale - Length(s) + 1) + s;
+
+                s := s.Insert(Length(s) - scale, '.');
+
+                if (val < 0) then
+                    s := '-' + s;
+            end;
+            Result := TJSONString.Create(s);
+        end;
+        dkEnum:
+        begin
+            var enumValue := Value.AsEnum;
+            Result := TJSONString.Create(enumValue.DataType.Identifiers[enumValue.Value]);
+        end;
+        dkRecord:
+        begin
+            var recordValue := Value.AsRecord;
+            var recordType := recordValue.DataType;
+            jsonObject := TJSONObject.Create;
+            Result := jsonObject;
+            for i := 0 to recordType.FieldCount - 1 do
+            begin
+                jsonObject.AddPair(
+                    recordType.Fields[i].Name,
+                    ValueToJson(recordValue.Items[i]) // Items property returns TDataType.TValue
+                );
+            end;
+        end;
+        dkTuple:
+        begin
+            var tupleValue := Value.AsTuple;
+            jsonArray := TJSONArray.Create;
+            Result := jsonArray;
+            for i := 0 to tupleValue.ItemCount - 1 do
+                jsonArray.AddElement(ValueToJson(tupleValue.Items[i]));
+        end;
+        dkArray:
+        begin
+            var arrayValue := Value.AsArray;
+            jsonArray := TJSONArray.Create;
+            Result := jsonArray;
+            for i := 0 to arrayValue.ElementCount - 1 do
+                jsonArray.AddElement(ValueToJson(arrayValue.Items[i]));
+        end;
+        dkVector:
+        begin
+            var vectorValue := Value.AsVector;
+            jsonArray := TJSONArray.Create;
+            Result := jsonArray;
+            for i := 0 to vectorValue.ElementCount - 1 do
+                jsonArray.AddElement(ValueToJson(vectorValue.Items[i]));
+        end;
+        dkMethod: raise ENotSupportedException.Create('Cannot serialize a method type to JSON.');
+    else
+        raise ENotSupportedException.CreateFmt('Unsupported data kind: %s', [GetEnumName(TypeInfo(TDataKind), Ord(Value.DataType.Kind))]);
+    end;
+end;
+
+class function TDataJsonConverter.JsonToValue(const Json: TJSONValue; const DataType: TDataType): TDataType.TValue;
+var
+    jsonObject: TJSONObject;
+    jsonArray: TJSONArray;
+    items: TArray<IDataValue>;
+    i, idx: Integer;
+    val: Int64;
+begin
+    Assert(Assigned(DataType.DataType), 'DataType cannot be nil for deserialization');
+
+    case DataType.Kind of
+        dkVoid:
+            if (Json is TJSONNull) then
+                Result := TDataType.Void.Value
+            else
+                raise EConvertError.Create('JSON Null expected for Void type');
+        dkOrdinal: Result := DataType.AsOrdinal.CreateValue((Json as TJSONNumber).AsInt64);
+        dkFloat: Result := DataType.AsFloat.CreateValue((Json as TJSONNumber).AsDouble);
+        dkText: Result := DataType.AsText.CreateValue((Json as TJSONString).Value);
+        dkTimestamp: Result := DataType.AsTimestamp.CreateValue(ISO8601ToDate((Json as TJSONString).Value, True));
+        dkDecimal:
+        begin
+            // Handle string representation for precision, with fallback to number for compatibility.
+            var decimalType := DataType.AsDecimal;
+            if (Json is TJSONString) then
+            begin
+                var s := (Json as TJSONString).Value.Trim;
+                var isNegative := s.StartsWith('-');
+                if isNegative then
+                    s := s.Remove(0, 1); // remove sign
+
+                var dotPos := Pos('.', s);
+                var numFracDigits: Integer;
+                if (dotPos = 0) then
+                    numFracDigits := 0
+                else
+                begin
+                    numFracDigits := Length(s) - dotPos;
+                    s := s.Remove(dotPos - 1, 1); // remove dot
+                end;
+
+                val := StrToInt64(s);
+
+                var scaleDiff := decimalType.Scale - numFracDigits;
+                if (scaleDiff > 0) then // Not enough fractional digits
+                begin
+                    for i := 1 to scaleDiff do
+                        val := val * 10;
+                end
+                else if (scaleDiff < 0) then // Too many fractional digits
+                begin
+                    for i := 1 to -scaleDiff do
+                        val := val div 10;
+                end;
+
+                if isNegative then
+                    val := -val;
+
+                Result := decimalType.CreateValue(val);
+            end
+            else if (Json is TJSONNumber) then
+            begin
+                // Support numbers for compatibility, but this can lead to precision loss.
+                val := Round((Json as TJSONNumber).AsDouble * Power(10, decimalType.Scale));
+                Result := decimalType.CreateValue(val);
+            end
+            else
+                raise EConvertError.Create('JSON String or Number expected for Decimal type');
+        end;
+        dkEnum:
+        begin
+            var enumType := DataType.AsEnum;
+            idx := enumType.IndexOf((Json as TJSONString).Value);
+            if (idx < 0) then
+                raise EConvertError.CreateFmt('Invalid enum identifier "%s" for type %s', [Json.Value, DataType.Name]);
+            Result := enumType.CreateValue(idx);
+        end;
+        dkRecord:
+        begin
+            var recordType := DataType.AsRecord;
+            jsonObject := Json as TJSONObject;
+            SetLength(items, recordType.FieldCount);
+            for i := 0 to recordType.FieldCount - 1 do
+            begin
+                var field := recordType.Fields[i];
+                var jsonPair := jsonObject.Get(field.Name);
+                if not Assigned(jsonPair) then
+                    raise EConvertError.CreateFmt('Missing field "%s" for record type %s', [field.Name, DataType.Name]);
+
+                // Recursive call returns TDataType.TValue, which implicitly converts to IDataValue for the array
+                items[i] := JsonToValue(jsonPair.JsonValue, field.DataType);
+            end;
+            Result := recordType.CreateValue(items);
+        end;
+        dkTuple:
+        begin
+            var tupleType := DataType.AsTuple;
+            jsonArray := Json as TJSONArray;
+            if (jsonArray.Count <> IDataTupleType(tupleType).ItemCount) then
+                raise EConvertError
+                    .CreateFmt('JSON array size (%d) does not match tuple size (%d)', [jsonArray.Count, tupleType.ItemCount]);
+
+            SetLength(items, IDataTupleType(tupleType).ItemCount);
+            for i := 0 to IDataTupleType(tupleType).ItemCount - 1 do
+            begin
+                var itemType := IDataTupleType(tupleType).ItemType[i];
+                items[i] := JsonToValue(jsonArray.Items[i], itemType);
+            end;
+            Result := tupleType.CreateValue(items);
+        end;
+        dkArray:
+        begin
+            var arrayType := DataType.AsArray;
+            jsonArray := Json as TJSONArray;
+            SetLength(items, jsonArray.Count);
+            for i := 0 to jsonArray.Count - 1 do
+                items[i] := JsonToValue(jsonArray.Items[i], arrayType.ElementType);
+            Result := arrayType.CreateValue(items);
+        end;
+        dkVector:
+        begin
+            var vectorType := DataType.AsVector;
+            jsonArray := Json as TJSONArray;
+            if (jsonArray.Count <> vectorType.ElementCount) then
+                raise EConvertError
+                    .CreateFmt('JSON array size (%d) does not match vector size (%d)', [jsonArray.Count, vectorType.ElementCount]);
+            SetLength(items, jsonArray.Count);
+            for i := 0 to jsonArray.Count - 1 do
+                items[i] := JsonToValue(jsonArray.Items[i], vectorType.ElementType);
+            Result := vectorType.CreateValue(items);
+        end;
+        dkMethod: raise ENotSupportedException.Create('Cannot deserialize a method type from JSON.');
+    else
+        raise ENotSupportedException.CreateFmt('Unsupported data kind: %s', [GetEnumName(TypeInfo(TDataKind), Ord(DataType.Kind))]);
+    end;
+end;
+
+end.

Src/Data/Myc.Data.Types.RTTI.pas

@@ -7,10 +7,7 @@ uses
     System.RTTI,
     Myc.Data.Types;
 
-type
-    TValueHelper = record helper for TDataType.TValue
-        function AsTValue: TValue;
-    end;
+function AsTValue(const Value: TDataType.TValue): TValue;
 
 function RttiTypeToDataType(rttiType: TRttiType): TDataType;
 
@@ -69,16 +66,16 @@ end;
 
 { TValueHelper }
 
-function TValueHelper.AsTValue: TValue;
+function AsTValue(const Value: TDataType.TValue): TValue;
 begin
-    case DataType.Kind of
+    case Value.DataType.Kind of
         dkVoid: Result := TValue.Empty;
-        dkOrdinal: Result := TValue.From<Int64>(AsOrdinal.Value);
-        dkFloat: Result := TValue.From<Double>(AsFloat.Value);
-        dkText: Result := TValue.From<string>(AsText.Value);
-        dkTimestamp: Result := TValue.From<TDateTime>(AsTimestamp.Value);
-        dkEnum: Result := TValue.From<Integer>(AsEnum.Value);
-        dkMethod: Result := TValue.From<TDataMethodProc>(AsMethod.Value);
+        dkOrdinal: Result := TValue.From<Int64>(Value.AsOrdinal.Value);
+        dkFloat: Result := TValue.From<Double>(Value.AsFloat.Value);
+        dkText: Result := TValue.From<string>(Value.AsText.Value);
+        dkTimestamp: Result := TValue.From<TDateTime>(Value.AsTimestamp.Value);
+        dkEnum: Result := TValue.From<Integer>(Value.AsEnum.Value);
+        dkMethod: Result := TValue.From<TDataMethodProc>(Value.AsMethod.Value);
     else
         raise EInvalidOpException.Create('Unsupported data type');
     end;

Src/Data/Myc.Data.Types.pas

@@ -169,7 +169,13 @@ type
     end;
 
     IDataTupleType = interface(IDataType)
+        {$region 'private'}
+        function GetItemCount: Integer;
+        function GetItemType(Idx: Integer): IDataType;
+        {$endregion}
         function CreateValue(const AItems: array of IDataValue): IDataTupleValue;
+        property ItemCount: Integer read GetItemCount;
+        property ItemType[Idx: Integer]: IDataType read GetItemType;
     end;
 
     IDataArrayValue = interface(IDataValue)
@@ -219,20 +225,6 @@ type
             public
                 constructor Create(const ADataValue: IDataValue);
 
-                // Casting
-                function AsOrdinal: IDataOrdinalValue; inline;
-                function AsFloat: IDataFloatValue; inline;
-                function AsText: IDataTextValue; inline;
-                function AsTimestamp: IDataTimestampValue; inline;
-                function AsDecimal: IDataDecimalValue; inline;
-                function AsRecord: IDataRecordValue; inline;
-                function AsTuple: IDataTupleValue; inline;
-                function AsArray: IDataArrayValue; inline;
-                function AsVector: IDataVectorValue; inline;
-                function AsEnum: IDataEnumValue; inline;
-                function AsMethod: IDataMethodValue; inline;
-                function AsVoid: IDataVoidValue; inline;
-
                 class operator Implicit(const A: IDataValue): TDataType.TValue; overload; inline;
                 class operator Implicit(const A: TDataType.TValue): IDataValue; overload; inline;
 
@@ -466,11 +458,15 @@ type
                     end;
             private
                 FTupleType: IDataTupleType;
+                function GetItemCount: Integer; inline;
+                function GetItemType(Idx: Integer): IDataType; inline;
             public
                 constructor Create(const ATupleType: IDataTupleType);
                 class operator Implicit(const A: IDataTupleType): TDataType.TTuple; overload; inline;
                 class operator Implicit(const A: TDataType.TTuple): IDataTupleType; overload; inline;
                 function CreateValue(const AItems: array of IDataValue): TDataType.TTuple.TValue;
+                property ItemCount: Integer read GetItemCount;
+                property ItemType[Idx: Integer]: IDataType read GetItemType;
             end;
 
             TArray = record
@@ -560,6 +556,23 @@ type
                 function CreateValue(const Proc: TProc): TDataType.TMethod.TValue; inline;
             end;
 
+            // Helper to cast a generic TValue to a specific value helper.
+            TValueHelper = record helper for TValue
+            public
+                function AsVoid: TVoid.TValue; inline;
+                function AsOrdinal: TOrdinal.TValue; inline;
+                function AsFloat: TFloat.TValue; inline;
+                function AsText: TText.TValue; inline;
+                function AsTimestamp: TTimestamp.TValue; inline;
+                function AsDecimal: TDecimal.TValue; inline;
+                function AsRecord: TRecord.TValue; inline;
+                function AsTuple: TTuple.TValue; inline;
+                function AsArray: TArray.TValue; inline;
+                function AsVector: TVector.TValue; inline;
+                function AsEnum: TEnum.TValue; inline;
+                function AsMethod: TMethod.TValue; inline;
+            end;
+
     strict private
         FDataType: IDataType;
         function GetName: String; inline;
@@ -1247,6 +1260,16 @@ begin
     Result.Create(FTupleType.CreateValue(AItems));
 end;
 
+function TDataType.TTuple.GetItemCount: Integer;
+begin
+    Result := FTupleType.ItemCount;
+end;
+
+function TDataType.TTuple.GetItemType(Idx: Integer): IDataType;
+begin
+    Result := FTupleType.ItemType[Idx];
+end;
+
 class operator TDataType.TTuple.Implicit(const A: IDataTupleType): TDataType.TTuple;
 begin
     Result.FTupleType := A;
@@ -1590,90 +1613,6 @@ begin
     FDataValue := ADataValue;
 end;
 
-function TDataType.TValue.AsArray: IDataArrayValue;
-begin
-    if (FDataValue.DataType.Kind <> dkArray) then
-        raise EInvalidCast.Create('Array expected');
-    Result := IDataArrayValue(FDataValue);
-end;
-
-function TDataType.TValue.AsDecimal: IDataDecimalValue;
-begin
-    if (FDataValue.DataType.Kind <> dkDecimal) then
-        raise EInvalidCast.Create('Decimal expected');
-    Result := IDataDecimalValue(FDataValue);
-end;
-
-function TDataType.TValue.AsEnum: IDataEnumValue;
-begin
-    if (FDataValue.DataType.Kind <> dkEnum) then
-        raise EInvalidCast.Create('Enum expected');
-    Result := IDataEnumValue(FDataValue);
-end;
-
-function TDataType.TValue.AsFloat: IDataFloatValue;
-begin
-    if (FDataValue.DataType.Kind <> dkFloat) then
-        raise EInvalidCast.Create('Float expected');
-    Result := IDataFloatValue(FDataValue);
-end;
-
-function TDataType.TValue.AsMethod: IDataMethodValue;
-begin
-    if (FDataValue.DataType.Kind <> dkMethod) then
-        raise EInvalidCast.Create('Method expected');
-    Result := IDataMethodValue(FDataValue);
-end;
-
-function TDataType.TValue.AsOrdinal: IDataOrdinalValue;
-begin
-    if (FDataValue.DataType.Kind <> dkOrdinal) then
-        raise EInvalidCast.Create('Ordinal expected');
-    Result := IDataOrdinalValue(FDataValue);
-end;
-
-function TDataType.TValue.AsRecord: IDataRecordValue;
-begin
-    if (FDataValue.DataType.Kind <> dkRecord) then
-        raise EInvalidCast.Create('Record expected');
-    Result := IDataRecordValue(FDataValue);
-end;
-
-function TDataType.TValue.AsText: IDataTextValue;
-begin
-    if (FDataValue.DataType.Kind <> dkText) then
-        raise EInvalidCast.Create('Text expected');
-    Result := IDataTextValue(FDataValue);
-end;
-
-function TDataType.TValue.AsTimestamp: IDataTimestampValue;
-begin
-    if (FDataValue.DataType.Kind <> dkTimestamp) then
-        raise EInvalidCast.Create('Timestamp expected');
-    Result := IDataTimestampValue(FDataValue);
-end;
-
-function TDataType.TValue.AsTuple: IDataTupleValue;
-begin
-    if (FDataValue.DataType.Kind <> dkTuple) then
-        raise EInvalidCast.Create('Tuple expected');
-    Result := IDataTupleValue(FDataValue);
-end;
-
-function TDataType.TValue.AsVector: IDataVectorValue;
-begin
-    if (FDataValue.DataType.Kind <> dkVector) then
-        raise EInvalidCast.Create('Vector expected');
-    Result := IDataVectorValue(FDataValue);
-end;
-
-function TDataType.TValue.AsVoid: IDataVoidValue;
-begin
-    if (FDataValue.DataType.Kind <> dkVoid) then
-        raise EInvalidCast.Create('Void expected');
-    Result := IDataVoidValue(FDataValue);
-end;
-
 function TDataType.TValue.GetDataType: IDataType;
 begin
     if Assigned(FDataValue) then
@@ -1769,4 +1708,90 @@ begin
     Result.Create(IDataVectorType(FDataType));
 end;
 
+{ TDataType.TValueHelper }
+
+function TDataType.TValueHelper.AsArray: TDataType.TArray.TValue;
+begin
+    if (FDataValue.DataType.Kind <> dkArray) then
+        raise EInvalidCast.Create('Array expected');
+    Result.Create(IDataArrayValue(FDataValue));
+end;
+
+function TDataType.TValueHelper.AsDecimal: TDecimal.TValue;
+begin
+    if (FDataValue.DataType.Kind <> dkDecimal) then
+        raise EInvalidCast.Create('Decimal expected');
+    Result.Create(IDataDecimalValue(FDataValue));
+end;
+
+function TDataType.TValueHelper.AsEnum: TDataType.TEnum.TValue;
+begin
+    if (FDataValue.DataType.Kind <> dkEnum) then
+        raise EInvalidCast.Create('Enum expected');
+    Result.Create(IDataEnumValue(FDataValue));
+end;
+
+function TDataType.TValueHelper.AsFloat: TDataType.TFloat.TValue;
+begin
+    if (FDataValue.DataType.Kind <> dkFloat) then
+        raise EInvalidCast.Create('Float expected');
+    Result.Create(IDataFloatValue(FDataValue));
+end;
+
+function TDataType.TValueHelper.AsMethod: TDataType.TMethod.TValue;
+begin
+    if (FDataValue.DataType.Kind <> dkMethod) then
+        raise EInvalidCast.Create('Method expected');
+    Result.Create(IDataMethodValue(FDataValue));
+end;
+
+function TDataType.TValueHelper.AsOrdinal: TDataType.TOrdinal.TValue;
+begin
+    if (FDataValue.DataType.Kind <> dkOrdinal) then
+        raise EInvalidCast.Create('Ordinal expected');
+    Result.Create(IDataOrdinalValue(FDataValue));
+end;
+
+function TDataType.TValueHelper.AsRecord: TDataType.TRecord.TValue;
+begin
+    if (FDataValue.DataType.Kind <> dkRecord) then
+        raise EInvalidCast.Create('Record expected');
+    Result.Create(IDataRecordValue(FDataValue));
+end;
+
+function TDataType.TValueHelper.AsText: TDataType.TText.TValue;
+begin
+    if (FDataValue.DataType.Kind <> dkText) then
+        raise EInvalidCast.Create('Text expected');
+    Result.Create(IDataTextValue(FDataValue));
+end;
+
+function TDataType.TValueHelper.AsTimestamp: TDataType.TTimestamp.TValue;
+begin
+    if (FDataValue.DataType.Kind <> dkTimestamp) then
+        raise EInvalidCast.Create('Timestamp expected');
+    Result.Create(IDataTimestampValue(FDataValue));
+end;
+
+function TDataType.TValueHelper.AsTuple: TDataType.TTuple.TValue;
+begin
+    if (FDataValue.DataType.Kind <> dkTuple) then
+        raise EInvalidCast.Create('Tuple expected');
+    Result.Create(IDataTupleValue(FDataValue));
+end;
+
+function TDataType.TValueHelper.AsVector: TDataType.TVector.TValue;
+begin
+    if (FDataValue.DataType.Kind <> dkVector) then
+        raise EInvalidCast.Create('Vector expected');
+    Result.Create(IDataVectorValue(FDataValue));
+end;
+
+function TDataType.TValueHelper.AsVoid: TDataType.TVoid.TValue;
+begin
+    if (FDataValue.DataType.Kind <> dkVoid) then
+        raise EInvalidCast.Create('Void expected');
+    Result.Create(IDataVoidValue(FDataValue));
+end;
+
 end.

Src/Data/TestDataTypes.JSON.pas

@@ -0,0 +1,412 @@
+unit TestDataTypes.JSON;
+
+interface
+
+uses
+    System.JSON,
+    DUnitX.TestFramework;
+
+type
+    [TestFixture]
+    [IgnoreMemoryLeaks]
+    TTestDataTypesJSON = class
+    private
+        FJson: TJSONValue;
+    public
+        [Setup]
+        procedure SetUp;
+        [TearDown]
+        procedure TearDown;
+
+        [Test]
+        procedure TestVoid;
+
+        [Test]
+        [TestCase('Positive', '12345')]
+        [TestCase('Negative', '-54321')]
+        [TestCase('Zero', '0')]
+        procedure TestOrdinal(const AValue: Int64);
+
+        [Test]
+        [TestCase('Positive', '123.456')]
+        [TestCase('Negative', '-543.21')]
+        [TestCase('Zero', '0.0')]
+        procedure TestFloat(const AValue: Double);
+
+        [Test]
+        [TestCase('Simple', 'Hello World')]
+        [TestCase('Empty', '')]
+        [TestCase('SpecialChars', 'äöüß#+*?%&/()=')]
+        procedure TestText(const AValue: string);
+
+        [Test]
+        procedure TestTimestamp;
+
+        [Test]
+        [TestCase('Scale4_Positive', '1234567,4,123.4567')]
+        [TestCase('Scale2_Negative', '-987,2,-9.87')]
+        [TestCase('Scale5_Small', '123,5,0.00123')]
+        [TestCase('Scale0_Int', '123,0,123')]
+        [TestCase('Scale2_Zero', '0,2,0.00')]
+        [TestCase('Scale0_Zero', '0,0,0')]
+        procedure TestDecimal(const AValue: Int64; AScale: Integer; const AExpectedJsonString: string);
+
+        [Test]
+        procedure TestEnum;
+        [Test]
+        procedure TestRecord;
+        [Test]
+        procedure TestTuple;
+        [Test]
+        procedure TestArray;
+        [Test]
+        procedure TestVector;
+        [Test]
+        procedure TestMethodFails;
+        [Test]
+        procedure TestNullValue;
+    end;
+
+implementation
+
+uses
+    System.SysUtils,
+    System.DateUtils,
+    System.Math,
+    Myc.Data.Types,
+    Myc.Data.Types.JSON;
+
+{ TTestDataTypesJSON }
+
+procedure TTestDataTypesJSON.SetUp;
+begin
+    FJson := nil;
+end;
+
+procedure TTestDataTypesJSON.TearDown;
+begin
+    FJson.Free;
+end;
+
+procedure TTestDataTypesJSON.TestVoid;
+var
+    voidType: TDataType.TVoid;
+    voidValue: TDataType.TVoid.TValue;
+    deserializedValue: TDataType.TValue;
+begin
+    // Setup
+    voidType := TDataType.Void;
+    voidValue := voidType.Value;
+
+    // Serialize
+    FJson := TDataJsonConverter.ValueToJson(voidValue);
+    Assert.IsNotNull(FJson, 'JSON value should not be nil');
+    Assert.IsTrue(FJson is TJSONNull, 'Void should serialize to JSON Null');
+
+    // Deserialize
+    deserializedValue := TDataJsonConverter.JsonToValue(FJson, voidType);
+    Assert.IsNotNull(deserializedValue.DataValue, 'Deserialized value should not be nil');
+    Assert.AreEqual(dkVoid, deserializedValue.DataType.Kind, 'Deserialized type kind should be dkVoid');
+end;
+
+procedure TTestDataTypesJSON.TestOrdinal(const AValue: Int64);
+var
+    ordType: TDataType.TOrdinal;
+    ordValue: TDataType.TOrdinal.TValue;
+    deserializedValue: TDataType.TValue;
+begin
+    // Setup
+    ordType := TDataType.Ordinal;
+    ordValue := ordType.CreateValue(AValue);
+
+    // Serialize
+    FJson := TDataJsonConverter.ValueToJson(ordValue);
+    Assert.IsTrue(FJson is TJSONNumber, 'Ordinal should serialize to JSON Number');
+    Assert.AreEqual(AValue, (FJson as TJSONNumber).AsInt64, 'Serialized value mismatch');
+
+    // Deserialize
+    deserializedValue := TDataJsonConverter.JsonToValue(FJson, ordType);
+    Assert.AreEqual(dkOrdinal, deserializedValue.DataType.Kind, 'Deserialized type kind should be dkOrdinal');
+    Assert.AreEqual(AValue, deserializedValue.AsOrdinal.Value, 'Deserialized value mismatch');
+end;
+
+procedure TTestDataTypesJSON.TestFloat(const AValue: Double);
+var
+    floatType: TDataType.TFloat;
+    floatValue: TDataType.TFloat.TValue;
+    deserializedValue: TDataType.TValue;
+begin
+    // Setup
+    floatType := TDataType.Float;
+    floatValue := floatType.CreateValue(AValue);
+
+    // Serialize
+    FJson := TDataJsonConverter.ValueToJson(floatValue);
+    Assert.IsTrue(FJson is TJSONNumber, 'Float should serialize to JSON Number');
+    Assert.AreEqual(AValue, (FJson as TJSONNumber).AsDouble, 1E-9, 'Serialized value mismatch');
+
+    // Deserialize
+    deserializedValue := TDataJsonConverter.JsonToValue(FJson, floatType);
+    Assert.AreEqual(dkFloat, deserializedValue.DataType.Kind, 'Deserialized type kind should be dkFloat');
+    Assert.AreEqual(AValue, deserializedValue.AsFloat.Value, 1E-9, 'Deserialized value mismatch');
+end;
+
+procedure TTestDataTypesJSON.TestText(const AValue: string);
+var
+    textType: TDataType.TText;
+    textValue: TDataType.TText.TValue;
+    deserializedValue: TDataType.TValue;
+begin
+    // Setup
+    textType := TDataType.Text;
+    textValue := textType.CreateValue(AValue);
+
+    // Serialize
+    FJson := TDataJsonConverter.ValueToJson(textValue);
+    Assert.IsTrue(FJson is TJSONString, 'Text should serialize to JSON String');
+    Assert.AreEqual(AValue, (FJson as TJSONString).Value, 'Serialized value mismatch');
+
+    // Deserialize
+    deserializedValue := TDataJsonConverter.JsonToValue(FJson, textType);
+    Assert.AreEqual(dkText, deserializedValue.DataType.Kind, 'Deserialized type kind should be dkText');
+    Assert.AreEqual(AValue, deserializedValue.AsText.Value, 'Deserialized value mismatch');
+end;
+
+procedure TTestDataTypesJSON.TestTimestamp;
+var
+    tsType: TDataType.TTimestamp;
+    tsValue: TDataType.TTimestamp.TValue;
+    deserializedValue: TDataType.TValue;
+    testVal: TDateTime;
+begin
+    // Setup
+    testVal := EncodeDateTime(2025, 8, 27, 17, 30, 15, 500);
+    tsType := TDataType.Timestamp;
+    tsValue := tsType.CreateValue(testVal);
+
+    // Serialize
+    FJson := TDataJsonConverter.ValueToJson(tsValue);
+    Assert.IsTrue(FJson is TJSONString, 'Timestamp should serialize to JSON String');
+    Assert.AreEqual(DateToISO8601(testVal, true), (FJson as TJSONString).Value, 'Serialized value mismatch');
+
+    // Deserialize
+    deserializedValue := TDataJsonConverter.JsonToValue(FJson, tsType);
+    Assert.AreEqual(dkTimestamp, deserializedValue.DataType.Kind, 'Deserialized type kind should be dkTimestamp');
+    Assert.IsTrue(CompareDateTime(testVal, deserializedValue.AsTimestamp.Value) = 0, 'Deserialized value mismatch');
+end;
+
+procedure TTestDataTypesJSON.TestDecimal(const AValue: Int64; AScale: Integer; const AExpectedJsonString: string);
+var
+    decType: TDataType.TDecimal;
+    decValue: TDataType.TDecimal.TValue;
+    deserializedValue: TDataType.TValue;
+begin
+    // Setup
+    decType := TDataType.DecimalOf(AScale);
+    decValue := decType.CreateValue(AValue);
+
+    // Serialize
+    FJson := TDataJsonConverter.ValueToJson(decValue);
+    Assert.IsTrue(FJson is TJSONString, 'Decimal should serialize to JSON String');
+    Assert.AreEqual(AExpectedJsonString, (FJson as TJSONString).Value, 'Serialized string value mismatch');
+
+    // Deserialize
+    deserializedValue := TDataJsonConverter.JsonToValue(FJson, decType);
+    Assert.AreEqual(dkDecimal, deserializedValue.DataType.Kind, 'Deserialized type kind should be dkDecimal');
+    Assert.AreEqual(AValue, deserializedValue.AsDecimal.Value, 'Deserialized value mismatch');
+    Assert.AreEqual(AScale, deserializedValue.AsDecimal.DataType.Scale, 'Deserialized scale mismatch');
+
+    // Test Deserialization from Number (compatibility)
+    FJson.Free; // Free previous value before creating new one
+    FJson := TJSONNumber.Create(AValue / Power(10, AScale));
+    deserializedValue := TDataJsonConverter.JsonToValue(FJson, decType);
+    Assert.AreEqual(AValue, deserializedValue.AsDecimal.Value, 'Deserialized value from number mismatch');
+end;
+
+procedure TTestDataTypesJSON.TestEnum;
+var
+    enumType: TDataType.TEnum;
+    enumValue: TDataType.TEnum.TValue;
+    deserializedValue: TDataType.TValue;
+begin
+    // Setup
+    enumType := TDataType.EnumOf('MyEnum', ['Red', 'Green', 'Blue']);
+    enumValue := enumType.CreateValue(1); // Green
+
+    // Serialize
+    FJson := TDataJsonConverter.ValueToJson(enumValue);
+    Assert.IsTrue(FJson is TJSONString, 'Enum should serialize to JSON String');
+    Assert.AreEqual('Green', (FJson as TJSONString).Value, 'Serialized value mismatch');
+
+    // Deserialize
+    deserializedValue := TDataJsonConverter.JsonToValue(FJson, enumType);
+    Assert.AreEqual(dkEnum, deserializedValue.DataType.Kind, 'Deserialized type kind should be dkEnum');
+    Assert.AreEqual(1, deserializedValue.AsEnum.Value, 'Deserialized value mismatch');
+end;
+
+procedure TTestDataTypesJSON.TestRecord;
+var
+    recordType: TDataType.TRecord;
+    idVal: TDataType.TOrdinal.TValue;
+    nameVal: TDataType.TText.TValue;
+    recordValue: TDataType.TRecord.TValue;
+    deserializedValue: TDataType.TValue;
+begin
+    // Setup
+    recordType := TDataType.RecordOf([TDataRecordField.Create('ID', TDataType.Ordinal), TDataRecordField.Create('Name', TDataType.Text)]);
+    idVal := TDataType.Ordinal.CreateValue(99);
+    nameVal := TDataType.Text.CreateValue('TestRecord');
+    recordValue := recordType.CreateValue([idVal, nameVal]);
+
+    // Serialize
+    FJson := TDataJsonConverter.ValueToJson(recordValue);
+    Assert.IsTrue(FJson is TJSONObject, 'Record should serialize to JSON Object');
+
+    // Deserialize
+    deserializedValue := TDataJsonConverter.JsonToValue(FJson, recordType);
+    Assert.AreEqual(dkRecord, deserializedValue.DataType.Kind, 'Deserialized type kind should be dkRecord');
+    var desRecord := deserializedValue.AsRecord;
+    Assert.AreEqual(Int64(99), desRecord.Items[0].AsOrdinal.Value, 'Deserialized record field ID mismatch');
+    Assert.AreEqual('TestRecord', desRecord.Items[1].AsText.Value, 'Deserialized record field Name mismatch');
+end;
+
+procedure TTestDataTypesJSON.TestTuple;
+var
+    tupleType: TDataType.TTuple;
+    idVal: TDataType.TOrdinal.TValue;
+    nameVal: TDataType.TText.TValue;
+    tupleValue: TDataType.TTuple.TValue;
+    deserializedValue: TDataType.TValue;
+begin
+    // Setup
+    tupleType := TDataType.TupleOf([TDataType.Ordinal, TDataType.Text]);
+    idVal := TDataType.Ordinal.CreateValue(101);
+    nameVal := TDataType.Text.CreateValue('TestTuple');
+    tupleValue := tupleType.CreateValue([idVal, nameVal]);
+
+    // Serialize
+    FJson := TDataJsonConverter.ValueToJson(tupleValue);
+    Assert.IsTrue(FJson is TJSONArray, 'Tuple should serialize to JSON Array');
+
+    // Deserialize
+    deserializedValue := TDataJsonConverter.JsonToValue(FJson, tupleType);
+    Assert.AreEqual(dkTuple, deserializedValue.DataType.Kind, 'Deserialized type kind should be dkTuple');
+    var desTuple := deserializedValue.AsTuple;
+    Assert.AreEqual(Int64(101), desTuple.Items[0].AsOrdinal.Value, 'Deserialized tuple item 0 mismatch');
+    Assert.AreEqual('TestTuple', desTuple.Items[1].AsText.Value, 'Deserialized tuple item 1 mismatch');
+end;
+
+procedure TTestDataTypesJSON.TestArray;
+var
+    arrayType: TDataType.TArray;
+    val1, val2: TDataType.TText.TValue;
+    arrayValue: TDataType.TArray.TValue;
+    deserializedValue: TDataType.TValue;
+begin
+    // Setup
+    arrayType := TDataType.ArrayOf(TDataType.Text);
+    val1 := TDataType.Text.CreateValue('A');
+    val2 := TDataType.Text.CreateValue('B');
+    arrayValue := arrayType.CreateValue([val1, val2]);
+
+    // Serialize
+    FJson := TDataJsonConverter.ValueToJson(arrayValue);
+    Assert.IsTrue(FJson is TJSONArray, 'Array should serialize to JSON Array');
+
+    // Deserialize
+    deserializedValue := TDataJsonConverter.JsonToValue(FJson, arrayType);
+    Assert.AreEqual(dkArray, deserializedValue.DataType.Kind, 'Deserialized type kind should be dkArray');
+    var desArray := deserializedValue.AsArray;
+    Assert.AreEqual(2, desArray.ElementCount, 'Deserialized array element count mismatch');
+    Assert.AreEqual('A', desArray.Items[0].AsText.Value, 'Deserialized array item 0 mismatch');
+    Assert.AreEqual('B', desArray.Items[1].AsText.Value, 'Deserialized array item 1 mismatch');
+end;
+
+procedure TTestDataTypesJSON.TestVector;
+var
+    vectorType: TDataType.TVector;
+    val1, val2: TDataType.TOrdinal.TValue;
+    vectorValue: TDataType.TVector.TValue;
+    deserializedValue: TDataType.TValue;
+    jsonArray: TJSONArray;
+begin
+    // Setup
+    vectorType := TDataType.VectorOf(TDataType.Ordinal, 2);
+    val1 := TDataType.Ordinal.CreateValue(10);
+    val2 := TDataType.Ordinal.CreateValue(20);
+    vectorValue := vectorType.CreateValue([val1, val2]);
+
+    // Serialize
+    FJson := TDataJsonConverter.ValueToJson(vectorValue);
+    Assert.IsTrue(FJson is TJSONArray, 'Vector should serialize to JSON Array');
+
+    // Deserialize
+    deserializedValue := TDataJsonConverter.JsonToValue(FJson, vectorType);
+    Assert.AreEqual(dkVector, deserializedValue.DataType.Kind, 'Deserialized type kind should be dkVector');
+    var desVector := deserializedValue.AsVector;
+    Assert.AreEqual(2, desVector.ElementCount, 'Deserialized vector element count mismatch');
+    Assert.AreEqual(Int64(10), desVector.Items[0].AsOrdinal.Value, 'Deserialized vector item 0 mismatch');
+    Assert.AreEqual(Int64(20), desVector.Items[1].AsOrdinal.Value, 'Deserialized vector item 1 mismatch');
+
+    // Test wrong size deserialization
+    jsonArray := nil;
+    try
+        jsonArray := TJSONArray.Create;
+        jsonArray.Add(1);
+        Assert.WillRaise(
+            procedure begin TDataJsonConverter.JsonToValue(jsonArray, vectorType); end,
+            EConvertError,
+            'Deserializing a JSON array with wrong size for a vector should raise an exception'
+        );
+    finally
+        jsonArray.Free;
+    end;
+end;
+
+procedure TTestDataTypesJSON.TestMethodFails;
+var
+    methodType: TDataType.TMethod;
+    methodValue: TDataType.TMethod.TValue;
+begin
+    // Setup
+    methodType := TDataType.MethodOf(TDataType.Ordinal, TDataType.Ordinal);
+    methodValue := methodType.CreateValue(function(const AValue: TDataType.TValue): TDataType.TValue begin Result := AValue; end);
+
+    // Test Serialization
+    Assert.WillRaise(
+        procedure begin TDataJsonConverter.ValueToJson(methodValue).Free; end,
+        ENotSupportedException,
+        'Serializing a method should raise an exception'
+    );
+
+    // Test Deserialization
+    FJson := TJSONNull.Create;
+    //TODO Fails with "Method did not throw any exceptions. Deserializing a method should raise an exception"
+    Assert.WillRaise(
+        procedure begin TDataJsonConverter.JsonToValue(FJson, methodType); end,
+        ENotSupportedException,
+        'Deserializing a method should raise an exception'
+    );
+end;
+
+procedure TTestDataTypesJSON.TestNullValue;
+var
+    value: TDataType.TValue;
+    deserializedValue: TDataType.TValue;
+begin
+    // Setup
+    value := TDataType.Void.Value;
+
+    // Serialize
+    FJson := TDataJsonConverter.ValueToJson(value);
+    Assert.IsTrue(FJson is TJSONNull, 'nil IDataValue should serialize to JSON Null');
+
+    // Deserialize
+    deserializedValue := TDataJsonConverter.JsonToValue(FJson, TDataType.Void);
+    Assert.IsTrue(deserializedValue.DataType.Kind = dkVoid, 'JSON Null should deserialize to a TValue with a nil DataValue');
+end;
+
+initialization
+    TDUnitX.RegisterTestFixture(TTestDataTypesJSON);
+
+end.

Src/Data/TestDataTypes.pas

@@ -8,7 +8,7 @@ uses
 type
     [TestFixture]
     [IgnoreMemoryLeaks]
-    TMyTestObject = class
+    TTestDataTypes = class
     public
         [Test]
         procedure TestRecords;
@@ -48,9 +48,10 @@ uses
     System.Rtti,
     System.TypInfo,
     Myc.Data.Types,
-    Myc.Data.Types.RTTI;
+    Myc.Data.Types.RTTI,
+    Myc.Data.Types.JSON;
 
-procedure TMyTestObject.TestRecords;
+procedure TTestDataTypes.TestRecords;
 var
     intType: TDataType.TOrdinal;
     floatType: TDataType.TFloat;
@@ -129,7 +130,7 @@ begin
     );
 end;
 
-procedure TMyTestObject.TestRecords_Generic;
+procedure TTestDataTypes.TestRecords_Generic;
 var
     dataType: TDataType.TRecord;
     dataValue: TDataType.TRecord.TValue;
@@ -159,7 +160,7 @@ begin
     Assert.AreEqual('<A: 1, B: two, C: 3>', IDataValue(dataValue).AsString, 'Generic record AsString is incorrect');
 end;
 
-procedure TMyTestObject.TestTuples;
+procedure TTestDataTypes.TestTuples;
 var
     intValue: TDataType.TOrdinal.TValue;
     floatValue: TDataType.TFloat.TValue;
@@ -193,7 +194,7 @@ begin
     Assert.AreEqual('Tuple<Integer, Float>', type1.Name, 'The type name for all tuples should be Tuple');
 end;
 
-procedure TMyTestObject.TestTuples_Generic;
+procedure TTestDataTypes.TestTuples_Generic;
 var
     tupleValue: TDataType.TTuple.TValue;
     item: TDataType.TOrdinal.TValue;
@@ -219,7 +220,7 @@ begin
     Assert.AreEqual('(1, 2, 3, 4, 5, 6)', IDataValue(tupleValue).AsString, 'Generic tuple AsString is incorrect');
 end;
 
-procedure TMyTestObject.TestArrays;
+procedure TTestDataTypes.TestArrays;
 var
     intType: TDataType.TOrdinal;
     floatType: TDataType.TFloat;
@@ -283,7 +284,7 @@ begin
     );
 end;
 
-procedure TMyTestObject.TestArrays_OptimizedAndGeneric;
+procedure TTestDataTypes.TestArrays_OptimizedAndGeneric;
 var
     arrayType: TDataType.TArray;
     empty1, empty2, single, generic: TDataType.TArray.TValue;
@@ -316,7 +317,7 @@ begin
     Assert.AreEqual('[1, 2, 3]', IDataValue(generic).AsString, 'Generic array AsString is incorrect');
 end;
 
-procedure TMyTestObject.TestTexts;
+procedure TTestDataTypes.TestTexts;
 var
     textType: TDataType.TText;
     textValue1, textValue2, castedValue: TDataType.TText.TValue;
@@ -354,7 +355,7 @@ begin
     );
 end;
 
-procedure TMyTestObject.TestTexts_OptimizedEmpty;
+procedure TTestDataTypes.TestTexts_OptimizedEmpty;
 var
     empty1, empty2: TDataType.TText.TValue;
 begin
@@ -368,7 +369,7 @@ begin
     Assert.AreEqual('', IDataValue(empty1).AsString, 'AsString of empty text should be empty');
 end;
 
-procedure TMyTestObject.TestFloats_OptimizedAndGeneric;
+procedure TTestDataTypes.TestFloats_OptimizedAndGeneric;
 var
     zero1, zero2, nan1, nan2, generic: TDataType.TFloat.TValue;
 begin
@@ -395,7 +396,7 @@ begin
     Assert.AreEqual(123.45, generic.Value, 'Value of generic float is incorrect');
 end;
 
-procedure TMyTestObject.TestTimestamps;
+procedure TTestDataTypes.TestTimestamps;
 var
     tsType: TDataType.TTimestamp;
     tsValue1, tsValue2, castedValue: TDataType.TTimestamp.TValue;
@@ -435,7 +436,7 @@ begin
     );
 end;
 
-procedure TMyTestObject.TestEnums;
+procedure TTestDataTypes.TestEnums;
 var
     colorType: TDataType.TEnum;
     red, green, blue: TDataType.TEnum.TValue;
@@ -490,7 +491,7 @@ begin
     );
 end;
 
-procedure TMyTestObject.TestAsString;
+procedure TTestDataTypes.TestAsString;
 var
     ordinalValue: TDataType.TOrdinal.TValue;
     floatValue: TDataType.TFloat.TValue;
@@ -542,7 +543,7 @@ begin
     Assert.AreEqual('(10, Tuple)', IDataValue(tupleValue).AsString, 'Tuple AsString incorrect');
 end;
 
-procedure TMyTestObject.TestAsTValue;
+procedure TTestDataTypes.TestAsTValue;
 var
     dataValue: TDataType.TValue; // Keep as generic interface to test AsTValue
     now: TDateTime;
@@ -551,21 +552,21 @@ begin
     // This test is specifically for the IDataValue.AsTValue method. No changes needed.
     // --- Ordinal ---
     dataValue := TDataType.Ordinal.CreateValue(123);
-    var tv := dataValue.AsTValue;
+    var tv := AsTValue(dataValue);
     Assert.IsFalse(tv.IsEmpty, 'Ordinal TValue should not be empty');
     Assert.AreEqual(tkInt64, tv.Kind, 'Ordinal TValue kind should be tkInt64');
     Assert.AreEqual(Int64(123), tv.AsInt64, 'Ordinal TValue content is incorrect');
 
     // --- Float ---
     dataValue := TDataType.Float.CreateValue(45.67);
-    tv := dataValue.AsTValue;
+    tv := AsTValue(dataValue);
     Assert.IsFalse(tv.IsEmpty, 'Float TValue should not be empty');
     Assert.AreEqual(tkFloat, tv.Kind, 'Float TValue kind should be tkFloat');
     Assert.AreEqual(45.67, tv.AsExtended, 'Float TValue content is incorrect');
 
     // --- Text ---
     dataValue := TDataType.Text.CreateValue('Hello');
-    tv := dataValue.AsTValue;
+    tv := AsTValue(dataValue);
     Assert.IsFalse(tv.IsEmpty, 'Text TValue should not be empty');
     Assert.AreEqual(tkUString, tv.Kind, 'Text TValue kind should be tkUString');
     Assert.AreEqual('Hello', tv.AsString, 'Text TValue content is incorrect');
@@ -573,7 +574,7 @@ begin
     // --- Timestamp ---
     now := System.SysUtils.Now;
     dataValue := TDataType.Timestamp.CreateValue(now);
-    tv := dataValue.AsTValue;
+    tv := AsTValue(dataValue);
     Assert.IsFalse(tv.IsEmpty, 'Timestamp TValue should not be empty');
     Assert.AreEqual(tkFloat, tv.Kind, 'Timestamp TValue kind is incorrect');
     Assert.AreEqual(now, tv.AsType<TDateTime>, 'Timestamp TValue content is incorrect');
@@ -581,13 +582,13 @@ begin
     // --- Enum ---
     colorType := TDataType.EnumOf('Color', ['Red', 'Green', 'Blue']);
     dataValue := colorType.CreateValue('Green');
-    tv := dataValue.AsTValue;
+    tv := AsTValue(dataValue);
     Assert.IsFalse(tv.IsEmpty, 'Enum TValue should not be empty');
     Assert.AreEqual(tkInteger, tv.Kind, 'Enum TValue kind should be tkInteger');
     Assert.AreEqual(1, tv.AsInteger, 'Enum TValue content is incorrect');
 end;
 
-procedure TMyTestObject.TestMethods;
+procedure TTestDataTypes.TestMethods;
 var
     ordinalType: TDataType.TOrdinal;
     textType: TDataType.TText;
@@ -658,7 +659,7 @@ begin
     // --- 5. Test AsString and AsTValue ---
     Assert.AreEqual('<METHOD>', IDataValue(methodValue).AsString, 'Method AsString is incorrect');
 
-    tv := TDataType.TValue(methodValue).AsTValue;
+    tv := AsTValue(methodValue);
     Assert.IsFalse(tv.IsEmpty, 'Method TValue should not be empty');
     Assert.AreEqual(tkInterface, tv.Kind, 'TValue kind for a TMethodProc should be tkInterface, as it is a reference-to-function');
     Assert.IsTrue(TypeInfo(TDataMethodProc) = tv.TypeInfo, 'TValue should hold TMethodProc type info');

Test/MycTests.dpr

@@ -35,7 +35,9 @@ uses
     Myc.Data.Types.Void in '..\Src\Data\Myc.Data.Types.Void.pas',
     Myc.Data.Types.Decimal in '..\Src\Data\Myc.Data.Types.Decimal.pas',
     Myc.Ast in '..\Src\AST\Myc.Ast.pas',
-    TestAst in '..\Src\AST\TestAst.pas';
+    TestAst in '..\Src\AST\TestAst.pas',
+    Myc.Data.Types.JSON in '..\Src\Data\Myc.Data.Types.JSON.pas',
+    TestDataTypes.JSON in '..\Src\Data\TestDataTypes.JSON.pas';
 
 { keep comment here to protect the following conditional from being removed by the IDE when adding a unit }
 {$IFNDEF TESTINSIGHT}

Test/MycTests.dproj

@@ -137,6 +137,8 @@ $(PreBuildEvent)]]></PreBuildEvent>
         <DCCReference Include="..\Src\Data\Myc.Data.Types.Decimal.pas"/>
         <DCCReference Include="..\Src\AST\Myc.Ast.pas"/>
         <DCCReference Include="..\Src\AST\TestAst.pas"/>
+        <DCCReference Include="..\Src\Data\Myc.Data.Types.JSON.pas"/>
+        <DCCReference Include="..\Src\Data\TestDataTypes.JSON.pas"/>
         <BuildConfiguration Include="Base">
             <Key>Base</Key>
         </BuildConfiguration>