From 1e7f22a211c922b714d4c530666dc3c0d7635b3c Mon Sep 17 00:00:00 2001
From: Frederik Gheysels <frederik.gheysels@codit.eu>
Date: Wed, 13 Dec 2023 21:53:39 +0100
Subject: [PATCH] Do not generate DataType property in Xml serialization
 property

---
 .../DateTimeTypeTests.cs                      | 59 ++++++++++++++++++-
 XmlSchemaClassGenerator/TypeModel.cs          |  4 +-
 2 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/XmlSchemaClassGenerator.Tests/DateTimeTypeTests.cs b/XmlSchemaClassGenerator.Tests/DateTimeTypeTests.cs
index e51ed7b..5cd62ce 100644
--- a/XmlSchemaClassGenerator.Tests/DateTimeTypeTests.cs
+++ b/XmlSchemaClassGenerator.Tests/DateTimeTypeTests.cs
@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Reflection.Metadata;
 using System.Text;
 using System.Threading.Tasks;
 using System.Xml.Schema;
@@ -46,10 +47,66 @@ private static IEnumerable<string> ConvertXml(string xsd, Generator generatorPro
             return writer.Content;
         }
 
+        [Fact]
+        public void WhenDateTimeOffsetIsUsed_NoDataTypePropertyIsPresent()
+        {
+            var xsd = @$"<?xml version=""1.0"" encoding=""UTF-8""?>
+<xs:schema elementFormDefault=""qualified"" xmlns:xs=""http://www.w3.org/2001/XMLSchema"">
+	<xs:complexType name=""document"">
+		<xs:sequence>
+			<xs:element name=""someDate"" type=""xs:dateTime"" />
+		</xs:sequence>
+	</xs:complexType>
+</xs:schema>";
+
+            var generatedType = ConvertXml(
+                xsd, new()
+                {
+                    NamespaceProvider = new()
+                    {
+                        GenerateNamespace = _ => "Test"
+                    },
+                    DateTimeWithTimeZone = true
+                });
+
+            var expectedXmlSerializationAttribute = "[System.Xml.Serialization.XmlElementAttribute(\"someDate\")]";
+            var generatedProperty = generatedType.First();
+
+            Assert.Contains(expectedXmlSerializationAttribute, generatedProperty);
+        }
+
+        [Fact]
+        public void WhenDateTimeOffsetIsNotUsed_DataTypePropertyIsPresent()
+        {
+            var xsd = @$"<?xml version=""1.0"" encoding=""UTF-8""?>
+<xs:schema elementFormDefault=""qualified"" xmlns:xs=""http://www.w3.org/2001/XMLSchema"">
+	<xs:complexType name=""document"">
+		<xs:sequence>
+			<xs:element name=""someDate"" type=""xs:dateTime"" />
+		</xs:sequence>
+	</xs:complexType>
+</xs:schema>";
+
+            var generatedType = ConvertXml(
+                xsd, new()
+                {
+                    NamespaceProvider = new()
+                    {
+                        GenerateNamespace = _ => "Test"
+                    },
+                    DateTimeWithTimeZone = false
+                });
+
+            var expectedXmlSerializationAttribute = "[System.Xml.Serialization.XmlElementAttribute(\"someDate\", DataType=\"dateTime\")]";
+            var generatedProperty = generatedType.First();
+
+            Assert.Contains(expectedXmlSerializationAttribute, generatedProperty);
+        }
+
         [Theory]
         [InlineData(false, "System.DateTime")]
         [InlineData(true, "System.DateTimeOffset")]
-        public void TestFallbackType(bool dateTimeWithTimeZone, string expectedType)
+        public void TestCorrectDateTimeDataType(bool dateTimeWithTimeZone, string expectedType)
         {
             var xsd = @$"<?xml version=""1.0"" encoding=""UTF-8""?>
 <xs:schema elementFormDefault=""qualified"" xmlns:xs=""http://www.w3.org/2001/XMLSchema"">
diff --git a/XmlSchemaClassGenerator/TypeModel.cs b/XmlSchemaClassGenerator/TypeModel.cs
index 2e954fc..5dcfacc 100644
--- a/XmlSchemaClassGenerator/TypeModel.cs
+++ b/XmlSchemaClassGenerator/TypeModel.cs
@@ -1092,7 +1092,9 @@ private IEnumerable<CodeAttributeDeclaration> GetAttributes(bool isArray, TypeMo
                     while (xmlSchemaType != null)
                     {
                         var qualifiedName = xmlSchemaType.GetQualifiedName();
-                        if (qualifiedName.Namespace == XmlSchema.Namespace && qualifiedName.Name != "anySimpleType")
+
+                        if ((qualifiedName.Namespace == XmlSchema.Namespace && qualifiedName.Name != "anySimpleType") &&
+                            (xmlSchemaType.Datatype.ValueType == typeof(DateTime) && configuration.DateTimeWithTimeZone) == false)
                         {
                             args.Add(new("DataType", new CodePrimitiveExpression(qualifiedName.Name)));
                             break;