Add support for DefaultValueAttributes

src/SoapCore.Tests/Wsdl/Services/DefaultValuesAttributesService.cs

@@ -0,0 +1,49 @@
+using System.ComponentModel;
+using System.ServiceModel;
+
+namespace SoapCore.Tests.Wsdl.Services
+{
+#pragma warning disable SA1649 // File name should match first type name
+#pragma warning disable SA1402 // File may only contain a single type
+	[ServiceContract(Namespace = "http://bagov.net")]
+	public interface IDefaultValueAttributesService
+	{
+		[OperationContract]
+		DefaultValueAttributesResponseType GetResponse();
+	}
+
+	public class DefaultValueAttributesService : IDefaultValueAttributesService
+	{
+		public DefaultValueAttributesResponseType GetResponse()
+		{
+			return new DefaultValueAttributesResponseType();
+		}
+	}
+
+	public class DefaultValueAttributesResponseType
+	{
+		public bool BooleanWithNoDefaultProperty { get; set; }
+
+		[DefaultValue(null)]
+		public bool BooleanWithDefaultNullProperty { get; set; }
+
+		[DefaultValue(false)]
+		public bool BooleanWithDefaultFalseProperty { get; set; }
+
+		[DefaultValue(true)]
+		public string BooleanWithDefaultTrueProperty { get; set; }
+
+		public int IntWithNoDefaultProperty { get; set; }
+
+		[DefaultValue(42)]
+		public int IntWithDefaultProperty { get; set; }
+
+		public string StringWithNoDefaultProperty { get; set; }
+
+		[DefaultValue(null)]
+		public string StringWithDefaultNullProperty { get; set; }
+
+		[DefaultValue("default")]
+		public string StringWithDefaultProperty { get; set; }
+	}
+}

src/SoapCore.Tests/Wsdl/WsdlTests.cs

@@ -748,6 +748,46 @@ public async Task CheckMessageHeadersServiceWsdl()
 			Assert.IsNotNull(stringPropertyElement);
 		}
 
+		[TestMethod]
+		public async Task CheckDefaultValueAttributesServiceWsdl()
+		{
+			var wsdl = await GetWsdlFromMetaBodyWriter<DefaultValueAttributesService>(SoapSerializer.XmlSerializer);
+			Trace.TraceInformation(wsdl);
+			Assert.IsNotNull(wsdl);
+
+			Assert.IsFalse(wsdl.Contains("name=\"\""));
+
+			var root = XElement.Parse(wsdl);
+			var nm = Namespaces.CreateDefaultXmlNamespaceManager();
+
+			var booleanWithNoDefaultPropertyElement = root.XPathSelectElement("//xsd:element[@name='BooleanWithNoDefaultProperty' and @minOccurs='1' and @maxOccurs='1' and not(@default)]", nm);
+			Assert.IsNotNull(booleanWithNoDefaultPropertyElement);
+
+			var booleanWithDefaultNullPropertyElement = root.XPathSelectElement("//xsd:element[@name='BooleanWithDefaultNullProperty' and @minOccurs='1' and @maxOccurs='1' and not(@default)]", nm);
+			Assert.IsNotNull(booleanWithDefaultNullPropertyElement);
+
+			var booleanWithDefaultFalsePropertyElement = root.XPathSelectElement("//xsd:element[@name='BooleanWithDefaultFalseProperty' and @minOccurs='0' and @maxOccurs='1' and @default='false']", nm);
+			Assert.IsNotNull(booleanWithDefaultFalsePropertyElement);
+
+			var booleanWithDefaultTruePropertyElement = root.XPathSelectElement("//xsd:element[@name='BooleanWithDefaultTrueProperty' and @minOccurs='0' and @maxOccurs='1' and @default='true']", nm);
+			Assert.IsNotNull(booleanWithDefaultTruePropertyElement);
+
+			var intWithNoDefaultPropertyElement = root.XPathSelectElement("//xsd:element[@name='IntWithNoDefaultProperty' and @minOccurs='1' and @maxOccurs='1' and not(@default)]", nm);
+			Assert.IsNotNull(intWithNoDefaultPropertyElement);
+
+			var intWithDefaultPropertyElement = root.XPathSelectElement("//xsd:element[@name='IntWithDefaultProperty' and @minOccurs='0' and @maxOccurs='1' and @default='42']", nm);
+			Assert.IsNotNull(intWithDefaultPropertyElement);
+
+			var stringWithNoDefaultPropertyElement = root.XPathSelectElement("//xsd:element[@name='StringWithNoDefaultProperty' and @minOccurs='0' and @maxOccurs='1' and not(@default)]", nm);
+			Assert.IsNotNull(stringWithNoDefaultPropertyElement);
+
+			var stringWithDefaultNullPropertyElement = root.XPathSelectElement("//xsd:element[@name='StringWithDefaultNullProperty' and @minOccurs='0' and @maxOccurs='1' and not(@default)]", nm);
+			Assert.IsNotNull(stringWithDefaultNullPropertyElement);
+
+			var stringWithDefaultPropertyElement = root.XPathSelectElement("//xsd:element[@name='StringWithDefaultProperty' and @minOccurs='0' and @maxOccurs='1' and @default='default']", nm);
+			Assert.IsNotNull(stringWithDefaultPropertyElement);
+		}
+
 		[TestMethod]
 		public async Task CheckDataContractKnownTypeAttributeServiceWsdl()
 		{

src/SoapCore/Meta/MetaBodyWriter.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.ComponentModel;
 using System.IO;
 using System.Linq;
 using System.Reflection;
@@ -875,7 +876,20 @@ private void AddSchemaTypePropertyOrField(XmlDictionaryWriter writer, MemberInfo
 			}
 			else
 			{
-				AddSchemaType(writer, toBuild, parentTypeToBuild.ChildElementName ?? member.Name, isArray: createListWithoutProxyType, isListWithoutWrapper: createListWithoutProxyType, isUnqualified: isUnqualified);
+				string defaultValue = null;
+				var defaultAttributeValue = member.GetCustomAttribute<DefaultValueAttribute>()?.Value;
+				if (defaultAttributeValue != null)
+				{
+					if (defaultAttributeValue is bool value)
+					{
+						defaultValue = value ? "true" : "false";
+					}
+					else
+					{
+						defaultValue = defaultAttributeValue.ToString();
+					}
+				}
+				AddSchemaType(writer, toBuild, parentTypeToBuild.ChildElementName ?? member.Name, isArray: createListWithoutProxyType, isListWithoutWrapper: createListWithoutProxyType, isUnqualified: isUnqualified, defaultValue: defaultValue);
 			}
 		}
 
@@ -895,7 +909,7 @@ private void AddSchemaType(XmlDictionaryWriter writer, Type type, string name, b
 			AddSchemaType(writer, new TypeToBuild(type), name, isArray, @namespace, isAttribute, isUnqualified: isUnqualified);
 		}
 
-		private void AddSchemaType(XmlDictionaryWriter writer, TypeToBuild toBuild, string name, bool isArray = false, string @namespace = null, bool isAttribute = false, bool isListWithoutWrapper = false, bool isUnqualified = false)
+		private void AddSchemaType(XmlDictionaryWriter writer, TypeToBuild toBuild, string name, bool isArray = false, string @namespace = null, bool isAttribute = false, bool isListWithoutWrapper = false, bool isUnqualified = false, string defaultValue = null)
 		{
 			var type = toBuild.Type;
 
@@ -982,8 +996,12 @@ private void AddSchemaType(XmlDictionaryWriter writer, TypeToBuild toBuild, stri
 				}
 				else
 				{
-					writer.WriteAttributeString("minOccurs", type.IsValueType ? "1" : "0");
+					writer.WriteAttributeString("minOccurs", type.IsValueType && defaultValue == null ? "1" : "0");
 					writer.WriteAttributeString("maxOccurs", "1");
+					if (defaultValue != null)
+					{
+						writer.WriteAttributeString("default", defaultValue);
+					}
 				}
 
 				if (string.IsNullOrEmpty(name))