Inject Update method

src/MapTo/MapTo.csproj

@@ -44,4 +44,8 @@
         <None Include="MapTo.props" Pack="true" PackagePath="build" Visible="false" />
     </ItemGroup>
 
+    <ItemGroup>
+      <Folder Include="bin\Release\netstandard2.0" />
+    </ItemGroup>
+    
 </Project>

src/MapTo/Sources/MapClassSource.cs

@@ -33,6 +33,7 @@ namespace MapTo.Sources
                     .GeneratePrivateConstructor(model)
                     .WriteLine()
                     .GenerateFactoryMethod(model)
+                    .GenerateUpdateMethod(model)
 
                     // End class declaration
                     .WriteClosingBracket()
@@ -80,15 +81,25 @@ namespace MapTo.Sources
                 .WriteLine($"if ({sourceClassParameterName} == null) throw new ArgumentNullException(nameof({sourceClassParameterName}));")
                 .WriteLine()
                 .WriteLine($"{mappingContextParameterName}.{MappingContextSource.RegisterMethodName}({sourceClassParameterName}, this);")
-                .WriteLine();
+                .WriteLine().
 
+            WriteProperties( model, sourceClassParameterName, mappingContextParameterName);
+
+            // End constructor declaration
+            return builder.WriteClosingBracket();
+        }
+
+        private static SourceBuilder WriteProperties(this SourceBuilder builder, MappingModel model,
+            string? sourceClassParameterName, string mappingContextParameterName)
+        {
             foreach (var property in model.MappedProperties)
             {
                 if (property.TypeConverter is null)
                 {
                     if (property.IsEnumerable)
                     {
-                        builder.WriteLine($"{property.Name} = {sourceClassParameterName}.{property.SourcePropertyName}.Select({mappingContextParameterName}.{MappingContextSource.MapMethodName}<{property.MappedSourcePropertyTypeName}, {property.EnumerableTypeArgument}>).ToList();");
+                        builder.WriteLine(
+                            $"{property.Name} = {sourceClassParameterName}.{property.SourcePropertyName}.Select({mappingContextParameterName}.{MappingContextSource.MapMethodName}<{property.MappedSourcePropertyTypeName}, {property.EnumerableTypeArgument}>).ToList();");
                     }
                     else
                     {
@@ -103,12 +114,13 @@ namespace MapTo.Sources
                         ? "null"
                         : $"new object[] {{ {string.Join(", ", property.TypeConverterParameters)} }}";
 
-                    builder.WriteLine($"{property.Name} = new {property.TypeConverter}().Convert({sourceClassParameterName}.{property.SourcePropertyName}, {parameters});");
-                }
+                    builder.WriteLine(
+                        $"{property.Name} = new {property.TypeConverter}().Convert({sourceClassParameterName}.{property.SourcePropertyName}, {parameters});");
                 }
 
-            // End constructor declaration
-            return builder.WriteClosingBracket();
+            }
+            return builder;
+
         }
 
         private static SourceBuilder GenerateFactoryMethod(this SourceBuilder builder, MappingModel model)
@@ -124,6 +136,20 @@ namespace MapTo.Sources
                 .WriteClosingBracket();
         }
         
+        private static SourceBuilder GenerateUpdateMethod(this SourceBuilder builder, MappingModel model)
+        {
+            var sourceClassParameterName = model.SourceTypeIdentifierName.ToCamelCase();
+
+             builder
+                .GenerateUpdaterMethodsXmlDocs(model, sourceClassParameterName)
+                .WriteLine($"public void {model.Options.NullableReferenceSyntax}Update({model.SourceType}{model.Options.NullableReferenceSyntax} {sourceClassParameterName})")
+                .WriteOpeningBracket()
+                .WriteProperties( model, sourceClassParameterName,"context" )
+                .WriteClosingBracket();
+
+             return builder;
+        }
+        
         private static SourceBuilder GenerateConvertorMethodsXmlDocs(this SourceBuilder builder, MappingModel model, string sourceClassParameterName)
         {
             if (!model.Options.GenerateXmlDocument)
@@ -140,6 +166,21 @@ namespace MapTo.Sources
                 .WriteLine($"/// <returns>A new instance of <see cred=\"{model.TypeIdentifierName}\"/> -or- <c>null</c> if <paramref name=\"{sourceClassParameterName}\"/> is <c>null</c>.</returns>");
         }
         
+        private static SourceBuilder GenerateUpdaterMethodsXmlDocs(this SourceBuilder builder, MappingModel model, string sourceClassParameterName)
+        {
+            if (!model.Options.GenerateXmlDocument)
+            {
+                return builder;
+            }
+
+            return builder
+                .WriteLine("/// <summary>")
+                .WriteLine($"/// Updates <see cref=\"{model.TypeIdentifierName}\"/> and sets its participating properties")
+                .WriteLine($"/// using the property values from <paramref name=\"{sourceClassParameterName}\"/>.")
+                .WriteLine("/// </summary>")
+                .WriteLine($"/// <param name=\"{sourceClassParameterName}\">The instance of <see cref=\"{model.SourceType}\"/> to use as source.</param>");
+        }
+
         private static SourceBuilder GenerateSourceTypeExtensionClass(this SourceBuilder builder, MappingModel model)
         {
             return builder

src/MapTo/Sources/MapRecordSource.cs

@@ -32,6 +32,7 @@ namespace MapTo.Sources
 
             builder
                 .GeneratePrivateConstructor(model)
+                
                 .WriteLine()
                 .GenerateFactoryMethod(model)
 
@@ -42,6 +43,7 @@ namespace MapTo.Sources
                 // Extension class declaration
                 .GenerateSourceTypeExtensionClass(model)
                 
+
                 // End namespace declaration
                 .WriteClosingBracket();
 
@@ -75,8 +77,25 @@ namespace MapTo.Sources
             builder
                 .WriteLine($"private protected {model.TypeIdentifierName}({MappingContextSource.ClassName} {mappingContextParameterName}, {model.SourceType} {sourceClassParameterName})")
                 .Indent()
-                .Write(": this(");
+                .Write(": this(").
 
+            WriteProperties(model, sourceClassParameterName, mappingContextParameterName)
+
+            .WriteLine(")")
+                .Unindent()
+                .WriteOpeningBracket()
+                .WriteLine($"if ({mappingContextParameterName} == null) throw new ArgumentNullException(nameof({mappingContextParameterName}));")
+                .WriteLine($"if ({sourceClassParameterName} == null) throw new ArgumentNullException(nameof({sourceClassParameterName}));")
+                .WriteLine()
+                .WriteLine($"{mappingContextParameterName}.{MappingContextSource.RegisterMethodName}({sourceClassParameterName}, this);");
+
+            // End constructor declaration
+            return builder.WriteClosingBracket();
+        }
+
+        private static SourceBuilder WriteProperties(this SourceBuilder builder, MappingModel model, string sourceClassParameterName,
+            string mappingContextParameterName)
+        {
             for (var i = 0; i < model.MappedProperties.Length; i++)
             {
                 var property = model.MappedProperties[i];
@@ -100,7 +119,8 @@ namespace MapTo.Sources
                         ? "null"
                         : $"new object[] {{ {string.Join(", ", property.TypeConverterParameters)} }}";
 
-                    builder.Write($"{property.Name}: new {property.TypeConverter}().Convert({sourceClassParameterName}.{property.SourcePropertyName}, {parameters})");
+                    builder.Write(
+                        $"{property.Name}: new {property.TypeConverter}().Convert({sourceClassParameterName}.{property.SourcePropertyName}, {parameters})");
                 }
 
                 if (i < model.MappedProperties.Length - 1)
@@ -109,16 +129,7 @@ namespace MapTo.Sources
                 }
             }
 
-            builder.WriteLine(")")
-                .Unindent()
-                .WriteOpeningBracket()
-                .WriteLine($"if ({mappingContextParameterName} == null) throw new ArgumentNullException(nameof({mappingContextParameterName}));")
-                .WriteLine($"if ({sourceClassParameterName} == null) throw new ArgumentNullException(nameof({sourceClassParameterName}));")
-                .WriteLine()
-                .WriteLine($"{mappingContextParameterName}.{MappingContextSource.RegisterMethodName}({sourceClassParameterName}, this);");
-
-            // End constructor declaration
-            return builder.WriteClosingBracket();
+            return builder;
         }
 
         private static SourceBuilder GenerateFactoryMethod(this SourceBuilder builder, MappingModel model)

version.json

@@ -1,6 +1,6 @@
 {
   "$schema": "https://raw.githubusercontent.com/dotnet/Nerdbank.GitVersioning/master/src/NerdBank.GitVersioning/version.schema.json",
-  "version": "0.7",
+  "version": "0.8",
   "semVer1NumericIdentifierPadding": 1,
   "publicReleaseRefSpec": [
     "^refs/heads/master$",