Add initial support for global configuration.

src/MapTo/Configuration/AccessModifier.cs

@@ -0,0 +1,9 @@
+namespace MapTo.Configuration
+{
+    internal enum AccessModifier
+    {
+        Public,
+        Internal,
+        Private
+    }
+}

src/MapTo/Configuration/MapToConfigurations.cs

@@ -0,0 +1,26 @@
+using System;
+using Microsoft.CodeAnalysis;
+
+namespace MapTo.Configuration
+{
+    internal sealed class MapToConfigurations
+    {
+        private MapToConfigurations(AccessModifier constructorAccessModifier)
+        {
+            ConstructorAccessModifier = constructorAccessModifier;
+        }
+
+        internal AccessModifier ConstructorAccessModifier { get; }
+
+        internal static MapToConfigurations From(GeneratorExecutionContext context)
+        {
+            var constructorAccessModifier = 
+                context.AnalyzerConfigOptions.GlobalOptions.TryGetValue("build_property.MapTo_ConstructorAccessModifier", out var ctorModifierValue) && 
+                Enum.TryParse<AccessModifier>(ctorModifierValue, out var ctorModifier) ? ctorModifier : AccessModifier.Public;
+
+            return new MapToConfigurations(
+                constructorAccessModifier
+            );
+        }
+    }
+}

src/MapTo/MapTo.csproj

@@ -4,7 +4,7 @@
         <TargetFramework>netstandard2.0</TargetFramework>
         <Nullable>enable</Nullable>
         <LangVersion>9</LangVersion>
-        
+
         <AssemblyName>MapTo</AssemblyName>
         <Description>An object to object mapping generator using Roslyn source generator.</Description>
         <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
@@ -25,7 +25,7 @@
             <_Parameter1>$(AssemblyName).Tests</_Parameter1>
         </AssemblyAttribute>
     </ItemGroup>
-    
+
     <ItemGroup>
         <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.2">
             <PrivateAssets>all</PrivateAssets>
@@ -34,12 +34,10 @@
         <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="3.8.0" />
     </ItemGroup>
 
-    <ItemGroup>
-      <None Remove="bin\Debug\netstandard2.0\MapTo.dll" />
-    </ItemGroup>
-
     <ItemGroup>
         <None Include="..\..\LICENSE" Pack="true" PackagePath="" Visible="false" />
         <None Include="$(OutputPath)\$(AssemblyName).dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false" />
+        <None Include="MapTo.props" Pack="true" PackagePath="build" Visible="false" />
     </ItemGroup>
+    
 </Project>

src/MapTo/MapTo.props

@@ -0,0 +1,5 @@
+<Project>
+    <ItemGroup>
+        <CompilerVisibleProperty Include="MapTo_ConstructorAccessModifier" />
+    </ItemGroup>
+</Project>

src/MapTo/MapToGenerator.cs

@@ -1,6 +1,7 @@
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Linq;
+using MapTo.Configuration;
 using MapTo.Extensions;
 using MapTo.Models;
 using Microsoft.CodeAnalysis;
@@ -31,15 +32,19 @@ namespace MapTo
 
         private static void AddGeneratedMappingsClasses(GeneratorExecutionContext context, IEnumerable<ClassDeclarationSyntax> candidateClasses)
         {
+            var configs = MapToConfigurations.From(context);
+            
             foreach (var classSyntax in candidateClasses)
             {
-                var model = CreateModel(context, classSyntax);
+                
+                var model = CreateModel(context, classSyntax, configs);
                 if (model is null)
                 {
                     continue;
                 }
-
+                
                 var (source, hintName) = SourceBuilder.GenerateSource(model);
+
                 context.AddSource(hintName, source);
                 context.ReportDiagnostic(Diagnostics.ClassMappingsGenerated(classSyntax.GetLocation(), model.ClassName));
             }
@@ -58,8 +63,8 @@ namespace MapTo
 
             return sourceTypeExpressionSyntax is not null ? model.GetTypeInfo(sourceTypeExpressionSyntax.Type).Type as INamedTypeSymbol : null;
         }
-
-        private static MapModel? CreateModel(GeneratorExecutionContext context, ClassDeclarationSyntax classSyntax)
+        
+        private static MapModel? CreateModel(GeneratorExecutionContext context, ClassDeclarationSyntax classSyntax, MapToConfigurations configs)
         {
             var root = classSyntax.GetCompilationUnit();
             var classSemanticModel = context.Compilation.GetSemanticModel(classSyntax.SyntaxTree);
@@ -86,7 +91,7 @@ namespace MapTo
                 context.ReportDiagnostic(Diagnostics.NoMatchingPropertyFoundError(classSyntax.GetLocation(), className, sourceClassName));
                 return null;
             }
-
+            
             return new MapModel(
                 root.GetNamespace(),
                 classSyntax.Modifiers,
@@ -94,7 +99,8 @@ namespace MapTo
                 sourceTypeSymbol.ContainingNamespace.ToString(),
                 sourceClassName,
                 sourceTypeSymbol.ToString(),
-                mappedProperties);
+                mappedProperties,
+                configs.ConstructorAccessModifier);
         }
         
         private static ImmutableArray<string> GetMappedProperties(ITypeSymbol classSymbol, ITypeSymbol sourceTypeSymbol)

src/MapTo/Models/MapModel.cs

@@ -1,9 +1,10 @@
 using System.Collections.Immutable;
+using MapTo.Configuration;
 using Microsoft.CodeAnalysis;
 
 namespace MapTo.Models
 {
-    public class MapModel
+    internal class MapModel
     {
         internal MapModel(
             string? ns,
@@ -12,7 +13,8 @@ namespace MapTo.Models
             string sourceNamespace,
             string sourceClassName,
             string sourceClassFullName,
-            ImmutableArray<string> mappedProperties)
+            ImmutableArray<string> mappedProperties, 
+            AccessModifier constructorAccessModifier)
         {
             Namespace = ns;
             ClassModifiers = classModifiers;
@@ -21,6 +23,7 @@ namespace MapTo.Models
             SourceClassName = sourceClassName;
             SourceClassFullName = sourceClassFullName;
             MappedProperties = mappedProperties;
+            ConstructorAccessModifier = constructorAccessModifier;
         }
 
         public string? Namespace { get; }
@@ -36,5 +39,7 @@ namespace MapTo.Models
         public string SourceClassFullName { get; }
 
         public ImmutableArray<string> MappedProperties { get; }
+        
+        public AccessModifier ConstructorAccessModifier { get; }
     }
 }

src/MapTo/SourceBuilder.cs

@@ -132,7 +132,7 @@ namespace MapTo
                 .PadLeft(Indent2).AppendFormat("/// using the property values from the specified <paramref name=\"{0}\"/>.", sourceClassParameterName).AppendLine()
                 .PadLeft(Indent2).AppendLine("/// </summary>")
                 .PadLeft(Indent2).AppendFormat("/// <exception cref=\"ArgumentNullException\">{0} is null</exception>", sourceClassParameterName).AppendLine()
-                .PadLeft(Indent2).AppendFormat("public {0}({1} {2})", model.ClassName, model.SourceClassFullName, sourceClassParameterName)
+                .PadLeft(Indent2).AppendFormat("{0} {1}({2} {3})", model.ConstructorAccessModifier.ToString().ToLower(), model.ClassName, model.SourceClassFullName, sourceClassParameterName)
                 .AppendOpeningBracket(Indent2)
                 .PadLeft(Indent3).AppendFormat("if ({0} == null) throw new ArgumentNullException(nameof({0}));", sourceClassParameterName).AppendLine()
                 .AppendLine();

test/TestConsoleApp/Program.cs

@@ -1,13 +1,5 @@
-using TestConsoleApp.ViewModels;
+using VM = TestConsoleApp.ViewModels;
+using Data = TestConsoleApp.Data.Models;
 
-namespace TestConsoleApp
-{
-    internal class Program
-    {
-        private static void Main(string[] args)
-        {
-            var userViewModel = User.From(new Data.Models.User());
-            var userViewModel2 = UserViewModel.From(new Data.Models.User());
-        }
-    }
-}
+var userViewModel = VM.User.From(new Data.User());
+var userViewModel2 = VM.UserViewModel.From(new Data.User()); 

test/TestConsoleApp/TestConsoleApp.csproj

@@ -6,6 +6,11 @@
     </PropertyGroup>
 
     <ItemGroup>
-      <ProjectReference Include="..\..\src\MapTo\MapTo.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
+        <ProjectReference Include="..\..\src\MapTo\MapTo.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false"/>
     </ItemGroup>
+
+    <Import Project="..\..\src\MapTo\MapTo.props"/>
+    <PropertyGroup>
+        <MapTo_ConstructorAccessModifier>Internal</MapTo_ConstructorAccessModifier>
+    </PropertyGroup>
 </Project>