added discriminated unions

Directory.Packages.props

@@ -1,28 +1,28 @@
 <Project>
-    <ItemGroup>
-        <PackageVersion Include="BenchmarkDotNet" Version="0.14.0"/>
-        <PackageVersion Include="CsvHelper" Version="33.0.1"/>
-        <PackageVersion Include="FluentAssertions" Version="6.12.0"/>
-        <PackageVersion Include="JetBrains.Profiler.Api" Version="1.4.6"/>
-        <PackageVersion Include="MessagePack" Version="2.5.172"/>
-        <PackageVersion Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="8.0.8"/>
-        <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.11.0"/>
-        <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Analyzer.Testing" Version="1.1.2"/>
-        <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.CodeFix.Testing" Version="1.1.2"/>
-        <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing" Version="1.1.2"/>
-        <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.11.0"/>
-        <PackageVersion Include="Microsoft.EntityFrameworkCore.Sqlite" Version="8.0.8"/>
-        <PackageVersion Include="Microsoft.EntityFrameworkCore.SqlServer" Version="8.0.8"/>
-        <PackageVersion Include="Microsoft.EntityFrameworkCore.Relational" Version="8.0.8"/>
-        <PackageVersion Include="Microsoft.Extensions.Logging.Console" Version="8.0.0"/>
-        <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.10.0"/>
-        <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="8.0.0"/>
-        <PackageVersion Include="Newtonsoft.Json" Version="13.0.3"/>
-        <PackageVersion Include="NSubstitute" Version="5.1.0"/>
-        <PackageVersion Include="NSubstitute.Analyzers.CSharp" Version="1.0.17"/>
-        <PackageVersion Include="Serilog.Extensions.Logging" Version="8.0.0"/>
-        <PackageVersion Include="Serilog.Sinks.Console" Version="6.0.0"/>
-        <PackageVersion Include="xunit" Version="2.9.0"/>
-        <PackageVersion Include="xunit.runner.visualstudio" Version="2.8.2"/>
-    </ItemGroup>
+  <ItemGroup>
+    <PackageVersion Include="BenchmarkDotNet" Version="0.14.0" />
+    <PackageVersion Include="CsvHelper" Version="33.0.1" />
+    <PackageVersion Include="FluentAssertions" Version="6.12.0" />
+    <PackageVersion Include="JetBrains.Profiler.Api" Version="1.4.8" />
+    <PackageVersion Include="MessagePack" Version="2.5.172" />
+    <PackageVersion Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="8.0.8" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.11.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Analyzer.Testing" Version="1.1.2" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.CodeFix.Testing" Version="1.1.2" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing" Version="1.1.2" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.11.0" />
+    <PackageVersion Include="Microsoft.EntityFrameworkCore.Sqlite" Version="8.0.8" />
+    <PackageVersion Include="Microsoft.EntityFrameworkCore.SqlServer" Version="8.0.8" />
+    <PackageVersion Include="Microsoft.EntityFrameworkCore.Relational" Version="8.0.8" />
+    <PackageVersion Include="Microsoft.Extensions.Logging.Console" Version="8.0.0" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />
+    <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="8.0.0" />
+    <PackageVersion Include="Newtonsoft.Json" Version="13.0.3" />
+    <PackageVersion Include="NSubstitute" Version="5.1.0" />
+    <PackageVersion Include="NSubstitute.Analyzers.CSharp" Version="1.0.17" />
+    <PackageVersion Include="Serilog.Extensions.Logging" Version="8.0.0" />
+    <PackageVersion Include="Serilog.Sinks.Console" Version="6.0.0" />
+    <PackageVersion Include="xunit" Version="2.9.0" />
+    <PackageVersion Include="xunit.runner.visualstudio" Version="2.8.2" />
+  </ItemGroup>
 </Project>

samples/Thinktecture.Runtime.Extensions.Samples/DiscriminatedUnions/DiscriminatedUnionsDemos.cs

@@ -0,0 +1,53 @@
+using Serilog;
+
+namespace Thinktecture.DiscriminatedUnions;
+
+public class DiscriminatedUnionsDemos
+{
+   public static void Demo(ILogger logger)
+   {
+      logger.Information("""
+
+
+                         ==== Demo for Union ====
+
+                         """);
+
+      TextOrNumber textOrNumberFromString = "text";
+      logger.Information("Implicitly casted from string: {TextOrNumberFromString}", textOrNumberFromString);
+
+      TextOrNumber textOrNumberFromInt = 42;
+      logger.Information("Implicitly casted from int: {TextOrNumberFromInt}", textOrNumberFromInt);
+
+      logger.Information("TextOrNumber from string: IsText = {IsText}", textOrNumberFromString.IsText);
+      logger.Information("TextOrNumber from string: IsNumber = {IsNumber}", textOrNumberFromString.IsNumber);
+      logger.Information("TextOrNumber from int: IsText = {IsText}", textOrNumberFromInt.IsText);
+      logger.Information("TextOrNumber from int: IsNumber = {IsNumber}", textOrNumberFromInt.IsNumber);
+
+      logger.Information("TextOrNumber from string: AsText = {AsText}", textOrNumberFromString.AsText);
+      logger.Information("TextOrNumber from int: AsNumber = {AsNumber}", textOrNumberFromInt.AsNumber);
+
+      logger.Information("TextOrNumber from string: Value = {Value}", textOrNumberFromString.Value);
+      logger.Information("TextOrNumber from int: Value = {Value}", textOrNumberFromInt.Value);
+
+      textOrNumberFromString.Switch(text: s => logger.Information("String Action: {Text}", s),
+                                    number: i => logger.Information("Int Action: {Number}", i));
+
+      textOrNumberFromString.Switch(logger,
+                                    text: static (l, s) => l.Information("String Action with context: {Text}", s),
+                                    number: static (l, i) => l.Information("Int Action with context: {Number}", i));
+
+      var switchResponse = textOrNumberFromInt.Switch(text: static s => $"String Func: {s}",
+                                                      number: static i => $"Int Func: {i}");
+      logger.Information("{Response}", switchResponse);
+
+      var switchResponseWithContext = textOrNumberFromInt.Switch(123.45,
+                                                                 text: static (ctx, s) => $"String Func with context: {ctx} | {s}",
+                                                                 number: static (ctx, i) => $"Int Func with context: {ctx} | {i}");
+      logger.Information("{Response}", switchResponseWithContext);
+
+      var mapResponse = textOrNumberFromString.Map(text: "Mapped string",
+                                                   number: "Mapped int");
+      logger.Information("{Response}", mapResponse);
+   }
+}

samples/Thinktecture.Runtime.Extensions.Samples/DiscriminatedUnions/TextOrNumber.cs

@@ -0,0 +1,8 @@
+namespace Thinktecture.DiscriminatedUnions;
+
+[Union<string, int>(T1IsNullableReferenceType = true,
+                    T1Name = "Text",
+                    T2Name = "Number",
+                    SwitchMethods = SwitchMapMethodsGeneration.DefaultWithPartialOverloads,
+                    MapMethods = SwitchMapMethodsGeneration.DefaultWithPartialOverloads)]
+public sealed partial class TextOrNumber;

samples/Thinktecture.Runtime.Extensions.Samples/Program.cs

@@ -1,4 +1,5 @@
 using Serilog;
+using Thinktecture.DiscriminatedUnions;
 using Thinktecture.EmptyClass;
 using Thinktecture.SmartEnums;
 using Thinktecture.ValueObjects;
@@ -13,6 +14,7 @@ public static void Main()
 
       SmartEnumDemos.Demo(logger);
       ValueObjectDemos.Demo(logger);
+      DiscriminatedUnionsDemos.Demo(logger);
       EmptyActionDemos.Demo();
       EmptyCollectionsDemos.Demo();
    }

src/Thinktecture.Runtime.Extensions.SourceGenerator/CodeAnalysis/ComparableCodeGenerator.cs

@@ -33,7 +33,7 @@ public int CompareTo(object? obj)
          return 1;
 
       if(obj is not ").AppendTypeFullyQualified(state.Type).Append(@" item)
-         throw new global::System.ArgumentException(""Argument must be of type \""").Append(state.Type.TypeMinimallyQualified).Append(@"\""."", nameof(obj));
+         throw new global::System.ArgumentException(""Argument must be of type \""").AppendTypeMinimallyQualified(state.Type).Append(@"\""."", nameof(obj));
 
       return this.CompareTo(item);
    }

src/Thinktecture.Runtime.Extensions.SourceGenerator/CodeAnalysis/Constants.cs

@@ -70,5 +70,15 @@ public static class SmartEnum
          public const string KEYED_FULL_NAME = "Thinktecture.SmartEnumAttribute`1";
          public const string KEYLESS_FULL_NAME = "Thinktecture.SmartEnumAttribute";
       }
+
+      public static class Union
+      {
+         public const string NAMESPACE = "Thinktecture";
+         public const string NAME = "UnionAttribute";
+         public const string FULL_NAME_2_TYPES = "Thinktecture.UnionAttribute`2";
+         public const string FULL_NAME_3_TYPES = "Thinktecture.UnionAttribute`3";
+         public const string FULL_NAME_4_TYPES = "Thinktecture.UnionAttribute`4";
+         public const string FULL_NAME_5_TYPES = "Thinktecture.UnionAttribute`5";
+      }
    }
 }

src/Thinktecture.Runtime.Extensions.SourceGenerator/CodeAnalysis/Diagnostics/ThinktectureRuntimeExtensionsAnalyzer.cs

@@ -41,7 +41,8 @@ public sealed class ThinktectureRuntimeExtensionsAnalyzer : DiagnosticAnalyzer
                                                                                                               DiagnosticsDescriptors.PrimaryConstructorNotAllowed,
                                                                                                               DiagnosticsDescriptors.CustomKeyMemberImplementationNotFound,
                                                                                                               DiagnosticsDescriptors.CustomKeyMemberImplementationTypeMismatch,
-                                                                                                              DiagnosticsDescriptors.IndexBasedSwitchAndMapMustUseNamedParameters);
+                                                                                                              DiagnosticsDescriptors.IndexBasedSwitchAndMapMustUseNamedParameters,
+                                                                                                              DiagnosticsDescriptors.TypeMustBeClass);
 
    /// <inheritdoc />
    public override void Initialize(AnalysisContext context)
@@ -51,6 +52,7 @@ public override void Initialize(AnalysisContext context)
 
       context.RegisterOperationAction(AnalyzeSmartEnum, OperationKind.Attribute);
       context.RegisterOperationAction(AnalyzeValueObject, OperationKind.Attribute);
+      context.RegisterOperationAction(AnalyzeUnion, OperationKind.Attribute);
 
       context.RegisterOperationAction(AnalyzeMethodCall, OperationKind.Invocation);
    }
@@ -177,6 +179,56 @@ private static void AnalyzeValueObject(OperationAnalysisContext context)
       }
    }
 
+   private static void AnalyzeUnion(OperationAnalysisContext context)
+   {
+      if (context.ContainingSymbol.Kind != SymbolKind.NamedType
+          || context.Operation is not IAttributeOperation { Operation: IObjectCreationOperation attrCreation }
+          || context.ContainingSymbol is not INamedTypeSymbol type
+          || type.TypeKind == TypeKind.Error
+          || type.DeclaringSyntaxReferences.IsDefaultOrEmpty)
+      {
+         return;
+      }
+
+      try
+      {
+         if (!attrCreation.Type.IsUnionAttribute())
+            return;
+
+         var locationOfFirstDeclaration = type.Locations.IsDefaultOrEmpty ? Location.None : type.Locations[0]; // a representative for all
+
+         ValidateUnion(context, type, attrCreation, locationOfFirstDeclaration);
+      }
+      catch (Exception ex)
+      {
+         context.ReportDiagnostic(Diagnostic.Create(DiagnosticsDescriptors.ErrorDuringCodeAnalysis,
+                                                    Location.None,
+                                                    type.ToFullyQualifiedDisplayString(), ex.Message));
+      }
+   }
+
+   private static void ValidateUnion(OperationAnalysisContext context,
+                                     INamedTypeSymbol type,
+                                     IObjectCreationOperation attribute,
+                                     Location locationOfFirstDeclaration)
+   {
+      if (type.IsRecord || type.TypeKind is not TypeKind.Class)
+      {
+         ReportDiagnostic(context, DiagnosticsDescriptors.TypeMustBeClass, locationOfFirstDeclaration, type);
+         return;
+      }
+
+      if (type.ContainingType is not null) // is nested class
+      {
+         ReportDiagnostic(context, DiagnosticsDescriptors.TypeCannotBeNestedClass, locationOfFirstDeclaration, type);
+         return;
+      }
+
+      EnsureNoPrimaryConstructor(context, type);
+      TypeMustBePartial(context, type);
+      TypeMustNotBeGeneric(context, type, locationOfFirstDeclaration, "Union");
+   }
+
    private static void ValidateKeyedValueObject(OperationAnalysisContext context,
                                                 IReadOnlyList<InstanceMemberInfo>? assignableMembers,
                                                 INamedTypeSymbol type,

src/Thinktecture.Runtime.Extensions.SourceGenerator/CodeAnalysis/DiagnosticsDescriptors.cs

@@ -29,6 +29,7 @@ internal static class DiagnosticsDescriptors
    public static readonly DiagnosticDescriptor CustomKeyMemberImplementationNotFound = new("TTRESG044", "Custom implementation of the key member not found", $"Provide a custom implementation of the key member. Implement a field or property '{{0}}'. Use '{Constants.Attributes.Properties.KEY_MEMBER_NAME}' to change the name.", nameof(ThinktectureRuntimeExtensionsAnalyzer), DiagnosticSeverity.Error, true);
    public static readonly DiagnosticDescriptor CustomKeyMemberImplementationTypeMismatch = new("TTRESG045", "Key member type mismatch", "The type of the key member '{0}' must be '{2}' instead of '{1}'", nameof(ThinktectureRuntimeExtensionsAnalyzer), DiagnosticSeverity.Error, true);
    public static readonly DiagnosticDescriptor IndexBasedSwitchAndMapMustUseNamedParameters = new("TTRESG046", "The arguments of \"Switch\" and \"Map\" must named", "Not all arguments of \"Switch/Map\" on the enumeration '{0}' are named", nameof(ThinktectureRuntimeExtensionsAnalyzer), DiagnosticSeverity.Error, true);
+   public static readonly DiagnosticDescriptor TypeMustBeClass = new("TTRESG047", "The type must be a class", "The type '{0}' must be a class", nameof(ThinktectureRuntimeExtensionsAnalyzer), DiagnosticSeverity.Error, true);
 
    public static readonly DiagnosticDescriptor ErrorDuringCodeAnalysis = new("TTRESG098", "Error during code analysis", "Error during code analysis of '{0}': '{1}'", nameof(ThinktectureRuntimeExtensionsAnalyzer), DiagnosticSeverity.Warning, true);
    public static readonly DiagnosticDescriptor ErrorDuringGeneration = new("TTRESG099", "Error during code generation", "Error during code generation for '{0}': '{1}'", nameof(ThinktectureRuntimeExtensionsAnalyzer), DiagnosticSeverity.Error, true);

src/Thinktecture.Runtime.Extensions.SourceGenerator/CodeAnalysis/DiscriminatedUnions/AllEnumSettings.cs

@@ -0,0 +1,60 @@
+namespace Thinktecture.CodeAnalysis.DiscriminatedUnions;
+
+public sealed class AllUnionSettings : IEquatable<AllUnionSettings>
+{
+   public bool SkipToString { get; }
+   public SwitchMapMethodsGeneration SwitchMethods { get; }
+   public SwitchMapMethodsGeneration MapMethods { get; }
+   public IReadOnlyList<MemberTypeSetting> MemberTypeSettings { get; }
+   public StringComparison DefaultStringComparison { get; }
+
+   public AllUnionSettings(AttributeData attribute, int numberOfMemberTypes)
+   {
+      SkipToString = attribute.FindSkipToString() ?? false;
+      SwitchMethods = attribute.FindSwitchMethods();
+      MapMethods = attribute.FindMapMethods();
+      DefaultStringComparison = attribute.FindDefaultStringComparison();
+
+      var memberTypeSettings = new MemberTypeSetting[numberOfMemberTypes];
+      MemberTypeSettings = memberTypeSettings;
+
+      for (var i = 0; i < numberOfMemberTypes; i++)
+      {
+         memberTypeSettings[i] = new MemberTypeSetting(attribute.FindTxIsNullableReferenceType(i + 1),
+                                                       attribute.FindTxName(i + 1));
+      }
+   }
+
+   public override bool Equals(object? obj)
+   {
+      return obj is AllUnionSettings enumSettings && Equals(enumSettings);
+   }
+
+   public bool Equals(AllUnionSettings? other)
+   {
+      if (other is null)
+         return false;
+      if (ReferenceEquals(this, other))
+         return true;
+
+      return SkipToString == other.SkipToString
+             && SwitchMethods == other.SwitchMethods
+             && MapMethods == other.MapMethods
+             && DefaultStringComparison == other.DefaultStringComparison
+             && MemberTypeSettings.SequenceEqual(other.MemberTypeSettings);
+   }
+
+   public override int GetHashCode()
+   {
+      unchecked
+      {
+         var hashCode = SkipToString.GetHashCode();
+         hashCode = (hashCode * 397) ^ SwitchMethods.GetHashCode();
+         hashCode = (hashCode * 397) ^ MapMethods.GetHashCode();
+         hashCode = (hashCode * 397) ^ (int)DefaultStringComparison;
+         hashCode = (hashCode * 397) ^ MemberTypeSettings.ComputeHashCode();
+
+         return hashCode;
+      }
+   }
+}

src/Thinktecture.Runtime.Extensions.SourceGenerator/CodeAnalysis/DiscriminatedUnions/MemberTypeSetting.cs

@@ -0,0 +1,34 @@
+namespace Thinktecture.CodeAnalysis.DiscriminatedUnions;
+
+public readonly struct MemberTypeSetting : IEquatable<MemberTypeSetting>, IHashCodeComputable
+{
+   public bool IsNullableReferenceType { get; }
+   public string? Name { get; }
+
+   public MemberTypeSetting(
+      bool isNullableReferenceType,
+      string? name)
+   {
+      IsNullableReferenceType = isNullableReferenceType;
+      Name = name;
+   }
+
+   public override bool Equals(object? obj)
+   {
+      return obj is MemberTypeSetting other && Equals(other);
+   }
+
+   public bool Equals(MemberTypeSetting other)
+   {
+      return IsNullableReferenceType == other.IsNullableReferenceType
+             && Name == other.Name;
+   }
+
+   public override int GetHashCode()
+   {
+      unchecked
+      {
+         return (IsNullableReferenceType.GetHashCode() * 397) ^ (Name?.GetHashCode() ?? 0);
+      }
+   }
+}