Ne4to · Ne4to · Mar 19, 2024 · Mar 13, 2024 · Mar 19, 2024
diff --git a/N.SourceGenerators.UnionTypes.sln b/N.SourceGenerators.UnionTypes.sln
@@ -38,6 +38,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BusinessLogic", "examples\B
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "N.SourceGenerators.UnionTypes.BehaviorTests", "tests\N.SourceGenerators.UnionTypes.BehaviorTests\N.SourceGenerators.UnionTypes.BehaviorTests.csproj", "{5DD23F15-E950-4538-BF17-8BC5A7F4F720}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "LegacyFramework", "examples\LegacyFramework\LegacyFramework.csproj", "{E90A05B8-3085-4DC6-857A-5D87ECEBC99B}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -55,6 +57,7 @@ Global
 		{3B72811B-AA6E-4263-B0E9-931648D636BC} = {432FABD2-1B70-4E29-935B-AEE6D93559E2}
 		{007DEABA-55E6-4AF8-95D7-B869D6B46126} = {432FABD2-1B70-4E29-935B-AEE6D93559E2}
 		{5DD23F15-E950-4538-BF17-8BC5A7F4F720} = {08535BFD-5C2B-4D8B-90B7-520C578BA7E4}
+		{E90A05B8-3085-4DC6-857A-5D87ECEBC99B} = {432FABD2-1B70-4E29-935B-AEE6D93559E2}
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
 		{2C39796B-5B3A-42F9-84DF-0501A44030B7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
@@ -85,5 +88,9 @@ Global
 		{5DD23F15-E950-4538-BF17-8BC5A7F4F720}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{5DD23F15-E950-4538-BF17-8BC5A7F4F720}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{5DD23F15-E950-4538-BF17-8BC5A7F4F720}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E90A05B8-3085-4DC6-857A-5D87ECEBC99B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E90A05B8-3085-4DC6-857A-5D87ECEBC99B}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E90A05B8-3085-4DC6-857A-5D87ECEBC99B}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E90A05B8-3085-4DC6-857A-5D87ECEBC99B}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal
diff --git a/examples/DataAccess/DataAccess.csproj b/examples/DataAccess/DataAccess.csproj
@@ -1,5 +1,5 @@
 <Project Sdk="Microsoft.NET.Sdk">
-
+    
     <ItemGroup>
         <ProjectReference Include="..\..\src\N.SourceGenerators.UnionTypes\N.SourceGenerators.UnionTypes.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
     </ItemGroup>

diff --git a/examples/LegacyFramework/LegacyFramework.csproj b/examples/LegacyFramework/LegacyFramework.csproj
@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netstandard2.0</TargetFramework>
+<!--        <LangVersion>8.0</LangVersion>-->
+        <ImplicitUsings>disable</ImplicitUsings>
+        <Nullable>disable</Nullable>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\..\src\N.SourceGenerators.UnionTypes\N.SourceGenerators.UnionTypes.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <None Update="Properties\launchSettings.json">
+        <CopyToOutputDirectory>Never</CopyToOutputDirectory>
+        <CopyToPublishDirectory>Never</CopyToPublishDirectory>
+        <ExcludeFromSingleFile>true</ExcludeFromSingleFile>
+      </None>
+    </ItemGroup>
+</Project>
diff --git a/examples/LegacyFramework/Properties/launchSettings.json b/examples/LegacyFramework/Properties/launchSettings.json
@@ -0,0 +1,8 @@
+{
+    "profiles": {
+      "Debug Generators": {
+        "commandName": "DebugRoslynComponent",
+        "targetProject": "LegacyFramework.csproj"
+      }
+    }
+  }
diff --git a/examples/LegacyFramework/Result.cs b/examples/LegacyFramework/Result.cs
@@ -0,0 +1,25 @@
+using N.SourceGenerators.UnionTypes;
+
+namespace LegacyFramework
+{
+    public class Foo
+    {
+    }
+
+    public class Bar
+    {
+    }
+
+
+    [UnionType(typeof(Foo))]
+    [UnionType(typeof(Bar))]
+    public partial class Result
+    {
+    }
+
+    [UnionType(typeof(Foo))]
+    [UnionType(typeof(Bar))]
+    public partial struct StructResult
+    {
+    }
+}
diff --git a/src/N.SourceGenerators.UnionTypes/Extensions/ConditionalSyntaxExtensions.cs b/src/N.SourceGenerators.UnionTypes/Extensions/ConditionalSyntaxExtensions.cs
@@ -125,4 +125,14 @@ public static ParameterSyntax AddAttributeListsWhen(
             ? syntax.AddAttributeLists(items)
             : syntax;
     }
+
+    public static SyntaxTriviaList AddWhen(
+        this SyntaxTriviaList syntax,
+        bool condition,
+        SyntaxTrivia trivia)
+    {
+        return condition
+            ? syntax.Add(trivia)
+            : syntax;
+    }
 }
diff --git a/src/N.SourceGenerators.UnionTypes/Helpers/RoslynUtils.cs b/src/N.SourceGenerators.UnionTypes/Helpers/RoslynUtils.cs
@@ -70,6 +70,14 @@ public static ThrowStatementSyntax ThrowInvalidOperationException(ExpressionSynt
             SyntaxFactory.Argument(expression)
         );
     }
+
+    public static ThrowStatementSyntax ThrowArgumentNullException(ExpressionSyntax expression)
+    {
+        return ThrowException(
+            "System.ArgumentNullException",
+            SyntaxFactory.Argument(expression)
+        );
+    }
 
     public static ThrowStatementSyntax ThrowException(string type, params ArgumentSyntax[] arguments)
     {

diff --git a/src/N.SourceGenerators.UnionTypes/Models/CompilationContext.cs b/src/N.SourceGenerators.UnionTypes/Models/CompilationContext.cs
@@ -0,0 +1,7 @@
+namespace N.SourceGenerators.UnionTypes.Models;
+
+internal record CompilationContext(
+    bool SupportsNotNullWhenAttribute, 
+    bool SupportsThrowIfNull, 
+    bool NullableContextEnabled,
+    bool SupportsAutoDefaultField);
diff --git a/src/N.SourceGenerators.UnionTypes/N.SourceGenerators.UnionTypes.csproj b/src/N.SourceGenerators.UnionTypes/N.SourceGenerators.UnionTypes.csproj
@@ -2,15 +2,15 @@
 
     <PropertyGroup>
         <TargetFramework>netstandard2.0</TargetFramework>
-        <LangVersion>11</LangVersion>
+        <LangVersion>12</LangVersion>
         <!-- Generates a package at build -->
         <GeneratePackageOnBuild>false</GeneratePackageOnBuild>
         <!-- Do not include the generator as a lib dependency -->
         <IncludeBuildOutput>false</IncludeBuildOutput>
         <IsRoslynComponent>true</IsRoslynComponent>
         <IsPackable>true</IsPackable>
         <PackageOutputPath>./nupkg</PackageOutputPath>
-        <VersionPrefix>0.26.0</VersionPrefix>
+        <VersionPrefix>0.27.0</VersionPrefix>
         <EnableNETAnalyzers>true</EnableNETAnalyzers>
         <NoWarn>$(NoWarn);NU5128</NoWarn>
     </PropertyGroup>

diff --git a/src/N.SourceGenerators.UnionTypes/UnionTypesGenerator.Attributes.cs b/src/N.SourceGenerators.UnionTypes/UnionTypesGenerator.Attributes.cs
@@ -15,7 +15,9 @@ public partial class UnionTypesGenerator
 
     private const string UnionTypeAttributeText = $$"""
         {{AutoGeneratedComment}}
+        #if NETCOREAPP3_1_OR_GREATER
         #nullable enable
+        #endif
         using System;
         using System.Runtime.CompilerServices;
 
@@ -25,12 +27,24 @@ namespace N.SourceGenerators.UnionTypes
             internal sealed class UnionTypeAttribute : Attribute
             {
                 public Type Type { get; }
+        #if NETCOREAPP3_1_OR_GREATER
                 public string? Alias { get; }
+        #else
+                public string Alias { get; }
+        #endif
                 public int Order { get; }
                 public bool AllowNull { get; set; }
+        #if NETCOREAPP3_1_OR_GREATER
                 public object? TypeDiscriminator { get; set; }
-
+        #else
+                public object TypeDiscriminator { get; set; }
+        #endif
+
+        #if NETCOREAPP3_1_OR_GREATER
                 public UnionTypeAttribute(Type type, string? alias = null, [CallerLineNumber] int order = 0)
+        #else
+                public UnionTypeAttribute(Type type, string alias = null, [CallerLineNumber] int order = 0)
+        #endif
                 {
                     Type = type;
                     Alias = alias;
@@ -42,7 +56,9 @@ public UnionTypeAttribute(Type type, string? alias = null, [CallerLineNumber] in
 
     private const string GenericUnionTypeAttributeText = $$"""
         {{AutoGeneratedComment}}
+        #if NETCOREAPP3_1_OR_GREATER
         #nullable enable
+        #endif
         using System;
         using System.Runtime.CompilerServices;
 
@@ -51,16 +67,24 @@ namespace N.SourceGenerators.UnionTypes
             [AttributeUsage(AttributeTargets.GenericParameter, Inherited = false, AllowMultiple = false)]
             internal sealed class GenericUnionTypeAttribute : Attribute
             {
+        #if NETCOREAPP3_1_OR_GREATER
                 public string? Alias { get; set; }
                 public bool AllowNull { get; set; }
                 public object? TypeDiscriminator { get; set; }
+        #else
+                public string Alias { get; set; }
+                public bool AllowNull { get; set; }
+                public object TypeDiscriminator { get; set; }
+        #endif
             }
         }
         """;
 
     private const string JsonPolymorphicUnionAttributeText = $$"""
         {{AutoGeneratedComment}}
+        #if NETCOREAPP3_1_OR_GREATER
         #nullable enable
+        #endif
         using System;
         using System.Runtime.CompilerServices;
 
@@ -69,14 +93,20 @@ namespace N.SourceGenerators.UnionTypes
             [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct, Inherited = false, AllowMultiple = false)]
             internal sealed class JsonPolymorphicUnionAttribute : Attribute
             {
+        #if NETCOREAPP3_1_OR_GREATER
                 public string? TypeDiscriminatorPropertyName { get; set; }
+        #else
+                public string TypeDiscriminatorPropertyName { get; set; }
+        #endif    
             }
         }
         """;
 
     private const string UnionConverterFromAttributeText = $$"""
         {{AutoGeneratedComment}}
+        #if NETCOREAPP3_1_OR_GREATER
         #nullable enable
+        #endif
         using System;
         using System.Runtime.CompilerServices;
 
@@ -97,7 +127,9 @@ public UnionConverterFromAttribute(Type fromType)
 
     private const string UnionConverterToAttributeText = $$"""
         {{AutoGeneratedComment}}
+        #if NETCOREAPP3_1_OR_GREATER
         #nullable enable
+        #endif
         using System;
         using System.Runtime.CompilerServices;
 
@@ -117,7 +149,9 @@ public UnionConverterToAttribute(Type toType)
         """;
 
     private const string UnionConverterAttributeText = """
+        #if NETCOREAPP3_1_OR_GREATER
         #nullable enable
+        #endif
         using System;
         using System.Runtime.CompilerServices;
 
@@ -128,9 +162,17 @@ sealed class UnionConverterAttribute : Attribute
             {
                 public Type FromType { get; }
                 public Type ToType { get; }
+        #if NETCOREAPP3_1_OR_GREATER
                 public string? MethodName { get; }
+        #else
+                public string MethodName { get; }
+        #endif        
 
+        #if NETCOREAPP3_1_OR_GREATER
                 public UnionConverterAttribute(Type fromType, Type toType, string? methodName = null)
+        #else
+                public UnionConverterAttribute(Type fromType, Type toType, string methodName = null)
+        #endif
                 {
                     FromType = fromType;
                     ToType = toType;