Add unit tests for C# diagnostic analyzers

modules/mono/editor/Godot.NET.Sdk/Godot.NET.Sdk.sln

@@ -6,6 +6,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Godot.SourceGenerators", "G
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Godot.SourceGenerators.Sample", "Godot.SourceGenerators.Sample\Godot.SourceGenerators.Sample.csproj", "{7297A614-8DF5-43DE-9EAD-99671B26BD1F}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Godot.SourceGenerators.Tests", "Godot.SourceGenerators.Tests\Godot.SourceGenerators.Tests.csproj", "{07E6D201-35C9-4463-9B29-D16621EA733D}"
+EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "GodotSharp", "..\..\glue\GodotSharp\GodotSharp\GodotSharp.csproj", "{AEBF0036-DA76-4341-B651-A3F2856AB2FA}"
 EndProject
 Global
@@ -26,6 +28,10 @@ Global
 		{7297A614-8DF5-43DE-9EAD-99671B26BD1F}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{7297A614-8DF5-43DE-9EAD-99671B26BD1F}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{7297A614-8DF5-43DE-9EAD-99671B26BD1F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{07E6D201-35C9-4463-9B29-D16621EA733D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{07E6D201-35C9-4463-9B29-D16621EA733D}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{07E6D201-35C9-4463-9B29-D16621EA733D}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{07E6D201-35C9-4463-9B29-D16621EA733D}.Release|Any CPU.Build.0 = Release|Any CPU
 		{AEBF0036-DA76-4341-B651-A3F2856AB2FA}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{AEBF0036-DA76-4341-B651-A3F2856AB2FA}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{AEBF0036-DA76-4341-B651-A3F2856AB2FA}.Release|Any CPU.ActiveCfg = Release|Any CPU

modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators.Sample/GlobalClass.cs

@@ -0,0 +1,14 @@
+namespace Godot.SourceGenerators.Sample;
+
+[GlobalClass]
+public partial class CustomGlobalClass : GodotObject
+{
+}
+
+// This doesn't works because global classes can't have any generic type parameter.
+/*
+[GlobalClass]
+public partial class CustomGlobalClass<T> : Node
+{
+}
+*/

modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators.Sample/Godot.SourceGenerators.Sample.csproj

@@ -2,6 +2,7 @@
 
   <PropertyGroup>
     <TargetFramework>net6.0</TargetFramework>
+    <LangVersion>11</LangVersion>
   </PropertyGroup>
 
   <PropertyGroup>

modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators.Sample/MustBeVariantSamples.cs

@@ -0,0 +1,164 @@
+using System;
+using Godot.Collections;
+using Array = Godot.Collections.Array;
+
+namespace Godot.SourceGenerators.Sample;
+
+public class MustBeVariantMethods
+{
+    public void MustBeVariantMethodCalls()
+    {
+        Method<bool>();
+        Method<char>();
+        Method<sbyte>();
+        Method<byte>();
+        Method<short>();
+        Method<ushort>();
+        Method<int>();
+        Method<uint>();
+        Method<long>();
+        Method<ulong>();
+        Method<float>();
+        Method<double>();
+        Method<string>();
+        Method<Vector2>();
+        Method<Vector2I>();
+        Method<Rect2>();
+        Method<Rect2I>();
+        Method<Transform2D>();
+        Method<Vector3>();
+        Method<Vector3I>();
+        Method<Vector4>();
+        Method<Vector4I>();
+        Method<Basis>();
+        Method<Quaternion>();
+        Method<Transform3D>();
+        Method<Projection>();
+        Method<Aabb>();
+        Method<Color>();
+        Method<Plane>();
+        Method<Callable>();
+        Method<Signal>();
+        Method<GodotObject>();
+        Method<StringName>();
+        Method<NodePath>();
+        Method<Rid>();
+        Method<Dictionary>();
+        Method<Array>();
+        Method<byte[]>();
+        Method<int[]>();
+        Method<long[]>();
+        Method<float[]>();
+        Method<double[]>();
+        Method<string[]>();
+        Method<Vector2[]>();
+        Method<Vector3[]>();
+        Method<Color[]>();
+        Method<GodotObject[]>();
+        Method<StringName[]>();
+        Method<NodePath[]>();
+        Method<Rid[]>();
+
+        // This call fails because generic type is not Variant-compatible.
+        //Method<object>();
+    }
+
+    public void Method<[MustBeVariant] T>()
+    {
+    }
+
+    public void MustBeVariantClasses()
+    {
+        new ClassWithGenericVariant<bool>();
+        new ClassWithGenericVariant<char>();
+        new ClassWithGenericVariant<sbyte>();
+        new ClassWithGenericVariant<byte>();
+        new ClassWithGenericVariant<short>();
+        new ClassWithGenericVariant<ushort>();
+        new ClassWithGenericVariant<int>();
+        new ClassWithGenericVariant<uint>();
+        new ClassWithGenericVariant<long>();
+        new ClassWithGenericVariant<ulong>();
+        new ClassWithGenericVariant<float>();
+        new ClassWithGenericVariant<double>();
+        new ClassWithGenericVariant<string>();
+        new ClassWithGenericVariant<Vector2>();
+        new ClassWithGenericVariant<Vector2I>();
+        new ClassWithGenericVariant<Rect2>();
+        new ClassWithGenericVariant<Rect2I>();
+        new ClassWithGenericVariant<Transform2D>();
+        new ClassWithGenericVariant<Vector3>();
+        new ClassWithGenericVariant<Vector3I>();
+        new ClassWithGenericVariant<Vector4>();
+        new ClassWithGenericVariant<Vector4I>();
+        new ClassWithGenericVariant<Basis>();
+        new ClassWithGenericVariant<Quaternion>();
+        new ClassWithGenericVariant<Transform3D>();
+        new ClassWithGenericVariant<Projection>();
+        new ClassWithGenericVariant<Aabb>();
+        new ClassWithGenericVariant<Color>();
+        new ClassWithGenericVariant<Plane>();
+        new ClassWithGenericVariant<Callable>();
+        new ClassWithGenericVariant<Signal>();
+        new ClassWithGenericVariant<GodotObject>();
+        new ClassWithGenericVariant<StringName>();
+        new ClassWithGenericVariant<NodePath>();
+        new ClassWithGenericVariant<Rid>();
+        new ClassWithGenericVariant<Dictionary>();
+        new ClassWithGenericVariant<Array>();
+        new ClassWithGenericVariant<byte[]>();
+        new ClassWithGenericVariant<int[]>();
+        new ClassWithGenericVariant<long[]>();
+        new ClassWithGenericVariant<float[]>();
+        new ClassWithGenericVariant<double[]>();
+        new ClassWithGenericVariant<string[]>();
+        new ClassWithGenericVariant<Vector2[]>();
+        new ClassWithGenericVariant<Vector3[]>();
+        new ClassWithGenericVariant<Color[]>();
+        new ClassWithGenericVariant<GodotObject[]>();
+        new ClassWithGenericVariant<StringName[]>();
+        new ClassWithGenericVariant<NodePath[]>();
+        new ClassWithGenericVariant<Rid[]>();
+
+        // This class fails because generic type is not Variant-compatible.
+        //new ClassWithGenericVariant<object>();
+    }
+}
+
+public class ClassWithGenericVariant<[MustBeVariant] T>
+{
+}
+
+public class MustBeVariantAnnotatedMethods
+{
+    [GenericTypeAttribute<string>()]
+    public void MethodWithAttributeOk()
+    {
+    }
+
+    // This method definition fails because generic type is not Variant-compatible.
+    /*
+    [GenericTypeAttribute<object>()]
+    public void MethodWithWrongAttribute()
+    {
+    }
+    */
+}
+
+[GenericTypeAttribute<string>()]
+public class ClassVariantAnnotated
+{
+}
+
+// This class definition fails because generic type is not Variant-compatible.
+/*
+[GenericTypeAttribute<object>()]
+public class ClassNonVariantAnnotated
+{
+}
+*/
+
+[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true)]
+public class GenericTypeAttribute<[MustBeVariant] T> : Attribute
+{
+}

modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators.Tests/CSharpAnalyzerVerifier.cs

@@ -0,0 +1,56 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Testing;
+using Microsoft.CodeAnalysis.Testing.Verifiers;
+using Microsoft.CodeAnalysis.Text;
+
+namespace Godot.SourceGenerators.Tests;
+
+public static class CSharpAnalyzerVerifier<TAnalyzer>
+where TAnalyzer : DiagnosticAnalyzer, new()
+{
+    public class Test : CSharpAnalyzerTest<TAnalyzer, XUnitVerifier>
+    {
+        public Test()
+        {
+            ReferenceAssemblies = ReferenceAssemblies.Net.Net60;
+
+            SolutionTransforms.Add((Solution solution, ProjectId projectId) =>
+            {
+                Project project =
+                    solution.GetProject(projectId)!.AddMetadataReference(Constants.GodotSharpAssembly
+                        .CreateMetadataReference());
+
+                return project.Solution;
+            });
+        }
+    }
+
+    public static Task Verify(string sources, params DiagnosticResult[] expected)
+    {
+        return MakeVerifier(new string[] { sources }, expected).RunAsync();
+    }
+
+    public static Test MakeVerifier(ICollection<string> sources, params DiagnosticResult[] expected)
+    {
+        var verifier = new Test();
+
+        verifier.TestState.AnalyzerConfigFiles.Add(("/.globalconfig", $"""
+        is_global = true
+        build_property.GodotProjectDir = {Constants.ExecutingAssemblyPath}
+        """));
+
+        verifier.TestState.Sources.AddRange(sources.Select(source =>
+        {
+            return (source, SourceText.From(File.ReadAllText(Path.Combine(Constants.SourceFolderPath, source))));
+        }));
+
+        verifier.ExpectedDiagnostics.AddRange(expected);
+        return verifier;
+    }
+}

modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators.Tests/GlobalClassAnalyzerTests.cs

@@ -0,0 +1,20 @@
+using Xunit;
+
+namespace Godot.SourceGenerators.Tests;
+
+public class GlobalClassAnalyzerTests
+{
+    [Fact]
+    public async void GlobalClassMustDeriveFromGodotObjectTest()
+    {
+        const string GlobalClassGD0401 = "GlobalClass.GD0401.cs";
+        await CSharpAnalyzerVerifier<GlobalClassAnalyzer>.Verify(GlobalClassGD0401);
+    }
+
+    [Fact]
+    public async void GlobalClassMustNotBeGenericTest()
+    {
+        const string GlobalClassGD0402 = "GlobalClass.GD0402.cs";
+        await CSharpAnalyzerVerifier<GlobalClassAnalyzer>.Verify(GlobalClassGD0402);
+    }
+}

modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators.Tests/Godot.SourceGenerators.Tests.csproj

@@ -17,6 +17,8 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing.XUnit" Version="1.1.1" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.7.1" />
+    <PackageReference Include="Microsoft.CodeAnalysis.Testing.Verifiers.XUnit" Version="1.1.1" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Analyzer.Testing.XUnit" Version="1.1.1" />
     <PackageReference Include="xunit" Version="2.4.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators.Tests/MustBeVariantAnalyzerTests.cs

@@ -0,0 +1,20 @@
+using Xunit;
+
+namespace Godot.SourceGenerators.Tests;
+
+public class MustBeVariantAnalyzerTests
+{
+    [Fact]
+    public async void GenericTypeArgumentMustBeVariantTest()
+    {
+        const string MustBeVariantGD0301 = "MustBeVariant.GD0301.cs";
+        await CSharpAnalyzerVerifier<MustBeVariantAnalyzer>.Verify(MustBeVariantGD0301);
+    }
+
+    [Fact]
+    public async void GenericTypeParameterMustBeVariantAnnotatedTest()
+    {
+        const string MustBeVariantGD0302 = "MustBeVariant.GD0302.cs";
+        await CSharpAnalyzerVerifier<MustBeVariantAnalyzer>.Verify(MustBeVariantGD0302);
+    }
+}

modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators.Tests/TestData/Sources/GlobalClass.GD0401.cs

@@ -0,0 +1,22 @@
+using Godot;
+
+// This works because it inherits from GodotObject.
+[GlobalClass]
+public partial class CustomGlobalClass1 : GodotObject 
+{
+
+}
+
+// This works because it inherits from an object that inherits from GodotObject
+[GlobalClass]
+public partial class CustomGlobalClass2 : Node
+{
+
+}
+
+// This raises a GD0401 diagnostic error: global classes must inherit from GodotObject
+{|GD0401:[GlobalClass]
+public partial class CustomGlobalClass3 
+{
+
+}|}

modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators.Tests/TestData/Sources/GlobalClass.GD0402.cs

@@ -0,0 +1,15 @@
+using Godot;
+
+// This works because it inherits from GodotObject and it doesn't have any generic type parameter.
+[GlobalClass]
+public partial class CustomGlobalClass : GodotObject 
+{
+
+}
+
+// This raises a GD0402 diagnostic error: global classes can't have any generic type parameter
+{|GD0402:[GlobalClass]
+public partial class CustomGlobalClass<T> : GodotObject
+{
+
+}|}