chore: Use TUnit for the unit test, cleanup state (#1459)

* chore: Use TUnit for the unit test, cleanup state

* exclude tests folders from coverage

Author: glennawatson

.claude/settings.local.json

@@ -0,0 +1,6 @@
+ignore:
+  - src/tests
+  - "**/Tests/"
+  - "**/*.Tests/"
+  - "**/*.Test/"
+  - "**/TestRunner.*/"

CLAUDE.md

@@ -64,11 +64,8 @@
     <TreatWarningsAsErrors>falseTreatWarningsAsErrors>
   PropertyGroup>
   <PropertyGroup Condition="'$(IsTestProject)' == 'true'">
-    <EnableNUnitRunner>trueEnableNUnitRunner>
     <TestingPlatformDotnetTestSupport>trueTestingPlatformDotnetTestSupport>
-  PropertyGroup>
-  <PropertyGroup Condition="$(IsTestProject) or $(MSBuildProjectName.Contains('TestRunner'))">
-    <NoWarn>$(NoWarn);CA1031;CA1034;CA1040;CA1515;CA1707;CA1852;CA2000;CA2201NoWarn>
+    <NoWarn>$(NoWarn);CS1591NoWarn>
   PropertyGroup>
   <PropertyGroup Condition="'$(GITHUB_ACTIONS)' == 'true'">
     <ContinuousIntegrationBuild>trueContinuousIntegrationBuild>
@@ -81,17 +78,12 @@
       <CopyToOutputDirectory>PreserveNewestCopyToOutputDirectory>
     None>
 
+    <PackageReference Include="TUnit"/>
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
-    <PackageReference Include="NUnit" />
-    <PackageReference Include="NUnit3TestAdapter" />
+    <PackageReference Include="Verify.TUnit"/>
     <PackageReference Include="Microsoft.Testing.Extensions.CodeCoverage" />
-  ItemGroup>
-
-  <ItemGroup Condition="$(IsTestProject) or $(MSBuildProjectName.Contains('TestRunner'))">
-    <PackageReference Include="NUnit.Analyzers" />
     <PackageReference Include="Microsoft.Reactive.Testing" />
     <PackageReference Include="PublicApiGenerator" />
-    <PackageReference Include="Verify.NUnit" />
   ItemGroup>
 
   <ItemGroup Condition="'$(IsTestProject)' != 'true'">

codecov.yml

@@ -28,10 +28,8 @@
     <PackageVersion Include="System.Net.Http" Version="4.3.4" />
     <PackageVersion Include="System.Reactive" Version="6.1.0" />
     <PackageVersion Include="System.Text.RegularExpressions" Version="4.3.1" />
-    <PackageVersion Include="NUnit" Version="4.4.0" />
-    <PackageVersion Include="NUnit3TestAdapter" Version="6.0.1" />
-    <PackageVersion Include="NUnit.Analyzers" Version="4.11.2" />
-    <PackageVersion Include="Verify.NUnit" Version="31.9.2" />
+    <PackageVersion Include="TUnit" Version="1.7.7" />
+    <PackageVersion Include="Verify.TUnit" Version="31.9.3" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
     <PackageVersion Include="Microsoft.Reactive.Testing" Version="6.1.0" />
     <PackageVersion Include="Microsoft.Testing.Extensions.CodeCoverage" Version="18.1.0" />

src/Directory.Build.props

@@ -158,4 +158,30 @@ public IAppInstance Build()
         Current = _serviceProvider();
         return this;
     }
+
+    /// 
+    /// Gets the current state for test isolation. Used by test scopes.
+    /// 
+    /// A tuple containing HasBeenBuilt and UsingBuilder state.
+    internal static (bool hasBeenBuilt, bool usingBuilder) GetState() =>
+        (HasBeenBuilt, UsingBuilder);
+
+    /// 
+    /// Restores the state for test isolation. Used by test scopes.
+    /// 
+    /// The state to restore.
+    internal static void RestoreState((bool hasBeenBuilt, bool usingBuilder) state)
+    {
+        HasBeenBuilt = state.hasBeenBuilt;
+        UsingBuilder = state.usingBuilder;
+    }
+
+    /// 
+    /// Resets the state to default for test isolation. Used by test scopes.
+    /// 
+    internal static void ResetState()
+    {
+        HasBeenBuilt = false;
+        UsingBuilder = false;
+    }
 }

src/Directory.Packages.props

@@ -17,6 +17,7 @@
   <ItemGroup>
     <InternalsVisibleTo Include="Splat" />
     <InternalsVisibleTo Include="Splat.Tests" />
+    <InternalsVisibleTo Include="Splat.Common.Test" />
     <InternalsVisibleTo Include="Splat.Drawing" />
     <InternalsVisibleTo Include="Splat.Drawing.Tests" />
     <InternalsVisibleTo Include="Splat.TestRunner.Android" />

src/Splat.Builder/AppBuilder.cs

@@ -12,6 +12,7 @@ namespace System.Runtime.CompilerServices;
 
 /// 
 /// Indicates that a parameter captures the expression passed for another parameter as a string.
+/// Modification of Using SimonCropp's polyfill's library.
 /// 
 [ExcludeFromCodeCoverage]
 [DebuggerNonUserCode]

src/Splat.Builder/Splat.Builder.csproj

@@ -12,6 +12,7 @@ namespace System.Diagnostics.CodeAnalysis;
 
 /// 
 /// Indicates that a parameter captures the expression passed for another parameter as a string.
+/// Modification of Using SimonCropp's polyfill's library.
 /// 
 [ExcludeFromCodeCoverage]
 [DebuggerNonUserCode]

src/Splat.Core/Polyfills/CallerArgumentExpressionAttribute.cs

@@ -0,0 +1,25 @@
+// Copyright (c) 2025 ReactiveUI. All rights reserved.
+// Licensed to ReactiveUI under one or more agreements.
+// ReactiveUI licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+#if !NET
+
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+
+namespace System.Runtime.CompilerServices;
+
+/// 
+/// Reserved to be used by the compiler for tracking metadata. This class should not be used by developers in source code.
+/// Modification of Using SimonCropp's polyfill's library.
+/// 
+[ExcludeFromCodeCoverage]
+[DebuggerNonUserCode]
+internal static class IsExternalInit;
+
+#else
+using System.Runtime.CompilerServices;
+
+[assembly: TypeForwardedTo(typeof(IsExternalInit))]
+#endif