refactor: Use AutoDomainData attribute instead of directly mocking with NSubstitute

Directory.Packages.props

@@ -20,14 +20,14 @@
 		<PackageVersion Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
 	</ItemGroup>
 	<ItemGroup>
+		<PackageVersion Include="AutoFixture.AutoNSubstitute" Version="4.18.1" />
 		<PackageVersion Include="AutoFixture.Xunit2" Version="4.18.1" />
 		<PackageVersion Include="FluentAssertions" Version="6.12.0" />
 		<PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
 		<PackageVersion Include="Xunit.SkippableFact" Version="1.4.13" />
 		<PackageVersion Include="xunit" Version="2.9.0" />
 		<PackageVersion Include="xunit.runner.visualstudio" Version="2.8.2" />
 		<PackageVersion Include="coverlet.collector" Version="6.0.2" />
-		<PackageVersion Include="NSubstitute" Version="5.1.0" />
 		<PackageVersion Include="PublicApiGenerator" Version="11.1.0" />
 		<PackageVersion Include="NUnit" Version="4.2.2" />
 		<PackageVersion Include="NUnit.Analyzers" Version="4.3.0" />

Tests/Helpers/Testably.Abstractions.TestHelpers/AutoDomainDataAttribute.cs

@@ -0,0 +1,111 @@
+using AutoFixture;
+using AutoFixture.Xunit2;
+using AutoFixture.AutoNSubstitute;
+using System;
+using System.Linq;
+using System.Collections.Generic;
+
+namespace Testably.Abstractions.TestHelpers;
+
+/// <summary>
+///     Extension of <see cref="AutoDataAttribute"/> that uses applies domain-specific customizations.
+/// </summary>
+public class AutoDomainDataAttribute : AutoDataAttribute
+{
+	private Type? _customizeWith;
+	private readonly FixtureFactory _fixtureFactory;
+
+	/// <summary>
+	///     Extension of <see cref="AutoDataAttribute"/> that uses applies domain-specific customizations.
+	/// </summary>
+	public AutoDomainDataAttribute() : this(new FixtureFactory())
+	{
+	}
+
+	private AutoDomainDataAttribute(FixtureFactory fixtureFactory)
+		: base(fixtureFactory.GetFixtureFactory)
+	{
+		_fixtureFactory = fixtureFactory;
+	}
+
+	/// <summary>
+	///     Adds an additional <see cref="ICustomization"/> that is applied for only this test.
+	/// </summary>
+	public Type? CustomizeWith
+	{
+		get
+		{
+			return _customizeWith;
+		}
+		set
+		{
+			_customizeWith = value;
+			_fixtureFactory.CustomizeWith(value);
+		}
+	}
+
+	private sealed class FixtureFactory
+	{
+		private ICustomization? _customizeWith;
+		private static Lazy<ICustomization[]> _domainCustomisation { get; } = new(Initialize);
+
+		public IFixture GetFixtureFactory()
+		{
+			var fixture = new Fixture();
+			fixture.Customize(new AutoNSubstituteCustomization());
+			foreach (var domainCustomization in _domainCustomisation.Value)
+			{
+				domainCustomization.Customize(fixture);
+			}
+			if (_customizeWith != null)
+			{
+				fixture.Customize(_customizeWith);
+			}
+			return fixture;
+		}
+
+		public void CustomizeWith(Type? type)
+		{
+			Type customizationInterface = typeof(ICustomization);
+			if (type != null &&
+				customizationInterface.IsAssignableFrom(type))
+			{
+				try
+				{
+					_customizeWith = (ICustomization?)Activator.CreateInstance(type);
+				}
+				catch (Exception ex)
+				{
+					throw new InvalidOperationException(
+						$"Could not instantiate customization with '{type.Name}'!", ex);
+				}
+			}
+		}
+
+		private static ICustomization[] Initialize()
+		{
+			List<ICustomization> domainCustomizations = new();
+			Type autoDataCustomizationInterface = typeof(IAutoDataCustomization);
+			foreach (Type type in AppDomain.CurrentDomain.GetAssemblies()
+				.SelectMany(a => a.GetTypes())
+				.Where(x => x.IsClass)
+				.Where(autoDataCustomizationInterface.IsAssignableFrom))
+			{
+				try
+				{
+					IAutoDataCustomization? domainCustomization = (IAutoDataCustomization?)Activator.CreateInstance(type);
+					if (domainCustomization != null)
+					{
+						domainCustomizations.Add(domainCustomization);
+					}
+				}
+				catch (Exception ex)
+				{
+					throw new InvalidOperationException(
+						$"Could not instantiate auto data customization '{type.Name}'!", ex);
+				}
+			}
+			return domainCustomizations.ToArray();
+		}
+	}
+}

Tests/Helpers/Testably.Abstractions.TestHelpers/IAutoDataCustomization.cs

@@ -0,0 +1,10 @@
+using AutoFixture;
+
+namespace Testably.Abstractions.TestHelpers;
+
+/// <summary>
+///     Marks customizations of <see cref="IFixture"/> that should always be applied when using the <see cref="AutoDomainDataAttribute"/>.
+/// </summary>
+public interface IAutoDataCustomization : ICustomization
+{
+}

Tests/Helpers/Testably.Abstractions.TestHelpers/Testably.Abstractions.TestHelpers.csproj

@@ -19,7 +19,8 @@
 	</ItemGroup>
 
 	<ItemGroup>
-		<PackageReference Remove="AutoFixture.Xunit2" />
+		<PackageReference Include="AutoFixture.AutoNSubstitute" />
+		<PackageReference Include="AutoFixture.Xunit2" />
 		<PackageReference Remove="Microsoft.NET.Test.Sdk" />
 		<PackageReference Remove="xunit" />
 		<PackageReference Remove="xunit.runner.visualstudio" />

Tests/Testably.Abstractions.AccessControl.Tests/Internal/AccessControlHelperTests.cs

@@ -1,16 +1,14 @@
-using NSubstitute;
-using System.IO;
+using System.IO;
 using Testably.Abstractions.Helpers;
 
 namespace Testably.Abstractions.AccessControl.Tests.Internal;
 
 public sealed class AccessControlHelperTests
 {
-	[Fact]
-	public void GetExtensibilityOrThrow_CustomDirectoryInfo_ShouldThrowNotSupportedException()
+	[Theory]
+	[AutoDomainData]
+	public void GetExtensibilityOrThrow_CustomDirectoryInfo_ShouldThrowNotSupportedException(IDirectoryInfo sut)
 	{
-		IDirectoryInfo? sut = Substitute.For<IDirectoryInfo>();
-
 		Exception? exception = Record.Exception(() =>
 		{
 			sut.GetExtensibilityOrThrow();
@@ -22,11 +20,10 @@ public void GetExtensibilityOrThrow_CustomDirectoryInfo_ShouldThrowNotSupportedE
 			.Contain(sut.GetType().Name);
 	}
 
-	[Fact]
-	public void GetExtensibilityOrThrow_CustomFileInfo_ShouldThrowNotSupportedException()
+	[Theory]
+	[AutoDomainData]
+	public void GetExtensibilityOrThrow_CustomFileInfo_ShouldThrowNotSupportedException(IFileInfo sut)
 	{
-		IFileInfo? sut = Substitute.For<IFileInfo>();
-
 		Exception? exception = Record.Exception(() =>
 		{
 			sut.GetExtensibilityOrThrow();
@@ -116,5 +113,5 @@ public void ThrowIfMissing_MissingFileInfo_ShouldThrowFileNotFoundException()
 		exception!.Message.Should().Contain($"'{sut.FullName}'");
 	}
 
-	private class CustomFileSystemStream() : FileSystemStream(Null, ".", false);
+	private sealed class CustomFileSystemStream() : FileSystemStream(Null, ".", false);
 }

Tests/Testably.Abstractions.AccessControl.Tests/Testably.Abstractions.AccessControl.Tests.csproj

@@ -13,7 +13,6 @@
 
 	<ItemGroup>
 		<ProjectReference Include="..\Helpers\Testably.Abstractions.Tests.SourceGenerator\Testably.Abstractions.Tests.SourceGenerator.csproj" OutputItemType="Analyzer" />
-		<PackageReference Include="NSubstitute" />
 	</ItemGroup>
 
 	<PropertyGroup>