304NotModified · 304NotModified · Mar 12, 2026
diff --git a/src/Directory.Build.props b/src/Directory.Build.props
@@ -1,15 +1,18 @@
 <Project>
 
-  <Import Project="$([MSBuild]::GetPathOfFileAbove('Directory.Build.props', '$(MSBuildThisFileDirectory)../'))" />
+	<Import Project="$([MSBuild]::GetPathOfFileAbove('Directory.Build.props', '$(MSBuildThisFileDirectory)../'))" />
 
-  <PropertyGroup>
-    <Authors>Julian Verdurmen</Authors>
-    <Product>JulianVerdurmen.SlnxValidator</Product>
-    <Deterministic>true</Deterministic>
-    <ContinuousIntegrationBuild Condition="'$(GITHUB_ACTIONS)' == 'true'">true</ContinuousIntegrationBuild>
-    <IsPackable>false</IsPackable>
-    <PackageLicenseExpression>MIT</PackageLicenseExpression>
-    <RepositoryUrl>https://github.com/304NotModified/SLNX-validator</RepositoryUrl>
-  </PropertyGroup>
+	<PropertyGroup>
+		<Authors>Julian Verdurmen</Authors>
+		<Product>JulianVerdurmen.SlnxValidator</Product>
+		<Deterministic>true</Deterministic>
+		<ContinuousIntegrationBuild Condition="'$(GITHUB_ACTIONS)' == 'true'">true</ContinuousIntegrationBuild>
+		<IsPackable>false</IsPackable>
+		<PackageLicenseExpression>MIT</PackageLicenseExpression>
+		<RepositoryUrl>https://github.com/304NotModified/SLNX-validator</RepositoryUrl>
+	</PropertyGroup>
+	<ItemGroup>
+		<InternalsVisibleTo Include="$(MSBuildProjectName).Tests" />
+	</ItemGroup>
 
 </Project>
diff --git a/src/SLNX-validator.Core/FileSystem/ISlnxFileResolver.cs b/src/SLNX-validator.Core/FileSystem/ISlnxFileResolver.cs
@@ -0,0 +1,7 @@
+namespace JulianVerdurmen.SlnxValidator.Core.FileSystem
+{
+    public interface ISlnxFileResolver
+    {
+        IReadOnlyList<string> Resolve(string input);
+    }
+}
diff --git a/src/SLNX-validator.Core/FileSystem/SlnxFileResolver.cs b/src/SLNX-validator.Core/FileSystem/SlnxFileResolver.cs
@@ -1,6 +1,6 @@
 namespace JulianVerdurmen.SlnxValidator.Core.FileSystem;
 
-public sealed class SlnxFileResolver(IFileSystem fileSystem)
+internal sealed class SlnxFileResolver(IFileSystem fileSystem) : ISlnxFileResolver
 {
     /// <summary>
     /// Resolves one or more .slnx file paths from the given input.

diff --git a/src/SLNX-validator.Core/ServiceCollectionExtensions.cs b/src/SLNX-validator.Core/ServiceCollectionExtensions.cs
@@ -13,8 +13,8 @@ public static IServiceCollection AddSlnxValidator(this IServiceCollection servic
         services.AddSingleton<ISonarReporter, SonarReporter>();
         services.AddSingleton<ISlnxXsdProvider, SlnxXsdProvider>();
         services.AddSingleton<IXsdValidator, XsdValidator>();
-        services.AddSingleton<Validation.SlnxValidator>();
-        services.AddSingleton<SlnxFileResolver>();
+        services.AddSingleton<ISlnxValidator, Validation.SlnxValidator>();
+        services.AddSingleton<ISlnxFileResolver, SlnxFileResolver>();
         return services;
     }
 }
diff --git a/src/SLNX-validator.Core/Validation/ISlnxValidator.cs b/src/SLNX-validator.Core/Validation/ISlnxValidator.cs
@@ -0,0 +1,8 @@
+using JulianVerdurmen.SlnxValidator.Core.ValidationResults;
+
+namespace JulianVerdurmen.SlnxValidator.Core.Validation;
+
+public interface ISlnxValidator
+{
+    Task<ValidationResult> ValidateAsync(string slnxContent, string slnxDirectory, CancellationToken cancellationToken = default);
+}
diff --git a/src/SLNX-validator.Core/Validation/SlnxValidator.cs b/src/SLNX-validator.Core/Validation/SlnxValidator.cs
@@ -5,7 +5,7 @@
 
 namespace JulianVerdurmen.SlnxValidator.Core.Validation;
 
-public sealed class SlnxValidator(IFileSystem fileSystem, IXsdValidator xsdValidator)
+internal sealed class SlnxValidator(IFileSystem fileSystem, IXsdValidator xsdValidator) : ISlnxValidator
 {
     /// <summary>
     /// Validates a .slnx file against the XSD schema and checks that all referenced files exist on disk.

diff --git a/src/SLNX-validator.Core/Validation/SlnxXsdProvider.cs b/src/SLNX-validator.Core/Validation/SlnxXsdProvider.cs
@@ -2,7 +2,7 @@
 
 namespace JulianVerdurmen.SlnxValidator.Core.Validation;
 
-public sealed class SlnxXsdProvider : ISlnxXsdProvider
+internal sealed class SlnxXsdProvider : ISlnxXsdProvider
 {
     // Source: https://github.com/microsoft/vs-solutionpersistence/blob/main/src/Microsoft.VisualStudio.SolutionPersistence/Serializer/Xml/Slnx.xsd
     private const string XsdResourceName = "JulianVerdurmen.SlnxValidator.Slnx.xsd";

diff --git a/src/SLNX-validator.Core/Validation/XsdValidator.cs b/src/SLNX-validator.Core/Validation/XsdValidator.cs
@@ -4,7 +4,7 @@
 
 namespace JulianVerdurmen.SlnxValidator.Core.Validation;
 
-public sealed class XsdValidator(ISlnxXsdProvider xsdProvider) : IXsdValidator
+internal sealed class XsdValidator(ISlnxXsdProvider xsdProvider) : IXsdValidator
 {
     public async Task ValidateAsync(string slnxContent, ValidationResult result, CancellationToken cancellationToken)
     {

diff --git a/src/SLNX-validator/ValidationCollector.cs b/src/SLNX-validator/ValidationCollector.cs
@@ -1,10 +1,10 @@
 using JulianVerdurmen.SlnxValidator.Core.FileSystem;
+using JulianVerdurmen.SlnxValidator.Core.Validation;
 using JulianVerdurmen.SlnxValidator.Core.ValidationResults;
-using CoreSlnxValidator = JulianVerdurmen.SlnxValidator.Core.Validation.SlnxValidator;
 
 namespace JulianVerdurmen.SlnxValidator;
 
-internal sealed class ValidationCollector(IFileSystem fileSystem, CoreSlnxValidator validator)
+internal sealed class ValidationCollector(IFileSystem fileSystem, ISlnxValidator validator)
 {
     public async Task<IReadOnlyList<FileValidationResult>> CollectAsync(IReadOnlyList<string> files, CancellationToken cancellationToken)
     {

diff --git a/src/SLNX-validator/ValidatorRunner.cs b/src/SLNX-validator/ValidatorRunner.cs
@@ -4,7 +4,7 @@
 
 namespace JulianVerdurmen.SlnxValidator;
 
-internal sealed class ValidatorRunner(SlnxFileResolver resolver, ValidationCollector collector, ISonarReporter sonarReporter)
+internal sealed class ValidatorRunner(ISlnxFileResolver resolver, ValidationCollector collector, ISonarReporter sonarReporter)
 {
     public async Task<int> RunAsync(string input, string? sonarqubeReportPath, bool continueOnError, CancellationToken cancellationToken)
     {

diff --git a/tests/Directory.Build.props b/tests/Directory.Build.props
@@ -14,6 +14,7 @@
     <PackageReference Include="Microsoft.Testing.Extensions.CodeCoverage" Version="18.*" />
     <PackageReference Include="AwesomeAssertions" Version="9.4.*" />
     <PackageReference Include="Verify.TUnit" Version="31.*" />
+    <PackageReference Include="NSubstitute" Version="5.*" />
   </ItemGroup>
 
 </Project>
diff --git a/tests/SLNX-validator.Tests/ValidatorRunnerTests.cs b/tests/SLNX-validator.Tests/ValidatorRunnerTests.cs
@@ -2,19 +2,16 @@
 using JulianVerdurmen.SlnxValidator.Core.FileSystem;
 using JulianVerdurmen.SlnxValidator.Core.SonarQubeReporting;
 using JulianVerdurmen.SlnxValidator.Core.Validation;
-using CoreSlnxValidator = JulianVerdurmen.SlnxValidator.Core.Validation.SlnxValidator;
-
+using NSubstitute;
 namespace JulianVerdurmen.SlnxValidator.Tests;
 
 public class ValidatorRunnerTests
 {
     private static ValidatorRunner CreateRunner(IFileSystem fileSystem)
     {
-        var resolver = new SlnxFileResolver(fileSystem);
-        var validator = new CoreSlnxValidator(fileSystem, new XsdValidator(new SlnxXsdProvider()));
-        var collector = new ValidationCollector(fileSystem, validator);
+        var collector = new ValidationCollector(fileSystem, Substitute.For<ISlnxValidator>());
         var sonarReporter = new SonarReporter(fileSystem);
-        return new ValidatorRunner(resolver, collector, sonarReporter);
+        return new ValidatorRunner(Substitute.For<ISlnxFileResolver>(), collector, sonarReporter);
     }
 
     [Test]