🧪 Architecture tests to enforce Domain purity

VerticalSliceArchitectureTemplate.sln

@@ -16,6 +16,8 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "tests", "tests", "{21C89A08
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "VerticalSliceArchitectureTemplate.Unit.Tests", "tests\VerticalSliceArchitectureTemplate.Unit.Tests\VerticalSliceArchitectureTemplate.Unit.Tests.csproj", "{07A76FBE-083C-49AA-856E-0C1B95DEB7B2}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "VerticalSliceArchitecture.ArchTests", "tests\VerticalSliceArchitecture.ArchTests\VerticalSliceArchitecture.ArchTests.csproj", "{C07689FD-DF63-46DB-B5C6-93B73CD72C5E}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -30,9 +32,14 @@ Global
 		{07A76FBE-083C-49AA-856E-0C1B95DEB7B2}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{07A76FBE-083C-49AA-856E-0C1B95DEB7B2}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{07A76FBE-083C-49AA-856E-0C1B95DEB7B2}.Release|Any CPU.Build.0 = Release|Any CPU
+		{C07689FD-DF63-46DB-B5C6-93B73CD72C5E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{C07689FD-DF63-46DB-B5C6-93B73CD72C5E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{C07689FD-DF63-46DB-B5C6-93B73CD72C5E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{C07689FD-DF63-46DB-B5C6-93B73CD72C5E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{8EB413BD-C5DF-49A5-A372-4AEAF4999952} = {92C5999C-A447-479E-8630-064E6FDC78DA}
 		{07A76FBE-083C-49AA-856E-0C1B95DEB7B2} = {21C89A08-D942-45BE-A302-4EEB543573C0}
+		{C07689FD-DF63-46DB-B5C6-93B73CD72C5E} = {21C89A08-D942-45BE-A302-4EEB543573C0}
 	EndGlobalSection
 EndGlobal

src/VerticalSliceArchitectureTemplate/Features/Todos/Domain/Todo.cs

@@ -29,4 +29,4 @@ public void Complete()
 
         StagedEvents.Add(new TodoCompletedEvent(Id));
     }
-}
+}

src/VerticalSliceArchitectureTemplate/Program.cs

@@ -36,4 +36,6 @@
 
 app.RegisterEndpoints(appAssembly);
 
-app.Run();
+app.Run();
+
+public partial class Program;

tests/VerticalSliceArchitecture.ArchTests/ArchitectureTests.cs

@@ -0,0 +1,69 @@
+using FluentAssertions;
+using VerticalSliceArchitecture.ArchTests.Common;
+using Xunit.Abstractions;
+
+namespace VerticalSliceArchitecture.ArchTests;
+
+public class ArchitectureTests : TestBase
+{
+    private readonly ITestOutputHelper _outputHelper;
+
+    public ArchitectureTests(ITestOutputHelper outputHelper)
+    {
+        _outputHelper = outputHelper;
+    }
+
+    private readonly string[] _applicationNamespaces =
+    [
+        "Queries",
+        "Application",
+        "Commands"
+    ];
+
+    private readonly string[] _domainNamespaces =
+    [
+        "Domain"
+    ];
+
+    private readonly string[] _infrastructureNamespaces =
+    [
+        "Infrastructure",
+        "Persistence"
+    ];
+
+    [Fact]
+    public void Domain_Should_Not_Depend_On_Infrastructure()
+    {
+        // Arrange
+        var domainTypes = TypesMatchingAnyPattern(_domainNamespaces);
+        var infraTypes = TypesMatchingAnyPattern(_infrastructureNamespaces);
+
+        // Act
+        var result = domainTypes
+            .ShouldNot()
+            .HaveDependencyOnAny(infraTypes.GetNames())
+            .GetResult();
+
+        // Assert
+        result.DumpFailingTypes(_outputHelper);
+        result.IsSuccessful.Should().BeTrue();
+    }
+
+    [Fact]
+    public void Domain_Should_Not_Depend_On_Application()
+    {
+        // Arrange
+        var domainTypes = TypesMatchingAnyPattern(_domainNamespaces);
+        var applicationTypes = TypesMatchingAnyPattern(_applicationNamespaces);
+
+        // Act
+        var result = domainTypes
+            .ShouldNot()
+            .HaveDependencyOnAny(applicationTypes.GetNames())
+            .GetResult();
+
+        // Assert
+        result.DumpFailingTypes(_outputHelper);
+        result.IsSuccessful.Should().BeTrue();
+    }
+}

tests/VerticalSliceArchitecture.ArchTests/Common/TestResultExtensions.cs

@@ -0,0 +1,18 @@
+using NetArchTest.Rules;
+using Xunit.Abstractions;
+
+namespace VerticalSliceArchitecture.ArchTests.Common;
+
+public static class TestResultExtensions
+{
+    public static void DumpFailingTypes(this TestResult result, ITestOutputHelper outputHelper)
+    {
+        if (result.IsSuccessful)
+            return;
+
+        outputHelper.WriteLine("Failing Types:");
+
+        foreach (var type in result.FailingTypes)
+            outputHelper.WriteLine(type.FullName);
+    }
+}

tests/VerticalSliceArchitecture.ArchTests/GlobalUsings.cs

@@ -0,0 +1 @@
+global using Xunit;

tests/VerticalSliceArchitecture.ArchTests/PredicateListExt.cs

@@ -0,0 +1,11 @@
+using NetArchTest.Rules;
+
+namespace VerticalSliceArchitecture.ArchTests;
+
+public static class PredicateListExt
+{
+    public static string?[] GetNames(this PredicateList list)
+    {
+        return list.GetTypes().Select(x => x.FullName).ToArray();
+    }
+}

tests/VerticalSliceArchitecture.ArchTests/TestBase.cs

@@ -0,0 +1,28 @@
+using NetArchTest.Rules;
+using System.Diagnostics;
+
+namespace VerticalSliceArchitecture.ArchTests;
+
+public abstract class TestBase
+{
+    private static readonly Types ProgramTypes = Types.InAssembly(typeof(Program).Assembly);
+
+    protected PredicateList TypesMatchingAnyPattern(params string[] patterns)
+    {
+        var output = ProgramTypes.That();
+
+        for (var index = 0; index < patterns.Length; index++)
+        {
+            var pattern = patterns[index];
+
+            if (index == patterns.Length - 1)
+            {
+                return output.ResideInNamespaceContaining(pattern);
+            }
+
+            output = output.ResideInNamespaceContaining(pattern).Or();
+        }
+
+        throw new UnreachableException();
+    }
+}

tests/VerticalSliceArchitecture.ArchTests/VerticalSliceArchitecture.ArchTests.csproj

@@ -0,0 +1,31 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>net8.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+
+        <IsPackable>false</IsPackable>
+        <IsTestProject>true</IsTestProject>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <PackageReference Include="FluentAssertions" Version="6.12.0" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.0"/>
+        <PackageReference Include="NetArchTest.Rules" Version="1.3.2" />
+        <PackageReference Include="xunit" Version="2.4.2"/>
+        <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
+            <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+            <PrivateAssets>all</PrivateAssets>
+        </PackageReference>
+        <PackageReference Include="coverlet.collector" Version="6.0.0">
+            <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+            <PrivateAssets>all</PrivateAssets>
+        </PackageReference>
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\..\src\VerticalSliceArchitectureTemplate\VerticalSliceArchitectureTemplate.csproj" />
+    </ItemGroup>
+
+</Project>