Modernize Sextant multi-TFM builds with OS-aware MSBuild (no .NET Framework) (#893)

Copilot · glennawatson · Copilot · web-flow · commit b14dc0343328 · 2025-09-07T20:14:13.000+10:00
Co-authored-by: copilot-swe-agent[bot] &lt;198982749+Copilot@users.noreply.github.com&gt;
Co-authored-by: glennawatson &lt;5834289+glennawatson@users.noreply.github.com&gt;
Co-authored-by: Copilot &lt;175728472+Copilot@users.noreply.github.com&gt;
diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
@@ -35,6 +35,8 @@ Always reference these instructions first and fallback to search or bash command
   dotnet build Sextant.sln --configuration Release
   ```
   Build time: **2-5 minutes**. Set timeout to 10+ minutes for full solution builds.
+  
+  **Note**: The build system automatically selects appropriate target frameworks based on your OS. No manual TFM configuration needed.
 
 - Individual project builds (faster for development):
   ```bash
@@ -43,6 +45,11 @@ Always reference these instructions first and fallback to search or bash command
   dotnet build Sextant.Tests/Sextant.Tests.csproj --configuration Release
   ```
 
+- **Cross-platform considerations**: 
+  - Linux: Builds core .NET and Android targets
+  - Windows: Builds all targets including Windows and Apple (via Pair-to-Mac)
+  - macOS: Builds core .NET, Android, and Apple targets
+
 ### Testing
 - **Full test suite**:
   ```bash
@@ -273,6 +280,30 @@ public partial class SextantNavigationService : IViewStackService
 
 ## Target Framework Support
 
+### Centralized Multi-TFM Build System
+Sextant uses a centralized, OS-aware build system defined in `src/Directory.Build.props` that automatically selects appropriate target frameworks based on the host operating system:
+
+#### TFM Property Groups
+- **`SextantModernTargets`**: `net8.0;net9.0` - Used by tests and benchmarks that don't need .NET Standard
+- **`SextantCoreTargets`**: `netstandard2.0;net8.0;net9.0` - Used by core libraries for broad compatibility
+- **`SextantMauiTargetFrameworks`**: OS-aware composition for MAUI projects including platform-specific targets
+
+#### OS-Aware Target Selection
+- **Linux builds**: Core targets + Android (`netstandard2.0;net8.0;net9.0;net9.0-android`)
+- **Windows builds**: Core + Android + Windows + Apple + Tizen (supports Pair-to-Mac for iOS development)
+- **macOS builds**: Core + Android + Apple + Tizen
+
+#### Project TFM Usage
+- **Core libraries** (Sextant, Sextant.Mocks): Use `$(SextantCoreTargets)` for maximum compatibility
+- **MAUI libraries** (Sextant.Maui, Sextant.Plugins.Popup): Use `$(SextantMauiTargetFrameworks)` for platform-specific support
+- **Tests/Benchmarks**: Use `$(SextantModernTargets)` since they don't need .NET Standard support
+
+#### Benefits
+- **Cross-platform builds**: No manual TFM editing needed across different operating systems
+- **Consistent targeting**: Centralized TFM management reduces configuration drift
+- **Build optimization**: Only compiles relevant targets for each OS, reducing build time
+- **Maintainability**: Easy to update TFMs across entire solution from single location
+
 ### Supported Frameworks
 - **netstandard2.0** - Broad compatibility with .NET Framework and older .NET Core
 - **net8.0** - Modern .NET with performance improvements
diff --git a/Samples/Directory.Build.props b/Samples/Directory.Build.props
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project>
+  <!-- Import the main Directory.Build.props from src -->
+  <Import Project="../src/Directory.Build.props" />
+</Project>
diff --git a/Samples/SextantSample.Maui/SextantSample.Maui.csproj b/Samples/SextantSample.Maui/SextantSample.Maui.csproj
@@ -1,8 +1,7 @@
 ﻿<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net9.0-android;net9.0-ios</TargetFrameworks>
-    <TargetFrameworks Condition="$([MSBuild]::IsOSPlatform('windows'))">$(TargetFrameworks);net9.0-windows10.0.19041.0</TargetFrameworks>
+    <TargetFrameworks>$(SextantMauiTargetFrameworks)</TargetFrameworks>
     <OutputType>Exe</OutputType>
     <UseMaui>true</UseMaui>
     <SingleProject>true</SingleProject>
diff --git a/src/Benchmarks/Sextant.Benchmarks.csproj b/src/Benchmarks/Sextant.Benchmarks.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPackable>false</IsPackable>
-    <TargetFrameworks>net462;net9.0</TargetFrameworks>
+    <TargetFrameworks>$(SextantModernTargets)</TargetFrameworks>
     <PlatformTarget>AnyCPU</PlatformTarget>
     <DebugType>pdbonly</DebugType>
     <DebugSymbols>true</DebugSymbols>
diff --git a/src/Directory.Build.props b/src/Directory.Build.props
@@ -32,6 +32,48 @@
     <PublishRepositoryUrl>true</PublishRepositoryUrl>
     <NoWarn>$(NoWarn);CA1510;IDE0130</NoWarn>
   </PropertyGroup>
+  <!-- =========================
+       TFM Bucket Definitions  
+       ========================= -->
+  <PropertyGroup>
+    <!-- Modern .NET TFMs only (net8/net9) - for tests/benchmarks -->
+    <SextantModernTargets>net8.0;net9.0</SextantModernTargets>
+    
+    <!-- Core TFMs buildable on all OSes (netstandard + modern) - for libraries -->
+    <SextantCoreTargets>netstandard2.0;$(SextantModernTargets)</SextantCoreTargets>
+
+    <!-- MAUI/Platform TFMs -->
+    <SextantAndroidTargets>net9.0-android</SextantAndroidTargets>
+    <SextantWindowsTargets>net9.0-windows10.0.17763.0</SextantWindowsTargets>
+    <SextantAppleTargets>net9.0-ios;net9.0-macos;net9.0-maccatalyst;net9.0-tvos</SextantAppleTargets>
+
+    <!-- MAUI specific targets (no netstandard) -->
+    <SextantMauiCoreTargets>net9.0</SextantMauiCoreTargets>
+  </PropertyGroup>
+
+  <!-- =========================
+       OS-Aware Composition
+       ========================= -->
+  <PropertyGroup>
+    <!-- Base always-present for full framework support -->
+    <SextantFinalTargetFrameworks>$(SextantCoreTargets)</SextantFinalTargetFrameworks>
+
+    <!-- Android: allowed on any OS (workload-dependent; no OS gate needed) -->
+    <SextantFinalTargetFrameworks>$(SextantFinalTargetFrameworks);$(SextantAndroidTargets)</SextantFinalTargetFrameworks>
+
+    <!-- Windows MAUI/Desktop: only on Windows hosts, Windows can include "everything"-->
+    <SextantFinalTargetFrameworks Condition="$([MSBuild]::IsOsPlatform('Windows'))">$(SextantFinalTargetFrameworks);$(SextantWindowsTargets);$(SextantAppleTargets)</SextantFinalTargetFrameworks>
+
+    <!-- Apple (iOS/macOS/MacCatalyst/tvOS): on macOS and on Windows (Pair-to-Mac) -->
+    <SextantFinalTargetFrameworks Condition="$([MSBuild]::IsOsPlatform('OSX'))">$(SextantFinalTargetFrameworks);$(SextantAppleTargets)</SextantFinalTargetFrameworks>
+
+    <!-- MAUI specific composition (no netstandard) -->
+    <SextantMauiTargetFrameworks>$(SextantMauiCoreTargets)</SextantMauiTargetFrameworks>
+    <SextantMauiTargetFrameworks>$(SextantMauiTargetFrameworks);$(SextantAndroidTargets)</SextantMauiTargetFrameworks>
+    <SextantMauiTargetFrameworks Condition="$([MSBuild]::IsOsPlatform('Windows'))">$(SextantMauiTargetFrameworks);$(SextantWindowsTargets);$(SextantAppleTargets)</SextantMauiTargetFrameworks>
+    <SextantMauiTargetFrameworks Condition="$([MSBuild]::IsOsPlatform('OSX'))">$(SextantMauiTargetFrameworks);$(SextantAppleTargets)</SextantMauiTargetFrameworks>
+  </PropertyGroup>
+
   <PropertyGroup Condition="'$(GITHUB_ACTIONS)' == 'true'">
     <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
   </PropertyGroup>
diff --git a/src/Sample/SextantSample.Core/SextantSample.ViewModels.csproj b/src/Sample/SextantSample.Core/SextantSample.ViewModels.csproj
@@ -1,7 +1,7 @@
 ﻿<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;net8.0;net9.0</TargetFrameworks>
+    <TargetFrameworks>$(SextantCoreTargets)</TargetFrameworks>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
diff --git a/src/Sextant.Avalonia/Sextant.Avalonia.csproj b/src/Sextant.Avalonia/Sextant.Avalonia.csproj
@@ -1,6 +1,6 @@
 ﻿<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;net8.0;net9.0</TargetFrameworks>
+    <TargetFrameworks>$(SextantCoreTargets)</TargetFrameworks>
     <RootNamespace>Sextant.Avalonia</RootNamespace>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/Sextant.Maui/Sextant.Maui.csproj b/src/Sextant.Maui/Sextant.Maui.csproj
@@ -1,7 +1,6 @@
 ﻿<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>net9.0</TargetFrameworks>
-    <TargetFrameworks Condition="$([MSBuild]::IsOSPlatform('windows'))">$(TargetFrameworks);net9.0-windows10.0.19041.0</TargetFrameworks>
+    <TargetFrameworks>$(SextantMauiTargetFrameworks)</TargetFrameworks>
     <ImplicitUsings>enable</ImplicitUsings>
     <UseMaui>true</UseMaui>
   </PropertyGroup>
diff --git a/src/Sextant.Mocks/Sextant.Mocks.csproj b/src/Sextant.Mocks/Sextant.Mocks.csproj
@@ -1,8 +1,7 @@
 ﻿<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;net9.0</TargetFrameworks>
-    <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net462;</TargetFrameworks>
+    <TargetFrameworks>$(SextantCoreTargets)</TargetFrameworks>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
diff --git a/src/Sextant.Plugins.Popup/Sextant.Plugins.Popup.csproj b/src/Sextant.Plugins.Popup/Sextant.Plugins.Popup.csproj
@@ -1,7 +1,6 @@
 ﻿<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>net9.0</TargetFrameworks>
-    <TargetFrameworks Condition="$([MSBuild]::IsOSPlatform('windows'))">$(TargetFrameworks);net9.0-windows10.0.19041.0</TargetFrameworks>
+    <TargetFrameworks>$(SextantMauiTargetFrameworks)</TargetFrameworks>
     <UseMaui>true</UseMaui>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/Sextant.Tests/DependencyResolverMixinTests.cs b/src/Sextant.Tests/DependencyResolverMixinTests.cs
@@ -14,14 +14,25 @@ namespace Sextant.Tests;
 /// Tests the IMutableDependencyResolver extension class.
 /// </summary>
 [TestFixture]
+[NonParallelizable]
 public sealed class DependencyResolverMixinTests
 {
     /// <summary>
     /// Tests the register view model factory method.
     /// </summary>
     [TestFixture]
+    [NonParallelizable]
     public sealed class TheRegisterViewModelFactoryMethod
     {
+        /// <summary>
+        /// Sets up the test by clearing the dependency resolver.
+        /// </summary>
+        [SetUp]
+        public void SetUp()
+        {
+            Locator.CurrentMutable.UnregisterAll<IViewModelFactory>();
+        }
+
         /// <summary>
         /// Should register the view model factory.
         /// </summary>
@@ -60,8 +71,18 @@ public void Should_Register_View_Model_Factory_With_Factory()
     /// Tests the register view method.
     /// </summary>
     [TestFixture]
+    [NonParallelizable]
     public sealed class TheRegisterViewMethod
     {
+        /// <summary>
+        /// Sets up the test by clearing the dependency resolver.
+        /// </summary>
+        [SetUp]
+        public void SetUp()
+        {
+            Locator.CurrentMutable.UnregisterAll<IViewFor<NavigableViewModelMock>>();
+        }
+
         /// <summary>
         /// Should register the view stack service.
         /// </summary>
@@ -103,6 +124,16 @@ public void Should_Register_View_Factory()
     [NonParallelizable]
     public sealed class TheRegisterViewForNavigationMethod
     {
+        /// <summary>
+        /// Sets up the test by clearing the dependency resolver.
+        /// </summary>
+        [SetUp]
+        public void SetUp()
+        {
+            Locator.CurrentMutable.UnregisterAll<IViewFor<NavigableViewModelMock>>();
+            Locator.CurrentMutable.UnregisterAll<NavigableViewModelMock>();
+        }
+
         /// <summary>
         /// Should register the view for navigation.
         /// </summary>
diff --git a/src/Sextant.Tests/Navigation/DestructibleTests.cs b/src/Sextant.Tests/Navigation/DestructibleTests.cs
@@ -17,12 +17,14 @@ namespace Sextant.Tests;
 /// Test a <see cref="IDestructible"/> implementation.
 /// </summary>
 [TestFixture]
+[NonParallelizable]
 public sealed class DestructibleTests
 {
     /// <summary>
     /// Tests the destroy method.
     /// </summary>
     [TestFixture]
+    [NonParallelizable]
     public class TheDestroyMethod
     {
         /// <summary>
diff --git a/src/Sextant.Tests/Navigation/NavigationViewResetStackTests.cs b/src/Sextant.Tests/Navigation/NavigationViewResetStackTests.cs
@@ -24,6 +24,7 @@ namespace Sextant.Tests.Navigation;
 /// Tests for NavigationView resetStack behavior.
 /// </summary>
 [TestFixture]
+[NonParallelizable]
 public sealed class NavigationViewResetStackTests
 {
     private IViewLocator _viewLocator = null!;
diff --git a/src/Sextant.Tests/Sextant.Tests.csproj b/src/Sextant.Tests/Sextant.Tests.csproj
@@ -1,26 +1,25 @@
 ﻿<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>net9.0;</TargetFrameworks>
+    <TargetFrameworks>$(SextantModernTargets)</TargetFrameworks>
     <IsPackable>false</IsPackable>
     <LangVersion>latest</LangVersion>    
     <Nullable>enable</Nullable>    
   </PropertyGroup>
 
-  <ItemGroup>
-    <PackageReference Include="NUnit" />
-    <PackageReference Include="NUnit3TestAdapter" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" />
-    <PackageReference Include="NSubstitute" />
-    <PackageReference Include="Microsoft.Reactive.Testing" />
-    <PackageReference Include="ReactiveUI.Testing" />
-    <PackageReference Include="PublicApiGenerator" />
-    <PackageReference Include="DiffEngine" />
-    <PackageReference Include="Verify.NUnit" />
-  </ItemGroup>
-
   <ItemGroup>
     <ProjectReference Include="..\Sextant.Mocks\Sextant.Mocks.csproj" />
     <ProjectReference Include="..\Sextant\Sextant.csproj" />
+  </ItemGroup>
+  
+  <ItemGroup Condition="'$(TargetFramework)' == 'net9.0'">
     <ProjectReference Include="..\Sextant.Maui\Sextant.Maui.csproj" />
   </ItemGroup>
+  
+  <PropertyGroup Condition="'$(TargetFramework)' == 'net9.0'">
+    <DefineConstants>$(DefineConstants);HAS_MAUI</DefineConstants>
+  </PropertyGroup>
+  
+ <ItemGroup Condition="'$(TargetFramework)' != 'net9.0'">
+    <Compile Remove="Navigation\NavigationViewResetStackTests.cs" />
+  </ItemGroup>  
 </Project>
diff --git a/src/Sextant.Tests/ViewModelFactoryTests.cs b/src/Sextant.Tests/ViewModelFactoryTests.cs
@@ -12,12 +12,14 @@ namespace Sextant.Tests;
 /// Tests the <see cref="ViewModelFactory"/>.
 /// </summary>
 [TestFixture]
+[NonParallelizable]
 public sealed class ViewModelFactoryTests
 {
     /// <summary>
     /// Tests the currently registered view model factory parameter.
     /// </summary>
     [TestFixture]
+    [NonParallelizable]
     public class CurrentPropertyTests
     {
         /// <summary>
diff --git a/src/Sextant/Sextant.csproj b/src/Sextant/Sextant.csproj
@@ -1,6 +1,6 @@
 ﻿<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;net8.0;net9.0</TargetFrameworks>
+    <TargetFrameworks>$(SextantCoreTargets)</TargetFrameworks>
     <RootNamespace>Sextant</RootNamespace>
     <Nullable>enable</Nullable>
   </PropertyGroup>
