Support winrt consumption using CsWinRT reference

src/common/Microsoft.DotNet.UpgradeAssistant.Abstractions/IProject.cs

@@ -21,6 +21,8 @@ public interface IProject
 
         IEnumerable<IProject> ProjectReferences { get; }
 
+        public IEnumerable<string> AllProjectReferences { get; }
+
         IEnumerable<Reference> FrameworkReferences { get; }
 
         INuGetReferences NuGetReferences { get; }

src/components/Microsoft.DotNet.UpgradeAssistant.MSBuild/MSBuildProject.cs

@@ -42,6 +42,8 @@ public MSBuildProject(
 
         public string Id => Context.SolutionInfo.GetProjectId(FileInfo.FullName);
 
+        public IEnumerable<string> AllProjectReferences => GetRoslynProject().AllProjectReferences.Select(projRef => projRef.ProjectId.ToString());
+
         public IEnumerable<IProject> ProjectReferences => GetRoslynProject().ProjectReferences.Select(p =>
         {
             var project = Context.Workspace.CurrentSolution.GetProject(p.ProjectId);

src/extensions/windows/Microsoft.DotNet.UpgradeAssistant.Extensions.Windows/UWPtoWinAppSDKUpgrade/WinUIPropertiesUpdater.cs

@@ -4,7 +4,9 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Globalization;
 using System.IO;
+using System.Linq;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
@@ -18,6 +20,10 @@ public class WinUIPropertiesUpdater : IUpdater<IProject>
     {
         public const string RuleID = "UA302";
 
+        private const string CsWinRTLogMessage = "A CsWinRTIncludes property with value {0} has been added.\n" +
+                            "If your project assembly name differs from {0}, update this value with the assembly name.\n" +
+                            "Read more about CsWinRT here: https://docs.microsoft.com/en-us/windows/apps/develop/platform/csharp-winrt/";
+
         public string Id => typeof(WinUIPropertiesUpdater).FullName;
 
         public string Title => "Update WinUI Project Properties";
@@ -69,6 +75,19 @@ public async Task<IUpdaterResult> ApplyAsync(IUpgradeContext context, ImmutableA
                     }
                 }
 
+                foreach (var projRef in project.AllProjectReferences)
+                {
+                    if (projRef.Contains(".vcxproj"))
+                    {
+                        var projectName = ParseProjectNameWithExtension(projRef, ".vcxproj");
+                        var csWinRTIncludesValue = projectFile.GetPropertyValue("CsWinRTIncludes") ?? string.Empty;
+                        var delimiter = csWinRTIncludesValue.Trim().Length == 0 || csWinRTIncludesValue.EndsWith(";") ? string.Empty : ";";
+                        projectFile.SetPropertyValue("CsWinRTIncludes", $"{csWinRTIncludesValue}{delimiter}{projectName}");
+
+                        _logger.LogInformation(string.Format(CsWinRTLogMessage, projectName));
+                    }
+                }
+
                 projectFile.AddItem(new ProjectItemDescriptor(ProjectItemType.Compile) { Remove = "App.xaml.old.cs" });
                 projectFile.AddItem(new ProjectItemDescriptor(ProjectItemType.None) { Include = "App.xaml.old.cs" });
                 projectFile.RemoveItem(new ProjectItemDescriptor(ProjectItemType.Content) { Include = "Properties\\Default.rd.xml" });
@@ -85,6 +104,20 @@ public async Task<IUpdaterResult> ApplyAsync(IUpgradeContext context, ImmutableA
                 new List<string>());
         }
 
+        private string ParseProjectNameWithExtension(string projectReference, string extension)
+        {
+            var index = projectReference.IndexOf(".vcxproj");
+            index--;
+            StringBuilder sb = new StringBuilder();
+            while (index > -1 && char.IsLetterOrDigit(projectReference[index]))
+            {
+                sb.Append(projectReference[index]);
+                index--;
+            }
+
+            return new string(sb.ToString().Reverse().ToArray());
+        }
+
         public async Task<IUpdaterResult> IsApplicableAsync(IUpgradeContext context, ImmutableArray<IProject> inputs, CancellationToken token)
         {
             await Task.Yield();

src/extensions/windows/Microsoft.DotNet.UpgradeAssistant.Extensions.Windows/UWPtoWinAppSDKUpgrade/WinUIReferenceAnalyzer.cs

@@ -6,6 +6,7 @@
 using System.Collections.Immutable;
 using System.Linq;
 using System.Text;
+using System.Text.RegularExpressions;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.DotNet.UpgradeAssistant.Dependencies;
@@ -18,6 +19,9 @@ internal class WinUIReferenceAnalyzer : IDependencyAnalyzer
     {
         public string Name => "Windows App SDK package analysis";
 
+        private const string CsWinRTPackageName = "Microsoft.Windows.CsWinRT";
+        private const string CsWinRTVersion = "1.6.4";
+
         private readonly IPackageLoader _packageLoader;
         private readonly ILogger _logger;
 
@@ -34,6 +38,13 @@ public async Task AnalyzeAsync(IProject project, IDependencyAnalysisState state,
                 return;
             }
 
+            if (project.AllProjectReferences.Any(id => id.Contains(".vcxproj")))
+            {
+                var newPackage = new NuGetReference(CsWinRTPackageName, CsWinRTVersion);
+                state.Packages.Add(newPackage,
+                    new OperationDetails() { Risk = BuildBreakRisk.Medium, Details = ImmutableList.Create<string>(newPackage.Name) });
+            }
+
             foreach (var package in state.Packages)
             {
                 if (package.Name.StartsWith("Microsoft.Toolkit", StringComparison.Ordinal))