Use new serializer library to parse solution files

Directory.Packages.props

@@ -72,6 +72,7 @@
     <PackageVersion Include="Microsoft.VisualStudio.ProjectSystem.Managed" Version="17.2.0-beta1-20502-01" />
     <PackageVersion Include="Microsoft.VisualStudio.ProjectSystem.Managed.VS" Version="17.2.0-beta1-20502-01" />
     <PackageVersion Include="Microsoft.VisualStudio.ProjectSystem.VS" Version="17.4.221-pre" />
+    <PackageVersion Include="Microsoft.VisualStudio.SolutionPersistence" Version="1.0.28" />
     <!-- Microsoft.VisualStudio.SDK has vulnerable dependencies System.Text.json and Microsoft.IO.Redist. When it's upgraded, try removing the pinned packages -->
     <PackageVersion Include="Microsoft.VisualStudio.SDK" Version="17.11.39714" />
     <PackageVersion Include="Microsoft.VisualStudio.Sdk.TestFramework.Xunit" Version="17.11.8" />
@@ -192,6 +193,7 @@
       <_allowBuildFromSourcePackage Include="Microsoft.Extensions.CommandLineUtils.Sources" />
       <_allowBuildFromSourcePackage Include="Microsoft.Extensions.FileProviders.Abstractions" />
       <_allowBuildFromSourcePackage Include="Microsoft.Extensions.FileSystemGlobbing" />
+      <_allowBuildFromSourcePackage Include="Microsoft.VisualStudio.SolutionPersistence" />
       <_allowBuildFromSourcePackage Include="Microsoft.Web.Xdt" />
       <_allowBuildFromSourcePackage Include="Newtonsoft.Json" />
       <_allowBuildFromSourcePackage Include="System.Collections.Immutable" />

NuGet.Config

@@ -30,6 +30,7 @@
       <package pattern="Microsoft.*" />
       <package pattern="Microsoft.Build.Framework" />
       <package pattern="Microsoft.NET.StringTools" />
+      <package pattern="Microsoft.VisualStudio.SolutionPersistence" />
       <package pattern="Microsoft.VisualStudio.TemplateWizardInterface" />
       <package pattern="moq" />
       <package pattern="MSTest.TestAdapter" />

eng/SourceBuildPrebuiltBaseline.xml

@@ -46,6 +46,7 @@
     <UsagePattern IdentityGlob="Microsoft.NETCore.Platforms/*" />
     <UsagePattern IdentityGlob="Microsoft.NETCore.Targets/*" />
     <UsagePattern IdentityGlob="Microsoft.VisualStudio.Setup.Configuration.Interop/*" />
+    <UsagePattern IdentityGlob="Microsoft.VisualStudio.SolutionPersistence/*" />
     <UsagePattern IdentityGlob="Microsoft.Web.Xdt/*" />
     <UsagePattern IdentityGlob="Microsoft.Win32.Registry/*" />
     <UsagePattern IdentityGlob="Microsoft.Win32.SystemEvents/*" />

src/NuGet.Core/NuGet.CommandLine.XPlat/Commands/PackageReferenceCommands/ListPackage/ListPackageCommandRunner.cs

@@ -58,8 +58,10 @@ public async Task<int> ExecuteCommandAsync(ListPackageArgs listPackageArgs)
 
             //If the given file is a solution, get the list of projects
             //If not, then it's a project, which is put in a list
-            var projectsPaths = Path.GetExtension(listPackageArgs.Path).Equals(".sln", PathUtility.GetStringComparisonBasedOnOS()) ?
-                           MSBuildAPIUtility.GetProjectsFromSolution(listPackageArgs.Path).Where(f => File.Exists(f)) :
+            var projectsPaths =
+                (Path.GetExtension(listPackageArgs.Path).Equals(".sln", PathUtility.GetStringComparisonBasedOnOS()) ||
+                     Path.GetExtension(listPackageArgs.Path).Equals(".slnx", PathUtility.GetStringComparisonBasedOnOS())) ?
+                           (await MSBuildAPIUtility.GetProjectsFromSolution(listPackageArgs.Path, listPackageArgs.CancellationToken)).Where(f => File.Exists(f)) :
                            new List<string>(new string[] { listPackageArgs.Path });
 
             MSBuildAPIUtility msBuild = listPackageReportModel.MSBuildAPIUtility;

src/NuGet.Core/NuGet.CommandLine.XPlat/Commands/Why/WhyCommand.cs

@@ -7,6 +7,7 @@
 using System.CommandLine.Help;
 using System.CommandLine.Parsing;
 using System.IO;
+using System.Threading.Tasks;
 using Microsoft.Extensions.CommandLineUtils;
 
 namespace NuGet.CommandLine.XPlat.Commands.Why
@@ -36,7 +37,7 @@ public static void GetWhyCommand(CliCommand rootCommand)
             Register(rootCommand, CommandOutputLogger.Create, WhyCommandRunner.ExecuteCommand);
         }
 
-        internal static void Register(CliCommand rootCommand, Func<ILoggerWithColor> getLogger, Func<WhyCommandArgs, int> action)
+        internal static void Register(CliCommand rootCommand, Func<ILoggerWithColor> getLogger, Func<WhyCommandArgs, Task<int>> action)
         {
             var whyCommand = new DocumentedCommand("why", Strings.WhyCommand_Description, "https://aka.ms/dotnet/nuget/why");
 
@@ -97,7 +98,7 @@ bool HasPathArgument(ArgumentResult ar)
             whyCommand.Options.Add(frameworks);
             whyCommand.Options.Add(help);
 
-            whyCommand.SetAction((parseResult) =>
+            whyCommand.SetAction(async (parseResult, cancellationToken) =>
             {
                 ILoggerWithColor logger = getLogger();
 
@@ -107,9 +108,10 @@ bool HasPathArgument(ArgumentResult ar)
                         parseResult.GetValue(path),
                         parseResult.GetValue(package),
                         parseResult.GetValue(frameworks),
-                        logger);
+                        logger,
+                        cancellationToken);
 
-                    int exitCode = action(whyCommandArgs);
+                    int exitCode = await action(whyCommandArgs);
                     return exitCode;
                 }
                 catch (ArgumentException ex)

src/NuGet.Core/NuGet.CommandLine.XPlat/Commands/Why/WhyCommandArgs.cs

@@ -5,6 +5,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Threading;
 
 namespace NuGet.CommandLine.XPlat.Commands.Why
 {
@@ -14,6 +15,7 @@ internal class WhyCommandArgs
         public string Package { get; }
         public List<string> Frameworks { get; }
         public ILoggerWithColor Logger { get; }
+        public CancellationToken CancellationToken { get; }
 
         /// <summary>
         /// A constructor for the arguments of the 'why' command.
@@ -22,16 +24,19 @@ internal class WhyCommandArgs
         /// <param name="package">The package for which we show the dependency graphs.</param>
         /// <param name="frameworks">The target framework(s) for which we show the dependency graphs.</param>
         /// <param name="logger"></param>
+        /// <param name="cancellationToken"></param>
         public WhyCommandArgs(
             string path,
             string package,
             List<string> frameworks,
-            ILoggerWithColor logger)
+            ILoggerWithColor logger,
+            CancellationToken cancellationToken)
         {
             Path = path ?? throw new ArgumentNullException(nameof(path));
             Package = package ?? throw new ArgumentNullException(nameof(package));
             Frameworks = frameworks ?? throw new ArgumentNullException(nameof(frameworks));
             Logger = logger ?? throw new ArgumentNullException(nameof(logger));
+            CancellationToken = cancellationToken;
         }
     }
 }

src/NuGet.Core/NuGet.CommandLine.XPlat/Commands/Why/WhyCommandRunner.cs

@@ -7,6 +7,9 @@
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
+using System.Runtime.CompilerServices;
+using System.Threading;
+using System.Threading.Tasks;
 using Microsoft.Build.Evaluation;
 using NuGet.ProjectModel;
 
@@ -20,7 +23,7 @@ internal static class WhyCommandRunner
         /// Executes the 'why' command.
         /// </summary>
         /// <param name="whyCommandArgs">CLI arguments for the 'why' command.</param>
-        public static int ExecuteCommand(WhyCommandArgs whyCommandArgs)
+        public static async Task<int> ExecuteCommand(WhyCommandArgs whyCommandArgs)
         {
             bool validArgumentsUsed = ValidatePathArgument(whyCommandArgs.Path, whyCommandArgs.Logger)
                                         && ValidatePackageArgument(whyCommandArgs.Package, whyCommandArgs.Logger);
@@ -30,10 +33,10 @@ public static int ExecuteCommand(WhyCommandArgs whyCommandArgs)
             }
 
             string targetPackage = whyCommandArgs.Package;
-            IEnumerable<(string assetsFilePath, string? projectPath)> assetsFiles;
+            IAsyncEnumerable<(string assetsFilePath, string? projectPath)> assetsFiles;
             try
             {
-                assetsFiles = FindAssetsFiles(whyCommandArgs.Path, whyCommandArgs.Logger);
+                assetsFiles = FindAssetsFilesAsync(whyCommandArgs.Path, whyCommandArgs.Logger, whyCommandArgs.CancellationToken);
             }
             catch (ArgumentException ex)
             {
@@ -47,7 +50,7 @@ public static int ExecuteCommand(WhyCommandArgs whyCommandArgs)
             }
 
             bool anyErrors = false;
-            foreach ((string assetsFilePath, string? projectPath) in assetsFiles)
+            await foreach ((string assetsFilePath, string? projectPath) in assetsFiles)
             {
                 LockFile? assetsFile = GetProjectAssetsFile(assetsFilePath, projectPath, whyCommandArgs.Logger);
 
@@ -88,15 +91,15 @@ public static int ExecuteCommand(WhyCommandArgs whyCommandArgs)
             return anyErrors ? ExitCodes.Error : ExitCodes.Success;
         }
 
-        private static IEnumerable<(string assetsFilePath, string? projectPath)> FindAssetsFiles(string path, ILoggerWithColor logger)
+        private static async IAsyncEnumerable<(string assetsFilePath, string? projectPath)> FindAssetsFilesAsync(string path, ILoggerWithColor logger, [EnumeratorCancellation] CancellationToken cancellationToken = default)
         {
             if (XPlatUtility.IsJsonFile(path))
             {
                 yield return (path, null);
                 yield break;
             }
 
-            var projectPaths = MSBuildAPIUtility.GetListOfProjectsFromPathArgument(path);
+            var projectPaths = await MSBuildAPIUtility.GetListOfProjectsFromPathArgumentAsync(path, cancellationToken);
             foreach (string projectPath in projectPaths.NoAllocEnumerate())
             {
                 Project project = MSBuildAPIUtility.GetProject(projectPath);

src/NuGet.Core/NuGet.CommandLine.XPlat/NuGet.CommandLine.XPlat.csproj

@@ -18,6 +18,7 @@
     <PackageReference Include="Microsoft.Extensions.CommandLineUtils.Sources" PrivateAssets="All" />
     <PackageReference Include="Microsoft.Build" ExcludeAssets="runtime" />
     <PackageReference Include="System.CommandLine" />
+    <PackageReference Include="Microsoft.VisualStudio.SolutionPersistence" />
   </ItemGroup>
 
   <!-- Microsoft.Build.Locator is needed when debugging, but should not be used in the assemblies we insert. -->

src/NuGet.Core/NuGet.CommandLine.XPlat/Utility/MSBuildAPIUtility.cs

@@ -7,9 +7,14 @@
 using System.IO;
 using System.Linq;
 using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
 using Microsoft.Build.Construction;
 using Microsoft.Build.Evaluation;
 using Microsoft.Build.Execution;
+using Microsoft.VisualStudio.SolutionPersistence;
+using Microsoft.VisualStudio.SolutionPersistence.Model;
+using Microsoft.VisualStudio.SolutionPersistence.Serializer;
 using NuGet.Common;
 using NuGet.Frameworks;
 using NuGet.LibraryModel;
@@ -79,18 +84,19 @@ private static Project GetProject(string projectCSProjPath, IDictionary<string,
             return new Project(projectRootElement, globalProperties, toolsVersion: null);
         }
 
-        internal static IEnumerable<string> GetProjectsFromSolution(string solutionPath)
+        internal static async Task<IEnumerable<string>> GetProjectsFromSolution(string solutionPath, CancellationToken cancellationToken = default)
         {
-            var sln = SolutionFile.Parse(solutionPath);
-            return sln.ProjectsInOrder.Select(p => p.AbsolutePath);
+            ISolutionSerializer serializer = SolutionSerializers.GetSerializerByMoniker(solutionPath);
+            SolutionModel solution = await serializer.OpenAsync(solutionPath, cancellationToken);
+            return solution.SolutionProjects.Select(p => p.FilePath);
         }
 
         /// <summary>
         /// Get the list of project paths from the input 'path' argument. Path must be a directory, solution file or project file.
         /// </summary>
         /// <returns>List of project paths. Returns null if path was a directory with none or multiple project/solution files.</returns>
         /// <exception cref="ArgumentException">Throws an exception if the directory has none or multiple project/solution files.</exception>
-        internal static IEnumerable<string> GetListOfProjectsFromPathArgument(string path)
+        internal static async Task<IEnumerable<string>> GetListOfProjectsFromPathArgumentAsync(string path, CancellationToken cancellationToken = default)
         {
             string fullPath = Path.GetFullPath(path);
 
@@ -116,7 +122,7 @@ internal static IEnumerable<string> GetListOfProjectsFromPathArgument(string pat
             }
 
             return XPlatUtility.IsSolutionFile(projectOrSolutionFile)
-                        ? MSBuildAPIUtility.GetProjectsFromSolution(projectOrSolutionFile).Where(f => File.Exists(f))
+                        ? (await MSBuildAPIUtility.GetProjectsFromSolution(projectOrSolutionFile, cancellationToken)).Where(f => File.Exists(f))
                         : [projectOrSolutionFile];
         }
 

src/NuGet.Core/NuGet.CommandLine.XPlat/Utility/XPlatUtility.cs

@@ -132,7 +132,7 @@ internal static bool IsSolutionFile(string fileName)
             {
                 var extension = System.IO.Path.GetExtension(fileName);
 
-                return string.Equals(extension, ".sln", StringComparison.OrdinalIgnoreCase);
+                return string.Equals(extension, ".sln", StringComparison.OrdinalIgnoreCase) || string.Equals(extension, ".slnx", StringComparison.OrdinalIgnoreCase);
             }
 
             return false;

test/NuGet.Core.FuncTests/NuGet.XPlat.FuncTest/ListPackageTests.cs

@@ -261,17 +261,17 @@ static void SetupCredentialServiceMock(Mock<ICredentialService> mockedCredential
                         return outCredentials != null;
                     });
             }
+        }
 
-            static async Task RestoreProjectsAsync(SimpleTestPathContext pathContext, SimpleTestProjectContext projectA, SimpleTestProjectContext projectB, ITestOutputHelper testOutputHelper)
-            {
-                var settings = Settings.LoadDefaultSettings(Path.GetDirectoryName(pathContext.SolutionRoot), Path.GetFileName(pathContext.NuGetConfig), null);
-                var packageSourceProvider = new PackageSourceProvider(settings);
+        static async Task RestoreProjectsAsync(SimpleTestPathContext pathContext, SimpleTestProjectContext projectA, SimpleTestProjectContext projectB, ITestOutputHelper testOutputHelper)
+        {
+            var settings = Settings.LoadDefaultSettings(Path.GetDirectoryName(pathContext.SolutionRoot), Path.GetFileName(pathContext.NuGetConfig), null);
+            var packageSourceProvider = new PackageSourceProvider(settings);
 
-                var sources = packageSourceProvider.LoadPackageSources();
+            var sources = packageSourceProvider.LoadPackageSources();
 
-                await RestoreProjectAsync(settings, pathContext, projectA, sources, testOutputHelper);
-                await RestoreProjectAsync(settings, pathContext, projectB, sources, testOutputHelper);
-            }
+            await RestoreProjectAsync(settings, pathContext, projectA, sources, testOutputHelper);
+            await RestoreProjectAsync(settings, pathContext, projectB, sources, testOutputHelper);
 
             static async Task RestoreProjectAsync(ISettings settings,
                 SimpleTestPathContext pathContext,
@@ -290,6 +290,63 @@ static async Task RestoreProjectAsync(ISettings settings,
             }
         }
 
+        [InlineData(true)]
+        [InlineData(false)]
+        [Theory]
+        public async Task CanListPackagesForProjectsInSolutions(bool useSlnx)
+        {
+            // Arrange
+            using var pathContext = new SimpleTestPathContext();
+
+            var packageA100 = new SimpleTestPackageContext("A", "1.0.0");
+            var packageB100 = new SimpleTestPackageContext("B", "1.0.0");
+
+            await SimpleTestPackageUtility.CreatePackagesAsync(
+                    pathContext.PackageSource,
+                    packageA100,
+                    packageB100);
+
+            var projectA = SimpleTestProjectContext.CreateNETCore("ProjectA", pathContext.SolutionRoot, "net6.0");
+            var projectB = SimpleTestProjectContext.CreateNETCore("ProjectB", pathContext.SolutionRoot, "net6.0");
+
+            projectA.AddPackageToAllFrameworks(packageA100);
+            projectB.AddPackageToAllFrameworks(packageB100);
+
+            var solution = new SimpleTestSolutionContext(pathContext.SolutionRoot, useSlnx);
+            solution.Projects.Add(projectA);
+            solution.Projects.Add(projectB);
+            solution.Create(pathContext.SolutionRoot);
+
+            using var mockServer = new FileSystemBackedV3MockServer(pathContext.PackageSource, isPrivateFeed: true);
+            mockServer.Start();
+            pathContext.Settings.AddSource(sourceName: "private-source", sourceUri: mockServer.ServiceIndexUri, allowInsecureConnectionsValue: bool.TrueString);
+
+            // List package command requires restore to be run before it can list packages.
+            await RestoreProjectsAsync(pathContext, projectA, projectB, _testOutputHelper);
+
+            var output = new StringBuilder();
+            var error = new StringBuilder();
+            using TextWriter consoleOut = new StringWriter(output);
+            using TextWriter consoleError = new StringWriter(error);
+            var logger = new TestLogger(_testOutputHelper);
+            ListPackageCommandRunner listPackageCommandRunner = new();
+            var packageRefArgs = new ListPackageArgs(
+                                        path: solution.SolutionPath,
+                                        packageSources: [new(mockServer.ServiceIndexUri)],
+                                        frameworks: ["net6.0"],
+                                        reportType: ReportType.Vulnerable,
+                                        renderer: new ListPackageConsoleRenderer(consoleOut, consoleError),
+                                        includeTransitive: false,
+                                        prerelease: false,
+                                        highestPatch: false,
+                                        highestMinor: false,
+                                        logger: logger,
+                                        cancellationToken: CancellationToken.None);
+
+            int result = await listPackageCommandRunner.ExecuteCommandAsync(packageRefArgs);
+            Assert.True(result == 0, userMessage: logger.ShowMessages());
+        }
+
         private void VerifyCommand(Action<string, Mock<IListPackageCommandRunner>, CommandLineApplication, Func<LogLevel>> verify)
         {
             // Arrange