Add restore support to the language server

src/Features/LanguageServer/Microsoft.CodeAnalysis.LanguageServer/LanguageServer/Handler/Restore/RestorableProjectsHandler.cs

@@ -0,0 +1,53 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Composition;
+using Microsoft.CodeAnalysis.Host.Mef;
+using Microsoft.CodeAnalysis.LanguageServer.Handler;
+using Microsoft.CodeAnalysis.LanguageServer.Handler.DebugConfiguration;
+using Microsoft.CodeAnalysis.PooledObjects;
+using Roslyn.Utilities;
+
+namespace Microsoft.CodeAnalysis.LanguageServer;
+
+/// <summary>
+/// Handler that allows the client to retrieve a set of restorable projects.
+/// Used to populate a list of projects that can be restored.
+/// </summary>
+[ExportCSharpVisualBasicStatelessLspService(typeof(RestorableProjectsHandler)), Shared]
+[Method(MethodName)]
+[method: ImportingConstructor]
+[method: Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
+internal class RestorableProjectsHandler(ProjectTargetFrameworkManager projectTargetFrameworkManager) : ILspServiceRequestHandler<string[]>
+{
+    internal const string MethodName = "workspace/restorableProjects";
+
+    public bool MutatesSolutionState => false;
+
+    public bool RequiresLSPSolution => true;
+
+    public Task<string[]> HandleRequestAsync(RequestContext context, CancellationToken cancellationToken)
+    {
+        Contract.ThrowIfNull(context.Solution);
+
+        using var _ = ArrayBuilder<string>.GetInstance(out var projectsBuilder);
+        foreach (var project in context.Solution.Projects)
+        {
+            // Restorable projects are dotnet core projects with file paths.
+            if (project.FilePath != null && projectTargetFrameworkManager.IsDotnetCoreProject(project.Id))
+            {
+                projectsBuilder.Add(project.FilePath);
+            }
+        }
+
+        // We may have multiple projects with the same file path in multi-targeting scenarios.
+        // They'll all get restored together so we only want one result per project file.
+        var projects = projectsBuilder.Distinct().ToArray();
+
+        // Ensure the client gets a consistent ordering.
+        Array.Sort(projects, StringComparer.OrdinalIgnoreCase);
+
+        return Task.FromResult(projects.ToArray());
+    }
+}

src/Features/LanguageServer/Microsoft.CodeAnalysis.LanguageServer/LanguageServer/Handler/Restore/RestoreHandler.cs

@@ -0,0 +1,107 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.Immutable;
+using System.Composition;
+using Microsoft.CodeAnalysis.Host.Mef;
+using Roslyn.Utilities;
+
+namespace Microsoft.CodeAnalysis.LanguageServer.Handler;
+
+/// <summary>
+/// Given an input project (or none), runs restore on the project and streams the output
+/// back to the client to display.
+/// </summary>
+[ExportCSharpVisualBasicStatelessLspService(typeof(RestoreHandler)), Shared]
+[Method(MethodName)]
+[method: ImportingConstructor]
+[method: Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
+internal class RestoreHandler(DotnetCliHelper dotnetCliHelper) : ILspServiceRequestHandler<RestoreParams, RestorePartialResult[]>
+{
+    internal const string MethodName = "workspace/restore";
+
+    public bool MutatesSolutionState => false;
+
+    public bool RequiresLSPSolution => true;
+
+    public async Task<RestorePartialResult[]> HandleRequestAsync(RestoreParams request, RequestContext context, CancellationToken cancellationToken)
+    {
+        Contract.ThrowIfNull(context.Solution);
+        using var progress = BufferedProgress.Create(request.PartialResultToken);
+
+        progress.Report(new RestorePartialResult(LanguageServerResources.Restore, LanguageServerResources.Restore_started));
+
+        var restorePaths = GetRestorePaths(request, context.Solution, context);
+        if (restorePaths.IsEmpty)
+        {
+            progress.Report(new RestorePartialResult(LanguageServerResources.Restore, LanguageServerResources.Nothing_found_to_restore));
+            return progress.GetValues() ?? [];
+        }
+
+        await RestoreAsync(restorePaths, progress, cancellationToken);
+
+        progress.Report(new RestorePartialResult(LanguageServerResources.Restore, $"{LanguageServerResources.Restore_complete}{Environment.NewLine}"));
+        return progress.GetValues() ?? [];
+    }
+
+    private async Task RestoreAsync(ImmutableArray<string> pathsToRestore, BufferedProgress<RestorePartialResult> progress, CancellationToken cancellationToken)
+    {
+        foreach (var path in pathsToRestore)
+        {
+            var arguments = $"restore \"{path}\"";
+            var workingDirectory = Path.GetDirectoryName(path);
+            var stageName = string.Format(LanguageServerResources.Restoring_0, Path.GetFileName(path));
+            ReportProgress(progress, stageName, string.Format(LanguageServerResources.Running_dotnet_restore_on_0, path));
+
+            var process = dotnetCliHelper.Run(arguments, workingDirectory, shouldLocalizeOutput: true);
+
+            process.OutputDataReceived += (sender, args) => ReportProgress(progress, stageName, args.Data);
+            process.ErrorDataReceived += (sender, args) => ReportProgress(progress, stageName, args.Data);
+            process.BeginOutputReadLine();
+            process.BeginErrorReadLine();
+
+            await process.WaitForExitAsync(cancellationToken);
+
+            if (process.ExitCode != 0)
+            {
+                throw new InvalidOperationException(LanguageServerResources.Failed_to_run_restore_see_output_for_details);
+            }
+        }
+
+        static void ReportProgress(BufferedProgress<RestorePartialResult> progress, string stage, string? restoreOutput)
+        {
+            if (restoreOutput != null)
+            {
+                progress.Report(new RestorePartialResult(stage, restoreOutput));
+            }
+        }
+    }
+
+    private static ImmutableArray<string> GetRestorePaths(RestoreParams request, Solution solution, RequestContext context)
+    {
+        if (request.ProjectFilePath != null)
+        {
+            return ImmutableArray.Create(request.ProjectFilePath);
+        }
+
+        // No file paths were specified - this means we should restore all projects in the solution.
+        // If there is a valid solution path, use that as the restore path.
+        if (solution.FilePath != null)
+        {
+            return ImmutableArray.Create(solution.FilePath);
+        }
+
+        // We don't have an addressable solution, so lets find all addressable projects.
+        // We can only restore projects with file paths as we are using the dotnet CLI to address them.
+        // We also need to remove duplicates as in multi targeting scenarios there will be multiple projects with the same file path.
+        var projects = solution.Projects
+            .Select(p => p.FilePath)
+            .WhereNotNull()
+            .Distinct()
+            .ToImmutableArray();
+
+        context.TraceInformation($"Found {projects.Length} restorable projects from {solution.Projects.Count()} projects in solution");
+        return projects;
+    }
+}

src/Features/LanguageServer/Microsoft.CodeAnalysis.LanguageServer/LanguageServer/Handler/Restore/RestoreParams.cs

@@ -0,0 +1,19 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Runtime.Serialization;
+using Microsoft.VisualStudio.LanguageServer.Protocol;
+using Newtonsoft.Json;
+
+namespace Microsoft.CodeAnalysis.LanguageServer.Handler;
+
+[DataContract]
+internal record RestoreParams(
+    [property: DataMember(Name = "projectFilePath"), JsonProperty(NullValueHandling = NullValueHandling.Ignore)] string? ProjectFilePath
+) : IPartialResultParams<RestorePartialResult>
+{
+    [DataMember(Name = Methods.PartialResultTokenName)]
+    [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
+    public IProgress<RestorePartialResult>? PartialResultToken { get; set; }
+}

src/Features/LanguageServer/Microsoft.CodeAnalysis.LanguageServer/LanguageServer/Handler/Restore/RestorePartialResult.cs

@@ -0,0 +1,13 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Runtime.Serialization;
+
+namespace Microsoft.CodeAnalysis.LanguageServer.Handler;
+
+[DataContract]
+internal record RestorePartialResult(
+    [property: DataMember(Name = "stage")] string Stage,
+    [property: DataMember(Name = "message")] string Message
+);

src/Features/LanguageServer/Microsoft.CodeAnalysis.LanguageServer/LanguageServerResources.resx

@@ -150,12 +150,18 @@
   <data name="Failed_to_read_runsettings_file_at_0:1" xml:space="preserve">
     <value>Failed to read .runsettings file at {0}:{1}</value>
   </data>
+  <data name="Failed_to_run_restore_see_output_for_details" xml:space="preserve">
+    <value>Failed to run restore, see output for details</value>
+  </data>
   <data name="Found_0_tests_in_1" xml:space="preserve">
     <value>Found {0} tests in {1}</value>
   </data>
   <data name="Message" xml:space="preserve">
     <value>Message</value>
   </data>
+  <data name="Nothing_found_to_restore" xml:space="preserve">
+    <value>Nothing found to restore</value>
+  </data>
   <data name="No_test_methods_found_in_requested_range" xml:space="preserve">
     <value>No test methods found in requested range</value>
   </data>
@@ -168,6 +174,21 @@
   <data name="Projects_failed_to_load_because_MSBuild_could_not_be_found" xml:space="preserve">
     <value>Projects failed to load because the .NET Framework build tools could not be found. Try installing Visual Studio or the Visual Studio Build Tools package, or check the logs for details.</value>
   </data>
+  <data name="Restore" xml:space="preserve">
+    <value>Restore</value>
+  </data>
+  <data name="Restore_complete" xml:space="preserve">
+    <value>Restore complete</value>
+  </data>
+  <data name="Restore_started" xml:space="preserve">
+    <value>Restore started</value>
+  </data>
+  <data name="Restoring_0" xml:space="preserve">
+    <value>Restoring {0}</value>
+  </data>
+  <data name="Running_dotnet_restore_on_0" xml:space="preserve">
+    <value>Running dotnet restore on {0}</value>
+  </data>
   <data name="Running_tests" xml:space="preserve">
     <value>Running tests...</value>
   </data>