Add support for workspace/workspaceFolders request (#7990)

* Add support for workspace/workspaceFolders message. New requirement from pylance

* Wasn't handling the project add/remove scenario too

Python/Product/PythonTools/PythonTools.csproj

@@ -325,6 +325,7 @@
     <Compile Include="PythonTools\LanguageServerClient\WorkspaceFolderChanged\DidChangeWorkspaceFoldersParams.cs" />
     <Compile Include="PythonTools\LanguageServerClient\WorkspaceFolderChanged\WorkspaceFolder.cs" />
     <Compile Include="PythonTools\LanguageServerClient\WorkspaceFolderChanged\WorkspaceFoldersChangeEvent.cs" />
+    <Compile Include="PythonTools\LanguageServerClient\WorkspaceFolders\WorkspaceFoldersArgs.cs" />
     <Compile Include="PythonTools\Logging\LogHubLogger.cs" />
     <Compile Include="PythonTools\Navigation\Navigable\NavigableSymbol.cs" />
     <Compile Include="PythonTools\Navigation\Navigable\NavigableSymbolSource.cs" />

Python/Product/PythonTools/PythonTools/LanguageServerClient/PythonLanguageClient.cs

@@ -97,6 +97,7 @@ namespace Microsoft.PythonTools.LanguageServerClient {
         private bool _workspaceFoldersSupported = false;
         private bool _isDebugging = LanguageServer.IsDebugging();
         private bool _sentInitialWorkspaceFolders = false;
+        private List<WorkspaceFolder> _workspaceFolders = new List<WorkspaceFolder>();
         private FileWatcher.Listener _fileListener;
         private static TaskCompletionSource<int> _readyTcs = new System.Threading.Tasks.TaskCompletionSource<int>();
         private bool _loaded = false;
@@ -200,6 +201,7 @@ namespace Microsoft.PythonTools.LanguageServerClient {
             customTarget.WorkspaceFolderChangeRegistered += OnWorkspaceFolderWatched;
             customTarget.AnalysisComplete += OnAnalysisComplete;
             customTarget.WorkspaceConfiguration += OnWorkspaceConfiguration;
+            customTarget.WorkspaceFolders += OnWorkspaceFolders;
             await StartAsync.InvokeAsync(this, EventArgs.Empty);
         }
 
@@ -232,6 +234,11 @@ namespace Microsoft.PythonTools.LanguageServerClient {
             args.requestResult = result.ToArray();
         }
 
+        private async Task OnWorkspaceFolders(object sender, WorkspaceFolders.WorkspaceFoldersArgs args) {
+            // Return our current list of workspace folders
+            args.requestResult = this._workspaceFolders;
+        }
+
         public async Task OnServerInitializedAsync() {
             IsInitialized = true;
             // Set _workspaceFoldersSupported to true and send to either workspace open or solution open
@@ -592,6 +599,7 @@ namespace Microsoft.PythonTools.LanguageServerClient {
                 // Send just this workspace folder. Assumption here is that the language client will be destroyed/recreated on
                 // each workspace open
                 var folder = new WorkspaceFolder { uri = new System.Uri(WorkspaceService.CurrentWorkspace.Location), name = WorkspaceService.CurrentWorkspace.GetName() };
+                this._workspaceFolders.Add(folder);
                 await InvokeDidChangeWorkspaceFoldersAsync(new WorkspaceFolder[] { folder }, new WorkspaceFolder[0]);
             }
         }
@@ -607,6 +615,7 @@ namespace Microsoft.PythonTools.LanguageServerClient {
                         await InvokeDidChangeWorkspaceFoldersAsync(new WorkspaceFolder[0], folders.ToArray());
                     }
                 });
+                this._workspaceFolders.Clear();
                 _workspaceFoldersSupported = false;
                 IsInitialized = false;
                 _sentInitialWorkspaceFolders = false;
@@ -620,6 +629,7 @@ namespace Microsoft.PythonTools.LanguageServerClient {
                     // If workspace folders are supported, then send our workspace folders
                     var folders = from n in this.ProjectContextProvider.ProjectNodes
                                   select new WorkspaceFolder { uri = new System.Uri(n.BaseURI.Directory), name = n.Name };
+                    this._workspaceFolders = new List<WorkspaceFolder>(folders);
                     if (folders.Any()) {
                         await InvokeDidChangeWorkspaceFoldersAsync(folders.ToArray(), new WorkspaceFolder[0]);
                     }
@@ -630,9 +640,10 @@ namespace Microsoft.PythonTools.LanguageServerClient {
         private void OnProjectAdded(EnvDTE.Project project) {
             if (_workspaceFoldersSupported) {
                 JoinableTaskContext.Factory.RunAsync(async () => {
-                    var pythonProject = project as PythonProjectNode;
+                    var pythonProject = project.GetPythonProject() as PythonProjectNode;
                     if (pythonProject != null) {
                         var folder = new WorkspaceFolder { uri = new System.Uri(pythonProject.BaseURI.Directory), name = project.Name };
+                        this._workspaceFolders.Add(folder);
                         await InvokeDidChangeWorkspaceFoldersAsync(new WorkspaceFolder[] { folder }, new WorkspaceFolder[0]);
                     }
                 });
@@ -642,9 +653,13 @@ namespace Microsoft.PythonTools.LanguageServerClient {
         private void OnProjectRemoved(EnvDTE.Project project) {
             if (_workspaceFoldersSupported) {
                 JoinableTaskContext.Factory.RunAsync(async () => {
-                    var pythonProject = project as PythonProjectNode;
+                    var pythonProject = project.GetPythonProject() as PythonProjectNode;
                     if (pythonProject != null) {
                         var folder = new WorkspaceFolder { uri = new System.Uri(pythonProject.BaseURI.Directory), name = project.Name };
+                        var entry = this._workspaceFolders.Find((f) => f.uri.ToString() == folder.uri.ToString());
+                        if (entry != null) {
+                            this._workspaceFolders.Remove(entry);
+                        }
                         await InvokeDidChangeWorkspaceFoldersAsync(new WorkspaceFolder[0], new WorkspaceFolder[] { folder });
                     }
                 });

Python/Product/PythonTools/PythonTools/LanguageServerClient/PythonLanguageClientCustomTarget.cs

@@ -29,6 +29,7 @@ using Task = System.Threading.Tasks.Task;
 
 using Microsoft.PythonTools.LanguageServerClient.WorkspaceConfiguration;
 using Microsoft.PythonTools.LanguageServerClient.FileWatcher;
+using Microsoft.PythonTools.LanguageServerClient.WorkspaceFolders;
 
 namespace Microsoft.PythonTools.LanguageServerClient {
     internal class PythonLanguageClientCustomTarget {
@@ -89,6 +90,11 @@ namespace Microsoft.PythonTools.LanguageServerClient {
         /// </summary>
         internal event AsyncEventHandler<ConfigurationArgs> WorkspaceConfiguration;
 
+        /// <summary>
+        /// Event fired when pylance sends a workspace/workspaceFolders request
+        /// </summary>
+        internal event AsyncEventHandler<WorkspaceFoldersArgs> WorkspaceFolders;
+
         [JsonRpcMethod("telemetry/event")]
         public void OnTelemetryEvent(JToken arg) {
             if (!(arg is JObject telemetry)) {
@@ -175,5 +181,23 @@ namespace Microsoft.PythonTools.LanguageServerClient {
                 return null;
             }
         }
+
+        [JsonRpcMethod("workspace/workspaceFolders")]
+        public async Task<object> OnWorkspaceFolders() {
+            try {
+                // Should be no arguments (see request here: https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#workspace_workspaceFolders)
+                if (this.WorkspaceFolders != null) {
+                    var eventArgs = new WorkspaceFoldersArgs { requestResult = null };
+                    await this.WorkspaceFolders.InvokeAsync(this, eventArgs);
+                    return eventArgs.requestResult;
+                }
+                return null;
+            } catch {
+                return null;
+            }
+        }
+    }
+
+    internal class EmptyEventArgs {
     }
 }

Python/Product/PythonTools/PythonTools/LanguageServerClient/WorkspaceFolders/WorkspaceFoldersArgs.cs

@@ -0,0 +1,11 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Microsoft.PythonTools.LanguageServerClient.WorkspaceFolders {
+    internal class WorkspaceFoldersArgs {
+        public object requestResult;
+    }
+}

package.json

@@ -2,6 +2,6 @@
     "name":  "ptvs",
     "private":  true,
     "devDependencies":  {
-                            "@pylance/pylance":  "2024.8.1"
+                            "@pylance/pylance":  "2024.8.2"
                         }
 }