Fix #2313: Clear terminal scrollback in-band

Author: w3lld1

src/PowerShellEditorServices/Services/Extension/EditorOperationsService.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
+using System;
 using Microsoft.PowerShell.EditorServices.Extensions;
 using Microsoft.PowerShell.EditorServices.Services.PowerShell.Host;
 using Microsoft.PowerShell.EditorServices.Services.TextDocument;
@@ -17,15 +18,18 @@ internal class EditorOperationsService : IEditorOperations
         private readonly PsesInternalHost _psesHost;
         private readonly WorkspaceService _workspaceService;
         private readonly ILanguageServerFacade _languageServer;
+        private readonly ConfigurationService _configurationService;
 
         public EditorOperationsService(
             PsesInternalHost psesHost,
             WorkspaceService workspaceService,
-            ILanguageServerFacade languageServer)
+            ILanguageServerFacade languageServer,
+            ConfigurationService configurationService)
         {
             _psesHost = psesHost;
             _workspaceService = workspaceService;
             _languageServer = languageServer;
+            _configurationService = configurationService;
         }
 
         public async Task<EditorContext> GetEditorContextAsync()
@@ -260,6 +264,12 @@ public async Task SetStatusBarMessageAsync(string message, int? timeout)
 
         public void ClearTerminal()
         {
+            if (_configurationService.CurrentSettings.IntegratedConsole.ForceClearScrollbackBuffer)
+            {
+                Console.Write("\u001b[3J");
+                return;
+            }
+
             if (!TestHasLanguageServer(warnUser: false))
             {
                 return;

src/PowerShellEditorServices/Services/Workspace/LanguageServerSettings.cs

@@ -21,6 +21,7 @@ internal class LanguageServerSettings
         public CodeFormattingSettings CodeFormatting { get; set; }
         public CodeFoldingSettings CodeFolding { get; set; }
         public PesterSettings Pester { get; set; }
+        public IntegratedConsoleSettings IntegratedConsole { get; set; }
         public string Cwd { get; set; }
         public bool EnableReferencesCodeLens { get; set; } = true;
         public bool AnalyzeOpenDocumentsOnly { get; set; }
@@ -31,6 +32,7 @@ public LanguageServerSettings()
             CodeFormatting = new CodeFormattingSettings();
             CodeFolding = new CodeFoldingSettings();
             Pester = new PesterSettings();
+            IntegratedConsole = new IntegratedConsoleSettings();
         }
 
         public void Update(
@@ -47,6 +49,7 @@ public void Update(
                     CodeFormatting = new CodeFormattingSettings(settings.CodeFormatting);
                     CodeFolding.Update(settings.CodeFolding, logger);
                     Pester.Update(settings.Pester, logger);
+                    IntegratedConsole = new IntegratedConsoleSettings(settings.IntegratedConsole);
                     Cwd = settings.Cwd;
                     EnableReferencesCodeLens = settings.EnableReferencesCodeLens;
                     AnalyzeOpenDocumentsOnly = settings.AnalyzeOpenDocumentsOnly;
@@ -55,6 +58,21 @@ public void Update(
         }
     }
 
+    internal class IntegratedConsoleSettings
+    {
+        public IntegratedConsoleSettings() { }
+
+        public IntegratedConsoleSettings(IntegratedConsoleSettings integratedConsoleSettings)
+        {
+            if (integratedConsoleSettings is not null)
+            {
+                ForceClearScrollbackBuffer = integratedConsoleSettings.ForceClearScrollbackBuffer;
+            }
+        }
+
+        public bool ForceClearScrollbackBuffer { get; set; }
+    }
+
     internal class ScriptAnalysisSettings
     {
         private readonly object updateLock = new();

test/PowerShellEditorServices.Test/Extensions/EditorOperationsServiceTests.cs

@@ -6,13 +6,21 @@
 using Microsoft.Extensions.Logging.Abstractions;
 using Microsoft.PowerShell.EditorServices.Extensions;
 using Microsoft.PowerShell.EditorServices.Services;
+using Microsoft.PowerShell.EditorServices.Services.Configuration;
 using Microsoft.PowerShell.EditorServices.Services.Extension;
 using Microsoft.PowerShell.EditorServices.Services.TextDocument;
+using Newtonsoft.Json;
 using OmniSharp.Extensions.LanguageServer.Protocol;
 using Xunit;
 
 namespace PowerShellEditorServices.Test.Extensions
 {
+    [CollectionDefinition("Console", DisableParallelization = true)]
+    public class ConsoleCollectionDefinition
+    {
+    }
+
+    [Collection("Console")]
     [Trait("Category", "Extensions")]
     public class EditorOperationsServiceTests
     {
@@ -36,7 +44,8 @@ public void GetWorkspaceOpenDocumentsReturnsOnlyOpenDocumentsAndCurrentInMemoryS
             EditorOperationsService editorOperationsService = new(
                 psesHost: null,
                 workspaceService,
-                languageServer: null);
+                languageServer: null,
+                new ConfigurationService());
 
             WorkspaceOpenDocument[] documents = editorOperationsService.GetWorkspaceOpenDocuments();
 
@@ -60,7 +69,8 @@ public void GetWorkspaceOpenDocumentsTracksEditedAndUntitledSaveStates()
             EditorOperationsService editorOperationsService = new(
                 psesHost: null,
                 workspaceService,
-                languageServer: null);
+                languageServer: null,
+                new ConfigurationService());
 
             WorkspaceOpenDocument[] initialDocuments = editorOperationsService.GetWorkspaceOpenDocuments();
             Assert.Contains(initialDocuments, static document => document.Path.EndsWith("open-saved.ps1") && document.Saved);
@@ -87,6 +97,45 @@ public void GetWorkspaceOpenDocumentsTracksEditedAndUntitledSaveStates()
             Assert.Contains(savedDocuments, static document => document.Path.StartsWith("untitled:", StringComparison.Ordinal) && !document.Saved);
         }
 
+        [Fact]
+        public void LanguageServerSettingsUpdatesForceClearScrollbackBuffer()
+        {
+            LanguageServerSettings incomingSettings = JsonConvert.DeserializeObject<LanguageServerSettings>(
+                "{\"integratedConsole\":{\"forceClearScrollbackBuffer\":true}}");
+            LanguageServerSettings currentSettings = new();
+
+            currentSettings.Update(incomingSettings, workspaceRootPath: string.Empty, NullLogger.Instance);
+
+            Assert.True(currentSettings.IntegratedConsole.ForceClearScrollbackBuffer);
+        }
+
+        [Fact]
+        public void ClearTerminalWritesEraseSavedLinesWhenConfigured()
+        {
+            WorkspaceService workspaceService = new(NullLoggerFactory.Instance);
+            ConfigurationService configurationService = new();
+            configurationService.CurrentSettings.IntegratedConsole.ForceClearScrollbackBuffer = true;
+            EditorOperationsService editorOperationsService = new(
+                psesHost: null,
+                workspaceService,
+                languageServer: null,
+                configurationService);
+            StringWriter output = new();
+            TextWriter originalOutput = Console.Out;
+
+            try
+            {
+                Console.SetOut(output);
+                editorOperationsService.ClearTerminal();
+            }
+            finally
+            {
+                Console.SetOut(originalOutput);
+            }
+
+            Assert.Equal("\u001b[3J", output.ToString());
+        }
+
         private static ScriptFile CreateFileBuffer(WorkspaceService workspaceService, string fileName)
         {
             string filePath = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString("N"), fileName);