Fix bad output when console repl is disabled

Author: rjmholt

src/PowerShellEditorServices/Services/PowerShell/Host/NullPSHostRawUI.cs

@@ -0,0 +1,58 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using System;
+using System.Management.Automation.Host;
+
+namespace Microsoft.PowerShell.EditorServices.Services.PowerShell.Host
+{
+    internal class NullPSHostRawUI : PSHostRawUserInterface
+    {
+        private readonly BufferCell[,] _buffer;
+
+        public NullPSHostRawUI()
+        {
+            _buffer = new BufferCell[0, 0];
+        }
+
+        public override ConsoleColor BackgroundColor { get; set; }
+        public override Size BufferSize { get; set; }
+        public override Coordinates CursorPosition { get; set; }
+        public override int CursorSize { get; set; }
+        public override ConsoleColor ForegroundColor { get; set; }
+
+        public override bool KeyAvailable => false;
+
+        public override Size MaxPhysicalWindowSize => MaxWindowSize;
+
+        public override Size MaxWindowSize => new Size { Width = _buffer.GetLength(0), Height = _buffer.GetLength(1) };
+
+        public override Coordinates WindowPosition { get; set; }
+        public override Size WindowSize { get; set; }
+        public override string WindowTitle { get; set; }
+
+        public override void FlushInputBuffer()
+        {
+            // Do nothing
+        }
+
+        public override BufferCell[,] GetBufferContents(Rectangle rectangle) => _buffer;
+
+        public override KeyInfo ReadKey(ReadKeyOptions options) => default;
+
+        public override void ScrollBufferContents(Rectangle source, Coordinates destination, Rectangle clip, BufferCell fill)
+        {
+            // Do nothing
+        }
+
+        public override void SetBufferContents(Coordinates origin, BufferCell[,] contents)
+        {
+            // Do nothing
+        }
+
+        public override void SetBufferContents(Rectangle rectangle, BufferCell fill)
+        {
+            // Do nothing
+        }
+    }
+}

src/PowerShellEditorServices/Services/PowerShell/Host/NullPSHostUI.cs

@@ -0,0 +1,90 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Management.Automation;
+using System.Management.Automation.Host;
+using System.Security;
+
+namespace Microsoft.PowerShell.EditorServices.Services.PowerShell.Host
+{
+    internal class NullPSHostUI : PSHostUserInterface
+    {
+        public NullPSHostUI()
+        {
+            RawUI = new NullPSHostRawUI();
+        }
+
+        public override PSHostRawUserInterface RawUI { get; }
+
+        public override Dictionary<string, PSObject> Prompt(string caption, string message, Collection<FieldDescription> descriptions)
+        {
+            return new Dictionary<string, PSObject>();
+        }
+
+        public override int PromptForChoice(string caption, string message, Collection<ChoiceDescription> choices, int defaultChoice)
+        {
+            return 0;
+        }
+
+        public override PSCredential PromptForCredential(string caption, string message, string userName, string targetName, PSCredentialTypes allowedCredentialTypes, PSCredentialUIOptions options)
+        {
+            return new PSCredential(userName: string.Empty, password: new SecureString());
+        }
+
+        public override PSCredential PromptForCredential(string caption, string message, string userName, string targetName)
+            => PromptForCredential(caption, message, userName, targetName, PSCredentialTypes.Default, PSCredentialUIOptions.Default);
+
+        public override string ReadLine()
+        {
+            return string.Empty;
+        }
+
+        public override SecureString ReadLineAsSecureString()
+        {
+            return new SecureString();
+        }
+
+        public override void Write(ConsoleColor foregroundColor, ConsoleColor backgroundColor, string value)
+        {
+            // Do nothing
+        }
+
+        public override void Write(string value)
+        {
+            // Do nothing
+        }
+
+        public override void WriteDebugLine(string message)
+        {
+            // Do nothing
+        }
+
+        public override void WriteErrorLine(string value)
+        {
+            // Do nothing
+        }
+
+        public override void WriteLine(string value)
+        {
+            // Do nothing
+        }
+
+        public override void WriteProgress(long sourceId, ProgressRecord record)
+        {
+            // Do nothing
+        }
+
+        public override void WriteVerboseLine(string message)
+        {
+            // Do nothing
+        }
+
+        public override void WriteWarningLine(string message)
+        {
+            // Do nothing
+        }
+    }
+}

src/PowerShellEditorServices/Services/PowerShell/Host/PsesInternalHost.cs

@@ -103,7 +103,9 @@ public PsesInternalHost(
             Version = hostInfo.Version;
 
             DebugContext = new PowerShellDebugContext(loggerFactory, languageServer, this);
-            UI = new EditorServicesConsolePSHostUserInterface(loggerFactory, _readLineProvider, hostInfo.PSHost.UI);
+            UI = hostInfo.ConsoleReplEnabled
+                ? new EditorServicesConsolePSHostUserInterface(loggerFactory, _readLineProvider, hostInfo.PSHost.UI)
+                : new NullPSHostUI();
         }
 
         public override CultureInfo CurrentCulture => _hostInfo.PSHost.CurrentCulture;
@@ -590,6 +592,11 @@ private void RunExecutionLoop()
 
         private void DoOneRepl(CancellationToken cancellationToken)
         {
+            if (!_hostInfo.ConsoleReplEnabled)
+            {
+                return;
+            }
+
             // When a task must run in the foreground, we cancel out of the idle loop and return to the top level.
             // At that point, we would normally run a REPL, but we need to immediately execute the task.
             // So we set _skipNextPrompt to do that.