feat(compatibility): ✨ Enhance input handling and add HasPendingInput method

* Improved input handling by checking for pending input before draining.
* Introduced `HasPendingInput` method to encapsulate input availability logic.
* Refactored `RenderToString` method in `SpectreRenderBridge` for better error handling and clarity.
* Updated `Writer` class to use consistent parameter naming conventions.
* Fixed window rectangle calculations in test helper for accurate buffer retrieval.

Author: trackd

src/PSTextMate/Sixel/Compatibility.cs

@@ -34,8 +34,9 @@ internal static string GetControlSequenceResponse(string controlSequence) {
         const int maxRetries = 2;
 
         lock (s_controlSequenceLock) {
-            // Drain any stale bytes that may have leaked from prior VT interactions.
-            DrainPendingInput();
+            if (HasPendingInput()) {
+                return string.Empty;
+            }
 
             for (int retry = 0; retry < maxRetries; retry++) {
                 try {
@@ -89,6 +90,19 @@ internal static string GetControlSequenceResponse(string controlSequence) {
         return string.Empty;
     }
 
+    private static bool HasPendingInput() {
+        if (Console.IsOutputRedirected || Console.IsInputRedirected) {
+            return false;
+        }
+
+        try {
+            return Console.KeyAvailable;
+        }
+        catch {
+            return false;
+        }
+    }
+
     /// <summary>
     /// Attempts to read a key if one is available.
     /// </summary>

src/PSTextMate/Utilities/SpectreRenderBridge.cs

@@ -18,16 +18,18 @@ public static class SpectreRenderBridge {
     public static string RenderToString(object renderableObject, bool escapeAnsi = false, int? width = null) {
         ArgumentNullException.ThrowIfNull(renderableObject);
 
-        string rendered = renderableObject is IRenderable localRenderable
-            ? RenderLocal(localRenderable, width)
-            : RenderForeign(renderableObject, width);
-
-        return rendered.Length != 0
-            ? escapeAnsi ? VTHelpers.StripAnsi(rendered) : rendered
-            : throw new ArgumentException(
+        string rendered;
+        if (renderableObject is IRenderable localRenderable) {
+            rendered = RenderLocal(localRenderable, width);
+        }
+        else if (!TryRenderForeign(renderableObject, width, out rendered)) {
+            throw new ArgumentException(
                 $"Object of type '{renderableObject.GetType().FullName}' does not implement a supported Spectre IRenderable shape.",
                 nameof(renderableObject)
             );
+        }
+
+        return escapeAnsi ? VTHelpers.StripAnsi(rendered) : rendered;
     }
 
     /// <summary>
@@ -87,7 +89,8 @@ private static string RenderLocal(IRenderable renderable, int? width) {
         return writer.ToString();
     }
 
-    private static string RenderForeign(object renderableObject, int? width) {
+    private static bool TryRenderForeign(object renderableObject, int? width, out string rendered) {
+        rendered = string.Empty;
         Type valueType = renderableObject.GetType();
         Assembly assembly = valueType.Assembly;
 
@@ -101,15 +104,15 @@ private static string RenderForeign(object renderableObject, int? width) {
             || ansiConsoleSettingsType is null
             || ansiConsoleOutputType is null
             || foreignRenderableType?.IsInstanceOfType(renderableObject) != true) {
-            return string.Empty;
+            return false;
         }
 
         using StringWriter writer = new(new StringBuilder(1024), CultureInfo.InvariantCulture);
         object? output = Activator.CreateInstance(ansiConsoleOutputType, writer);
         object? settings = Activator.CreateInstance(ansiConsoleSettingsType);
         PropertyInfo? outProperty = ansiConsoleSettingsType.GetProperty("Out");
         if (output is null || settings is null || outProperty is null || !outProperty.CanWrite) {
-            return string.Empty;
+            return false;
         }
 
         outProperty.SetValue(settings, output);
@@ -121,7 +124,7 @@ private static string RenderForeign(object renderableObject, int? width) {
                 && parameters[0].ParameterType == ansiConsoleSettingsType);
         object? console = createMethod?.Invoke(null, [settings]);
         if (console is null) {
-            return string.Empty;
+            return false;
         }
 
         if (width is int targetWidth && targetWidth > 0) {
@@ -136,7 +139,8 @@ private static string RenderForeign(object renderableObject, int? width) {
         MethodInfo? writeMethod = console.GetType().GetMethod("Write", [foreignRenderableType]);
         if (writeMethod is not null) {
             _ = writeMethod.Invoke(console, [renderableObject]);
-            return writer.ToString();
+            rendered = writer.ToString();
+            return true;
         }
 
         Type? extType = assembly.GetType("Spectre.Console.AnsiConsoleExtensions");
@@ -146,11 +150,12 @@ private static string RenderForeign(object renderableObject, int? width) {
                 && method.GetParameters() is { Length: 2 } parameters
                 && parameters[1].ParameterType == foreignRenderableType);
         if (extWriteMethod is null) {
-            return string.Empty;
+            return false;
         }
 
         _ = extWriteMethod.Invoke(null, [console, renderableObject]);
-        return writer.ToString();
+        rendered = writer.ToString();
+        return true;
     }
 
     private static CallSite<Func<CallSite, object, IRenderable>> CreateConvertToRenderableCallSite() {

src/PSTextMate/Utilities/Writer.cs

@@ -32,21 +32,21 @@ public static string Write(IRenderable renderable) {
     /// Renders highlighted text to string.
     /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public static string? Write(HighlightedText highlightedText, bool autoPage = false, bool FromFormat = false) {
+    public static string? Write(HighlightedText highlightedText, bool autoPage = false, bool fromFormat = false) {
         ArgumentNullException.ThrowIfNull(highlightedText);
 
         if (highlightedText.Page || (autoPage && ShouldPage(highlightedText))) {
             var pager = new Pager(highlightedText);
             pager.Show();
-            if (FromFormat) VTHelpers.MoveCursorRowUp(2);
+            if (fromFormat) VTHelpers.MoveCursorRowUp(2);
             return null;
         }
 
         // Sixel payload must be written as raw control sequences. Converting to a string
         // and flowing through host formatting can strip DCS wrappers and print payload text.
         if (ContainsImageRenderables(highlightedText.Renderables)) {
             AnsiConsole.Write(highlightedText);
-            if (FromFormat) VTHelpers.MoveCursorRowUp(2);
+            if (fromFormat) VTHelpers.MoveCursorRowUp(2);
             return null;
         }
 

tests/testhelper.psm1

@@ -29,8 +29,8 @@ function Get-HostBuffer {
     $windowRect = [System.Management.Automation.Host.Rectangle]::new(
         $windowPosition.X,
         $windowPosition.Y,
-        ($windowPosition.X + $windowWidth),
-        ($windowPosition.Y + $windowHeight))
+        ($windowPosition.X + $windowWidth - 1),
+        ($windowPosition.Y + $windowHeight - 1))
     $windowBuffer = $host.UI.RawUI.GetBufferContents($windowRect)
     foreach ($x in 0..($windowHeight - 1)) {
         $row = foreach ($y in 0..($windowWidth - 1)) {