Fix CmdPal alias keystroke race condition

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/AliasManager.cs

@@ -40,23 +40,54 @@ public AliasManager(TopLevelCommandManager tlcManager, ISettingsService settings
 
     public bool CheckAlias(string searchText)
     {
+        // Try exact match first (handles both direct aliases like ">" and
+        // indirect aliases when the user types exactly "file ").
         if (_settingsService.Settings.Aliases.TryGetValue(searchText, out var alias))
         {
-            try
-            {
-                var topLevelCommand = _topLevelCommandManager.LookupCommand(alias.CommandId);
-                if (topLevelCommand is not null)
-                {
-                    WeakReferenceMessenger.Default.Send<ClearSearchMessage>();
+            return TryFireAlias(alias, remainingText: string.Empty);
+        }
 
-                    WeakReferenceMessenger.Default.Send<PerformCommandMessage>(topLevelCommand.GetPerformCommandMessage());
-                    return true;
-                }
+        // For indirect aliases the debounce timer may deliver text beyond
+        // the prefix (e.g. "file test" when the user typed fast). Check if
+        // the search text starts with any known indirect alias prefix (#41736).
+        foreach (var kv in _settingsService.Settings.Aliases)
+        {
+            var candidateAlias = kv.Value;
+            if (!candidateAlias.IsDirect
+                && searchText.Length > kv.Key.Length
+                && searchText.StartsWith(kv.Key, StringComparison.Ordinal))
+            {
+                var extraText = searchText[kv.Key.Length..];
+                return TryFireAlias(candidateAlias, extraText);
             }
-            catch
+        }
+
+        return false;
+    }
+
+    private bool TryFireAlias(CommandAlias alias, string remainingText)
+    {
+        try
+        {
+            var topLevelCommand = _topLevelCommandManager.LookupCommand(alias.CommandId);
+            if (topLevelCommand is not null)
             {
+                WeakReferenceMessenger.Default.Send<ClearSearchMessage>();
+                WeakReferenceMessenger.Default.Send<PerformCommandMessage>(topLevelCommand.GetPerformCommandMessage());
+
+                // If there was text typed after the alias prefix, forward it so
+                // keystrokes aren't lost (#41736).
+                if (!string.IsNullOrEmpty(remainingText))
+                {
+                    WeakReferenceMessenger.Default.Send(new SetSearchTextMessage(remainingText));
+                }
+
+                return true;
             }
         }
+        catch
+        {
+        }
 
         return false;
     }

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Messages/SetSearchTextMessage.cs

@@ -0,0 +1,11 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+
+/// <summary>
+/// Sent after an alias triggers navigation to forward any text the user
+/// typed beyond the alias prefix to the destination page (#41736).
+/// </summary>
+public record SetSearchTextMessage(string Text);

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/SearchBar.xaml.cs

@@ -30,6 +30,7 @@ public sealed partial class SearchBar : UserControl,
     IRecipient<FocusSearchBoxMessage>,
     IRecipient<UpdateSuggestionMessage>,
     IRecipient<FocusParamMessage>,
+    IRecipient<SetSearchTextMessage>,
     ICurrentPageAware
 {
     private readonly DispatcherQueue _queue = DispatcherQueue.GetForCurrentThread();
@@ -40,6 +41,9 @@ public sealed partial class SearchBar : UserControl,
     private readonly DispatcherQueueTimer _debounceTimer = DispatcherQueue.GetForCurrentThread().CreateTimer();
     private bool _isBackspaceHeld;
 
+    // Text to apply after the next page navigation completes (alias overflow, #41736).
+    private string? _pendingSearchText;
+
     // Inline text suggestions
     // In 0.4-0.5 we would replace the text of the search box with the TextToSuggest
     // This was really cool for navigating paths in run and pretty much nowhere else.
@@ -74,7 +78,6 @@ public PageViewModel? CurrentPageViewModel
 
     private static void OnCurrentPageViewModelChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
     {
-        //// TODO: If the Debounce timer hasn't fired, we may want to store the current Filter in the OldValue/prior VM, but we don't want that to go actually do work...
         var @this = (SearchBar)d;
 
         if (@this is not null
@@ -86,11 +89,31 @@ private static void OnCurrentPageViewModelChanged(DependencyObject d, Dependency
         if (@this is not null
             && e.NewValue is PageViewModel page)
         {
-            // TODO: In some cases we probably want commands to clear a filter
-            // somewhere in the process, so we need to figure out when that is.
-            @this.FilterBox.Text = page.SearchTextBox;
+            // Stop any pending debounce so a stale callback doesn't overwrite
+            // the new page's search text after we set it here (#41736).
+            @this._debounceTimer.Stop();
+
+            // If an alias stored overflow text, apply it instead of the page default.
+            var pending = @this._pendingSearchText;
+            @this._pendingSearchText = null;
+
+            var textToSet = pending ?? page.SearchTextBox;
+            @this.FilterBox.Text = textToSet;
             @this.FilterBox.Select(@this.FilterBox.Text.Length, 0);
 
+            if (pending is not null)
+            {
+                // Defer pushing overflow text into the ViewModel so the page
+                // can finish initializing without a premature cancellation.
+                @this._queue.TryEnqueue(() =>
+                {
+                    if (@this.CurrentPageViewModel == page)
+                    {
+                        page.SearchTextBox = textToSet;
+                    }
+                });
+            }
+
             page.PropertyChanged += @this.Page_PropertyChanged;
 
             if (page is ListViewModel listViewModel)
@@ -123,14 +146,25 @@ public SearchBar()
         WeakReferenceMessenger.Default.Register<FocusSearchBoxMessage>(this);
         WeakReferenceMessenger.Default.Register<UpdateSuggestionMessage>(this);
         WeakReferenceMessenger.Default.Register<FocusParamMessage>(this);
+        WeakReferenceMessenger.Default.Register<SetSearchTextMessage>(this);
     }
 
     public void ClearSearch()
     {
-        // TODO GH #239 switch back when using the new MD text block
-        // _ = _queue.EnqueueAsync(() =>
+        // Cancel any pending debounce to prevent stale text from being
+        // written after the clear (fixes alias keystroke race #41736).
+        _debounceTimer.Stop();
+
+        // Capture the current page so the queued clear only applies if we're
+        // still on the same page (avoids clearing a newly-navigated page).
+        var page = CurrentPageViewModel;
         _queue.TryEnqueue(new(() =>
         {
+            if (CurrentPageViewModel != page)
+            {
+                return;
+            }
+
             this.FilterBox.Text = string.Empty;
 
             if (CurrentPageViewModel is not null)
@@ -499,6 +533,12 @@ public void Receive(GoHomeMessage message)
 
     public void Receive(FocusSearchBoxMessage message) => Focus();
 
+    public void Receive(SetSearchTextMessage message)
+    {
+        // Store the text to apply after the next page navigation (#41736).
+        _pendingSearchText = message.Text;
+    }
+
     private void Focus()
     {
         this.DispatcherQueue.TryEnqueue(DispatcherQueuePriority.Low, () =>