Preserve draft text when navigating command history with arrow keys

PolyPilot.Tests/CommandHistoryTests.cs

@@ -9,7 +9,7 @@ public class CommandHistoryTests
     public void Navigate_EmptyHistory_ReturnsNull()
     {
         var history = new CommandHistory();
-        Assert.Null(history.Navigate(up: true));
+        Assert.Null(history.Navigate(up: true, currentText: "draft"));
         Assert.Null(history.Navigate(up: false));
     }
 
@@ -58,19 +58,19 @@ public void Navigate_Up_CyclesThroughAllEntries()
     }
 
     [Fact]
-    public void Navigate_UpThenDown_NavigatesCorrectly()
+    public void Navigate_UpThenDown_RestoresDraft()
     {
         var history = new CommandHistory();
         history.Add("first");
         history.Add("second");
         history.Add("third");
 
-        Assert.Equal("third", history.Navigate(up: true)!.Value.Text);
+        Assert.Equal("third", history.Navigate(up: true, currentText: "my draft")!.Value.Text);
         Assert.Equal("second", history.Navigate(up: true)!.Value.Text);
         // Down goes back toward newest
         Assert.Equal("third", history.Navigate(up: false)!.Value.Text);
-        // Past end clears to empty
-        Assert.Equal("", history.Navigate(up: false)!.Value.Text);
+        // Past end restores the original draft
+        Assert.Equal("my draft", history.Navigate(up: false)!.Value.Text);
     }
 
     [Fact]
@@ -148,14 +148,58 @@ public void IsNavigating_TrueAfterUpFalseAfterReturningToEnd()
     }
 
     [Fact]
-    public void Navigate_Down_PastEnd_ReturnsEmpty()
+    public void Navigate_Down_PastEnd_RestoresDraftOrEmpty()
     {
         var history = new CommandHistory();
         history.Add("cmd");
 
-        // Already past end, navigate down
+        // Already past end, navigate down — no draft saved, returns empty
         var result = history.Navigate(up: false);
         Assert.NotNull(result);
         Assert.Equal("", result!.Value.Text);
     }
+
+    [Fact]
+    public void Navigate_DraftPreservedThroughFullCycle()
+    {
+        var history = new CommandHistory();
+        history.Add("old1");
+        history.Add("old2");
+
+        // User is typing "work in progress", presses up
+        Assert.Equal("old2", history.Navigate(up: true, currentText: "work in progress")!.Value.Text);
+        Assert.Equal("old1", history.Navigate(up: true)!.Value.Text);
+        // All the way back down
+        Assert.Equal("old2", history.Navigate(up: false)!.Value.Text);
+        Assert.Equal("work in progress", history.Navigate(up: false)!.Value.Text);
+        Assert.False(history.IsNavigating);
+    }
+
+    [Fact]
+    public void Navigate_EmptyDraftPreserved()
+    {
+        var history = new CommandHistory();
+        history.Add("cmd");
+
+        // User presses up with empty input
+        Assert.Equal("cmd", history.Navigate(up: true, currentText: "")!.Value.Text);
+        // Down restores empty draft
+        Assert.Equal("", history.Navigate(up: false)!.Value.Text);
+    }
+
+    [Fact]
+    public void Add_ClearsDraft()
+    {
+        var history = new CommandHistory();
+        history.Add("old");
+
+        // Navigate up with a draft
+        history.Navigate(up: true, currentText: "my draft");
+        // Send a message — this should clear the draft
+        history.Add("new message");
+
+        // Navigate up then down — draft should be gone (empty, not "my draft")
+        Assert.Equal("new message", history.Navigate(up: true, currentText: "")!.Value.Text);
+        Assert.Equal("", history.Navigate(up: false)!.Value.Text);
+    }
 }

PolyPilot/Components/Pages/Dashboard.razor

@@ -1000,7 +1000,7 @@
                             if ((e.key === 'ArrowUp' && atStart) || (e.key === 'ArrowDown' && (atEnd || histNavActive))) {
                                 if (sessionName && window.__dashRef) {
                                     e.preventDefault();
-                                    window.__dashRef.invokeMethodAsync('JsNavigateHistory', sessionName, e.key === 'ArrowUp').then(function(isNav) {
+                                    window.__dashRef.invokeMethodAsync('JsNavigateHistory', sessionName, e.key === 'ArrowUp', ta.value || '').then(function(isNav) {
                                         if (!window.__histNavActive) window.__histNavActive = {};
                                         window.__histNavActive[sessionName] = isNav;
                                     }).catch(function() {
@@ -3640,12 +3640,12 @@
     }
 
     [JSInvokable]
-    public async Task<bool> JsNavigateHistory(string sessionName, bool up)
+    public async Task<bool> JsNavigateHistory(string sessionName, bool up, string? currentText = null)
     {
         if (!commandHistoryBySession.TryGetValue(sessionName, out var hist))
             return false;
 
-        var result = hist.Navigate(up);
+        var result = hist.Navigate(up, currentText);
         if (result == null) return false;
 
         var (text, cursorAtStart) = result.Value;

PolyPilot/Models/CommandHistory.cs

@@ -2,11 +2,14 @@ namespace PolyPilot.Models;
 
 /// <summary>
 /// Manages per-session command history with up/down navigation.
+/// Preserves the user's in-progress draft when entering history mode
+/// and restores it when navigating back down past the newest entry.
 /// </summary>
 public class CommandHistory
 {
     private readonly List<string> _entries = new();
     private int _index;
+    private string? _draft;
     private const int MaxEntries = 50;
 
     public int Count => _entries.Count;
@@ -23,6 +26,7 @@ public void Add(string command)
             if (_entries.Count > MaxEntries) _entries.RemoveAt(0);
         }
         _index = _entries.Count; // past the end = "no selection"
+        _draft = null; // draft consumed — message was sent
     }
 
     /// <summary>
@@ -31,16 +35,22 @@ public void Add(string command)
     /// false when navigating down (so next ArrowDown fires immediately).
     /// Returns null if history is empty.
     /// </summary>
-    public (string Text, bool CursorAtStart)? Navigate(bool up)
+    /// <param name="up">True for ArrowUp (older), false for ArrowDown (newer).</param>
+    /// <param name="currentText">The current input text — saved as draft on first up-navigation.</param>
+    public (string Text, bool CursorAtStart)? Navigate(bool up, string? currentText = null)
     {
         if (_entries.Count == 0) return null;
 
+        // Stash the draft when first entering history mode
+        if (up && !IsNavigating)
+            _draft = currentText ?? "";
+
         if (up)
             _index = Math.Max(0, _index - 1);
         else
             _index = Math.Min(_entries.Count, _index + 1);
 
-        var text = _index < _entries.Count ? _entries[_index] : "";
+        var text = _index < _entries.Count ? _entries[_index] : (_draft ?? "");
         return (text, up);
     }
 }