Fixes #4076 cursor text field (#4077)

* Add test for TextField cursor position

* Add comment and one more assert

* Fix cursor position at the end

* Remove unused local field

---------

Co-authored-by: BDisp <bd.bdisp@gmail.com>

Tests/TerminalGuiFluentTesting/FakeOutput.cs

@@ -24,5 +24,10 @@ internal class FakeOutput : IConsoleOutput
     public void SetCursorVisibility (CursorVisibility visibility) { }
 
     /// <inheritdoc/>
-    public void SetCursorPosition (int col, int row) { }
+    public void SetCursorPosition (int col, int row) { CursorPosition = new Point (col, row); }
+
+    /// <summary>
+    /// The last value set by calling <see cref="SetCursorPosition"/>
+    /// </summary>
+    public Point CursorPosition { get; private set; }
 }

Tests/TerminalGuiFluentTesting/GuiTestContext.cs

@@ -706,10 +706,14 @@ public class GuiTestContext : IDisposable
     ///     is found (of Type T) or all views are looped through (back to the beginning)
     ///     in which case triggers hard stop and Exception
     /// </summary>
+    /// <param name="evaluator">Delegate that returns true if the passed View is the one
+    /// you are trying to focus. Leave <see langword="null"/> to focus the first view of type
+    /// <typeparamref name="T"/></param>
     /// <returns></returns>
     /// <exception cref="ArgumentException"></exception>
-    public GuiTestContext Focus<T> (Func<T, bool> evaluator) where T : View
+    public GuiTestContext Focus<T> (Func<T, bool>? evaluator = null) where T : View
     {
+        evaluator ??= _ => true;
         Toplevel? t = Application.Top;
 
         HashSet<View> seen = new ();
@@ -816,4 +820,13 @@ public class GuiTestContext : IDisposable
 
         return this;
     }
+
+    /// <summary>
+    /// Returns the last set position of the cursor.
+    /// </summary>
+    /// <returns></returns>
+    public Point GetCursorPosition ()
+    {
+        return _output.CursorPosition;
+    }
 }