fix: ApplicationImpl.Invoke throws NotInitializedException after Dispose (#5163)

Terminal.Gui/App/ApplicationImpl.Run.cs

@@ -55,6 +55,11 @@ internal partial class ApplicationImpl
     /// <inheritdoc/>
     public void Invoke (Action<IApplication>? action)
     {
+        if (!Initialized)
+        {
+            throw new NotInitializedException (nameof (Invoke));
+        }
+
         // If we are already on the main UI thread
         if (TopRunnableView is IRunnable { IsRunning: true } && MainThreadId == Thread.CurrentThread.ManagedThreadId)
         {
@@ -75,6 +80,13 @@ public void Invoke (Action<IApplication>? action)
     /// <inheritdoc/>
     public void Invoke (Action action)
     {
+        ArgumentNullException.ThrowIfNull (action);
+
+        if (!Initialized)
+        {
+            throw new NotInitializedException (nameof (Invoke));
+        }
+
         // If we are already on the main UI thread
         if (TopRunnableView is IRunnable { IsRunning: true } && MainThreadId == Thread.CurrentThread.ManagedThreadId)
         {

Terminal.Gui/App/IApplication.cs

@@ -354,6 +354,9 @@ public interface IApplication : IDisposable
     ///         iteration.
     ///     </para>
     /// </remarks>
+    /// <exception cref="NotInitializedException">
+    ///     Thrown when <see cref="Init"/> has not been called or after <see cref="IDisposable.Dispose"/> has been called.
+    /// </exception>
     void Invoke (Action<IApplication>? action);
 
     /// <summary>Runs <paramref name="action"/> on the main UI loop thread.</summary>
@@ -365,6 +368,9 @@ public interface IApplication : IDisposable
     ///         iteration.
     ///     </para>
     /// </remarks>
+    /// <exception cref="NotInitializedException">
+    ///     Thrown when <see cref="Init"/> has not been called or after <see cref="IDisposable.Dispose"/> has been called.
+    /// </exception>
     void Invoke (Action action);
 
     #endregion Iteration & Invoke

Tests/UnitTests.NonParallelizable/Application/ApplicationInvokeLifecycleTests.cs

@@ -0,0 +1,77 @@
+// Claude - Opus 4.7
+#nullable enable
+
+namespace UnitTests.NonParallelizable.ApplicationTests;
+
+/// <summary>
+///     Tests asserting <see cref="IApplication.Invoke(Action)"/> and
+///     <see cref="IApplication.Invoke(System.Action{IApplication})"/> contract relative to the
+///     <see cref="IApplication.Init"/> / <see cref="IDisposable.Dispose"/> lifecycle.
+///     Regression coverage for issue #5163.
+/// </summary>
+public class ApplicationInvokeLifecycleTests
+{
+    [Fact]
+    public void Invoke_Action_BeforeInit_Throws_NotInitializedException ()
+    {
+        IApplication app = Application.Create ();
+
+        try
+        {
+            Assert.Throws<NotInitializedException> (() => app.Invoke (() => { }));
+        }
+        finally
+        {
+            app.Dispose ();
+        }
+    }
+
+    [Fact]
+    public void Invoke_ActionOfApplication_BeforeInit_Throws_NotInitializedException ()
+    {
+        IApplication app = Application.Create ();
+
+        try
+        {
+            Assert.Throws<NotInitializedException> (() => app.Invoke (static _ => { }));
+        }
+        finally
+        {
+            app.Dispose ();
+        }
+    }
+
+    [Fact]
+    public void Invoke_Action_AfterDispose_Throws_NotInitializedException ()
+    {
+        IApplication app = Application.Create ();
+
+        try
+        {
+            app.Init (DriverRegistry.Names.ANSI);
+        }
+        finally
+        {
+            app.Dispose ();
+        }
+
+        Assert.Throws<NotInitializedException> (() => app.Invoke (() => { }));
+    }
+
+    [Fact]
+    public void Invoke_ActionOfApplication_AfterDispose_Throws_NotInitializedException ()
+    {
+        IApplication app = Application.Create ();
+
+        try
+        {
+            app.Init (DriverRegistry.Names.ANSI);
+        }
+        finally
+        {
+            app.Dispose ();
+        }
+
+        Assert.Throws<NotInitializedException> (() => app.Invoke (static _ => { }));
+    }
+}