Terminal.Gui/UnitTests/Application/RunStateTests.cs

// Alias Console to MockConsole so we don't accidentally use Console

namespace Terminal.Gui.ApplicationTests;

/// <summary>These tests focus on Application.RunState and the various ways it can be changed.</summary>
public class RunStateTests
{
    public RunStateTests ()
    {
#if DEBUG_IDISPOSABLE
        Responder.Instances.Clear ();
        RunState.Instances.Clear ();
#endif
    }

    [Fact]
    public void Begin_End_Cleans_Up_RunState ()
    {
        // Setup Mock driver
        Init ();

        // Test null Toplevel
        Assert.Throws<ArgumentNullException> (() => Application.Begin (null));

        var top = new Toplevel ();
        RunState rs = Application.Begin (top);
        Assert.NotNull (rs);
        Assert.Equal (top, Application.Current);
        Application.End (rs);

        Assert.Null (Application.Current);
        Assert.NotNull (Application.Top);
        Assert.NotNull (Application.MainLoop);
        Assert.NotNull (Application.Driver);

        top.Dispose ();
        Shutdown ();

#if DEBUG_IDISPOSABLE
        Assert.True (rs.WasDisposed);
#endif

        Assert.Null (Application.Top);
        Assert.Null (Application.MainLoop);
        Assert.Null (Application.Driver);
    }

    [Fact]
    public void Dispose_Cleans_Up_RunState ()
    {
        var rs = new RunState (null);
        Assert.NotNull (rs);

        // Should not throw because Toplevel was null
        rs.Dispose ();
#if DEBUG_IDISPOSABLE
        Assert.True (rs.WasDisposed);
#endif
        var top = new Toplevel ();
        rs = new RunState (top);
        Assert.NotNull (rs);

        // Should throw because Toplevel was not cleaned up
        Assert.Throws<InvalidOperationException> (() => rs.Dispose ());

        rs.Toplevel.Dispose ();
        rs.Toplevel = null;
        rs.Dispose ();
#if DEBUG_IDISPOSABLE
        Assert.True (rs.WasDisposed);
        Assert.True (top.WasDisposed);
#endif
    }

    [Fact]
    public void New_Creates_RunState ()
    {
        var rs = new RunState (null);
        Assert.Null (rs.Toplevel);

        var top = new Toplevel ();
        rs = new RunState (top);
        Assert.Equal (top, rs.Toplevel);
    }

    private void Init ()
    {
        Application.Init (new FakeDriver ());
        Assert.NotNull (Application.Driver);
        Assert.NotNull (Application.MainLoop);
        Assert.NotNull (SynchronizationContext.Current);
    }

    private void Shutdown ()
    {
        Application.Shutdown ();
#if DEBUG_IDISPOSABLE

        // Validate there are no outstanding RunState-based instances left
        foreach (RunState inst in RunState.Instances)
        {
            Assert.True (inst.WasDisposed);
        }
#endif
    }
}