AtomUI/tests/AtomUI.Desktop.Controls.Tests/NavMenu/NavMenuImplementationContractTests.cs

using Avalonia.Input;
using Avalonia.Controls.Templates;
using Shouldly;
using Xunit;

namespace AtomUI.Desktop.Controls.Tests.NavMenu;

public class NavMenuImplementationContractTests
{
    [Fact]
    public void NavMenuNode_Exposes_Command_Configuration_Without_Becoming_Command_Source()
    {
        var node = new NavMenuNode();

        typeof(INavMenuNode).GetProperty(nameof(INavMenuNode.Command)).ShouldNotBeNull();
        typeof(INavMenuNode).GetProperty(nameof(INavMenuNode.CommandParameter)).ShouldNotBeNull();
        NavMenuNode.CommandProperty.ShouldNotBeNull();
        NavMenuNode.CommandParameterProperty.ShouldNotBeNull();
        node.Command.ShouldBeNull();
        node.CommandParameter.ShouldBeNull();
        node.ShouldNotBeAssignableTo<ICommandSource>();
    }

    [Fact]
    public void NavMenu_Entry_Composition_Public_Contract_Is_Strongly_Typed_And_Backward_Compatible()
    {
        typeof(INavMenuEntry).IsAssignableFrom(typeof(INavMenuNode)).ShouldBeTrue();

        var interfaceEntries = typeof(INavMenuNode).GetProperty(nameof(INavMenuNode.Entries));
        interfaceEntries.ShouldNotBeNull();
        interfaceEntries.PropertyType.ShouldBe(typeof(IEnumerable<INavMenuEntry>));

        var nodeEntries = typeof(NavMenuNode).GetProperty(nameof(NavMenuNode.Entries));
        nodeEntries.ShouldNotBeNull();
        nodeEntries.PropertyType.ShouldBe(typeof(IList<INavMenuEntry>));

        typeof(NavMenuGroup).GetProperty(nameof(NavMenuGroup.Header)).ShouldNotBeNull();
        typeof(NavMenuGroup).GetProperty(nameof(NavMenuGroup.HeaderTemplate)).ShouldNotBeNull();
        typeof(NavMenuGroup).GetProperty(nameof(NavMenuGroup.Entries))!
                            .PropertyType.ShouldBe(typeof(IList<INavMenuEntry>));
        typeof(INavMenuEntry).IsAssignableFrom(typeof(NavMenuDivider)).ShouldBeTrue();
    }

    [Fact]
    public void NavMenu_Root_Composition_Public_Contract_Exposes_Fixed_Slots_And_Entry_Spacing()
    {
        var menu = new AtomUI.Desktop.Controls.NavMenu();

        typeof(AtomUI.Desktop.Controls.NavMenu).GetProperty(nameof(menu.Header))!
                                                  .PropertyType.ShouldBe(typeof(object));
        typeof(AtomUI.Desktop.Controls.NavMenu).GetProperty(nameof(menu.HeaderTemplate))!
                                                  .PropertyType.ShouldBe(typeof(IDataTemplate));
        typeof(AtomUI.Desktop.Controls.NavMenu).GetProperty(nameof(menu.Footer))!
                                                  .PropertyType.ShouldBe(typeof(object));
        typeof(AtomUI.Desktop.Controls.NavMenu).GetProperty(nameof(menu.FooterTemplate))!
                                                  .PropertyType.ShouldBe(typeof(IDataTemplate));
        typeof(AtomUI.Desktop.Controls.NavMenu).GetProperty(nameof(menu.ItemSpacing))!
                                                  .PropertyType.ShouldBe(typeof(double));

        menu.Header.ShouldBeNull();
        menu.HeaderTemplate.ShouldBeNull();
        menu.Footer.ShouldBeNull();
        menu.FooterTemplate.ShouldBeNull();
        menu.ItemSpacing.ShouldBe(0d);
    }

    [Fact]
    public void Inline_Keyboard_Navigation_Does_Not_Flatten_Items_On_Each_Key()
    {
        var source = ReadRepoFile("src/AtomUI.Desktop.Controls/NavMenu/NavMenuInteractionHandlerBase.cs");

        source.ShouldNotContain("new List<NavMenuItem>");
    }

    private static string ReadRepoFile(string relativePath)
    {
        var directory = new DirectoryInfo(AppContext.BaseDirectory);
        while (directory is not null)
        {
            var path = Path.Combine(directory.FullName, relativePath);
            if (File.Exists(path))
            {
                return File.ReadAllText(path);
            }

            directory = directory.Parent;
        }

        throw new FileNotFoundException($"Unable to locate repository file '{relativePath}'.");
    }
}