cursor-lang/CursorLang.Settings.Tests/AppTests.cs

using CursorLang.Core.Models;
using CursorLang.Core.Services;
using CursorLang.Settings.Services;
using CursorLang.Settings.ViewModels;
using CursorLang.Settings.Views;
using Microsoft.Extensions.DependencyInjection;

namespace CursorLang.Settings.Tests;

/// <summary>
/// What the container of the settings process is made of. The tests cannot build the
/// application whole — it would raise a window and take the place of the single
/// instance — but checking that everything needed is declared and resolvable works
/// without that.
/// </summary>
public sealed class AppTests
{
    [Theory]
    [InlineData(typeof(SettingsService))]
    [InlineData(typeof(ThemeService))]
    [InlineData(typeof(IThemeService))]
    [InlineData(typeof(MainWindowPlacement))]
    [InlineData(typeof(ILocalizationService))]
    [InlineData(typeof(IStartupService))]
    [InlineData(typeof(Version))]
    [InlineData(typeof(SettingsViewModel))]
    [InlineData(typeof(MainWindow))]
    [InlineData(typeof(AppSettings))]
    public void Everything_the_window_needs_is_declared_in_the_container(Type service)
    {
        Assert.Contains(Describe(), descriptor => descriptor.ServiceType == service);
    }

    /// <summary>
    /// The background half is not in here, and must not be.
    /// </summary>
    /// <remarks>
    /// The hook, the popup and the layout polling belong to the agent process now. A
    /// registration of any of them here would mean two applications watching the
    /// keyboard at once — and the second of them holding WPF while it did so.
    /// </remarks>
    [Theory]
    [InlineData("KeyboardLayoutService")]
    [InlineData("LayoutPopupService")]
    [InlineData("CapsLockHotkeyService")]
    [InlineData("LayoutNotificationCoordinator")]
    [InlineData("CapsLockSwitchCoordinator")]
    [InlineData("TrayIcon")]
    public void The_background_half_is_not_in_the_settings_container(string name)
    {
        Assert.DoesNotContain(Describe(), descriptor => descriptor.ServiceType.Name.Contains(name));
    }

    // The settings and the theme have to be shared by the whole window: a second copy
    // of them would mean lost edits or half the controls in the wrong colours
    [Fact]
    public void Everything_in_the_container_is_declared_as_a_single_copy()
    {
        Assert.All(Describe(), descriptor =>
            Assert.Equal(ServiceLifetime.Singleton, descriptor.Lifetime));
    }

    [Fact]
    public void Every_service_is_declared_once()
    {
        var types = Describe().Select(descriptor => descriptor.ServiceType).ToList();

        Assert.Equal(types.Count, types.Distinct().Count());
    }

    /// <summary>
    /// The dependencies of every service have to be resolvable. The check runs
    /// while the container is built and creates no services itself.
    /// </summary>
    [Fact]
    public void The_service_dependencies_come_together_with_nothing_missing()
    {
        var services = new ServiceCollection();
        App.ConfigureServices(services);

        ServiceProvider provider = services.BuildServiceProvider(new ServiceProviderOptions
        {
            ValidateOnBuild = true,
            ValidateScopes = true,
        });

        // Ensure the provider was built successfully — this serves as an assertion
        // so the test framework recognizes this as a meaningful test.
        Assert.NotNull(provider);

        provider.Dispose();
    }

    [Fact]
    public void The_settings_come_from_the_settings_service()
    {
        ServiceDescriptor settings = Describe()
            .Single(descriptor => descriptor.ServiceType == typeof(AppSettings));

        // The settings are not created anew but read from disk by the service
        Assert.NotNull(settings.ImplementationFactory);
    }

    [Fact]
    public void The_theme_and_its_interface_are_one_service()
    {
        ServiceDescriptor theme = Describe()
            .Single(descriptor => descriptor.ServiceType == typeof(IThemeService));

        Assert.NotNull(theme.ImplementationFactory);
    }

    private static ServiceCollection Describe()
    {
        var services = new ServiceCollection();
        App.ConfigureServices(services);

        return services;
    }
}