lightweight variant (#1)

Reviewed-on: #1
Co-authored-by: Aleksandr Neychev <alexnejchev73@gmail.com>

CursorLang.Settings.Tests/AppTests.cs

@@ -0,0 +1,122 @@
+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(IUpdateService))]
+    [InlineData(typeof(UpdateOptions))]
+    [InlineData(typeof(SettingsViewModel))]
+    [InlineData(typeof(UpdateViewModel))]
+    [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;
+    }
+}