using System.Runtime.CompilerServices;
using ReactiveUI.Builder;

namespace PLib.Tests;

/// <summary>
/// Brings ReactiveUI up before any test touches a view model.
/// </summary>
/// <remarks>
/// ReactiveUI 24 refuses to serve <c>WhenAnyValue</c> until it has been initialised, and the
/// application does that in <c>Program.Main</c> — which a test host never runs. Only the core
/// services are registered here: platform services are about dispatchers and bindings, and a
/// view model under test has neither.
/// </remarks>
internal static class ReactiveUiBootstrap
{
    [ModuleInitializer]
    internal static void Initialize() =>
        // BuildApp rather than Build: only the former marks ReactiveUI as initialised, and
        // that flag is exactly what WhenAnyValue checks.
        RxAppBuilder.CreateReactiveUIBuilder()
            .WithCoreServices()
            .BuildApp();
}