request/src/request.dispatcher.tests/ScalarBehaviourTests.cs

// Copyright (c) The Geekeey Authors
// SPDX-License-Identifier: EUPL-1.2

using Microsoft.Extensions.DependencyInjection;

namespace Geekeey.Request.Dispatcher.Tests;

internal sealed class ScalarBehaviourTests
{
	[Test]
	public async Task I_can_execute_the_closed_behaviour()
	{
		var sc = new ServiceCollection();
		sc.AddSingleton<ScalarTestTracker>();
		sc.AddRequestDispatcher(builder => builder
			.Add(typeof(ScalarTestHandler))
			.Add(typeof(ScalarTestBehavior)));
		var provider = sc.BuildServiceProvider();
		var dispatcher = provider.GetRequiredService<IRequestDispatcher>();
		var tracker = provider.GetRequiredService<ScalarTestTracker>();

		var request = new ScalarTestRequest { Value = "Hello" };
		var result = await dispatcher.DispatchAsync(request);

		await Assert.That(result).IsEquivalentTo("Hello-Handled");
		await Assert.That(tracker.Executed).IsTrue();
	}

	[Test]
	public async Task I_can_execute_the_open_behaviour()
	{
		var sc = new ServiceCollection();
		sc.AddSingleton<ScalarTestTracker>();
		sc.AddRequestDispatcher(builder => builder
			.Add(typeof(ScalarTestHandler))
			.Add(typeof(ScalarOpenBehavior<,>)));
		var provider = sc.BuildServiceProvider();
		var dispatcher = provider.GetRequiredService<IRequestDispatcher>();
		var tracker = provider.GetRequiredService<ScalarTestTracker>();

		var request = new ScalarTestRequest { Value = "Hello" };
		var result = await dispatcher.DispatchAsync(request);

		await Assert.That(result).IsEquivalentTo("Hello-Handled");
		await Assert.That(tracker.Executed).IsTrue();
	}

	[Test]
	public async Task I_can_chain_the_behaviours_in_order()
	{
		var sc = new ServiceCollection();
		sc.AddSingleton<ScalarTestTracker>();
		sc.AddRequestDispatcher(builder => builder
			.Add(typeof(ScalarTestHandler))
			.Add(typeof(ScalarChainedBehaviour1))
			.Add(typeof(ScalarChainedBehaviour2)));
		var provider = sc.BuildServiceProvider();
		var dispatcher = provider.GetRequiredService<IRequestDispatcher>();
		var tracker = provider.GetRequiredService<ScalarTestTracker>();

		var request = new ScalarTestRequest { Value = "Hello" };
		await dispatcher.DispatchAsync(request);

		// They are discovered in the order they appear in the assembly.
		// In this file: ChainedBehaviour1, ChainedBehaviour2
		await Assert.That(tracker.Log).Count().IsEqualTo(2);
		await Assert.That(tracker.Log[0]).IsEquivalentTo("Behaviour1");
		await Assert.That(tracker.Log[1]).IsEquivalentTo("Behaviour2");
	}

	[Test]
	public async Task I_can_work_with_a_generic_wrapper_request_and_the_open_behaviour()
	{
		var sc = new ServiceCollection();
		sc.AddSingleton<ScalarTestTracker>();
		sc.AddRequestDispatcher(builder => builder
			.Add(typeof(ScalarTestWrapperHandler<>))
			.Add(typeof(ScalarWrapperBehavior<>)));
		var provider = sc.BuildServiceProvider();
		var dispatcher = provider.GetRequiredService<IRequestDispatcher>();
		var tracker = provider.GetRequiredService<ScalarTestTracker>();

		var request = new ScalarTestWrapperRequest<int> { Item = 42 };
		var result = await dispatcher.DispatchAsync(request);

		await Assert.That(result).IsEquivalentTo("Handled-42");
		await Assert.That(tracker.Executed).IsTrue();
	}

	[Test]
	public async Task I_can_order_behaviours_explicitly_by_order_property()
	{
		var sc = new ServiceCollection();
		sc.AddSingleton<ScalarTestTracker>();
		sc.AddRequestDispatcher(builder => builder
			.Add(typeof(ScalarTestHandler))
			.AddBehavior<OrderedScalarBehaviorA>(2)
			.AddBehavior<OrderedScalarBehaviorB>(1));
		var provider = sc.BuildServiceProvider();
		var dispatcher = provider.GetRequiredService<IRequestDispatcher>();
		var tracker = provider.GetRequiredService<ScalarTestTracker>();

		var request = new ScalarTestRequest { Value = "Hello" };
		await dispatcher.DispatchAsync(request);

		// Registered A (order 2) then B (order 1) via AddBehavior; explicit order overrides discovery order.
		await Assert.That(tracker.Log).IsEquivalentTo(["OrderedB", "OrderedA"]);
	}

	[Test]
	public async Task I_can_maintain_the_ordering_between_open_and_closed_behaviours()
	{
		var sc = new ServiceCollection();
		sc.AddSingleton<ScalarTestTracker>();
		sc.AddRequestDispatcher(builder => builder
			.Add(typeof(ScalarTestHandler))
			.Add(typeof(ScalarOrderingOpenBehavior<,>))
			.Add(typeof(ScalarOrderingClosedBehavior)));
		var provider = sc.BuildServiceProvider();
		var dispatcher = provider.GetRequiredService<IRequestDispatcher>();
		var tracker = provider.GetRequiredService<ScalarTestTracker>();

		var request = new ScalarTestRequest { Value = "Order" };
		await dispatcher.DispatchAsync(request);

		await Assert.That(tracker.Log).Contains("OrderingOpen");
		await Assert.That(tracker.Log).Contains("OrderingClosed");
	}
}

// Moved to _fixtures