/Extensions/src/Ncqrs.EventBus.Tests/EventDemultiplexerSpecification.cs

using System;

using Ncqrs.Eventing;

using NUnit.Framework;

using FluentAssertions;



namespace Ncqrs.EventBus.Tests

{

    [TestFixture]

    public class EventDemultiplexerSpecification

    {

        [Test]

        public void When_event_source_is_not_blocked_event_is_passed_through_system()

        {

            Guid eventSourceId = Guid.NewGuid();

            int enqueuedToProcessingCount = 0;



            var sut = new Demultiplexer();

            sut.EventDemultiplexed += (s, e) => { enqueuedToProcessingCount++; };

            sut.Demultiplex(CreateElement(eventSourceId));



            enqueuedToProcessingCount.Should().Be(1);



        }



        [Test]

        public void Different_event_sources_does_not_block_each_other()

        {

            Guid firstEventSourceId = Guid.NewGuid();

            Guid secondEventSourceId = Guid.NewGuid();



            int enqueuedToProcessingCount = 0;



            var sut = new Demultiplexer();

            sut.EventDemultiplexed += (s, e) => { enqueuedToProcessingCount++; };

            sut.Demultiplex(CreateElement(firstEventSourceId));

            sut.Demultiplex(CreateElement(secondEventSourceId));



            enqueuedToProcessingCount.Should().Be(2);

        }



        [Test]

        public void When_event_source_is_blocked_event_is_enqueued()

        {

            Guid eventSourceId = Guid.NewGuid();



            int enqueuedToProcessingCount = 0;



            var sut = new Demultiplexer();

            sut.EventDemultiplexed += (s, e) => { enqueuedToProcessingCount++; };

            sut.Demultiplex(CreateElement(eventSourceId));

            sut.Demultiplex(CreateElement(eventSourceId));



            enqueuedToProcessingCount.Should().Be(1);

        }



        private static IProcessingElement CreateElement(Guid sourceId)

        {

            return new FakeProcessingElement

                       {

                           GroupingKey = sourceId,

                           UniqueId = Guid.NewGuid().ToString()

                       };

        }

    }

}