/Framework/src/Ncqrs.Tests/Eventing/Storage/Serialization/EventConverterTests.cs

using System;

using FluentAssertions;

using Ncqrs.Eventing.Storage;

using Ncqrs.Eventing.Storage.Serialization;

using Newtonsoft.Json.Linq;

using Rhino.Mocks;

using Xunit;



namespace Ncqrs.Tests.Eventing.Storage.Serialization

{

    public class EventConverterTests

    {

        private IEventTypeResolver _typeResolver;

        private IEventConverter _childConverter = new NullEventConverter();

        private const string EventName = "bob";



        public EventConverterTests()

        {

            _typeResolver = MockRepository.GenerateStub<IEventTypeResolver>();

            _typeResolver

                .Stub(x => x.EventNameFor(typeof(AnEvent)))

                .TentativeReturn()

                .Return(EventName);



            _childConverter = MockRepository.GenerateStub<IEventConverter>();

        }



        [Fact]

        public void Ctor()

        {

           var converter = new EventConverter(_typeResolver);

        }



        [Fact]

        public void Ctor_typeResolver_null()

        {

            var ex = Assert.Throws<ArgumentNullException>(() => new EventConverter(null));

            ex.ParamName.Should().Be("typeResolver");

        }



        [Fact]

        public void Upgrade()

        {

            var event1 = CreateEvent("foo");

            var event2 = CreateEvent("bar");

            var fooConverter = MockRepository.GenerateStub<IEventConverter>();

            var barConverter = MockRepository.GenerateStub<IEventConverter>();



            var converter = new EventConverter(_typeResolver);

            converter.AddConverter("foo", fooConverter);

            converter.AddConverter("bar", barConverter);



            converter.Upgrade(event1);

            converter.Upgrade(event2);



            fooConverter.AssertWasCalled(x => x.Upgrade(event1));

            barConverter.AssertWasCalled(x => x.Upgrade(event2));

        }



        [Fact]

        public void Upgrade_unknown_event()

        {

            var converter = new EventConverter(_typeResolver);

            converter.Upgrade(CreateEvent());

        }



        [Fact]

        public void Upgrade_theEvent_null()

        {

            var converter = new EventConverter(_typeResolver);

            var ex = Assert.Throws<ArgumentNullException>(() => converter.Upgrade(null));

            ex.ParamName.Should().Be("theEvent");

        }



        [Fact]

        public void AddConverter_ByType()

        {

            var anEvent = CreateEvent();

            var converter = new EventConverter(_typeResolver);

            converter.AddConverter(typeof(AnEvent), _childConverter);



            converter.Upgrade(anEvent);



            _childConverter.AssertWasCalled(x => x.Upgrade(anEvent));

        }



        [Fact]

        public void AddConverter_ByType_eventType_null()

        {

            var converter = new EventConverter(_typeResolver);

            var ex = Assert.Throws<ArgumentNullException>(() => converter.AddConverter((Type) null, _childConverter));

            ex.ParamName.Should().Be("eventType");

        }



        [Fact]

        public void AddConverter_ByType_converter_null()

        {

            var converter = new EventConverter(_typeResolver);

            var ex = Assert.Throws<ArgumentNullException>(() => converter.AddConverter(typeof(AnEvent), null));

            ex.ParamName.Should().Be("converter");

        }



        [Fact]

        public void AddConverter_ByName()

        {

            var anEvent = CreateEvent();

            var converter = new EventConverter(_typeResolver);

            converter.AddConverter(EventName, _childConverter);



            converter.Upgrade(anEvent);



            _childConverter.AssertWasCalled(x => x.Upgrade(anEvent));

        }



        [Fact]

        public void AddConverter_ByName_eventName_null()

        {

            var converter = new EventConverter(_typeResolver);

            var ex = Assert.Throws<ArgumentNullException>(() => converter.AddConverter((string) null, _childConverter));

            ex.ParamName.Should().Be("eventName");

        }



        [Fact]

        public void AddConverter_ByName_converter_null()

        {

            var converter = new EventConverter(_typeResolver);

            var ex = Assert.Throws<ArgumentNullException>(() => converter.AddConverter(EventName, null));

            ex.ParamName.Should().Be("converter");

        }



        [Fact]

        public void AddConverter_duplicate_name()

        {

            var converter = new EventConverter(_typeResolver);

            converter.AddConverter(EventName, _childConverter);



            var ex = Assert.Throws<ArgumentException>(() => converter.AddConverter(EventName, _childConverter));

            ex.ParamName.Should().Be("eventName");

            ex.Message.Should().StartWith("There is already a converter for event 'bob'.");

        }





        private StoredEvent<JObject> CreateEvent()

        {

            return CreateEvent(EventName);

        }



        private StoredEvent<JObject> CreateEvent(string name)

        {

            var id = new Guid("36C84164-B324-496A-9098-1A5D9945DD88");

            var sourceId = new Guid("A710F584-7134-4BAB-9741-75A35F9C1E02");

            var theDate = new DateTime(2000, 01, 01);



            JObject obj = new JObject();

            return new StoredEvent<JObject>(id, theDate, name, new Version(1, 0), sourceId, 1, obj);

        }



        private class AnEvent {}

    }

}