using System;
using UnitTestSharp;

namespace Amphora.UnitTests
{
    public class MessageFailureKindTests : TestFixture
    {
        public class CtorTests : TestFixture
        {
            public void KeepsTheMessage()
            {
                CheckEqual("That can't be reached.", FailureTestKinds.Unreachable.Message);
            }

            public void NullMessage_Throws()
            {
                CheckThrow(typeof(ArgumentNullException));
                new MessageFailureKind("Amphora.UnitTests.Unnamed", message: null);
            }
        }

        public class FailTests : TestFixture
        {
            public void CarriesOnlyTheKind()
            {
                Status failure = FailureTestKinds.Unreachable.Fail();

                CheckEqual(FailureTestKinds.Unreachable, failure.Kind);
                CheckNull(failure.Ref);
                CheckEqual(0L, failure.Bits);
            }

            public void AllocatesNothing()
            {
                CheckEqual(0L, Allocations.During(() => Allocations.StatusSink = FailureTestKinds.Unreachable.Fail()));
            }
        }

        public class DescribeTests : TestFixture
        {
            public void IsTheMessageWhateverTheContext()
            {
                Status failure = FailureTestKinds.Unreachable.Fail();

                CheckEqual("That can't be reached.",
                    FailureTestKinds.Unreachable.Describe(failure, context: "ignored"));
            }

            public void OtherKind_Throws()
            {
                Status other = BlockedCellKind.Instance.Fail(FailureTestKinds.Wall);

                CheckThrow(typeof(ArgumentException));
                FailureTestKinds.Unreachable.Describe(other, context: null);
            }
        }
    }
}