furniture-bff/tests/Furniture.Bff.Application.UnitTests/GetFurnitureAvailabilityHandlerTests.cs

using Furniture.Bff.Application.Adapters;
using Furniture.Bff.Application.Handlers;
using Furniture.Bff.Contracts.Api;
using Furniture.Service.Contracts.UseCases;

namespace Furniture.Bff.Application.UnitTests;

public class GetFurnitureAvailabilityHandlerTests
{
    [Fact]
    public async Task HandleAsync_WhenCalled_DelegatesToServiceClient()
    {
        var handler = new GetFurnitureAvailabilityHandler(
            new FakeFurnitureServiceClient(),
            new FakeFurnitureAvailabilityEdgeContractAdapter());

        var response = await handler.HandleAsync(new GetFurnitureAvailabilityApiRequest("FUR-001", "corr-123"));

        Assert.Equal("FUR-001", response.FurnitureId);
        Assert.Equal("Chair", response.DisplayName);
        Assert.Equal(3, response.QuantityAvailable);
    }

    private sealed class FakeFurnitureServiceClient : IFurnitureServiceClient
    {
        public Task<GetFurnitureAvailabilityResponse> GetAvailabilityAsync(GetFurnitureAvailabilityRequest request)
        {
            return Task.FromResult(new GetFurnitureAvailabilityResponse(request.FurnitureId, "Chair", 3));
        }
    }

    private sealed class FakeFurnitureAvailabilityEdgeContractAdapter : IFurnitureAvailabilityEdgeContractAdapter
    {
        public GetFurnitureAvailabilityRequest ToServiceRequest(GetFurnitureAvailabilityApiRequest request)
        {
            return new GetFurnitureAvailabilityRequest(request.FurnitureId, request.CorrelationId);
        }

        public GetFurnitureAvailabilityApiResponse ToApiResponse(GetFurnitureAvailabilityResponse response)
        {
            return new GetFurnitureAvailabilityApiResponse(
                response.FurnitureId,
                response.DisplayName,
                response.QuantityAvailable);
        }
    }
}