furniture-service/tests/Furniture.Service.Application.UnitTests/GetFurnitureAvailabilityUseCaseTests.cs

using BuildingBlock.Catalog.Contracts.Conventions;
using BuildingBlock.Catalog.Contracts.Products;
using BuildingBlock.Catalog.Contracts.Responses;
using BuildingBlock.Inventory.Contracts.Conventions;
using BuildingBlock.Inventory.Contracts.Requests;
using BuildingBlock.Inventory.Contracts.Responses;
using Furniture.Service.Application.Ports;
using Furniture.Service.Application.UseCases;
using Furniture.Service.Contracts.UseCases;
using Furniture.Domain.Contracts;
using Furniture.Domain.Decisions;

namespace Furniture.Service.Application.UnitTests;

public class GetFurnitureAvailabilityUseCaseTests
{
    [Fact]
    public async Task HandleAsync_WhenCalled_DelegatesToReadPort()
    {
        var decisionService = new FakeFurnitureAvailabilityDecisionService();
        var catalogPort = new FakeCatalogProductReadPort();
        var inventoryPort = new FakeFurnitureAvailabilityReadPort();
        var useCase = new GetFurnitureAvailabilityUseCase(decisionService, catalogPort, inventoryPort);

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

        Assert.Equal("FUR-001", response.FurnitureId);
        Assert.Equal("Chair", response.DisplayName);
        Assert.Equal(10, response.QuantityAvailable);
    }

    private sealed class FakeFurnitureAvailabilityDecisionService : IFurnitureAvailabilityDecisionService
    {
        public ProductContract BuildCatalogRequest(FurnitureAvailabilityDecisionRequest request)
        {
            return new ProductContract(
                new CatalogContractEnvelope("1.0.0", request.CorrelationId),
                request.FurnitureId,
                string.Empty);
        }

        public InventoryItemLookupRequest BuildInventoryRequest(FurnitureAvailabilityDecisionRequest request)
        {
            return new InventoryItemLookupRequest(
                new InventoryContractEnvelope("1.0.0", request.CorrelationId),
                request.FurnitureId);
        }

        public FurnitureAvailabilityDecisionResponse ComposeResponse(
            FurnitureAvailabilityDecisionRequest request,
            ProductContractResponse catalogResponse,
            InventoryItemLookupResponse inventoryResponse)
        {
            return new FurnitureAvailabilityDecisionResponse(
                request.FurnitureId,
                catalogResponse.DisplayName,
                inventoryResponse.QuantityAvailable);
        }
    }

    private sealed class FakeCatalogProductReadPort : ICatalogProductReadPort
    {
        public Task<ProductContractResponse> ReadProductAsync(ProductContract request)
        {
            return Task.FromResult(
                new ProductContractResponse(
                    new CatalogContractEnvelope("1.0.0", request.Envelope.CorrelationId),
                    request.ProductId,
                    "Chair"));
        }
    }

    private sealed class FakeFurnitureAvailabilityReadPort : IFurnitureAvailabilityReadPort
    {
        public Task<InventoryItemLookupResponse> ReadAvailabilityAsync(InventoryItemLookupRequest request)
        {
            return Task.FromResult(
                new InventoryItemLookupResponse(
                    new InventoryContractEnvelope("1.0.0", request.Envelope.CorrelationId),
                    request.ItemCode,
                    10));
        }
    }
}