ABP 框架测试中的“无法解析参数”错误

Posted 2023-02-15

【中文标题】ABP 框架测试中的“无法解析参数”错误

【英文标题】："Cannot resolve parameter" error in ABP Framework Test

【发布时间】：2021-02-25 14:47:01

【问题描述】：

我正在尝试编写测试代码：

public class SupplierAppServiceTests : ABCApplicationTestBase

    private readonly ISupplierAppService _supplierAppService;
    private readonly IWmsCompanyRepository _fakeRepo;

    public SupplierAppServiceTests()
    
        _fakeRepo = Substitute.For<IWmsCompanyRepository>();
        _supplierAppService = GetRequiredService<ISupplierAppService>();
    

    [Fact]
    public async Task Should_Be_Generate_Code()
    
        // Arrange
        _fakeRepo.CreateAsync(Arg.Any<WmsCompany>())
            .Returns(Task.CompletedTask);
        ...
    

但我收到此错误：

Autofac.Core.DependencyResolutionException : An exception was thrown while activating MyCompany.ABC.Application.CompanySuppliers.SupplierAppService.
    ---- Autofac.Core.DependencyResolutionException : None of the constructors found with 'Autofac.Core.Activators.Reflection.DefaultConstructorFinder' on type 'MyCompany.ABC.Application.CompanySuppliers.SupplierAppService' can be invoked with the available services and parameters:
    Cannot resolve parameter 'MyCompany.ABC.Domain.Wms.Companies.IWmsCompanyRepository wmsCompanyRepository' of constructor 'Void .ctor(MyCompany.ABC.Domain.Companies.SupplierManager, MyCompany.ABC.Domain.Companies.ISupplierRepository, MyCompany.ABC.Domain.Wms.Companies.IWmsCompanyRepository)'.

实现IWmsCompanyRepository的WmsCompanyRepository类（最后一个参数）向第三方的网络服务发出请求。

SupplierAppService:

public class SupplierAppService : ABCAppService, ISupplierAppService

    public SupplierAppService(SupplierManager supplierManager, ISupplierRepository supplierRepository, IWmsCompanyRepository wmsCompanyRepository)
    
        this.supplierManager = supplierManager;
        this.supplierRepository = supplierRepository;
        this.WmsCompanyRepository = wmsCompanyRepository;
    

    ...

IWmsCompanyRepository:

public interface IWmsCompanyRepository

     Task CreateAsync(WmsCompany company);

我在SupplierAppServiceTests 类的构造函数中更改了_supplierAppService 赋值

来自：

_supplierAppService = GetRequiredService<ISupplierAppService>();

到：

_supplierAppService = new SupplierAppService(_supplierManager, _supplierRepository, _fakeRepo);

SupplierAppService 的方法使用了ObjectMapper 属性，这次我收到了这个错误：

ObjectMapper -> System.ArgumentNullException : Value cannot be null. (Parameter 'provider') objectmapper

如何正确地将IWmsCompanyRepository 注入到SupplierAppService 以用于测试用例？

【参考方案1】：

将您的 _fakeRepo 单例添加到 services 以便可以为 SupplierAppService 解析。

public SupplierAppServiceTests()

    // _fakeRepo = Substitute.For<IWmsCompanyRepository>();
    _supplierAppService = GetRequiredService<ISupplierAppService>();


protected override void AfterAddApplication(IServiceCollection services)

    _fakeRepo = Substitute.For<IWmsCompanyRepository>();
    services.AddSingleton(_fakeRepo);

【参考方案2】：

我找到了解决方法， 我更改了 SupplierAppService 类：

将默认值IWmsCompanyRepository wmsCompanyRepository = null添加到ctor参数 将 WmsCompanyRepository 从字段更改为公共属性 将 WmsCompanyRepository 属性添加到 ISupplierAppService

---

public class SupplierAppService : ABCAppService , ISupplierAppService

   public IWmsCompanyRepository WmsCompanyRepository  get; set; 
   public SupplierAppService(SupplierManager supplierManager, ISupplierRepository supplierRepository,IWmsCompanyRepository wmsCompanyRepository = null)
   
      this.supplierManager = supplierManager;
      this.supplierRepository = supplierRepository;
      this.WmsCompanyRepository = wmsCompanyRepository;
   
 ...
 

并更改了 SupplierAppServiceTests ctor：

public SupplierAppServiceTests()

    _fakeRepo = Substitute.For<IWmsCompanyRepository>();
    _supplierAppService = GetRequiredService<ISupplierAppService>();
    _supplierAppService.WmsCompanyRepository = _fakeRepo;