ArchUnit测试异常排查：合规Command类触发失败提示

使用ArchUnit进行架构测试时，配置规则要求：实现IRequest的非抽象且名称以Command结尾的类，需位于匹配.+\.Commands\.的命名空间下。但符合条件的Command类（如SynchronizeMasterDataCommand等）却触发了FailedArchRuleException异常，错误提示反而显示这些类确实处于对应Commands命名空间中。

错误信息 #

Message: 
  ArchUnitNET.xUnit.FailedArchRuleException : "Classes that are Classes that are Classes that implement 'IRequest' and are not abstract and have name matching ".+Command$" and have name matching ".+Command$" should reside in namespace with full name matching ".+\.Commands\."" failed:
    Core.Application.MasterDataSync.Commands.SynchronizeMasterDataCommand does reside in Core.Application.MasterDataSync.Commands
    Core.Application.ManagerChain.Commands.CalculateManagerChainCommand does reside in Core.Application.ManagerChain.Commands
    Core.Application.EmployeeSync.Commands.SynchronizeEmployeeCommand does reside in Core.Application.EmployeeSync.Commands
    Core.Application.EmployeeFixedPaymentSummaries.Commands.SynchronizeLatestYearlyPaymentsCommand does reside in Core.Application.EmployeeFixedPaymentSummaries.Commands

相关代码 #

加载程序集代码 #

using System.Reflection;
using ArchUnitNET.Domain;
using ArchUnitNET.Loader;
using Assembly = System.Reflection.Assembly;

namespace Corsica.Tests.ArchUnit;

public static class Corsica
{
    public static readonly Architecture ARCHITECTURE =
        new ArchLoader()
            .LoadAssemblies(GetSolutionAssemblies())
            .Build();

    private static Assembly[] GetSolutionAssemblies()
    {
        var assemblies = Directory
            .GetFiles(AppDomain.CurrentDomain.BaseDirectory, "*.dll")
            .Select(x => Assembly.Load(AssemblyName.GetAssemblyName(x)))
            .Where(x => x.FullName!.StartsWith("Core"));
        return assemblies.ToArray();
    }
}

Command类代码 #

using MediatR;

namespace Core.Application.EmployeeFixedPaymentSummaries.Commands;
public class SynchronizeLatestYearlyPaymentsCommand : IRequest { }

using MediatR;

namespace Core.Application.EmployeeSync.Commands;

public class SynchronizeEmployeeCommand : IRequest { }

using MediatR;

namespace Core.Application.MasterDataSync.Commands;

public class SynchronizeMasterDataCommand : IRequest
{
}

using MediatR;

namespace Core.Application.ManagerChain.Commands;

public class CalculateManagerChainCommand : IRequest { }

测试类代码 #

using ArchUnitNET.Domain;
using ArchUnitNET.xUnit;
using MediatR;
using static ArchUnitNET.Fluent.ArchRuleDefinition;

namespace Corsica.Tests.ArchUnit;

public class Cqrs
{
    private static readonly IObjectProvider<IType> NON_ABSTRACT_CLASSES_IMPLEMENTING_IREQUEST =
            Classes()
                .That().AreAssignableTo(typeof(IRequest<>)).Or().AreAssignableTo(typeof(IRequest)).As("Classes that implement 'IRequest'")
                .And().AreNotAbstract()
                .And().HaveName(".+Command$", true);

    private static readonly IObjectProvider<IType> COMMANDS =
        Classes().That().Are(NON_ABSTRACT_CLASSES_IMPLEMENTING_IREQUEST)
            .And().HaveName(".+Command$", true);

    private static readonly IObjectProvider<IType> QUERIES =
        Classes().That().Are(NON_ABSTRACT_CLASSES_IMPLEMENTING_IREQUEST)
            .And().HaveName(".+Query$", true);

    [Fact]
    public void ClassesInheritingFromIRequestShouldHaveNameEndingWithCommandOrQuery()
    {
        Classes().That().Are(NON_ABSTRACT_CLASSES_IMPLEMENTING_IREQUEST)
            .Should().HaveName(".+(Command|Query)$", true).As("should have names ending with 'Command' or 'Query'")
            .Check(Corsica.ARCHITECTURE);
    }

    [Fact]
    public void CommandsShouldResideInCommandsNamespace()
    {
        Classes().That().Are(COMMANDS)
            .Should().ResideInNamespace(".+\.Commands\.", true)
            .Check(Corsica.ARCHITECTURE);
    }

    [Fact]
    public void QueriesShouldResideInQueriesNamespace()
    {
        Classes().That().Are(QUERIES)
            .Should().ResideInNamespace(".+\.Queries\.", true)
            .Check(Corsica.ARCHITECTURE);
    }

}

1. 正则表达式匹配错误：规则中使用的命名空间正则.+\.Commands\.要求命名空间必须包含.Commands.（末尾带点），但实际类的命名空间是Core.Application.MasterDataSync.Commands（末尾无点），导致正则不匹配，触发异常。
2. 重复过滤条件冗余：NON_ABSTRACT_CLASSES_IMPLEMENTING_IREQUEST已经过滤了名称以Command结尾的类，COMMANDS又重复添加了相同过滤条件，导致规则描述出现冗余（错误信息里的重复文字就是这个原因）。

1. 修正命名空间正则：将.+\.Commands\.改为.+\.Commands$，确保匹配以Commands结尾的命名空间：

   [Fact]
   public void CommandsShouldResideInCommandsNamespace()
   {
       Classes().That().Are(COMMANDS)
           .Should().ResideInNamespace(".+\.Commands$", true)
           .Check(Corsica.ARCHITECTURE);
   }
   

   也可以使用更直观的ArchUnit API：ResideInNamespaceContaining("Commands")，不过正则.+\.Commands$的匹配精度更高。

2. 移除重复过滤条件：优化NON_ABSTRACT_CLASSES_IMPLEMENTING_IREQUEST的定义，去掉提前过滤.+Command$的逻辑，因为后续需要区分Command和Query：

   private static readonly IObjectProvider<IType> NON_ABSTRACT_CLASSES_IMPLEMENTING_IREQUEST =
           Classes()
               .That().AreAssignableTo(typeof(IRequest<>)).Or().AreAssignableTo(typeof(IRequest)).As("Classes that implement 'IRequest'")
               .And().AreNotAbstract();
   

内容的提问来源于stack exchange，提问作者Lombardo